Knowledge and Self-use of Medicinal Plants by Health University Students in Brasília-Brazil

Introduction

The consumption of plants for medicinal purposes has increased in recent years, a tradition that has been passed from generation to generation. Medicinal plants have therapeutic properties, causing various effects on the human body, induced by phytochemicals. However, several professionals do not learn phytotherapy/herbal medicine as undergraduate students (Jamshed et al., 2016; Lapidus, 2007; Oliveira et al., 2012; Suchard et al., 2004). Different studies showed that physicians and university students studying health related courses do not have adequate knowledge of medicinal plants (Ameade et al., 2015; Frass et al., 2012; Hina et al., 2015; Jamshed et al., 2016; Johnson et al., 2008; Oliveira et al., 2012; Samara et al., 2019; Suchard et al., 2004). Despite this, several studies showed a high level of self-medication with herbal medicines by health students and professionals (Abahussain et al., 2007; Ambrose & Samuels, 2004; Awad et al., 2012; Brambila-Tapia et al., 2016; El Ezz & Ez-Elarab, 2011; Fahmy et al., 2010; Gyasi et al., 2016; Saha et al., 2017; Sawalha et al., 2008; Soroush et al., 2018). This practice is worrying because some of the biologically active compounds of plant origin can be harmful, and cause some adverse and toxic effects (Cheung et al., 2009; Krenzelok & Mrvos, 2011; Ng et al., 2019; Pan et al., 2017; Sriapha et al., 2015; Zamawe et al., 2018). To date, it is not clearly known whether these students search for scientific evidence about herbs before consuming them. Therefore, we seek to analyze the knowledge of university students in health related courses on medicinal plants and their self-use.

Methods

Results

Descriptive data

The sample size of this study was 50 university students in the health field, 84% of which were female and 16% male. Gender distributions across courses are displayed in Figure 1. The semesters that students were taking in undergraduate health courses were: Biomedicine course - 14% were in the 7th semester and 12% in the 8th semester; Biological Sciences - 2% were in the 3rd semester and 12% were in the 4th; Nursing course - 2% were in the 1st semester and 24% were in the 5th semester; and Pharmacy course - 34% were in the 8th semester, as shown in Table 1 (see underlying data (Eduardo et al., 2020)).

Figure 1. Distribution of study participants by gender and by undergraduate health course (Biological Sciences, Biomedicine, Nursing and Pharmacy), in the years 2014 and 2015.

Of the total of 50 students, 25 of them were aged 19 to 29, 13 were aged 30 to 39, 18 aged 40 to 49, and 4 aged 50 to 59 (Figure 2). Results show that most respondents 48 (96%; P <0.0001), had at some point in their life used medicinal plants for the alternative treatment of diseases. Of these, 46 (P <0.0001) reported they cured their illnesses, and only 4% did not report a positive effect after using medicinal plants (Figure 3A). In addition, of the individuals who used medicinal plants, 54% said that before using them, they researched the plants, for information such as the indications for use and the adverse effects that they can trigger, whereas 42% do not usually research the plants before ingesting them (Figure 3B). Most of the interviewees (68%) reported that used medicinal plant based on the recommendation of family members (Figure 4).

Figure 2. Distribution of students participating in the survey by age group.

Figure 3.

Distribution of students who had and did not have positive effects on the use of medicinal plants (Figure 3A). Figure 3B shows the distribution of academics who usually research the medicinal plant before ingesting it in the years 2014 and 2015.

Figure 4. Main sources of knowledge of medicinal plants in the alternative treatment of diseases.

Regarding the motivations that led to the consumption of medicinal plants, most reported stomach pain (30%), followed by headache, cough, colds, and pain in general (Figure 5).

Figure 5. Motivations for the use of medicinal plants by students, in the years 2014 and 2015.

The medicinal plants most used by academics are shown in Figure 6, where 44% of them mentioned they use a mixture of plants, such as chamomile (Matricaria chamomilla), lemon balm (Melissa officinalis), fennel (Pimpinella anisum) and pomegranate (Punica granatum), 30% said they use the boldo (Peumus boldus), 12% mentioned the Mexican tea (Dysphania ambrosioides). Raw survey results are available as Underlying data (Eduardo et al., 2020).

Figure 6. Main medicinal plants used by health academics, in the years 2014 and 2015.

Discussion

This study showed that although a high percentage of undergraduate students from a private health institution were able to know medicinal plants and use them, a significant fraction did not research before consumption. Only a minority did not obtain a positive result after consuming medicinal plants. These data corroborate the results obtained by several authors, which indicated the effectiveness of using medicinal plants for several problems such as constipation, colds, cough and bacterial infections and pain in general (Ameade et al., 2015; Lee et al., 2005; Nworu et al., 2015; Soroush et al., 2018).

Regarding the indication of plants consumed by students, most of them reported following family traditions. Other studies also showed the influence of family members or friends on the consumption of natural products (Ambrose & Samuels, 2004; Ameade et al., 2015; Gyasi et al., 2016; Lee et al., 2005; Nworu et al., 2015; Saha et al., 2017), particularly parents and grandparents (Oliveira et al., 2012; Otieno & Analo, 2012). These non-academic sources of information and the lack of courses on herbal medicine at the college (Jamshed et al., 2016; Lapidus, 2007; Oliveira et al., 2012; Suchard et al., 2004) may explain why physicians and other health professionals present inadequate knowledge of medicinal plants (Ameade et al., 2015; Frass et al., 2012; Hina et al., 2015; Jamshed et al., 2016; Johnson et al., 2008; Oliveira et al., 2012; Samara et al., 2019; Suchard et al., 2004). When herbal medicine is not taught, the belief that herbal treatment is an effective method becomes lower in senior medical students in relation to younger/1st year students (Akan et al., 2012; Beglaryan & Amirjanyan, 2012; Brambila-Tapia et al., 2016). Consequently, several studies showed a poor self-perceived competence or confidence of physicians and pharmacists in dealing with herbal medicines (Abahussain et al., 2007; Erku et al., 2017; Kemper et al., 2006; Xu & Levine, 2008). Some studies showed that undergraduate health students who take herbal courses – either because it is mandatory or a well-attended elective – show an increase in the level of knowledge about natural products, herb properties and usage (Cai & Boyd, 2018; Johnson et al., 2008; Karpa, 2012; Larrañeta, 2018; McKennon et al., 2018). However, the level of interest for learning this subject may be low. Medical students have reported poor interest in complementary and alternative medicine (CAM) (Frass et al., 2012), whereas pharmacy students have shown a strong interest in traditional Chinese medicine and medicinal herbalism (Freyman et al., 2006).

The high level of students’ self-medication/usage in the present study is in accordance with other studies (Abahussain et al., 2007; Ambrose & Samuels, 2004; Awad et al., 2012; Brambila-Tapia et al., 2016; El Ezz & Ez-Elarab, 2011; Fahmy et al., 2010; Gyasi et al., 2016; Saha et al., 2017; Sawalha et al., 2008; Soroush et al., 2018). University students studying health related courses use at least one herbal substance per year (Johnson & Blanchard, 2006). Actually, this practice may be didactic/instructive since self-experimentation has been shown to improve student learning in relation to active learning approaches (Eduardo et al., 2019).

Our finding that the self-administration of medicinal herbs occurs mostly without searching for more knowledge before their ingestion is in accordance with another study that showed a low percentage of university students that learned from personal research (Mackowiak et al., 2001). Health care professionals use more herbs for which there is scientific evidence of effectiveness (Gardiner et al., 2006) and health students believe one of the main barrier that limit the use of CAM is the lack/deficiency of scientific evidence (Awad et al., 2012; Brambila-Tapia et al., 2016; James & Bah, 2014; Saha et al., 2017; Samara et al., 2019; Zimmerman & Kandiah, 2012). Various articles investigating the source of knowledge/information about herbal medicine and related therapies did not mention scientific journals/magazines (Kilic et al., 2009). A recent study showed that pharmacy students gain must of their information about herbal medicine from non-scientific sources (Ashraf et al., 2019). Actually, scientific jounals and academic materials have been classified by university students as of low importance in terms of sources of knowledge regarding herbal medicine-related information (Gyasi et al., 2016) and less than one third of medical students use scientific magazines/journals as sources of information on medicinal plants (Samara et al., 2019). Other recent studies showed that medical and pharmacy students use social media and the internet as the main source of information about herbal medicine (Ashraf et al., 2019; James & Bah, 2014; Kilic et al., 2009; Nworu et al., 2015; Samara et al., 2019; Soroush et al., 2018). As a consequence, health professionals’ knowledge about medicinal plants do not come from scientific evidence (Frass et al., 2012; Oliveira et al., 2012). This non-scientific knowledge tend to be propagated by professionals, since consumers often consider pharmacists as a major source of information (Jamshed et al., 2016; Siti et al., 2009). An exception was observed in a study with chinese nursing students, which reported books, news papers and magazines as the most common sources of knowledge (Mei-Ying et al., 2004). The low interest of health students in seeking scientific information on medicinal plants is worrying because pharmacologically active compounds of natural origin may cause side effects, intoxication/poisoning and death (Cheung et al., 2009; Krenzelok & Mrvos, 2011; Ng et al., 2019; Pan et al., 2017; Sriapha et al., 2015; Zamawe et al., 2018). As discussed before, the offering of courses may improve the knowledge of students. However, courses offered at the university may use non-scientific information. The inclusion of evidence-based information about herbs/CAM into the curriculum in some medical and nursing schools failed to meet accepted standards of evidence-based medicine; the curricula on the integrative medicine were strongly biased in favor of CAM and many references were poor-quality clinical trials (Marcus & McCullough, 2009). A study reported that even after teaching CAM using evidence-based medicine, students showed only a modest increase on their skill level in understanding the medical literature (Forjuoh et al., 2003). However, courses of herbal/natural product that include bibliographic instruction on information seeking/searching skills increase students’ knowledge about reputable resources for evidence-based information on medicinal herbs (Diaz-Cruz & Bolten, 2016; Dvorkin et al., 2004; Karpa, 2012; Lapidus, 2007; McKennon et al., 2018).Students that are more familiar with PubMed/Medline databases reported that herbal medicine is applicable to their work (Owen & Fang, 2003). The participation in courses that teach how to search for evidence-based resources regarding herbal medicines make students gain confidence in responding to patient questions (McKennon et al., 2018). Additionally, courses underlying the use of natural products that are improved over the years – providing evidence-based medicine – have been shown to increase health students’ skills in providing advice to patients (Geldenhuys et al., 2015). These literature data together with our results corroborate the theory that evidence-based courses of herbal medicine should be offered more to students in health related courses at universities.

The responses of the students regarding the symptoms of the diseases treated with medicinal plants, there was a predominance of stomach pain, headache, and cough, however, some mentioned fever and pain in general. For these ailments, they used a mix of herbs such as chamomile, lemongrass, fennel, and pomegranate, or individual plants such as boldo and Mexican tea. These results corroborate with those obtained from a School of Pharmacy in London, where students mentioned the use of individual herbal remedies and mixed herbal remedies such as ginger, saffron, chamomile and arnica (Freymann et al., 2006), with some plants also mentioned in our study.

Our results indicate that a high proportion of health university students do not research before self-usage of medicinal plants and that most of their knowledge come from non-evidence based sources. This study had some limitations, the main one being the number of students who wanted to participate in the research. Although our sample size was larger than those of other studies (Soroush et al., 2018; Xu & Levine, 2008), the findings of the present study may not reflect general attitudes, and do not permit the generalizability of our results to all university students in health related courses, even specifically to Brazil. Another limitation of our study is that only health students were investigated. Due to the high prevalence of self-medication among different students of other courses, we consider it important that new studies assess and compare the perceived factors of self-medication among students of different areas.

We conclude that the self-consumption of medicinal plants by academics in health related courses of a private institution in Brasilia is high, with the practice stimulated mainly by family members. However, knowledge of adverse reactions may be limited, as a high proportion of the students do not research the plants before using them. Moreover, most of their knowledge of medicine herbs comes from non-evidence based sources. The use of an evidence-based teaching tool that addresses medicinal plants could be positive for university students in health sciences, as being able to provide information to the population is an essential skill.

Data availability