The effect of red-fleshed pitaya (<i>Hylocereus polyrhizus</i>) on heat shock protein 70 and cortisol expression in strenuous exercise induced rats

Novita Sari Harahap; Aznan Lelo; Ambrosius Purba; Awaluddin Sibuea; Rina Amelia; Zulaini Zulaini

doi:10.12688/f1000research.17533.2

Home Browse The effect of red-fleshed pitaya (Hylocereus polyrhizus) on heat shock...

ALL Metrics

Views

Downloads

Get PDF

Get XML

Export

▬

✚

Research Article

Revised

The effect of red-fleshed pitaya (Hylocereus polyrhizus) on heat shock protein 70 and cortisol expression in strenuous exercise induced rats

[version 2; peer review: 2 approved]

Novita Sari Harahap ¹, Aznan Lelo², Ambrosius Purba³, Awaluddin Sibuea⁴, Rina Amelia⁵, Zulaini Zulaini¹

Novita Sari Harahap ¹, Aznan Lelo², [...] Ambrosius Purba³, Awaluddin Sibuea⁴, Rina Amelia⁵, Zulaini Zulaini¹

PUBLISHED 29 Sep 2021

Author details Author details

¹ Department of Sports Sciences, Faculty of Sports Sciences, Universitas Negeri Medan, Medan, North Sumatra, 20221, Indonesia
² Department of Pharmacology, Faculty of Medicine, University of Sumatra Utara, Medan, North Sumatra, 20155, Indonesia
³ Department of Physiology, Faculty of Medicine, Padjajaran University, Bandung, West Java, 45363, Indonesia
⁴ Surgery Division, Dr. T. Mansyur Tanjung Balai Hospital, Tanjungbalai, North Sumatra, 21312, Indonesia
⁵ Department of Public Health, Faculty of Medicine, University of Sumatra Utara, Medan, North Sumatra, 20155, Indonesia

Novita Sari Harahap
Roles: Conceptualization, Investigation, Methodology, Resources, Writing – Original Draft Preparation

Aznan Lelo
Roles: Investigation, Methodology

Ambrosius Purba
Roles: Resources, Supervision

Awaluddin Sibuea
Roles: Resources

Rina Amelia
Roles: Resources

Zulaini Zulaini
Roles: Formal Analysis

OPEN PEER REVIEW

REVIEWER STATUS

Abstract

Background: Oxidative stress from exercise can contribute to damaging cells, increasing heat shock protein 70 (HSP70) and suppressing the immune system in the body. This research aimed to determine the antioxidant potential of red-fleshed pitaya extract on HSP70 and cortisol expression in rats which were subjected to strenuous exercise.
Methods: The subjects of this research were 32 Sprague Dawley male rats, aged 3 months, with an average weight of 200 g. Red-fleshed pitaya extract was obtained from methanol extraction process; a maceration technique was performed and the extract was concentrated using an air-drying method. Rats were randomly divided into four groups. Group 1 were subjected to strenuous exercise and treated with distilled water only; while Groups 2, 3 and 4 were subjected to strenuous exercise and treated with 100 mg/kg body weight, 200 mg/kg body weight and 300 mg/kg body weight of red-fleshed pitaya extract, respectively. Strenuous exercises in rats was performed by intense swimming of 20 min/day, 3 days a week for 3 weeks. HSP70 expression and cortisol were measured with Enzyme-Linked Immune Sorbent Assay (ELISA) method.
Results: There was a significant reduction of HSP70 (p=0.000) and cortisol expression (p=0.000) between the groups. Also, there was a significant difference in the average decreasing of HSP70 expression between group 4 and either groups 1 or 2 (p=0.000). However, a significant difference between groups 4 and 3 was not observed (p=0.813). Lastly, a significant difference was found in the average decrease of cortisol expression between groups 4 and 1 (p=0.000), 2 (p=0.000), and 3 (p=0.000) respectively.
Conclusion: Red-fleshed pitaya is potential to be utilized as antioxidant to decrease the HSP70 and cortisol expression.

Keywords

Red-fleshed pitaya, HSP70, cortisol, strenuous exercise

Corresponding author: Novita Sari Harahap

Competing interests: No competing interests were disclosed.

Grant information: The authors would like to acknowledge Ministry of Research, Technology and Higher Education of Republic of Indonesia for funding this research via Research Grant of Universitas Negeri Medan with contract number of 027/UN33.8/LL/2018.
The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Copyright: © 2021 Harahap NS et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

How to cite: Harahap NS, Lelo A, Purba A et al. The effect of red-fleshed pitaya (Hylocereus polyrhizus) on heat shock protein 70 and cortisol expression in strenuous exercise induced rats [version 2; peer review: 2 approved]. F1000Research 2021, 8:130 (https://doi.org/10.12688/f1000research.17533.2) First published: 30 Jan 2019, 8:130 (https://doi.org/10.12688/f1000research.17533.1) Latest published: 29 Sep 2021, 8:130 (https://doi.org/10.12688/f1000research.17533.2)

Revised Amendments from Version 1

The difference between this new version and version 1 is that in this new version, we can explain the antioxidant activity contained in red-fleshed pitaya that can affect heat shock protein 70 and the expression of cortisol. Red fleshed pitaya contains powerful antioxidants because it consists of various antioxidants, namely flavonoids, and polyphenol. Thus Red fleshed pitaya which has the potential as an antioxidant can reduce ROS and respond to HSP70 expression. We can explain that giving 3 doses of 100 mg/kg body weight, 200 mg/kg body weight, and 300 mg/kg body weight to find out what is the effective dose to neutralize oxidative stress due to strenuous physical exercise. So it is necessary to experiment with 3 doses, in accordance with the purpose of the study to find out the potential of Red-fleshed pitaya as an antioxidant and once to know the effective dose to reduce oxidative stress which is influence on HSP70 and cortisol expression in rats that were subjected strenuous exercise.

See the authors' detailed response to the review by Yusni Yusni

Introduction

Physical activity is an activity which has various influences and significant effects on the body. The effect of regular physical activity is a positive influence on biological functions, and will improve health and the antioxidant defense system in order to protect body from the negative effects of oxidative damage¹. Strenuous exercise tends to trigger free radical compound production. Moreover, this impairs the balance of free radicals and antioxidants as a result of oxidative stress^2–4. Research has discovered that oxidative stress from strenuous exercise reduces performance as it damages cells⁵, causing pain and muscles fatigues⁶, lowering antioxidant levels^7,8, increasing the expression of heat shock protein 70 (HSP70)^9,10 and suppressing the immune system¹¹. Increased RONS (Reactive Oxygen and Nitrogen Species) production during exercise has potential negative effects, transient increases in RONS seem to be a trigger for many exercise-induced adaptations in skeletal muscle. Exercise can stimulate increased concentration of HSP70 in muscles and plasma¹².

During an intense workout, self-defense and self-adaptation depend on the body condition which can be observed from HSP70 protein expression. Increases of HSP70 in muscles indicates a response to protect muscles cells from oxidative stress. HSP70 expression is an adaptation mechanism and a sign of damaging cells caused by oxidative stress¹³. Previous research reported that workouts increase HSP70 expression¹⁰. Strenuous exercise is a physical stressor in the body and as a result, adrenocorticotropic hormone(ACTH) is secreted by hypothalamus hypo-physis anterior and triggers the adrenal cortex to produce cortisol¹⁴. The escalation of cortisol is influenced by the intensity and duration of training that leads to a suppression of the immune system, resulting in a decline of antibody. Cortisol can be a sign that the body encounters a decline in the immune system due to heavy training¹⁵. Antioxidants can detoxify the lipid peroxide produced during exercise, which can eliminate radicals and reduce the inflammatory response to exercise. Therefore, it can prevent a muscle damage from exercise¹⁶.

The body needs exogenous antioxidants to neutralize and prevent chain reactions from free radicals formed from heavy physical trainings¹⁷. Sources of exogenous antioxidants are Vitamin E, C and also beta-carotene. External antioxidants from food or supplements can help the body to fight an excess of free radicals. In a previous study, proanthocyanidin from grape seed was given to rats for 2 weeks. As a result, it lowered malondialdehyde level and increased the superoxide dismutase and glutathione peroxidase was activated significantly. Furthermore, it reduced fatigue after physical activitie¹⁸.

Red-fleshed pitaya (Hylocereus polyrhizus) is a unique fruit with a lot of benefits. The fruit is recently popular among Indonesians and appears to be a natural antioxidant. Several in vitro studies have revealed that red-fleshed pitaya extract has the potential to be an antioxidant¹⁹. This research aimed to investigate the antioxidant potential in red-fleshed pitaya extract on HSP70 and cortisol expression in rats that were subjected to strenuous exercise. Red fleshed pitaya contains powerful antioxidants because it consists of various antioxidants, namely flavonoids, and polyphenol^20,21. Thus Red fleshed pitaya which has the potential as an antioxidant can reduce ROS and respond to HSP70 expression^22,23.

The study about exercise and the potential of red-fleshed pitaya as an antioxidant that affects HSP70 and cortisol expression is still limited. So this research purpose to find out the potential of red-fleshed pitaya as an antioxidant and once to know the effective dose to reduce oxidative stress which is influence on HSP70 and cortisol expression in rats that were subjected strenuous exercise.

Methods

Experimental animals

The subjects of this research were 32 Sprague Dawley male rats, aged 3 months, with an average weight of 200 g, were obtained from the Animal Holding Unit of the Pharmacy laboratory, University of Sumatera Utara, Indonesia.

All rats were sustained and maintained in groups (four mice per cage) in experimental animal cages of the Pharmacy laboratory, University of Sumatera Utara, Indonesia. The cage is made of plastic (30 x 20 x 10 cm) and covered with fine wire mesh. The base of the cage is covered with rice husk as thick as 0.5 - 1 cm and replaced every day during the research. The room light was controlled to be exactly at 12 hours light and 12 hours dark cycle, while the temperature 25–27°C and humidity of the room were adjusted to a normal range and fed with standard rat pellets 551, and drink (tap water) was given ad libitum.

Study design

The research applied a laboratory experiment method with random group posttest-only design. The male rats were obtained from the Pharmacy Laboratory, University of North Sumatra. The experimental animals were simple random sampling divided into four groups: Group 1 was subjected to strenuous exercise and treated with distilled water only; Group 2 was subjected to strenuous exercise and treated with dosage 100 mg/kg body weight of red-fleshed pitaya extract; Group 3 was subjected to strenuous exercise and treated with dosage 200 mg/kg body weight of red-fleshed pitaya extract; Group 4 was subjected to strenuous exercise and treated with dosage 300 mg/kg body weight of red-fleshed pitaya extract.

Giving 3 doses of 100 mg/kg body weight, 200 mg/kg body weight, and 300 mg/kg body weight to find out what is the optimal dose to neutralize oxidative stress due to strenuous physical exercise. So it is necessary to experiment with 3 doses, in accordance with the purpose of the study to find out the potential of Red-fleshed pitaya as an antioxidant and once to know the optimal dose to reduce oxidative stress.

Red-fleshed pitaya extract

Red-fleshed pitaya fruit, obtained from farmers, in Indonesia, was peeled, washed, cut into small pieces and then dried in a drying cabinet. After that, the fruit was blended using a blender. The fruit extract was isolated through maceration method by using ethanol 96% which has been distilled as much as 10 times the weight of red-fleshed pitaya powder. Red-fleshed pitaya fruit powder in a container had 96% ethanol added to it (ratio 1:7, fruit powder: ethanol), and then was soaked for 3 days then filtered and sealed. The macerates were collected in a container and then processed with rotary evaporator at a temperature of 45°C until the extract was thickened. After that, the same process of were repeated the remaining ethanol 96% for 3 days. The less thickened extract was then evaporated in a water bath until a thick extract was obtained.

100 mg red-fleshed pitaya extract was weighed. Then, it was gently ground using a pestle and mortar. After that, carboxy methyl cellulose (CMC) Na 0.5% solution was slowly added and ground until a homogeneous phase was achieved. Finally, the suspension was added to a 10 mL measuring flask until it reached the mark line. The allocation of red-fleshed pitaya extract, dosage of 100 mg/kg body weight, for instance: weight of 200 g, volume taken: 2 ml extract suspension. Dosage of 200 mg/kg body weight, for instance: weight of 200 g, volume taken: 4 ml extract suspension. Dosage of 300 mg/kg body weight, for instance: weight of 200 g, volume taken: 6 ml extract suspension.

Experimental procedures

Strenuous exercise given to all rats was a morning swim between 8–9 am for 20 minutes/day, 3 days a week over 21 days. The equipment used in this research was a 10-cm length and 25-cm diameter bath as a pool. Group 1, the rats received distilled water only; Group 2, the rats received 2 ml red-fleshed pitaya extract suspension; Group 3, the rats received 4 ml red-fleshed pitaya extract suspension; Group 4, the rats received 6 ml red-fleshed pitaya extract suspension. Administration of red-fleshed pitaya extract suspension and water was performed orally once daily for 21 days.

Testing for HSP70 and cortisol was conducted two days after the rats had completed a strenuous exercise, 3 days a week over 21 days. During the test, the rats were given a maximum training session by swimming as hard as they could until the rats drowned or showed fatigue symptoms such as the entire body almost dipped into water and limb movements slowed down. After that the rats were sacrificed by placing them in a jar containing cotton which was moistened with 10 ml of chloroform. After that, 2–3 ml blood was taken from the heart.

Blood samples were collected in micro tubes and centrifuged at 3000 rpm for 15 minutes. The serum was separated and stored at a temperature of 20°C until the analysis process would be carried out. Cortisol was measured with enzyme-linked immune sorbent assay (ELISA); Mouse Cortisol Elisa kit (catalog: E1483Mo, Brand Bioassay TL) and UV spectrophotometry at a wavelength of 450 nm. The HSP70 expression was recorded with ELISA; Mouse HSP70 Elisa Kit (catalog: E0302Mo, Brand Bioassay TL); the absorbance was indicated at 405 nm.

Statistical methods

Data was analyzed using SPSS 22 for Windows and displayed in tables and diagrams. Normality test was conducted through Shapiro-Wilk test (P > 0.05) in order to determine the average of normal distribution of sample data which is presented as mean ± SD. The result of the normality test was used for next analysis; parametric analysis was used for normal distribution, otherwise non-parametric analysis was used. The ANOVA statistical analysis was performed to indicate the effects of treatments for each group. If the significant result is obtained, then the procedure is followed by Least Significance Difference or Bonferroni tests.

Ethical approval

The research was performed on the animal subjects were in according with the ethical standards by the Animal Research Ethics Committees/AREC, Faculty of Mathematics and Natural Sciences University of Sumatera Utara, Indonesia (approval number 0011/KEPH-FMIPA/2018).

All efforts were made to reduce any suffering of the rats was during the experiments by following careful procedures and also by anaesthetizing the animal prior to scarifice to prevent experiencing any pain.

Results

A normality test indicated that the data are normally distributed (Table 1). HSP70 expression was decreased across all groups (69.57 vs 46.04 vs 31.47 vs 27.65 pg/mL). Group 4 had the lowest expression compared with the other groups. This research reveals a significant decrease in HSP70 expression (p=0.000) between the groups (Table 2).

Table 1. Normality test for heat shock protein 70 (HSP70) and cortisol expression.

Parameter	Group	Normality test
Parameter	Group	statistic	p-value
HSP70	Group 1	0.969	0.888
	Group 2	0.907	0.332
	Group 3	0.922	0.449
	Group 4	0.875	0.168
Cortisol	Group 1	0.923	0.451
	Group 2	0.962	0.833
	Group 3	0.939	0.603
	Group 4	0.900	0.290

Shapiro-wilk test, P>0.05

Table 2. Average heat-shock protein (HSP70) and cortisol expression in rats who were subjected to strenuous exercise and treated with distilled water (group 1), and 100 mg/ kg body weight (group 2), 200 mg/ kg body weight (group 3) and 300 mg/ kg body weight (group 4) red-fleshed pitaya extract, respectively.

Parameter	Group 1 (n=8)	Group 2 (n=8)	Group 3 (n=8)	Group 4 (n=8)	p-value
HSP70 (pg/ml)	69.57 ± 7.27	46.04 ± 6.45	31.47 ± 1.24	27.65 ± 1.72	0.000*
Cortisol (pg/ml)	119.02 ± 5.56	86.11 ± 11.40	62.94 ± 4.61	40.86 ± 10.94	0.000*

The mean ± SD HSP70 and cortisol expression in shown

Cortisol expression was also decreased across all groups (119.02 vs 86.11 vs 62.94 vs 40.86 pg/mL). Group 4 had the lowest expression compared with the other groups. An ANOVA test revealed a significant decrease in cortisol expression (p=0.000) between the groups (Table 2).

Figure 1 indicates a significant difference in the average decrease of HSP70 expression between group 4 and either group 1 or 2 (p=0.000). However, a significant difference between group 4 and group 3 (p=0.813) was not found. This means that group 4, with strenuous exercise and given 300 mg/kg body weight red-fleshed pitaya extract was indicated to be more effective for reducing HSP70 expression compared to group 1 and 2, with no big variance from group 3.

Figure 1. Effect of red-fleshed pitaya extract on HSP70 expression in rats that were given strenuous exercise.

Figure 2 confirms that a significant difference is revealed in the average decrease of cortisol expression between groups 4 and 1 (p=0.000), 2 (p=0.000), and 3 (p=0.000). It can be concluded that group 4 with strenuous exercise and 300 mg/kg body weight red-fleshed pitaya extract was more effective in reducing cortisol expression compared to the other groups.

Figure 2. Effect of red-fleshed pitaya extract on cortisol in rats that were given strenuous exercise.

Discussion

Based on the results of this research, it is found that strenuous exercise combined with daily red-fleshed pitaya extract consumption contributes to a declining expression of HSP70 and cortisol. The dosage of 300 mg/kg body weight red-fleshed pitaya extract was found to be the optimum amount in decreasing cortisol compared to 100 and 200 mg/kg body weight dosage. However, for both 300 mg/kg body weight and 200 mg/kg body weight dosage of red-fleshed pitaya extract could not provide any difference to HSP70 expression. Therefore, the red-fleshed pitaya extract can be categorized as a potential exogenous antioxidant to eliminate free radicals formed during strenuous exercise.

Free radicals are an element that possesses one or more unpaired electrons in its outermost orbital. Consequently, it is very reactive to cells or cell components in its surroundings. Commonly, a reactive element finds its pair by attacking and binding with adjacent electrons. Then, if this element reacts with another radical element, a new radical element will be formed. This will consistently continue to occur leading to an unavoidable chain reaction²⁴. During strenuous exercise, oxygen consumption rises by 20 times. The excess oxygen triggers the formation of free radicals with electrons released from the respiratory chain. Free radicals production from activity, especially superoxides, increases in the mitochondria²⁵. When an imbalance happens due to the excess of free radicals, oxidative stress occurs and damages the DNA. Moreover, proteins will lose their structure and function like enzymes and membrane receptor. Also, there will be damage in the lipid bilayer structure²⁶.

Strenuous exercise triggers the oxidative stress to occur, therefore, the HSP70 expression will elevate and resulting in a decrease of endogenous antioxidant activity. Strenuous exercise is associated with increased HSP70 expression due to oxidative stress²⁷. HSP70 is an important protein molecule for cell healing and preventing homeostasis and also increased expression as a cyto-protective effect. The HSP70 is induced strongly due to oxidative stress as cyto-protective to prevent the oxidative damages and heal the broken proteins²⁸. The increase of HSP70 expession is aimed to balance between ischemic condition, high temperature and the increased production of free radical²⁹. In this research, it is found that HSP70 expression tends to decrease in a group with strenuous exercise combined with red-fleshed pitaya extract.

The results of this research is in accordance to a research by Kassaf et al., (2003) that antioxidant supplementation is proven to be effective to slow down the HSP70 synthesis caused by high intensity exercise²⁹. Other researches have also by Petiz et al. (2017) which discovered that Vitamin A combined with high intensity acivities could prevent tissue damage and reduce endogenous antioxidant defense regulation in rats, which also suppressed the HSP70 expression³⁰.

The red-fleshed pitaya extract combined with strenuous exercise is proven to be able to inhibit the increasing of HSP70 expression. Red-flehed pitaya (Hylocereus polyrhizus) is one of the plants that can be used as a source of antioxidants because that red dragon fruit contains the most polyphenols compared to other species³¹. This is occured due to the potential of red-fleshed pitaya as an antioxidant that is able to balance the increasing amount of free radicals formed and impairs HSP70 synthesis induced by strenuous exercise³². Therefore, the HSP70 expession is lower compared to the groups that are not given by red-fleshed pitaya extract.

Physical activity appears to occur concomitantly with up-regulation of endogenous antioxidant systems and heat shock proteins (HSP) in skeletal muscle. While the main role of the antioxidant enzymes is to reduce oxidation and prevent oxidative damage, HSPs can prevent and reverse damage to proteins. Intriguingly, the HSPs work with the antioxidant systems, and collectively they have essential roles in cell homeostasis. Up-regulation of these proteins is, therefore, important adaptations for increased protection and recovery capacity in the face of cellular stress and damage induced by strenous exercise³³.

Physical training combined with low to medium dosage of red-fleshed pitaya extract were measured based on the ability and lead to immunomodulation effect that affect the body immune system and protect the body from cell damages, resulting in an effective condition to reduce the oxidative stress³⁴. Stress resulted from physical activity like oxidative stress is responded by hypothalamus to secrete corticotrophin realizing hormone (CRH) which then delivers a message to pituitary anterior. The pituitary produced adrenocorticotropic hormone (ACTH) which is useful to activate or affect adrenal cortex where cortisol hormone is secreted. Cortisol conttributes a massive influence to immune responses¹⁶ as a sign that the body is suffering from oxidative stress³⁵. In this research, cortisol hormone level tends to decreased in the group with strenuous exercise combined with red-fleshed pitaya extract.

This occurs since the red-fleshed pitaya extract is an effective antioxidant to reduce the risk of oxidative stress and is able to decrease the secretion of cortisol by reducing ACTH secretion in the hypothalamus and CRH in the pituitary gland³⁶

Increased cortisol levels after physical activity depends on the level of fitness, exercise intensity and exercise program³⁷. Exercise with heavy intensity tends to produce free radicals which can cause the production of the hormone cortisol to increase. Provision of red dragon fruit that contains antioxidant polyphenols can reduce the production of free radicals due to exercise thereby reducing cortisol levels³⁸.

Red-fleshed pitaya is the cactus fruit of the genus Hylocereus and Selenicereus. Red-fleshed pitaya is very popular and widely planted in Indonesia because it is known by the public as herbal medicine. Research by Widyaningsih et al., (2017) report that red-fleshed pitaya as an alternative treatment for anemia in pregnant women³⁹. The other studies by Irmayanti and Ardiaria (2016) report that Hylocereus Polyhizus can reduce cholesterol levels in rats⁴⁰.

Conclusion

Based on this research, it can be concluded that red-fleshed pitaya extract has the potential to be antioxidant with its anthocyanin content, and is able to eliminate oxidative stress due to strenuous exercise. It can be observed by the decreased pattern of HSP70 and cortisol expression in the strenuous exercise combined with red-fleshed pitaya extract group. Furthermore, we find out the optimum result was shown in potential of red-flehed pitaya as an antioxidant and the dosage of effective dose at 300 mg/kg body weight of red-fleshed pitaya extract. can reduce oxidative stress which is influence on HSP70 and cortisol expression in rats that were subjected strenuous exercise.

given dose at 300 mg/kg body weight of red-fleshed pitaya extract was indicated to be more effective for reducing HSP70 expression.

Data availability

Underlying data

Open Science Framework: The effect of red-fleshed pitaya (Hylocereus polyrhizus) on heat shock protein 70 and cortisol expression in strenuous exercise induced rats, https://doi.org/10.17605/OSF.IO/MGX4K⁴¹

Data are available under the terms of the Creative Commons Zero “No rights reserved” data waiver (CC0 1.0 Public domain dedication).

Faculty Opinions recommended

References

1. Yavari A, Javadi M, Mirmiran P, et al.: Exercise-induced oxidative stress and dietary antioxidants. Asian J Sports Med. 2015; 6(1): e24898. PubMed Abstract | Publisher Full Text | Free Full Text
2. Escribano BM, Tunez I, Requena F, et al.: Effects of an aerobic training program on oxidative stress biomarkers in bulls. Vet Med (Praha). 2010; 55(9): 422–428. Publisher Full Text
3. El Abed K, Rebai H, Bloomer RJ, et al.: Antioxidant status and oxidative stress at rest and in response to acute exercise in judokas and sedentary men. J Strength Cond Res. 2011; 25(9): 2400–9. PubMed Abstract | Publisher Full Text
4. Steinbacher P, Eckl P: Impact of oxidative stress on exercising skeletal muscle. Biomolecules. 2015; 5(2): 356–77. PubMed Abstract | Publisher Full Text | Free Full Text
5. Valko M, Leibfritz D, Moncol J, et al.: Free radicals and antioxidants in normal physiological functions and human disease. Int J Biochem Cell Biol. 2007; 39(1): 44–84. PubMed Abstract | Publisher Full Text
6. Macedo DV, Lazarim FL, Catanho da Silva FO, et al.: Is lactate production related to muscular fatigue? A pedagogical proposition using empirical facts. Adv Physiol Educ. 2009; 33(4): 302–7. PubMed Abstract | Publisher Full Text
7. Kürkçü R, Tekin A, Özda S, et al.: The effects of regular exercıse on oxıdatıve and antıoxıdatıve parameters ın young wrestlers. African J Pharm Pharmacol. 2010; 4(5): 244–251. Reference Source
8. Azizbeigi K, Azarbayjani MA, Peeri M, et al.: The effect of progressive resistance training on oxidative stress and antioxidant enzyme activity in erythrocytes in untrained men. Int J Sport Nutr Exerc Metab. 2013; 23(3): 230–8. PubMed Abstract | Publisher Full Text
9. Folkesson M, Mackey AL, Langberg H, et al.: The expression of heat shock protein in human skeletal muscle: effects of muscle fibre phenotype and training background. Acta Physiol (Oxf). 2013; 209(1): 26–33. PubMed Abstract | Publisher Full Text
10. Liu Y, Gampert L, Nething K, et al.: Response and function of skeletal muscle heat shock protein 70. Front Biosci. 2006; 11: 2802–27. PubMed Abstract | Publisher Full Text
11. Biller-Takahashi JD, Takahashi LS, Mingatto FE, et al.: The immune system is limited by oxidative stress: Dietary selenium promotes optimal antioxidative status and greatest immune defense in pacu Piaractus mesopotamicus. Fish Shellfish Immunol. 2015; 47(1): 360–7. PubMed Abstract | Publisher Full Text
12. Starnes JW, Choilawala AM, Taylor RP, et al.: Myocardial heat shock protein 70 expression in young and old rats after identical exercise programs. J Gerontol A Biol Sci Med Sci. 2005; 60(8): 963–969. PubMed Abstract | Publisher Full Text
12. Staib JL, Tümer N, Powers SK: Increased temperature and protein oxidation lead to HSP72 mRNA and protein accumulation in the in vivo exercised rat heart. Exp Physiol. 2009; 94(1): 71–80. PubMed Abstract | Publisher Full Text | Free Full Text
13. Usui T, Yoshikawa T, Ueda SY, et al.: Effects of acute prolonged strenuous exercise on the salivary stress markers and inflammatory cytokines. Jpn J Phys Fitness Sports Med. 2011; 60(3): 295–304. Publisher Full Text
14. Hill EE, Zacki E, Battaglini C, et al.: Exercise and circulating cortisol levels: the intensity threshold effect. J Endocrinol Invest. 2008; 31(7): 587–91. PubMed Abstract | Publisher Full Text
15. Peternelj TT, Coombes JS: Antioxidant supplementation during exercise training: beneficial or detrimental? Sports Med. 2011; 41(12): 1043–69. PubMed Abstract | Publisher Full Text
16. Gomez-Cabrera MC, Viña J, Ji LL: Interplay of oxidants and antioxidants during exercise: implications for muscle health. Phys Sportsmed. 2009; 37(4): 116–23. PubMed Abstract | Publisher Full Text
17. Belviranli M, Gökbel H: Acute exercise induced oxidative stress and antioxidant changes. Eur J Gen Med. 2006; 3(3): 126–131. Publisher Full Text
18. Nurul SR, Asmah R: Variability in nutritional composition and phytochemical properties of red pitaya (Hylocereus polyrhizus) from Malaysia and Australia. Int Food Res J. 2014; 21(4): 1689–1697. Reference Source
19. Sahlin K, Shabalina IG, Mattsson CM, et al.: Ultraendurance exercise increases the production of reactive oxygen species in isolated mitochondria from human skeletal muscle. J Appl Physiol (1985). 2010; 108(4): 780–7. PubMed Abstract | Publisher Full Text | Free Full Text
20. Chemah TC, Aminah A, Noriham A, et al.: Determination of pitaya seeds as a natural antioxidant and source of essential fatty acids. Int Food Res J. 2010; 17(4): 1003–1010. Reference Source
21. Adnan L, Osman A, Hamid AA: Antioxidant Activity of Different Extracts of RedPitaya (Hylocereus polyrhizus) Seed. Int J Food Prop. 2011; 14(6): 1171–1181. Publisher Full Text
22. Khassaf M, Child RB, McArdle A, et al.: Time course of responses of human skeletal muscle to exercise-induced oxidative stress. J App Physiol (1985). 2001; 90(3): 1031–1036. PubMed Abstract | Publisher Full Text
23. Morton JP, MacLaren, DPM, Cable NT, et al.: Time Course and Differential Responses of the Major Heat Shock Protein Families in Human Skeletal Muscle Following Acute Nondamaging Treadmill Exercise. J Appl Physiol (1985). 2006; 101(1): 176–82. PubMed Abstract | Publisher Full Text
24. Gomes EC, Silva AN, de Oliveira MR: Oxidants, antioxidants, and the beneficial roles of exercise-induced production of reactive species. Oxid Med Cell Longev. 2012; 2012: 756132. PubMed Abstract | Publisher Full Text | Free Full Text
25. Abruzzo PM, Esposito F, Marchionni C, et al.: Moderate exercise training induces ROS-related adaptations to skeletal muscles. Int J Sports Med. 2013; 34(8): 676–87. PubMed Abstract | Publisher Full Text
26. Krause M, Heck TG, Bittencourt A, et al.: The chaperone balance hypothesis: the importance of the extracellular to intracellular HSP70 ratio to inflammation-driven type 2 diabetes, the effect of exercise, and the implications for clinical management. Mediators Inflamm. 2015; 2015: 249205. PubMed Abstract | Publisher Full Text | Free Full Text
27. Paulsen G, Vissing K, Kalhovde JM, et al.: Maximal eccentric exercise induces a rapid accumulation of small heat shock proteins on myoﬁbrils and a delayed HSP70 response in humans. Am J Physiol Regul Integr Comp Physiol. 2007; 293(2): R844–R853. PubMed Abstract | Publisher Full Text
28. Lanneau D, Brunet M, Frisan E, et al.: Heat shock proteins: essential proteins for apoptosis regulation. J Cell Mol Med. 2008; 12(3): 743–61. PubMed Abstract | Publisher Full Text | Free Full Text
29. Khassaf M, McArdle A, Esanu C, et al.: Effect of vitamin C supplements on antioxidant defence and stress proteins in human lymphocytes and skeletal muscle. J Physiol. 2003; 549(Pt 2): 645–52. PubMed Abstract | Publisher Full Text | Free Full Text
30. Petiz LL, Girardi CS, Bortolin RC, et al.: Vitamin A Oral Supplementation Induces Oxidative Stress and Suppresses IL-10 and HSP70 in Skeletal Muscle of Trained Rats. Nutrients. 2017; 9(4): E353. PubMed Abstract | Publisher Full Text | Free Full Text
31. Rebecca OPS, Boyce AN, Chandra S: Pigment Identification and Antioxidant Properties of Red Dragon Fruits (Hylocereus polyrhizus). Afr J Biotechnol. 2010; 9(10): 1450–1454. Publisher Full Text
32. Baghaiee B, Karimi P, Siahkouhian M, et al.: Moderate aerobic exercise training decreases middle-aged induced pathologic cardiac hypertrophy by improving Klotho expression, MAPK signaling pathway, and oxidative stress status in Wistar rats. Iran J Basic Med Sci. 2018; 21(9): 911–919. PubMed Abstract | Publisher Full Text | Free Full Text
33. Morton JP, Kayani AC, McArdle A, et al.: The exercise-induced stress response of skeletal muscle, with specific emphasis on humans. Sports Med. 2009; 39(8): 643–62. PubMed Abstract | Publisher Full Text
34. Turner-Cobb JM, Palmer J, Aronson D, et al.: Diurnal cortisol and coping responses in close relatives of persons with acquired brain injury: a longitudinal mixed methods study. Brain Inj. 2010; 24(6): 893–903. PubMed Abstract | Publisher Full Text
35. Kraemer WJ, Ratamess NA: Hormonal responses and adaptations to resistance exercise and training. Sports Med. 2005; 35(4): 339–61. PubMed Abstract | Publisher Full Text
36. Starnes JW, Choilawala AM, Taylor RP, et al.: Myocardial heat shock protein 70 expression in young and old rats after identical exercise programs. J Gerontol A Biol Sci Med Sci. 2005; 60(8): 963–969. PubMed Abstract | Publisher Full Text
37. Leite RD, Prestes J, Rosa C, et al.: Acute effect of resistance training volume on hormonal responses in trained men. J Sports Med Phys Fitness. 2011; 51(2): 322–328. PubMed Abstract
38. Stachowicz M, Lebiedzinska A: The effect of diet components on the level of cortisol. Eur Food Res Technol. 2016; 242: 2001–2009. Publisher Full Text
39. Widyaningsih A, Setiyani O, Umaroh U, et al.: Effect Of Consuming Red Dragon Fruit (Hylocereus Costaricensis) Juice On The Levels Of Hemoglobin And Erythrocyte Among Pregnant Women. Belitung Nurs J. 2017; 3(3): 255–264. Publisher Full Text
40. Irmayanti L, Ardiaria M: Efek Pemberian Seduhan Kulit Buah Nagamerah (Hylocererus Polyhizus)Terhadap Kadar Kolesterol Ldl Tikus Sprague Dawley Dislipidemia. Journal of Nutrition College. 2016; 5(4): 530–538. Reference Source
41. Harahap NS: The Effect of Red-Fleshed Pitaya (Hylocereus Polyrhizus) on Heat Shock Protein 70 and Cortisol Expression in Strenuous Exercise Induced Rats. OSF. 2019. http://www.doi.org/10.17605/OSF.IO/MGX4K

Comments on this article Comments (0)

Version 2

VERSION 2 PUBLISHED 30 Jan 2019

Author details Author details

Novita Sari Harahap
Roles: Conceptualization, Investigation, Methodology, Resources, Writing – Original Draft Preparation

Aznan Lelo
Roles: Investigation, Methodology

Ambrosius Purba
Roles: Resources, Supervision

Awaluddin Sibuea
Roles: Resources

Rina Amelia
Roles: Resources

Zulaini Zulaini
Roles: Formal Analysis

Competing interests

No competing interests were disclosed.

Grant information

The authors would like to acknowledge Ministry of Research, Technology and Higher Education of Republic of Indonesia for funding this research via Research Grant of Universitas Negeri Medan with contract number of 027/UN33.8/LL/2018.
The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Article Versions (2)

version 2

Revised

Published: 29 Sep 2021, 8:130

https://doi.org/10.12688/f1000research.17533.2

version 1

Published: 30 Jan 2019, 8:130

https://doi.org/10.12688/f1000research.17533.1

© 2021 Harahap NS et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Download

Export To

metrics

	Views	Downloads
F1000Research	-	-
PubMed Central Data from PMC are received and updated monthly.	-	-

Citations

SEE MORE DETAILS

CITE

how to cite this article

Harahap NS, Lelo A, Purba A et al. The effect of red-fleshed pitaya (Hylocereus polyrhizus) on heat shock protein 70 and cortisol expression in strenuous exercise induced rats [version 2; peer review: 2 approved]. F1000Research 2021, 8:130 (https://doi.org/10.12688/f1000research.17533.2)

NOTE: If applicable, it is important to ensure the information in square brackets after the title is included in all citations of this article.

track

receive updates on this article

Track an article to receive email alerts on any updates to this article.

Open Peer Review

Version 2

VERSION 2

PUBLISHED 29 Sep 2021

Revised

Views

Reviewer Report 14 Oct 2021

Yusni Yusni, Department of Physiology, Universitas Syiah Kuala, Banda Aceh, Indonesia

Approved

https://doi.org/10.5256/f1000research.27866.r95720

I have read the details of the author's revision. I decide that I agree ... Continue reading

CITE

Report a concern

Respond or Comment

Version 1

VERSION 1

PUBLISHED 30 Jan 2019

Views

Reviewer Report 04 Mar 2020

Mohd Adzim Khalili Rohin, Faculty of Health Sciences, Sultan Zainal Abidin University (UniSZA), Kuala Nerus, Malaysia

Approved

https://doi.org/10.5256/f1000research.19175.r59870

It is an interesting manuscript. However, there are several grammatical issues and some typos that you should check very carefully.
My main concern about your manuscript is that you have not mentioned

It is an interesting manuscript. However, there are several grammatical issues and some typos that you should check very carefully.
My main concern about your manuscript is that you have not mentioned any strengths or limitations in your study.
The small number of rats per group is indeed a limitation and should be mentioned and taken into consideration before making conclusions.
This is a prospective study on the effect of red-fleshed pitaya (Hylocereus polyrhizus) on heat shock protein 70 and cortisol expression in strenuous exercise-induced rats.
The conclusion is weak in my opinion.
The study could be considered more as a pilot study than a proper study; however the results are interesting and should be indexed.

Is the work clearly and accurately presented and does it cite the current literature?

Yes
Is the study design appropriate and is the work technically sound?

Yes
Are sufficient details of methods and analysis provided to allow replication by others?

Yes
If applicable, is the statistical analysis and its interpretation appropriate?

Yes
Are all the source data underlying the results available to ensure full reproducibility?

Yes
Are the conclusions drawn adequately supported by the results?

Yes

Competing Interests: No competing interests were disclosed.

Reviewer Expertise: Functional Food & Nutraceuticals

I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard.

CITE

Report a concern

Respond or Comment

Views

Reviewer Report 08 Nov 2019

Yusni Yusni, Department of Physiology, Universitas Syiah Kuala, Banda Aceh, Indonesia

Approved with Reservations

https://doi.org/10.5256/f1000research.19175.r55888

Introduction:

Please explain why red-fleshed pitaya is thought to act as antioxidants that will affect the heat shock protein 70 and the expression of cortisol: include theoretical and other studies that support.

Introduction:

Please explain why red-fleshed pitaya is thought to act as antioxidants that will affect the heat shock protein 70 and the expression of cortisol: include theoretical and other studies that support.
The novelty of the article must be clearly explained in the introduction.

Methods:

Why use 3 doses, whereas the purpose of the study did not assess the effective dose? In the conclusion, also mention the effective dose.
Explain the results of the identification of the chemical content of red-fleshed pitaya and also the results of herbarium analysis because there is a possibility that Indonesia's geographical differences will affect its chemical content.
Explain the time of blood-sampling because cortisol production is influenced by circadian.

Discussion:

It is important to explain the role or mechanism of action of red-fleshed pitaya on heat shock protein 70 and cortisol expression.

Reference:

Use the latest references (from the last 5-10 years).

Note: There are some grammatical errors, you should use the proof-read service.

Is the work clearly and accurately presented and does it cite the current literature?

Yes
Is the study design appropriate and is the work technically sound?

Yes
Are sufficient details of methods and analysis provided to allow replication by others?

Yes
If applicable, is the statistical analysis and its interpretation appropriate?

Yes
Are all the source data underlying the results available to ensure full reproducibility?

Yes
Are the conclusions drawn adequately supported by the results?

Yes

Competing Interests: No competing interests were disclosed.

Reviewer Expertise: Medical Physiology: exercise physiology; endocrine and metabolic physiology

I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above.

CITE

Report a concern

Author Response 29 Nov 2019

Novita Sari Harahap, Department of Sports Sciences, Faculty of Sports Sciences, Universitas Negeri Medan, Medan, 20221, Indonesia

29 Nov 2019

Author Response

Introduction:
1. Please explain why red-fleshed pitaya is thought to act as antioxidants that will affect the heat shock protein 70 and the expression of cortisol: include theoretical and other studies ... Continue reading Introduction:
1. Please explain why red-fleshed pitaya is thought to act as antioxidants that will affect the heat shock protein 70 and the expression of cortisol: include theoretical and other studies that support.

Red fleshed pitaya has antioxidant activity. Red Dragon Fruit contains powerful antioxidants because it consists of various antioxidants, namely flavonoids, vitamin E, vitamin C (Lianiwati, 2011). The results of several studies stated the red dragon fruit (Hylocereus polyrhizus) has an anthocyanin content (Kanner et al., 2001) around 26,457 ppm. Dragon fruit contains flavonoids (Damayanti, 2016). Anthocyanin is a pigment that is classified as a type of water-soluble flavonoids. Anthocyanins are anthocyanidin and glucose compounds in organic acids (Shipp and Abdel Aal, 2010). Anthocyanins are believed to have a very good antioxidant effect. A study conducted at the University of Michigan in America showed that anthocyanin can destroy free radicals, more effectively than vitamin E which has been known as a powerful antioxidant. Other studies in the United States prove that anthocyanin is the most powerful antioxidant among other flavonoid classes. The content of anthocyanin is believed to inhibit various free radicals such as superoxide radicals and hydrogen peroxide. Anthocyanins and various forms of their derivatives can inhibit various oxidation reactions by various mechanisms (Astawan and Kasih, 2008). The results of previous studies ripe dragon fruit contains many organic acids (Stinzing, et al., 2004), protein (Le Bellec, et al., 2006), minerals such as potassium, magnesium, calcium and iron and vitamin C (Cal et al, 2003).

Increased RONS (Reactive Oxygen and Nitrogen Species) production during exercise has potential negative effects, transient increases in RONS seem to be a trigger for many exercise-induced adaptations in skeletal muscle (Powers et al. 2010). Exercise can stimulate an increased concentration of HSP70 in muscles and plasma.

Oxidative stress due to exercise can cause physiological functional changes because physical exercise is considered as a stimulus received by the hypothalamus, then the hypothalamus signals to the HPA axis, the HPA axis responds and gives positive and negative responses to the body (Guilliam & Edward, 2010). Then stimulates the hypothalamus and causes secretion of the hormone corticotrophin-releasing hormone (CRH), which stimulates the hypothalamus for ACTH secretion. Increased ACTH secretion, causes increased cortisol secretion (Usui et al, 2012).

Methods:

1. Why use 3 doses, whereas the purpose of the study did not assess the effective dose? In conclusion, also mention the effective dose.

Giving 3 doses of 100 mg/kg BW, 200 mg/kg BW and 300 mg/kg BW to find out what is the optimal dose to neutralize oxidative stress due to strenuous physical exercise. A dose of 100 mg/kg BW can also reduce oxidative stress but not as well as a dose of 300 mg/kg BW. So it is necessary to experiment with 3 doses, the purpose of the study to find out the potential of Red-fleshed pitaya as an antioxidant and once to know the optimal dose to reduce oxidative stress.

2. Explain the results of the identification of the chemical content of red-fleshed pitaya and also the results of herbarium analysis because there is a possibility that Indonesia's geographical differences will affect its chemical content.

Red-fleshed pitaya is the cactus fruit of the genera Hyloreceus and Selenicereus. Dragon fruit is very popular and widely planted in Indonesia because it is known by the public as herbal medicine (Evi, et al., 2007). From the results of previous studies, ripe dragon fruit contains many organic acids (Stinzing, et al., 2004), protein (Le Bellec, et al., 2006), minerals such as potassium, magnesium, calcium and iron and vitamin C (Cal et al., 2003).

3. Explain the time of blood-sampling because cortisol production is influenced by circadian.

Cortisol levels are affected by circadian rhythm. Blood drawn for examination of cortisol is done in the morning because it is a basal state of the body after resting at night. Also besides, our bodies have biological variations according to time, meaning that the analytical levels examined in the morning can give different results if examined in the afternoon. On examination of Cortisol, the levels will increase in the morning and reach the lowest levels in the afternoon. Then the blood draw is done in the morning according to the normal human biological clock, the most efficient and does not result in excessive fatigue.

Discussion:
1. It is important to explain the role or mechanism of action of red-fleshed pitaya on heat shock protein 70 and cortisol expression.

Research conducted by Rebecca et al (2010) shows that red dragon fruit contains the most polyphenols compared to other species, namely 86.13 ± 17.02 mg in 0.50 g of dried extract of red dragon fruit. Red dragon fruit (Hylocereus polyrhizus) is one of the plants that can be used as a source of antioxidants. Severe physical exercise is associated with increased HSP70 expression due to oxidative stress (Paulsen et al. 2007).
Oxidative stress causes damage to cells that will cause stress responses in the form of heat shock response (HSR). HSR is regulated at the level of transcription by a mechanism involving heat shock transcription factor (HSF), especially HSF-1. Increased HSF-1 will help in increasing HSP 70 expression in certain amounts/levels in serum and blood plasma (Baird et al., 2006).
Physical activity appears to occur concomitantly with the up-regulation of endogenous antioxidant systems (Powers and Jackson 2008) and heat shock proteins (HSP) in skeletal muscle (Morton et al. 2009b). While the main role of the antioxidant enzymes is to reduce oxidation and prevent oxidative damage, HSPs can prevent and reverse damage to proteins. Intriguingly, the HSPs work with the antioxidant systems, and collectively they have essential roles in cell homeostasis. Up-regulation of these proteins is, therefore, important adaptations for increased protection and recovery capacity in the face of cellular stress and damage induced by high-intensity exercise (Powers and Jackson 2008; Morton et al. 2009b).
Antioxidants have been shown to abolish the acute exercise-induced increases in HSP70 protein levels (Khassaf et al. 2003; Jackson et al. 2004).
Increased cortisol levels after physical activity depends on the level of fitness, exercise intensity and exercise program [Leite et al., 2011]. Exercise with heavy intensity tends to produce free radicals which can cause the production of the hormone cortisol to increase (Stachowicz, 2016).
The provision of red dragon fruit that contains antioxidant polyphenols can reduce the production of free radicals due to exercise thereby reducing cortisol levels.
Introduction:
1. Please explain why red-fleshed pitaya is thought to act as antioxidants that will affect the heat shock protein 70 and the expression of cortisol: include theoretical and other studies that support.

Red fleshed pitaya has antioxidant activity. Red Dragon Fruit contains powerful antioxidants because it consists of various antioxidants, namely flavonoids, vitamin E, vitamin C (Lianiwati, 2011). The results of several studies stated the red dragon fruit (Hylocereus polyrhizus) has an anthocyanin content (Kanner et al., 2001) around 26,457 ppm. Dragon fruit contains flavonoids (Damayanti, 2016). Anthocyanin is a pigment that is classified as a type of water-soluble flavonoids. Anthocyanins are anthocyanidin and glucose compounds in organic acids (Shipp and Abdel Aal, 2010). Anthocyanins are believed to have a very good antioxidant effect. A study conducted at the University of Michigan in America showed that anthocyanin can destroy free radicals, more effectively than vitamin E which has been known as a powerful antioxidant. Other studies in the United States prove that anthocyanin is the most powerful antioxidant among other flavonoid classes. The content of anthocyanin is believed to inhibit various free radicals such as superoxide radicals and hydrogen peroxide. Anthocyanins and various forms of their derivatives can inhibit various oxidation reactions by various mechanisms (Astawan and Kasih, 2008). The results of previous studies ripe dragon fruit contains many organic acids (Stinzing, et al., 2004), protein (Le Bellec, et al., 2006), minerals such as potassium, magnesium, calcium and iron and vitamin C (Cal et al, 2003).

Increased RONS (Reactive Oxygen and Nitrogen Species) production during exercise has potential negative effects, transient increases in RONS seem to be a trigger for many exercise-induced adaptations in skeletal muscle (Powers et al. 2010). Exercise can stimulate an increased concentration of HSP70 in muscles and plasma.

Oxidative stress due to exercise can cause physiological functional changes because physical exercise is considered as a stimulus received by the hypothalamus, then the hypothalamus signals to the HPA axis, the HPA axis responds and gives positive and negative responses to the body (Guilliam & Edward, 2010). Then stimulates the hypothalamus and causes secretion of the hormone corticotrophin-releasing hormone (CRH), which stimulates the hypothalamus for ACTH secretion. Increased ACTH secretion, causes increased cortisol secretion (Usui et al, 2012).

Methods:

1. Why use 3 doses, whereas the purpose of the study did not assess the effective dose? In conclusion, also mention the effective dose.

Giving 3 doses of 100 mg/kg BW, 200 mg/kg BW and 300 mg/kg BW to find out what is the optimal dose to neutralize oxidative stress due to strenuous physical exercise. A dose of 100 mg/kg BW can also reduce oxidative stress but not as well as a dose of 300 mg/kg BW. So it is necessary to experiment with 3 doses, the purpose of the study to find out the potential of Red-fleshed pitaya as an antioxidant and once to know the optimal dose to reduce oxidative stress.

2. Explain the results of the identification of the chemical content of red-fleshed pitaya and also the results of herbarium analysis because there is a possibility that Indonesia's geographical differences will affect its chemical content.

Red-fleshed pitaya is the cactus fruit of the genera Hyloreceus and Selenicereus. Dragon fruit is very popular and widely planted in Indonesia because it is known by the public as herbal medicine (Evi, et al., 2007). From the results of previous studies, ripe dragon fruit contains many organic acids (Stinzing, et al., 2004), protein (Le Bellec, et al., 2006), minerals such as potassium, magnesium, calcium and iron and vitamin C (Cal et al., 2003).

3. Explain the time of blood-sampling because cortisol production is influenced by circadian.

Cortisol levels are affected by circadian rhythm. Blood drawn for examination of cortisol is done in the morning because it is a basal state of the body after resting at night. Also besides, our bodies have biological variations according to time, meaning that the analytical levels examined in the morning can give different results if examined in the afternoon. On examination of Cortisol, the levels will increase in the morning and reach the lowest levels in the afternoon. Then the blood draw is done in the morning according to the normal human biological clock, the most efficient and does not result in excessive fatigue.

Discussion:
1. It is important to explain the role or mechanism of action of red-fleshed pitaya on heat shock protein 70 and cortisol expression.

Research conducted by Rebecca et al (2010) shows that red dragon fruit contains the most polyphenols compared to other species, namely 86.13 ± 17.02 mg in 0.50 g of dried extract of red dragon fruit. Red dragon fruit (Hylocereus polyrhizus) is one of the plants that can be used as a source of antioxidants. Severe physical exercise is associated with increased HSP70 expression due to oxidative stress (Paulsen et al. 2007).
Oxidative stress causes damage to cells that will cause stress responses in the form of heat shock response (HSR). HSR is regulated at the level of transcription by a mechanism involving heat shock transcription factor (HSF), especially HSF-1. Increased HSF-1 will help in increasing HSP 70 expression in certain amounts/levels in serum and blood plasma (Baird et al., 2006).
Physical activity appears to occur concomitantly with the up-regulation of endogenous antioxidant systems (Powers and Jackson 2008) and heat shock proteins (HSP) in skeletal muscle (Morton et al. 2009b). While the main role of the antioxidant enzymes is to reduce oxidation and prevent oxidative damage, HSPs can prevent and reverse damage to proteins. Intriguingly, the HSPs work with the antioxidant systems, and collectively they have essential roles in cell homeostasis. Up-regulation of these proteins is, therefore, important adaptations for increased protection and recovery capacity in the face of cellular stress and damage induced by high-intensity exercise (Powers and Jackson 2008; Morton et al. 2009b).
Antioxidants have been shown to abolish the acute exercise-induced increases in HSP70 protein levels (Khassaf et al. 2003; Jackson et al. 2004).
Increased cortisol levels after physical activity depends on the level of fitness, exercise intensity and exercise program [Leite et al., 2011]. Exercise with heavy intensity tends to produce free radicals which can cause the production of the hormone cortisol to increase (Stachowicz, 2016).
The provision of red dragon fruit that contains antioxidant polyphenols can reduce the production of free radicals due to exercise thereby reducing cortisol levels.
Competing Interests: I declare no competing interests Close
Report a concern
Author Response 29 Sep 2021

Novita Sari Harahap, Department of Sports Sciences, Faculty of Sports Sciences, Universitas Negeri Medan, Medan, 20221, Indonesia

29 Sep 2021

Author Response

Thank you for this thorough review of the manuscript and your insightful comments that have improved the clarity and quality of the paper. Below there is a point-by-point response to ... Continue reading Thank you for this thorough review of the manuscript and your insightful comments that have improved the clarity and quality of the paper. Below there is a point-by-point response to your inquiries.
The difference between this new version and version 1 is that in this new version, we can explain the antioxidant activity contained in red-fleshed pitaya that can affect heat shock protein 70 and the expression of cortisol. Red fleshed pitaya contains powerful antioxidants because it consists of various antioxidants, namely flavonoids, and polyphenol (Chemah et al. 2010; Adnan, 2011). Thus Red fleshed pitaya which has the potential as an antioxidant can reduce ROS and respond to HSP70 expression.
We can also explain that giving 3 doses of 100 mg/kg body weight, 200 mg/kg body weight, and 300 mg/kg body weight to find out what is the effective dose to neutralize oxidative stress due to strenuous physical exercise. So it is necessary to experiment with 3 doses, in accordance with the purpose of the study to find out the potential of Red-fleshed pitaya as an antioxidant and once to know the effective dose to reduce oxidative stress which is influence on HSP70 and cortisol expression in rats that were subjected strenuous exercise.
Red-fleshed pitaya is the cactus fruit of the genera Hyloreceus and Selenicereus. Red-fleshed pitaya is very popular and widely planted in Indonesia because it is known by the public as herbal medicine. Research by Widyaningsih et al., (2017) report that red-fleshed pitaya as an alternative treatment for anemia in pregnant women. The other studies by Irmayanti and Ardiaria (2016) report that red dragon fruit (Hylocereus Polyhizus) can reduce cholesterol levels in rats. This statement explains that red-fleshed pitaya have also affect difference.
Thank you for this thorough review of the manuscript and your insightful comments that have improved the clarity and quality of the paper. Below there is a point-by-point response to your inquiries.
The difference between this new version and version 1 is that in this new version, we can explain the antioxidant activity contained in red-fleshed pitaya that can affect heat shock protein 70 and the expression of cortisol. Red fleshed pitaya contains powerful antioxidants because it consists of various antioxidants, namely flavonoids, and polyphenol (Chemah et al. 2010; Adnan, 2011). Thus Red fleshed pitaya which has the potential as an antioxidant can reduce ROS and respond to HSP70 expression.
We can also explain that giving 3 doses of 100 mg/kg body weight, 200 mg/kg body weight, and 300 mg/kg body weight to find out what is the effective dose to neutralize oxidative stress due to strenuous physical exercise. So it is necessary to experiment with 3 doses, in accordance with the purpose of the study to find out the potential of Red-fleshed pitaya as an antioxidant and once to know the effective dose to reduce oxidative stress which is influence on HSP70 and cortisol expression in rats that were subjected strenuous exercise.
Red-fleshed pitaya is the cactus fruit of the genera Hyloreceus and Selenicereus. Red-fleshed pitaya is very popular and widely planted in Indonesia because it is known by the public as herbal medicine. Research by Widyaningsih et al., (2017) report that red-fleshed pitaya as an alternative treatment for anemia in pregnant women. The other studies by Irmayanti and Ardiaria (2016) report that red dragon fruit (Hylocereus Polyhizus) can reduce cholesterol levels in rats. This statement explains that red-fleshed pitaya have also affect difference.
Competing Interests: No competing interests were disclosed Close
Report a concern
Respond or Comment

COMMENTS ON THIS REPORT

Author Response 29 Nov 2019

Novita Sari Harahap, Department of Sports Sciences, Faculty of Sports Sciences, Universitas Negeri Medan, Medan, 20221, Indonesia

29 Nov 2019

Author Response

Introduction:
1. Please explain why red-fleshed pitaya is thought to act as antioxidants that will affect the heat shock protein 70 and the expression of cortisol: include theoretical and other studies ... Continue reading Introduction:
1. Please explain why red-fleshed pitaya is thought to act as antioxidants that will affect the heat shock protein 70 and the expression of cortisol: include theoretical and other studies that support.

Red fleshed pitaya has antioxidant activity. Red Dragon Fruit contains powerful antioxidants because it consists of various antioxidants, namely flavonoids, vitamin E, vitamin C (Lianiwati, 2011). The results of several studies stated the red dragon fruit (Hylocereus polyrhizus) has an anthocyanin content (Kanner et al., 2001) around 26,457 ppm. Dragon fruit contains flavonoids (Damayanti, 2016). Anthocyanin is a pigment that is classified as a type of water-soluble flavonoids. Anthocyanins are anthocyanidin and glucose compounds in organic acids (Shipp and Abdel Aal, 2010). Anthocyanins are believed to have a very good antioxidant effect. A study conducted at the University of Michigan in America showed that anthocyanin can destroy free radicals, more effectively than vitamin E which has been known as a powerful antioxidant. Other studies in the United States prove that anthocyanin is the most powerful antioxidant among other flavonoid classes. The content of anthocyanin is believed to inhibit various free radicals such as superoxide radicals and hydrogen peroxide. Anthocyanins and various forms of their derivatives can inhibit various oxidation reactions by various mechanisms (Astawan and Kasih, 2008). The results of previous studies ripe dragon fruit contains many organic acids (Stinzing, et al., 2004), protein (Le Bellec, et al., 2006), minerals such as potassium, magnesium, calcium and iron and vitamin C (Cal et al, 2003).

Increased RONS (Reactive Oxygen and Nitrogen Species) production during exercise has potential negative effects, transient increases in RONS seem to be a trigger for many exercise-induced adaptations in skeletal muscle (Powers et al. 2010). Exercise can stimulate an increased concentration of HSP70 in muscles and plasma.

Oxidative stress due to exercise can cause physiological functional changes because physical exercise is considered as a stimulus received by the hypothalamus, then the hypothalamus signals to the HPA axis, the HPA axis responds and gives positive and negative responses to the body (Guilliam & Edward, 2010). Then stimulates the hypothalamus and causes secretion of the hormone corticotrophin-releasing hormone (CRH), which stimulates the hypothalamus for ACTH secretion. Increased ACTH secretion, causes increased cortisol secretion (Usui et al, 2012).

Methods:

1. Why use 3 doses, whereas the purpose of the study did not assess the effective dose? In conclusion, also mention the effective dose.

Giving 3 doses of 100 mg/kg BW, 200 mg/kg BW and 300 mg/kg BW to find out what is the optimal dose to neutralize oxidative stress due to strenuous physical exercise. A dose of 100 mg/kg BW can also reduce oxidative stress but not as well as a dose of 300 mg/kg BW. So it is necessary to experiment with 3 doses, the purpose of the study to find out the potential of Red-fleshed pitaya as an antioxidant and once to know the optimal dose to reduce oxidative stress.

2. Explain the results of the identification of the chemical content of red-fleshed pitaya and also the results of herbarium analysis because there is a possibility that Indonesia's geographical differences will affect its chemical content.

Red-fleshed pitaya is the cactus fruit of the genera Hyloreceus and Selenicereus. Dragon fruit is very popular and widely planted in Indonesia because it is known by the public as herbal medicine (Evi, et al., 2007). From the results of previous studies, ripe dragon fruit contains many organic acids (Stinzing, et al., 2004), protein (Le Bellec, et al., 2006), minerals such as potassium, magnesium, calcium and iron and vitamin C (Cal et al., 2003).

3. Explain the time of blood-sampling because cortisol production is influenced by circadian.

Cortisol levels are affected by circadian rhythm. Blood drawn for examination of cortisol is done in the morning because it is a basal state of the body after resting at night. Also besides, our bodies have biological variations according to time, meaning that the analytical levels examined in the morning can give different results if examined in the afternoon. On examination of Cortisol, the levels will increase in the morning and reach the lowest levels in the afternoon. Then the blood draw is done in the morning according to the normal human biological clock, the most efficient and does not result in excessive fatigue.

Discussion:
1. It is important to explain the role or mechanism of action of red-fleshed pitaya on heat shock protein 70 and cortisol expression.

Research conducted by Rebecca et al (2010) shows that red dragon fruit contains the most polyphenols compared to other species, namely 86.13 ± 17.02 mg in 0.50 g of dried extract of red dragon fruit. Red dragon fruit (Hylocereus polyrhizus) is one of the plants that can be used as a source of antioxidants. Severe physical exercise is associated with increased HSP70 expression due to oxidative stress (Paulsen et al. 2007).
Oxidative stress causes damage to cells that will cause stress responses in the form of heat shock response (HSR). HSR is regulated at the level of transcription by a mechanism involving heat shock transcription factor (HSF), especially HSF-1. Increased HSF-1 will help in increasing HSP 70 expression in certain amounts/levels in serum and blood plasma (Baird et al., 2006).
Physical activity appears to occur concomitantly with the up-regulation of endogenous antioxidant systems (Powers and Jackson 2008) and heat shock proteins (HSP) in skeletal muscle (Morton et al. 2009b). While the main role of the antioxidant enzymes is to reduce oxidation and prevent oxidative damage, HSPs can prevent and reverse damage to proteins. Intriguingly, the HSPs work with the antioxidant systems, and collectively they have essential roles in cell homeostasis. Up-regulation of these proteins is, therefore, important adaptations for increased protection and recovery capacity in the face of cellular stress and damage induced by high-intensity exercise (Powers and Jackson 2008; Morton et al. 2009b).
Antioxidants have been shown to abolish the acute exercise-induced increases in HSP70 protein levels (Khassaf et al. 2003; Jackson et al. 2004).
Increased cortisol levels after physical activity depends on the level of fitness, exercise intensity and exercise program [Leite et al., 2011]. Exercise with heavy intensity tends to produce free radicals which can cause the production of the hormone cortisol to increase (Stachowicz, 2016).
The provision of red dragon fruit that contains antioxidant polyphenols can reduce the production of free radicals due to exercise thereby reducing cortisol levels.
Introduction:
1. Please explain why red-fleshed pitaya is thought to act as antioxidants that will affect the heat shock protein 70 and the expression of cortisol: include theoretical and other studies that support.

Red fleshed pitaya has antioxidant activity. Red Dragon Fruit contains powerful antioxidants because it consists of various antioxidants, namely flavonoids, vitamin E, vitamin C (Lianiwati, 2011). The results of several studies stated the red dragon fruit (Hylocereus polyrhizus) has an anthocyanin content (Kanner et al., 2001) around 26,457 ppm. Dragon fruit contains flavonoids (Damayanti, 2016). Anthocyanin is a pigment that is classified as a type of water-soluble flavonoids. Anthocyanins are anthocyanidin and glucose compounds in organic acids (Shipp and Abdel Aal, 2010). Anthocyanins are believed to have a very good antioxidant effect. A study conducted at the University of Michigan in America showed that anthocyanin can destroy free radicals, more effectively than vitamin E which has been known as a powerful antioxidant. Other studies in the United States prove that anthocyanin is the most powerful antioxidant among other flavonoid classes. The content of anthocyanin is believed to inhibit various free radicals such as superoxide radicals and hydrogen peroxide. Anthocyanins and various forms of their derivatives can inhibit various oxidation reactions by various mechanisms (Astawan and Kasih, 2008). The results of previous studies ripe dragon fruit contains many organic acids (Stinzing, et al., 2004), protein (Le Bellec, et al., 2006), minerals such as potassium, magnesium, calcium and iron and vitamin C (Cal et al, 2003).

Increased RONS (Reactive Oxygen and Nitrogen Species) production during exercise has potential negative effects, transient increases in RONS seem to be a trigger for many exercise-induced adaptations in skeletal muscle (Powers et al. 2010). Exercise can stimulate an increased concentration of HSP70 in muscles and plasma.

Oxidative stress due to exercise can cause physiological functional changes because physical exercise is considered as a stimulus received by the hypothalamus, then the hypothalamus signals to the HPA axis, the HPA axis responds and gives positive and negative responses to the body (Guilliam & Edward, 2010). Then stimulates the hypothalamus and causes secretion of the hormone corticotrophin-releasing hormone (CRH), which stimulates the hypothalamus for ACTH secretion. Increased ACTH secretion, causes increased cortisol secretion (Usui et al, 2012).

Methods:

1. Why use 3 doses, whereas the purpose of the study did not assess the effective dose? In conclusion, also mention the effective dose.

Giving 3 doses of 100 mg/kg BW, 200 mg/kg BW and 300 mg/kg BW to find out what is the optimal dose to neutralize oxidative stress due to strenuous physical exercise. A dose of 100 mg/kg BW can also reduce oxidative stress but not as well as a dose of 300 mg/kg BW. So it is necessary to experiment with 3 doses, the purpose of the study to find out the potential of Red-fleshed pitaya as an antioxidant and once to know the optimal dose to reduce oxidative stress.

2. Explain the results of the identification of the chemical content of red-fleshed pitaya and also the results of herbarium analysis because there is a possibility that Indonesia's geographical differences will affect its chemical content.

Red-fleshed pitaya is the cactus fruit of the genera Hyloreceus and Selenicereus. Dragon fruit is very popular and widely planted in Indonesia because it is known by the public as herbal medicine (Evi, et al., 2007). From the results of previous studies, ripe dragon fruit contains many organic acids (Stinzing, et al., 2004), protein (Le Bellec, et al., 2006), minerals such as potassium, magnesium, calcium and iron and vitamin C (Cal et al., 2003).

3. Explain the time of blood-sampling because cortisol production is influenced by circadian.

Cortisol levels are affected by circadian rhythm. Blood drawn for examination of cortisol is done in the morning because it is a basal state of the body after resting at night. Also besides, our bodies have biological variations according to time, meaning that the analytical levels examined in the morning can give different results if examined in the afternoon. On examination of Cortisol, the levels will increase in the morning and reach the lowest levels in the afternoon. Then the blood draw is done in the morning according to the normal human biological clock, the most efficient and does not result in excessive fatigue.

Discussion:
1. It is important to explain the role or mechanism of action of red-fleshed pitaya on heat shock protein 70 and cortisol expression.

Research conducted by Rebecca et al (2010) shows that red dragon fruit contains the most polyphenols compared to other species, namely 86.13 ± 17.02 mg in 0.50 g of dried extract of red dragon fruit. Red dragon fruit (Hylocereus polyrhizus) is one of the plants that can be used as a source of antioxidants. Severe physical exercise is associated with increased HSP70 expression due to oxidative stress (Paulsen et al. 2007).
Oxidative stress causes damage to cells that will cause stress responses in the form of heat shock response (HSR). HSR is regulated at the level of transcription by a mechanism involving heat shock transcription factor (HSF), especially HSF-1. Increased HSF-1 will help in increasing HSP 70 expression in certain amounts/levels in serum and blood plasma (Baird et al., 2006).
Physical activity appears to occur concomitantly with the up-regulation of endogenous antioxidant systems (Powers and Jackson 2008) and heat shock proteins (HSP) in skeletal muscle (Morton et al. 2009b). While the main role of the antioxidant enzymes is to reduce oxidation and prevent oxidative damage, HSPs can prevent and reverse damage to proteins. Intriguingly, the HSPs work with the antioxidant systems, and collectively they have essential roles in cell homeostasis. Up-regulation of these proteins is, therefore, important adaptations for increased protection and recovery capacity in the face of cellular stress and damage induced by high-intensity exercise (Powers and Jackson 2008; Morton et al. 2009b).
Antioxidants have been shown to abolish the acute exercise-induced increases in HSP70 protein levels (Khassaf et al. 2003; Jackson et al. 2004).
Increased cortisol levels after physical activity depends on the level of fitness, exercise intensity and exercise program [Leite et al., 2011]. Exercise with heavy intensity tends to produce free radicals which can cause the production of the hormone cortisol to increase (Stachowicz, 2016).
The provision of red dragon fruit that contains antioxidant polyphenols can reduce the production of free radicals due to exercise thereby reducing cortisol levels.
Competing Interests: I declare no competing interests Close
Report a concern
Author Response 29 Sep 2021

Novita Sari Harahap, Department of Sports Sciences, Faculty of Sports Sciences, Universitas Negeri Medan, Medan, 20221, Indonesia

29 Sep 2021

Author Response

Thank you for this thorough review of the manuscript and your insightful comments that have improved the clarity and quality of the paper. Below there is a point-by-point response to ... Continue reading Thank you for this thorough review of the manuscript and your insightful comments that have improved the clarity and quality of the paper. Below there is a point-by-point response to your inquiries.
The difference between this new version and version 1 is that in this new version, we can explain the antioxidant activity contained in red-fleshed pitaya that can affect heat shock protein 70 and the expression of cortisol. Red fleshed pitaya contains powerful antioxidants because it consists of various antioxidants, namely flavonoids, and polyphenol (Chemah et al. 2010; Adnan, 2011). Thus Red fleshed pitaya which has the potential as an antioxidant can reduce ROS and respond to HSP70 expression.
We can also explain that giving 3 doses of 100 mg/kg body weight, 200 mg/kg body weight, and 300 mg/kg body weight to find out what is the effective dose to neutralize oxidative stress due to strenuous physical exercise. So it is necessary to experiment with 3 doses, in accordance with the purpose of the study to find out the potential of Red-fleshed pitaya as an antioxidant and once to know the effective dose to reduce oxidative stress which is influence on HSP70 and cortisol expression in rats that were subjected strenuous exercise.
Red-fleshed pitaya is the cactus fruit of the genera Hyloreceus and Selenicereus. Red-fleshed pitaya is very popular and widely planted in Indonesia because it is known by the public as herbal medicine. Research by Widyaningsih et al., (2017) report that red-fleshed pitaya as an alternative treatment for anemia in pregnant women. The other studies by Irmayanti and Ardiaria (2016) report that red dragon fruit (Hylocereus Polyhizus) can reduce cholesterol levels in rats. This statement explains that red-fleshed pitaya have also affect difference.
Thank you for this thorough review of the manuscript and your insightful comments that have improved the clarity and quality of the paper. Below there is a point-by-point response to your inquiries.
The difference between this new version and version 1 is that in this new version, we can explain the antioxidant activity contained in red-fleshed pitaya that can affect heat shock protein 70 and the expression of cortisol. Red fleshed pitaya contains powerful antioxidants because it consists of various antioxidants, namely flavonoids, and polyphenol (Chemah et al. 2010; Adnan, 2011). Thus Red fleshed pitaya which has the potential as an antioxidant can reduce ROS and respond to HSP70 expression.
We can also explain that giving 3 doses of 100 mg/kg body weight, 200 mg/kg body weight, and 300 mg/kg body weight to find out what is the effective dose to neutralize oxidative stress due to strenuous physical exercise. So it is necessary to experiment with 3 doses, in accordance with the purpose of the study to find out the potential of Red-fleshed pitaya as an antioxidant and once to know the effective dose to reduce oxidative stress which is influence on HSP70 and cortisol expression in rats that were subjected strenuous exercise.
Red-fleshed pitaya is the cactus fruit of the genera Hyloreceus and Selenicereus. Red-fleshed pitaya is very popular and widely planted in Indonesia because it is known by the public as herbal medicine. Research by Widyaningsih et al., (2017) report that red-fleshed pitaya as an alternative treatment for anemia in pregnant women. The other studies by Irmayanti and Ardiaria (2016) report that red dragon fruit (Hylocereus Polyhizus) can reduce cholesterol levels in rats. This statement explains that red-fleshed pitaya have also affect difference.
Competing Interests: No competing interests were disclosed Close
Report a concern

Comments on this article Comments (0)

Version 2

VERSION 2 PUBLISHED 30 Jan 2019

Open Peer Review

Reviewer Status

Reviewer Reports

	Invited Reviewers
	1	2
Version 2 (revision) 29 Sep 21	read
Version 1 30 Jan 19	read	read

Yusni Yusni, Universitas Syiah Kuala, Banda Aceh, Indonesia
Mohd Adzim Khalili Rohin, Sultan Zainal Abidin University (UniSZA), Kuala Nerus, Malaysia

Comments on this article

All Comments(0)

Add a comment

Browse by related subjects

Back to all reports

Reviewer Report

6 Views

14 Oct 2021 | for Version 2

Yusni Yusni, Department of Physiology, Universitas Syiah Kuala, Banda Aceh, Indonesia

6 Views Cite this report Responses(0)

Approved

I have read the details of the author's revision. I decide that I agree with all revisions made by the author. I think this article deserves to be indexed.

Competing Interests

No competing interests were disclosed.

Reviewer Expertise

Medical Physiology: exercise physiology; endocrine and metabolic physiology

I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard.

Respond to this report

Responses (0)

Back to all reports

Reviewer Report

14 Views

04 Mar 2020 | for Version 1

Mohd Adzim Khalili Rohin, Faculty of Health Sciences, Sultan Zainal Abidin University (UniSZA), Kuala Nerus, Malaysia

14 Views Cite this report Responses(0)

Approved

It is an interesting manuscript. However, there are several grammatical issues and some typos that you should check very carefully.
My main concern about your manuscript is that you have not mentioned any strengths or limitations in your study.
The small number of rats per group is indeed a limitation and should be mentioned and taken into consideration before making conclusions.
This is a prospective study on the effect of red-fleshed pitaya (Hylocereus polyrhizus) on heat shock protein 70 and cortisol expression in strenuous exercise-induced rats.
The conclusion is weak in my opinion.
The study could be considered more as a pilot study than a proper study; however the results are interesting and should be indexed.

Is the work clearly and accurately presented and does it cite the current literature?

Yes
Is the study design appropriate and is the work technically sound?

Yes
Are sufficient details of methods and analysis provided to allow replication by others?

Yes
If applicable, is the statistical analysis and its interpretation appropriate?

Yes
Are all the source data underlying the results available to ensure full reproducibility?

Yes
Are the conclusions drawn adequately supported by the results?

Yes

Competing Interests

No competing interests were disclosed.

Reviewer Expertise

Functional Food & Nutraceuticals

I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard.

Respond to this report

Responses (0)

Back to all reports

Reviewer Report

31 Views

08 Nov 2019 | for Version 1

Yusni Yusni, Department of Physiology, Universitas Syiah Kuala, Banda Aceh, Indonesia

31 Views Cite this report Responses(2)

Approved With Reservations

Introduction:

Please explain why red-fleshed pitaya is thought to act as antioxidants that will affect the heat shock protein 70 and the expression of cortisol: include theoretical and other studies that support.
The novelty of the article must be clearly explained in the introduction.

Methods:

Why use 3 doses, whereas the purpose of the study did not assess the effective dose? In the conclusion, also mention the effective dose.
Explain the results of the identification of the chemical content of red-fleshed pitaya and also the results of herbarium analysis because there is a possibility that Indonesia's geographical differences will affect its chemical content.
Explain the time of blood-sampling because cortisol production is influenced by circadian.

Discussion:

It is important to explain the role or mechanism of action of red-fleshed pitaya on heat shock protein 70 and cortisol expression.

Reference:

Use the latest references (from the last 5-10 years).

Note: There are some grammatical errors, you should use the proof-read service.

Is the work clearly and accurately presented and does it cite the current literature?

Yes
Is the study design appropriate and is the work technically sound?

Yes
Are sufficient details of methods and analysis provided to allow replication by others?

Yes
If applicable, is the statistical analysis and its interpretation appropriate?

Yes
Are all the source data underlying the results available to ensure full reproducibility?

Yes
Are the conclusions drawn adequately supported by the results?

Yes

Competing Interests

No competing interests were disclosed.

Reviewer Expertise

Medical Physiology: exercise physiology; endocrine and metabolic physiology

Respond to this report

Responses (2)

Author Response

29 Nov 2019

Novita Sari Harahap, Department of Sports Sciences, Faculty of Sports Sciences, Universitas Negeri Medan, Medan, 20221, Indonesia

Introduction:
1. Please explain why red-fleshed pitaya is thought to act as antioxidants that will affect the heat shock protein 70 and the expression of cortisol: include theoretical and other studies that support.

Red fleshed pitaya has antioxidant activity. Red Dragon Fruit contains powerful antioxidants because it consists of various antioxidants, namely flavonoids, vitamin E, vitamin C (Lianiwati, 2011). The results of several studies stated the red dragon fruit (Hylocereus polyrhizus) has an anthocyanin content (Kanner et al., 2001) around 26,457 ppm. Dragon fruit contains flavonoids (Damayanti, 2016). Anthocyanin is a pigment that is classified as a type of water-soluble flavonoids. Anthocyanins are anthocyanidin and glucose compounds in organic acids (Shipp and Abdel Aal, 2010). Anthocyanins are believed to have a very good antioxidant effect. A study conducted at the University of Michigan in America showed that anthocyanin can destroy free radicals, more effectively than vitamin E which has been known as a powerful antioxidant. Other studies in the United States prove that anthocyanin is the most powerful antioxidant among other flavonoid classes. The content of anthocyanin is believed to inhibit various free radicals such as superoxide radicals and hydrogen peroxide. Anthocyanins and various forms of their derivatives can inhibit various oxidation reactions by various mechanisms (Astawan and Kasih, 2008). The results of previous studies ripe dragon fruit contains many organic acids (Stinzing, et al., 2004), protein (Le Bellec, et al., 2006), minerals such as potassium, magnesium, calcium and iron and vitamin C (Cal et al, 2003).

Increased RONS (Reactive Oxygen and Nitrogen Species) production during exercise has potential negative effects, transient increases in RONS seem to be a trigger for many exercise-induced adaptations in skeletal muscle (Powers et al. 2010). Exercise can stimulate an increased concentration of HSP70 in muscles and plasma.

Oxidative stress due to exercise can cause physiological functional changes because physical exercise is considered as a stimulus received by the hypothalamus, then the hypothalamus signals to the HPA axis, the HPA axis responds and gives positive and negative responses to the body (Guilliam & Edward, 2010). Then stimulates the hypothalamus and causes secretion of the hormone corticotrophin-releasing hormone (CRH), which stimulates the hypothalamus for ACTH secretion. Increased ACTH secretion, causes increased cortisol secretion (Usui et al, 2012).

Methods:

1. Why use 3 doses, whereas the purpose of the study did not assess the effective dose? In conclusion, also mention the effective dose.

Giving 3 doses of 100 mg/kg BW, 200 mg/kg BW and 300 mg/kg BW to find out what is the optimal dose to neutralize oxidative stress due to strenuous physical exercise. A dose of 100 mg/kg BW can also reduce oxidative stress but not as well as a dose of 300 mg/kg BW. So it is necessary to experiment with 3 doses, the purpose of the study to find out the potential of Red-fleshed pitaya as an antioxidant and once to know the optimal dose to reduce oxidative stress.

2. Explain the results of the identification of the chemical content of red-fleshed pitaya and also the results of herbarium analysis because there is a possibility that Indonesia's geographical differences will affect its chemical content.

Red-fleshed pitaya is the cactus fruit of the genera Hyloreceus and Selenicereus. Dragon fruit is very popular and widely planted in Indonesia because it is known by the public as herbal medicine (Evi, et al., 2007). From the results of previous studies, ripe dragon fruit contains many organic acids (Stinzing, et al., 2004), protein (Le Bellec, et al., 2006), minerals such as potassium, magnesium, calcium and iron and vitamin C (Cal et al., 2003).

3. Explain the time of blood-sampling because cortisol production is influenced by circadian.

Cortisol levels are affected by circadian rhythm. Blood drawn for examination of cortisol is done in the morning because it is a basal state of the body after resting at night. Also besides, our bodies have biological variations according to time, meaning that the analytical levels examined in the morning can give different results if examined in the afternoon. On examination of Cortisol, the levels will increase in the morning and reach the lowest levels in the afternoon. Then the blood draw is done in the morning according to the normal human biological clock, the most efficient and does not result in excessive fatigue.

Discussion:
1. It is important to explain the role or mechanism of action of red-fleshed pitaya on heat shock protein 70 and cortisol expression.

Research conducted by Rebecca et al (2010) shows that red dragon fruit contains the most polyphenols compared to other species, namely 86.13 ± 17.02 mg in 0.50 g of dried extract of red dragon fruit. Red dragon fruit (Hylocereus polyrhizus) is one of the plants that can be used as a source of antioxidants. Severe physical exercise is associated with increased HSP70 expression due to oxidative stress (Paulsen et al. 2007).
Oxidative stress causes damage to cells that will cause stress responses in the form of heat shock response (HSR). HSR is regulated at the level of transcription by a mechanism involving heat shock transcription factor (HSF), especially HSF-1. Increased HSF-1 will help in increasing HSP 70 expression in certain amounts/levels in serum and blood plasma (Baird et al., 2006).
Physical activity appears to occur concomitantly with the up-regulation of endogenous antioxidant systems (Powers and Jackson 2008) and heat shock proteins (HSP) in skeletal muscle (Morton et al. 2009b). While the main role of the antioxidant enzymes is to reduce oxidation and prevent oxidative damage, HSPs can prevent and reverse damage to proteins. Intriguingly, the HSPs work with the antioxidant systems, and collectively they have essential roles in cell homeostasis. Up-regulation of these proteins is, therefore, important adaptations for increased protection and recovery capacity in the face of cellular stress and damage induced by high-intensity exercise (Powers and Jackson 2008; Morton et al. 2009b).
Antioxidants have been shown to abolish the acute exercise-induced increases in HSP70 protein levels (Khassaf et al. 2003; Jackson et al. 2004).
Increased cortisol levels after physical activity depends on the level of fitness, exercise intensity and exercise program [Leite et al., 2011]. Exercise with heavy intensity tends to produce free radicals which can cause the production of the hormone cortisol to increase (Stachowicz, 2016).
The provision of red dragon fruit that contains antioxidant polyphenols can reduce the production of free radicals due to exercise thereby reducing cortisol levels.

View more View less

Competing Interests

I declare no competing interests

Author Response

29 Sep 2021

Novita Sari Harahap, Department of Sports Sciences, Faculty of Sports Sciences, Universitas Negeri Medan, Medan, 20221, Indonesia

Thank you for this thorough review of the manuscript and your insightful comments that have improved the clarity and quality of the paper. Below there is a point-by-point response to your inquiries.
The difference between this new version and version 1 is that in this new version, we can explain the antioxidant activity contained in red-fleshed pitaya that can affect heat shock protein 70 and the expression of cortisol. Red fleshed pitaya contains powerful antioxidants because it consists of various antioxidants, namely flavonoids, and polyphenol (Chemah et al. 2010; Adnan, 2011). Thus Red fleshed pitaya which has the potential as an antioxidant can reduce ROS and respond to HSP70 expression.
We can also explain that giving 3 doses of 100 mg/kg body weight, 200 mg/kg body weight, and 300 mg/kg body weight to find out what is the effective dose to neutralize oxidative stress due to strenuous physical exercise. So it is necessary to experiment with 3 doses, in accordance with the purpose of the study to find out the potential of Red-fleshed pitaya as an antioxidant and once to know the effective dose to reduce oxidative stress which is influence on HSP70 and cortisol expression in rats that were subjected strenuous exercise.
Red-fleshed pitaya is the cactus fruit of the genera Hyloreceus and Selenicereus. Red-fleshed pitaya is very popular and widely planted in Indonesia because it is known by the public as herbal medicine. Research by Widyaningsih et al., (2017) report that red-fleshed pitaya as an alternative treatment for anemia in pregnant women. The other studies by Irmayanti and Ardiaria (2016) report that red dragon fruit (Hylocereus Polyhizus) can reduce cholesterol levels in rats. This statement explains that red-fleshed pitaya have also affect difference.

View more View less

Competing Interests

No competing interests were disclosed

Alongside their report, reviewers assign a status to the article:

Approved - the paper is scientifically sound in its current form and only minor, if any, improvements are suggested

Approved with reservations - A number of small changes, sometimes more significant revisions are required to address specific details and improve the papers academic merit.

Not approved - fundamental flaws in the paper seriously undermine the findings and conclusions

[1] 1. Yavari A, Javadi M, Mirmiran P, et al.: Exercise-induced oxidative stress and dietary antioxidants. Asian J Sports Med. 2015; 6(1): e24898. PubMed Abstract | Publisher Full Text | Free Full Text

[2] 2. Escribano BM, Tunez I, Requena F, et al.: Effects of an aerobic training program on oxidative stress biomarkers in bulls. Vet Med (Praha). 2010; 55(9): 422–428. Publisher Full Text

[3] 3. El Abed K, Rebai H, Bloomer RJ, et al.: Antioxidant status and oxidative stress at rest and in response to acute exercise in judokas and sedentary men. J Strength Cond Res. 2011; 25(9): 2400–9. PubMed Abstract | Publisher Full Text

[4] 4. Steinbacher P, Eckl P: Impact of oxidative stress on exercising skeletal muscle. Biomolecules. 2015; 5(2): 356–77. PubMed Abstract | Publisher Full Text | Free Full Text

[5] 5. Valko M, Leibfritz D, Moncol J, et al.: Free radicals and antioxidants in normal physiological functions and human disease. Int J Biochem Cell Biol. 2007; 39(1): 44–84. PubMed Abstract | Publisher Full Text

[6] 6. Macedo DV, Lazarim FL, Catanho da Silva FO, et al.: Is lactate production related to muscular fatigue? A pedagogical proposition using empirical facts. Adv Physiol Educ. 2009; 33(4): 302–7. PubMed Abstract | Publisher Full Text

[7] 7. Kürkçü R, Tekin A, Özda S, et al.: The effects of regular exercıse on oxıdatıve and antıoxıdatıve parameters ın young wrestlers. African J Pharm Pharmacol. 2010; 4(5): 244–251. Reference Source

[8] 8. Azizbeigi K, Azarbayjani MA, Peeri M, et al.: The effect of progressive resistance training on oxidative stress and antioxidant enzyme activity in erythrocytes in untrained men. Int J Sport Nutr Exerc Metab. 2013; 23(3): 230–8. PubMed Abstract | Publisher Full Text

[9] 9. Folkesson M, Mackey AL, Langberg H, et al.: The expression of heat shock protein in human skeletal muscle: effects of muscle fibre phenotype and training background. Acta Physiol (Oxf). 2013; 209(1): 26–33. PubMed Abstract | Publisher Full Text

[10] 10. Liu Y, Gampert L, Nething K, et al.: Response and function of skeletal muscle heat shock protein 70. Front Biosci. 2006; 11: 2802–27. PubMed Abstract | Publisher Full Text

[11] 11. Biller-Takahashi JD, Takahashi LS, Mingatto FE, et al.: The immune system is limited by oxidative stress: Dietary selenium promotes optimal antioxidative status and greatest immune defense in pacu Piaractus mesopotamicus. Fish Shellfish Immunol. 2015; 47(1): 360–7. PubMed Abstract | Publisher Full Text

[12] 12. Starnes JW, Choilawala AM, Taylor RP, et al.: Myocardial heat shock protein 70 expression in young and old rats after identical exercise programs. J Gerontol A Biol Sci Med Sci. 2005; 60(8): 963–969. PubMed Abstract | Publisher Full Text

[13] 12. Staib JL, Tümer N, Powers SK: Increased temperature and protein oxidation lead to HSP72 mRNA and protein accumulation in the in vivo exercised rat heart. Exp Physiol. 2009; 94(1): 71–80. PubMed Abstract | Publisher Full Text | Free Full Text

[14] 13. Usui T, Yoshikawa T, Ueda SY, et al.: Effects of acute prolonged strenuous exercise on the salivary stress markers and inflammatory cytokines. Jpn J Phys Fitness Sports Med. 2011; 60(3): 295–304. Publisher Full Text

[15] 14. Hill EE, Zacki E, Battaglini C, et al.: Exercise and circulating cortisol levels: the intensity threshold effect. J Endocrinol Invest. 2008; 31(7): 587–91. PubMed Abstract | Publisher Full Text

[16] 15. Peternelj TT, Coombes JS: Antioxidant supplementation during exercise training: beneficial or detrimental? Sports Med. 2011; 41(12): 1043–69. PubMed Abstract | Publisher Full Text

[17] 16. Gomez-Cabrera MC, Viña J, Ji LL: Interplay of oxidants and antioxidants during exercise: implications for muscle health. Phys Sportsmed. 2009; 37(4): 116–23. PubMed Abstract | Publisher Full Text

[18] 17. Belviranli M, Gökbel H: Acute exercise induced oxidative stress and antioxidant changes. Eur J Gen Med. 2006; 3(3): 126–131. Publisher Full Text

[19] 18. Nurul SR, Asmah R: Variability in nutritional composition and phytochemical properties of red pitaya (Hylocereus polyrhizus) from Malaysia and Australia. Int Food Res J. 2014; 21(4): 1689–1697. Reference Source

[20] 19. Sahlin K, Shabalina IG, Mattsson CM, et al.: Ultraendurance exercise increases the production of reactive oxygen species in isolated mitochondria from human skeletal muscle. J Appl Physiol (1985). 2010; 108(4): 780–7. PubMed Abstract | Publisher Full Text | Free Full Text

[21] 20. Chemah TC, Aminah A, Noriham A, et al.: Determination of pitaya seeds as a natural antioxidant and source of essential fatty acids. Int Food Res J. 2010; 17(4): 1003–1010. Reference Source

[22] 21. Adnan L, Osman A, Hamid AA: Antioxidant Activity of Different Extracts of RedPitaya (Hylocereus polyrhizus) Seed. Int J Food Prop. 2011; 14(6): 1171–1181. Publisher Full Text

[23] 22. Khassaf M, Child RB, McArdle A, et al.: Time course of responses of human skeletal muscle to exercise-induced oxidative stress. J App Physiol (1985). 2001; 90(3): 1031–1036. PubMed Abstract | Publisher Full Text

[24] 23. Morton JP, MacLaren, DPM, Cable NT, et al.: Time Course and Differential Responses of the Major Heat Shock Protein Families in Human Skeletal Muscle Following Acute Nondamaging Treadmill Exercise. J Appl Physiol (1985). 2006; 101(1): 176–82. PubMed Abstract | Publisher Full Text

[25] 24. Gomes EC, Silva AN, de Oliveira MR: Oxidants, antioxidants, and the beneficial roles of exercise-induced production of reactive species. Oxid Med Cell Longev. 2012; 2012: 756132. PubMed Abstract | Publisher Full Text | Free Full Text

[26] 25. Abruzzo PM, Esposito F, Marchionni C, et al.: Moderate exercise training induces ROS-related adaptations to skeletal muscles. Int J Sports Med. 2013; 34(8): 676–87. PubMed Abstract | Publisher Full Text

[27] 26. Krause M, Heck TG, Bittencourt A, et al.: The chaperone balance hypothesis: the importance of the extracellular to intracellular HSP70 ratio to inflammation-driven type 2 diabetes, the effect of exercise, and the implications for clinical management. Mediators Inflamm. 2015; 2015: 249205. PubMed Abstract | Publisher Full Text | Free Full Text

[28] 27. Paulsen G, Vissing K, Kalhovde JM, et al.: Maximal eccentric exercise induces a rapid accumulation of small heat shock proteins on myoﬁbrils and a delayed HSP70 response in humans. Am J Physiol Regul Integr Comp Physiol. 2007; 293(2): R844–R853. PubMed Abstract | Publisher Full Text

[29] 28. Lanneau D, Brunet M, Frisan E, et al.: Heat shock proteins: essential proteins for apoptosis regulation. J Cell Mol Med. 2008; 12(3): 743–61. PubMed Abstract | Publisher Full Text | Free Full Text

[30] 29. Khassaf M, McArdle A, Esanu C, et al.: Effect of vitamin C supplements on antioxidant defence and stress proteins in human lymphocytes and skeletal muscle. J Physiol. 2003; 549(Pt 2): 645–52. PubMed Abstract | Publisher Full Text | Free Full Text

[31] 30. Petiz LL, Girardi CS, Bortolin RC, et al.: Vitamin A Oral Supplementation Induces Oxidative Stress and Suppresses IL-10 and HSP70 in Skeletal Muscle of Trained Rats. Nutrients. 2017; 9(4): E353. PubMed Abstract | Publisher Full Text | Free Full Text

[32] 31. Rebecca OPS, Boyce AN, Chandra S: Pigment Identification and Antioxidant Properties of Red Dragon Fruits (Hylocereus polyrhizus). Afr J Biotechnol. 2010; 9(10): 1450–1454. Publisher Full Text

[33] 32. Baghaiee B, Karimi P, Siahkouhian M, et al.: Moderate aerobic exercise training decreases middle-aged induced pathologic cardiac hypertrophy by improving Klotho expression, MAPK signaling pathway, and oxidative stress status in Wistar rats. Iran J Basic Med Sci. 2018; 21(9): 911–919. PubMed Abstract | Publisher Full Text | Free Full Text

[34] 33. Morton JP, Kayani AC, McArdle A, et al.: The exercise-induced stress response of skeletal muscle, with specific emphasis on humans. Sports Med. 2009; 39(8): 643–62. PubMed Abstract | Publisher Full Text

[35] 34. Turner-Cobb JM, Palmer J, Aronson D, et al.: Diurnal cortisol and coping responses in close relatives of persons with acquired brain injury: a longitudinal mixed methods study. Brain Inj. 2010; 24(6): 893–903. PubMed Abstract | Publisher Full Text

[36] 35. Kraemer WJ, Ratamess NA: Hormonal responses and adaptations to resistance exercise and training. Sports Med. 2005; 35(4): 339–61. PubMed Abstract | Publisher Full Text

[37] 36. Starnes JW, Choilawala AM, Taylor RP, et al.: Myocardial heat shock protein 70 expression in young and old rats after identical exercise programs. J Gerontol A Biol Sci Med Sci. 2005; 60(8): 963–969. PubMed Abstract | Publisher Full Text

[38] 37. Leite RD, Prestes J, Rosa C, et al.: Acute effect of resistance training volume on hormonal responses in trained men. J Sports Med Phys Fitness. 2011; 51(2): 322–328. PubMed Abstract

[39] 38. Stachowicz M, Lebiedzinska A: The effect of diet components on the level of cortisol. Eur Food Res Technol. 2016; 242: 2001–2009. Publisher Full Text

[40] 39. Widyaningsih A, Setiyani O, Umaroh U, et al.: Effect Of Consuming Red Dragon Fruit (Hylocereus Costaricensis) Juice On The Levels Of Hemoglobin And Erythrocyte Among Pregnant Women. Belitung Nurs J. 2017; 3(3): 255–264. Publisher Full Text

[41] 40. Irmayanti L, Ardiaria M: Efek Pemberian Seduhan Kulit Buah Nagamerah (Hylocererus Polyhizus)Terhadap Kadar Kolesterol Ldl Tikus Sprague Dawley Dislipidemia. Journal of Nutrition College. 2016; 5(4): 530–538. Reference Source

[42] 41. Harahap NS: The Effect of Red-Fleshed Pitaya (Hylocereus Polyrhizus) on Heat Shock Protein 70 and Cortisol Expression in Strenuous Exercise Induced Rats. OSF. 2019. http://www.doi.org/10.17605/OSF.IO/MGX4K

The effect of red-fleshed pitaya (Hylocereus polyrhizus) on heat shock protein 70 and cortisol expression in strenuous exercise induced rats

Abstract

Keywords

Revised Amendments from Version 1

Introduction

Methods

Experimental animals

Study design

Red-fleshed pitaya extract

Experimental procedures

Statistical methods

Ethical approval

Results

Table 1. Normality test for heat shock protein 70 (HSP70) and cortisol expression.

Figure 1. Effect of red-fleshed pitaya extract on HSP70 expression in rats that were given strenuous exercise.

Figure 2. Effect of red-fleshed pitaya extract on cortisol in rats that were given strenuous exercise.

Discussion

Conclusion

Data availability

Underlying data

References

Comments on this article Comments (0)

Open Peer Review

Comments on this article Comments (0)

Open Peer Review

Reviewer Status

Reviewer Reports

Comments on this article

Browse by related subjects

Competing Interests Policy

Stay Updated