Bibliographic analysis of Clinacanthus nutans papers in Scopus database (2000–2019) [version 1; peer review: 1 not approved]

Background: There has been an increasing trend in Clinacanthus nutans’ research, an important medicinal herb of Malaysia and Thailand, well known as an anti-viral, anti-cancer, and insect bite treatment. This study examines the trend in Clinacanthus nutans ’ research from 2000 to 2019 and compares the contribution of research on this topic from different institutions and authors. Methods: Publications from the Scopus database were retrieved using keywords and identify top ten institutions/universities, list of prominent authors, top ten  journals that published research, top five influential articles, top fifty cited papers, and global distribution of publications on Clinacanthus nutans. Microsoft Excel 2016, Wordcloud, SPSS version 26, and GunnMap 2 were used to analyse indicators. A total of 167 articles were identified from the Scopus database. All research publications were screened initially. Five articles (n=5) were removed due to the unavailability of the full-text version of the article. 162 articles were included in the final study. Results: Universiti Putra Malaysia and the Journal of Ethnopharmacology published the highest number of articles on Clinacanthus nutans. Herpes, antioxidant, phenolic, flavonoids, cancer, antimicrobial were common keywords identified using a word cloud. Over the past 20 years, the literature on Clinacanthus nutans has continuously grown, with the rate increasing after 2012. Conclusion: The prominent research on Clinacanthus nutans was based upon their identified and isolated bioactive constituents, and there is a need for more research on clinical trials.

Medicinal plants are a source of natural, semi-synthetic, or synthetic analogues with pharmacological potential and development of new therapeutic leads. 1 Their potentially curative properties' chemical source is the secondary metabolites of medicinal plants. 2 Traditional Chinese medicine (TCM) remedies have been used in China for centuries and often remain "different" from present Western medicine (WM), as they are still now primarily herbal mixtures. 3 There is an increasing trend in identifying and isolating bioactive compounds in the poly-mixture of TCM. For example, pericarpium citri reticulatae (Rutaceae), commonly called chen pi in Chinese, as a regulating qi drug, is most frequently used in several Chinese medicine prescriptions. 4 Clinacanthus nutans (Burm. f) Lindau (Acanthaceae) is indigenous to Southeast Asia. 5 It is commonly known as Belalai Gajah (Malay) and Phaya Yo (Thai). Clinacanthus nutans used in different therapies, such as for skin rashes, snake bites, lesions caused by herpes simplex virus, diabetic myelitis, and fever. 6 It is a good source of many flavonoids and phenolics. 7 Several in vivo and in vitro pharmacological activities have reported. The most promising activities consist of anti-inflammatory, 8 antioxidant, anti-tumour, 9 anti-viral 10 and antibacterial 11 activities.
Bibliometric analyses have used previously to study the measures of quality and impact of research performed in pharmacovigilance, 12 bioactive chemical constituents, 13 and health-related issues such as burns, 14 pressure ulcer, 15 mesothelioma, 16 colorectal cancer. 17 It has also used to understand the impact of an important research topic. For example, Nano-medicine is one of the emerging issues in the treatment of cancer, and a bibliometric analysis was performed to understand the global trends in this field. 18 The selection of the current topic is based upon the medicinal importance of Clinacanthus nutans in South East Asia. This study investigated trends in Clinacanthus nutans research in recent years using the Scopus database. The researcher analysed publication outcomes from the last 20 years (2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016)(2017)(2018)(2019). This first attempt to use bibliographic to analyse Clinacanthus nutans-related publications aims to understand better global trends in research of one of the most wellknown medicinal herb of Southeast Asia.

Methods
Data source and search strategy Clinacanthus nutans was used as a keyword to search inside the Scopus database. The data collection strictly follows the Scopus database and relevant articles indexed during the given time. Other databases, such as PubMed or Web of Science, are not part of the current study. In this study, the search terms were as follows: TITLE-ABS-KEY (clinacanthus AND nutans) AND PUBYEAR > 1999 AND PUBYEAR < 2020. A flow diagram of selected articles on Clinacanthus nutans is shown in Figure 1.

Information extraction
The data were downloaded from the Scopus database and imported manually into Microsoft Excel 2016 (RRID: SCR_016137); Google Sheets (RRID:SCR_017679) is an open access alternative. KYJ and QLC verified the data entry and collection. The entered data consist of articles, the first author, co-authors, h-index of the first and corresponding author from Scopus. The number of Scopus citation of selected articles were part of data collection. Other data consist of the name of journal/conference, journal ranking according to Scopus (CiteScore), date of publication according to the journal website, year of paper according to Scopus, data of submission of an article, date of acceptance, number of universities/organisation contributed to that publication, name of universities/organisation contributed to that publication, journal impact factor (CiteScore) taken from Scopus, type of article, most vital topic/category, subject area, keywords, list of the significant issue addressed, number of countries, location of authors, number of pages, number of references, number of figures, number of tables, an affiliation of the corresponding author, the association of the first author, funding and department/institution/faculty.

Results
Universiti Putra Malaysia contained the maximum number of record (n = 38), followed by University Sains Malaysia (n = 18). Table 1 shows the top 10 institutions/universities that published their research on Clinacanthus nutans.
Khatib, A., from the International Islamic University Malaysia was found to be the most prominent researcher to contribute to Clinacanthus nutans (n = 11). Abas, F., was the top female researcher that contributes from Universiti Putra Malaysia, Serdang, Malaysia, on Clinacanthus nutans (n = 10). A list of the most prominent authors in studying Clinacanthus nutans is shown in Table 2.
The Journal of Ethnopharmacology (ISSN 0378-8741) has published the highest number of records on Clinacanthus nutans (n = 9), whereas BMC Complementary and Alternative Medicine (ISSN 1472-6882) were second to published    Table 3 shows the top 10 journals publishing research on Clinacanthus nutans.
The authorship heat map shows some interesting facts. The number of authors has increased with time. There were few authors one of a paper in the initial years, but with time, the number of authors has increased to more than seven. This could be due to an increase in research on these medicinal herbs and increasing cross-collaboration among different institutions due to the rise in funding availability and utilisation of various resources from different universities ( Figure 2).
The top fifty most cited papers, as of February 27, 2020, on Clinacanthus nutans were identified and are shown in Table 5.
There is an increasing trend in the number of the published article since 2012. There was a high number of citations and a low number of an articles published in 2005. This year is considered the period of initiation of research on these medicinal plants. Bioactive compounds were identified, giving a pathway to carry out further study (Figure 4).
Malaysia was ranked as number one in producing papers on Clinacanthus nutans, followed by Thailand and then China. Figure 5 illustrates the global distribution of publication on Clinacanthus nutans.

Discussion
Clinacanthus nutans is one of the highly researched medicinal plants in recent years in Malaysia and Thailand. The bibliographic analysis helps to show the past trends on related topics, current research progress to identify the top researcher, institutions, and help find similar funding. Several articles published on bibliographic analysis in healthrelated fields. 33,34 There is limited literature available on the bibliographic analysis of medicinal plants. The research identifies many phytochemical and pre-clinical studies on Clinacanthus nutans. Current research is more focused on   toxicity studies 35-37 before preparing for clinical trials to evaluate its health benefits on humans. Although there is an increasing trend in pre-clinical studies on Clinacanthus nutans, there is a lack of protocols or research to conduct the clinical trial. The only available registered clinical trial when search through clinicaltrials.gov had the title "prevention of mucositis in patients with head and neck cancer treated with radiotherapy", 38 which completed in March 2018. The research also identified an increasing trend in research collaboration in recent years, which could be a positive direction for developing a new drug analogue or a multi-herb combination.

Conclusion
Clinacanthus nutans is one of the future potentially important herbs of Southeast Asia. Malaysia and Thailand were the most significant contributors to studies on the medicinal properties or therapeutic potential. Clinical research organisations could increase research collaboration with academia to reduce the literary gap, provide financial support, especially during a pandemic such as COVID-19; fasten the process of clinical trial and growing commercialisation of medicinal herbs, especially for herbal economies such as Malaysia and Thailand.

Ethics declarations
This study was secondary analysis based on previous published studies. Ethics approval and consent to participate is not applicable.

Consent for publication
Not applicable.

Data availability
Underlying data All data underlying the results are available as part of the article and no additional source data are required.

Contributors
All authors participated in the study conception and design. MSA performed the bibliographic analysis. KYJ and QLC interpreted the data, drafted and critically revised the manuscript and approved the final version to be published. All authors had full access to all the data and took responsibility for the data integrity and data analysis accuracy.

Aidi Ahmi
Tunku Puteri Intan Safinaz School of Accountancy, Universiti Utara Malaysia, Sintok, Malaysia This paper seems to have the interest to cover a bibliometric analysis of the Clinacanthus nutans over the past 20 years. However, while it has presented a few bibliometric indicators, this paper seems doesn't have a clear direction and objectives. I would suggest the aims of this paper and the research questions clearly being defined in the background section. The authors did specify that they want to analyze the trend but it seems too general.
I'm not sure if the problem statement is clearly being defined i.e. the reason why this bibliometric analysis is important to be conducted. The literature review on the subject matters also seems not convincing.
Why the results of the fundings are presented in the background section?

Methods
I'm not sure mentioning the author names in order to do the data entry and verification is proper in this academic paper.
○ Based on this statement: "The entered data consist of articles, the first author, co-authors, hindex of the first and corresponding author from Scopus." -I'm not sure the data entry still required as most of the data downloaded from Scopus were already completed. I'm not sure if the h-index of the first and corresponding author from Scopus is necessary to be collected while it not being presented in the results. The result presented is just about the top author (in which they can be not just the first or corresponding author). I don't think the h-index of the authors is necessary as well. The h-index of the publications probably more meaningful.
○ These statements seem quite confusing: "journal ranking according to Scopus (CiteScore)" and "journal impact factor (CiteScore)" -I think the definition of CiteScore has been misinterpreted here.

No
Competing Interests: No competing interests were disclosed.
Reviewer Expertise: Bibliometric analysis I confirm that I have read this submission and believe that I have an appropriate level of expertise to state that I do not consider it to be of an acceptable scientific standard, for reasons outlined above.
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