Aloe Vera is a perennial, drought-resisting, succulent plant belonging to the Asphodelaceae family. The name, aloe, is derived from the Arabic “alloeh“ or Hebrew “halal” meaning bitter shiny substance. It has a vast traditional role in indigenous system of medicine like Ayurveda, Siddha, Unani and homoeopathy.1 The Aloe Vera plant is a member of lily plant known as Aloe barbadensis, which is full of juice and closes like a cactus. Due to its cactus like feel, Aloe is often mistakenly called a “Desert Cacti”. Aloe Barbadensis miller or Aloe Vera, a semi tropical plant is one of the 250 species of Aloe. Most commonly used for its medicinal properties, Aloe Vera or the Sanskrit name “Ghee kunwar” is a member of Lilly family. The plant has lance-shaped, sharp pointed, and jagged and edged leaves.2
Aloe is native to North Africa and Spain, now the plant is also grown in the hot dry regions of Asia, Europe and America. Aloe Vera is found as the wild herb along the coast of south India. It is under cultivation in large areas in many parts of India viz; Tamil Nadu, Gujarat, Maharashtra etc.3 Aloes are often thought to only grow in hot and dry climates, but they actually grow in a variety of climates including desert, grassland, and coastal or even alpine locations.4
For centuries, it has been medicinally used for an array of ailments such as mild fever, wounds and burns, gastrointestinal disorders, diabetes, sexual vitality and fertility problems to cancer, immune modulation, AIDS and various skin diseases. In the pharmaceutical industry, it has been used for the manufacture of topical products such as ointments and gel preparations, as well as in the production of tablets and capsules. So, there is an urgent need to educate about the miraculous uses of Aloe Vera along with its cultivation methods for human race and popularize it for greater interest.5,6
There are more than 200 compounds found in Aloe barbadensis, about 75 of which have biological activity, Aloe Vera leaves contain a diverse array of compounds, including anthraquinones (e.g. aloe-emodin), anthrones and their glycosides (e.g. 10-(1, 5’ anhydroglucosyl)-aloeemodin- 9-anthrone, also known as aloin A and B), chromones, carbohydrates, proteins, glycoproteins, amino acids, organic acids, lipids, sugars, vitamins and minerals.5,6
Aloe Vera has number of uses and mainly they are used as a food preservative and medicine. Commercially, aloe can be found in pills, sprays, ointments, lotions, liquids, drinks, jellies, and creams. Numerous aloe species around the world are used for conditions ranging from dermatitis to cancer. Various studies have revealed that Aloe Vera leaf possesses many pharmaceutical activities, including antimicrobial, anticancer, antioxidant, anti-diabetic, anti-ulcer, hepato-protective, immune-modulatory and many more activities. Many of the health benefits associated with Aloe Vera have been attributed to the polysaccharides contained in the gel of the leaves.7,8,9,10,11,12,13,14
The main objectives of this study are to study the performance of Aloe Vera research during 2007-16, based on publications output covered in Scopus database. In particular, the study focuses on the following objectives: (i) To study the growth of world research output in Aloe Vera research and its citation impact; (ii) To study the international collaboration share of top 10 most productive countries; (iii) To study the global research output by broad subject areas and the dynamics of its growth and decline; (iv) To study the trends by identifying significant keywords; (v) To study the publication productivity and citation impact of top 20 most productive organizations and authors; (vi) To study the modes of communication in research and (vii) to study the characteristics of top 18 highly cited papers.
The study retrieved and downloaded 10-year publication data of the world in Aloe Vera research from the Scopus database (http://www.scopus.com) covering the period 2007-16. Keywords, such as “Aloe Vera’’ was incorporated in the search string and qualified these keywords with “keyword tag”, “Article Title tag”, and in addition incorporated in this search string the period ‘2007-16’ within “date range tag”. Finally, this search string was applied for searching global publication data on Aloe Vera research. The search string was subsequently refined, using analytical functions and tags in Scopus database, by “subject area tag”, “country tag”, “source title tag”, “journal title name” and “affiliation tag”, to get data/information on the distribution of publications output by subject, collaborating countries, author-wise, organization-wise and journal-wise, etc. For citation data, citations to publications were also collected from date of publication till 16 December 2016.
KEY (‘’aloe vera’’) AND PUBYEAR > 2006 AND PUBYEAR < 2017
The total research output of the world in field of Aloe Vera research cumulated to 1988 publications in 10 years during 2007-16. The annual output of the world in Aloe Vera research increased from 135 in the year 2007 to 174 publications in the year 2016, registering 3.91% growth per annum. The cumulative world output in Aloe Vera research in 5 years 2007-11 increased from 837 to 1151 publications during succeeding 5-year period 2012-16, registering 37.51% quinquennial growth. Of the total global publications output, 76.46% (1520) appeared as articles, 16.45% (327) as reviews, 2.26% (45) as conference papers, 1.21% (24) as letters, 1.06% (21) as articles in press, and the rest as notes, short surveys, editorials, book chapters and erratum. The citation impact of global publications on Aloe Vera research in 10 years averaged to 9.57 citations per publication (CPP) during 2007-16; five-yearly impact averaged to 16.30 CPP for the period 2007-11, which sharply declined to 4.67 CPP in the succeeding five-year 2012-16 Table 1.
Top 10 Most Productive Countries in Aloe Vera research
The global research output in the field of Aloe Vera research had originated from as many as 92 countries in the world during 2007-16. Of the 92 countries, 60 published 1-10 papers in 10 years, 23 countries 11-50 papers, 6 countries 51-100 papers and 3 counties 162 to 647 papers. The top 12 most productive countries in Aloe Vera research contributed 45 to 647 publications each during 2007-16 Table 2. The top 12 most productive countries in Aloe Vera research accounted for 79.18% global publication share and 84.94% citation share during 2007-16. Their five-yearly output accounted for 76.11% global publication share during 2007-11 which increased to 81.41% during succeeding 5-year period 2012-16. Country-wise, the global publication shares of top 12 countries varied widely 2.26% to 32.55% during 2007-16, with India accounting for the highest publication share (32.55%), followed by USA (11.52% share), Iran (8.15%), and China (4.63% share). The other 8 countries contributed their global publication share between 2.26% and 3.92% in 10 years during 2007-16. The global publication share registered an increase by 8.09% in Iran in five years period (2007-11 and 2012-16), followed by 6.27% in India, 1.31% in Pakistan, 1.22% in Italy, 0.99% in Thailand, 0.81% in Spain and 0.59% in Brazil. In other top 12 countries, like the USA, UK, Nigeria, China, and South Korea, their quinquennial global share registered decline between 0.11% and 8.17% during 2007-11 to 2012-16. Seven of top 12 countries scored relative citation index above the world average of 1: U.K. (1.82), Thailand and USA (1.63 each), Spain (1.23), Pakistan and China (1.15 each) and Italy (1.12) during 2007-16. India has though emerged as the world leader in Aloe Vera research, its performance in terms of relative citation index has below the world average (0.85).
The international collaborative output of top 12 most productive countries in Aloe Vera research as a national share in the country-wise output varied widely from 5.36% to 52.17%, with highest share coming from U.K. (52.17%), followed by USA (28.82%), Italy (26.92), Spain (24.44%), Pakistan (23.91%), Thailand (23.40%), China (21.74%), South Korea (17.65%), Brazil (15.38%), India (8.66%), Iran (8.02%) and Nigeria (5.36%) during 2007-16. Most surprisingly, India’s international collaborative share in its national output in Aloe Vera research has been marginal, 8.66%. This trend could be attributed to its global leadership in Aloe Vera research. Being recognized a global research hub in the field, India’s need for reliance on international collaboration in research has not been significant as it is by other top 12 most productive countries in Aloe Vera research.
Subject-Wise Distribution of Research Output
The global Aloe Vera research output published during 2007-16 is distributed across seven sub-fields (as identified in Scopus database classification), with medicine accounting for the highest publications share (40.90%), followed by pharmacology, toxicology and pharmaceutics (35.16%), agricultural and biological sciences (23.09%), biochemistry, genetics and molecular biology (20.27%), chemistry (7.90%), immunology and microbiology (6.24%) and engineering (5.38) during 2007-16. Its activity index, which computes change in research activity in the discipline over time 2007-11 to 2012-16 (world average activity index of a given subject is taken as 100), witnessed increase in biochemistry, genetics and molecular biology (from 93.12 to 105.0), chemistry (from 95.31 to 103.41) and engineering (from 62.15 to 127.52), as against decline of research activity in medicine (from 106.34 to 95.39), pharmacology, toxicology and pharmaceutics (from 100.58 to 99.58), agricultural and biological sciences (from 108.15 to 94.07) and immunology and microbiology (from 113.01 to 90.54) from 2007-11 to 2012-16. Chemistry, among various subjects registered the highest citations impact per paper of 13.99 CPP, followed by medicine (11.79), biochemistry, genetics and molecular biology (11.33), immunology and microbiology (8.40), pharmacology, toxicology and pharmaceutics (8.29), agricultural and biological sciences (7.69) and engineering (6.48) during 2007-16 Table 3.
Profile of Top 16 Most Productive Global Organizations
The productivity of top 16 most productive global organizations In Aloe Vera Research varied from 10 to 33 publications and together they contributed 11.47% (228) publication share and 12.87% (2448) citation share during 2007-16. The scientometric profile of these top 16 organizations is presented in Table 4. Four of these organizations registered publications output greater than the group average of 14.25: Tehran University of Medical Sciences, Iran (33 papers), Islamic Azad University, Isfahan, Iran (25 papers), Indian Institute of Technology, Kharagpur, India (21 papers) and Chula long University, Thailand (18 papers) during 2007-16. Nine organizations registered impact above the group average of 10.74 citations per publication during 2007-16: Universidad de La Serena, Chile (26.67), Amity University, Noida, India (21.10), Shahrekord University of Medical Sciences, Iran (15.82), Tehran University of Medical Sciences, Iran (14.09), Chula long University, Thailand (13.72), Mazandaran University of Medical Science, Iran (12.80), Univera Inc., Seoul, South Korea (12.31), Morinaga Milk Industry Co Ltd., Japan (11.82) and National University of Singapore (11.73) during 2007-16. Six organizations registered h-index above the group average of 5.87: Universidad de La Serena, Chile (12), Tehran University of Medical Sciences, Iran (11), Chula long University, Thailand (9), National University of Singapore (7), Univera Inc., Seoul, South Korea and Morinaga Milk Industry Co Ltd., Japan (6 each) during 2007-16. Seven organizations contributed international collaborative publications share above the group average of 17.54%: National University of Singapore (81.82%), Universidad de La Serena, Chile (50.0%), University of Tehran, Iran and UNESP-Universidade Estadual Pasilista, Brazil (40.0% each), Indian Institute of Technology, Kharagpur, India (19.05%), North West University, South Africa and Mashhad University of Medical Science, Iran (18.18% each) during 2007-16. Nine organizations registered the relative citation index above the group average (1.12) of all organizations: Universidad de La Serena, Chile (2.79), Amity University, Noida, India (2.20), Shahrekord University of Medical Sciences, Iran (1.65), Tehran University of Medical Sciences, Iran (1.47), Chula long University, Thailand (1.43), Mazandaran University of Medical Science, Iran (1.34), Univera Inc., Seoul, South Korea (1.29), Morinaga Milk Industry Co Ltd., Japan and National University of Singapore (1.23 each) during 2007-16.
|S.No||Subject*||Number of Papers (TP)||Activity Index||TC||CPP||%TP|
|2||Pharmacology, Toxicology and Pharmaceutics||296||403||699||100.58||99.58||5797||8.29||35.16|
|3||Agricultural and Biological Sciences||209||250||459||108.15||94.07||3531||7.69||23.09|
|4||Biochemistry, Genetics and Molecular Biology||158||245||403||93.12||105.00||4567||11.33||20.27|
|6||Immunology and Microbiology||59||65||124||113.01||90.54||1041||8.40||6.24|
Profile of Top 20 Most Productive Authors
The research productivity in the field of Aloe Vera research of top 20 most productive authors varied from 7 to 12 publications. Together they contributed 8.55% (170) global publication share and 13.82% (2628) citation share during 2007-16. The scientometric profile of these 20 authors is presented in Table 5. Nine authors registered publications output above the group average of 8.5: A. Vega-Galvez (12 papers), M.Tanaka (11 papers), M.Miranda (10 papers), M.Abdollahi, D.Martinez-Romero, S.Ramakrishna, M.Serrano, P.Thunyakitpisal and D.Valero (9 papers each) during 2007-16. Four authors registered impact above the group average of 15.46 citations per publication: J.Hamman (44.0), M.Miranda (28.10), A. Vega-Galvez (26.67) and M.Abdollahi (19.22) during 2007-16. Ten authors registered h-index above the group average of 5.9 of all authors: A. Vega-Galvez (12), M.Abdollahi and D.Martinez-Romero (9 each), M.Miranda and F.Gullen (8 each), S.Ramakrishna (7), J.Hamman, M.Serrano, D.Valero and M.Tanaka (6 each) during 2007-16. Four authors contributed international collaborative publications share above the group average of 12.35% of all authors: S.Ramakrishna (88.89%), A. Vega-Galvez (50.0%), J.Hamman (42.86%) and M.Miranda (30.0%) during 2007-16. Eight authors registered the relative citation index above the group average (1.62) of all authors: J.Hamman (4.60), M.Miranda (2.94), A. Vega-Galvez (2.79), M.Abdollahi (2.01), F.Gullen, S.Castillo and P.J.Zapata (1.63 each) and C.K.Lee (1.63) during 2007-16.
Medium of Research Communication
Of the total world output on Aloe Vera research, 79.08% (1930) appeared in journals, 16.38% (5673) in journals, 1.01% (20) in book series, 0.91% (18) in conference proceedings, 0.65%(13) as trade publications and 0.35% (7) as books, etc. during 2007-16. The top 15 most productive journals reported 11 to 58 papers each on Aloe Vera research; together they accounted for 16.01% (309 papers) of total Aloe Vera output published in journals during 2007-16. Aloe Vera research being reported increasingly in journals is gradually becoming a trend; for example, the top 15 most productive journals in five years has shown rise in their Aloe Vera output from 15.60% to 17.25% share between 2007-11 and 2012-16. The top ranking journal is Journal of Ethno-pharmacology (with 58 papers), followed by International Journal of Pharmacy and Pharmaceutical Science (38 papers), International Journal of Pharmaceutical Science Review and Research (29 papers), International Journal of Pharma and Bio Sciences (24 papers), etc. during 2007-16 Table 6.
Around 133 significant keywords having potential to identify comparative research trends in Aloe Vera research studies including pharmacological properties and medicinal uses were discovered from the global literature on science and medicine. These keywords are listed in Table 7 in the decreasing order of the frequency of their occurrence in the literature during 2007-16.
Highly Cited Papers
A total of 18 highly cited papers were identified each cumulating at least 100+ citations in 10 years during 2007-16. Together these 18 papers cumulated a total of 2656 citation, averaging 147.55 citations per paper, and individually cumulating 104 to 242 citations per paper in 10 years. Of the 18 highly cited papers, 9 resulted from the participation of research organizations in their role as stand-alone (non-collaborating) institutional authors and remaining 9 from two or more research organizations working in their role as collaborating partners per paper (all national collaborative). Among highly cited papers, the largest participation was seen from India (7 papers), followed by the USA and Brazil (2 papers each), Italy, Nigeria, Pakistan, South Africa and U.K. (1 paper each). These 18 highly cited papers involved the participation of 66 personal authors and 41 research organizations in total across globe. Of the 18 highly cited papers, 6 were published as articles and 12 as review papers. These 18 highly cited papers were published in 15 journals; Journal of Ethnopharmacology (4 papers) and 1 paper each in 14 other journals, namely Acta Oncology, Annals of Oncology, Asian Pacific Journal of Tropical Biomedicine, Burns, Corrosion Science, Cochrane Database of Systematic Reviews, Endocrine Metabolic and Immune Disorders, Food Chemistry, Free Radical Biology and Medicine, Indian Journal of Dermatology, Journal of Clinical Biochemistry and Nutrition, Journal of American Academy of Dermatology, Molecules and The Scientific World Journal.
Research publications data sourced from the Scopus database was analysed in this study to provide a quantitative and qualitative description of global Aloe Vera research covering 10 years period, 2007-16. The study showed that global Aloe Vera research registered 3.91% growth and averaged its global citation impact to 9.57 citations per paper in 10 years.
Nearly 1/3rd of global Aloe Vera research was mainly from India alone (32.55% global share) whereas other 11 top ranking countries accounted for global share between 2.26% and 11.52%. The top 12 most productive countries in Aloe Vera research together accounted for a high of 79.18% global share during 2007-16. Top ranking Asian countries in Aloe Vera research dominate in quantity of research whereas western countries in the ranking list dominate more in quality of research. For example, India, Iran, China, South Korea, Thailand, and Pakistan from Asia together accounted for 52.57% global share and comparatively the USA, the U.K., Brazil, Italy and Spain for 23.79% during 2007-16. In terms of quality of research, the USA, the U.K., Brazil, Italy and Spain performed better on citation impact (averaging 13.7 citations per paper) than that of India, Iran, China, South Korea, Thailand, and Pakistan (averaging 5.79 citations per paper). National share of western countries accounting for international collaborative publications in Aloe Vera research was greater (15.58% to 52.17% national share) compared to that of Asian countries (8.02% to 23.91% national share).
Medicine was the most sought after subject area of Aloe Vera research, accounting for (40.90%) the highest publications share, followed by pharmacology, toxicology and pharmaceutics (35.16%), agricultural and biological sciences (23.09%), biochemistry, genetics and molecular biology (20.27%), chemistry (7.90%), immunology and microbiology (6.24%) and engineering (5.38) during 2007-16. The top 20 most productive research organizations and the authors on Aloe Vera research collectively contributed 11.47% and 8.55% global publication share and 12.87% and13.82% global citation share respectively during 2007-16.
The journals medium accounted for 79.08% global share in Aloe Vera research with top 15 most productive journals accounting for 16.01% of total publications output in journals during 2007-16. These journals are Journal of Ethno-pharmacology (58), followed by International Journal of Pharmacy and Pharmaceutical Science (38 papers), International Journal of Pharmaceutical Science Review and Research (29 papers), International Journal of Pharma and Bio Sciences (24 papers), etc. during 2007-16. Of the total global Aloe Vera research output (1988), only 18 papers registered high citations, between 104 to 242 citations per paper. These 18 highly cited papers collectively cumulated a total of 2656 citation (averaging to 147.55 citations per paper), and involved the participation of 26 authors and 27 organizations in their publication.
Conclusively, this research study reveals that Asian countries (India, Iran, China, South Korea, Thailand and Pakistan) dominate in Aloe Vera research more in terms of quantity of research, whereas western countries (the USA, the UK, Italy, Brazil and Spain) dominate instead more in terms of quality of research. For enabling Asian counties to perform better in terms of quality of research, it is desirable that the stakeholders from Asian countries may give priority to Aloe Vera research, and encourage leading academic and research organizations from the Asia for international collaboration with counterparts from western countries.