Curcuma longa (Medicinal Plant) Research: A Scientometric Assessment of Global Publications Output during 1997-2016

Ahmed, Gupta, and Gupta: Curcuma longa (Medicinal Plant) Research: A Scientometric Assessment of Global Publications Output during 1997-2016

Authors

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INTRODUCTION

Curcuma longa (turmeric) is a small rhizomatous perennial herb of Zingiberaceae (Ginger family) native to southwest India and grow in Africa, especially in Nigeria and South Africa. The plant produces fleshy rhizomes of bright yellow to orange color in its root system, which are the source of the commercially available spice turmeric. In the form of root powder, turmeric is used for its flavoring properties as a spice, food preservative, and food-coloring agent. Turmeric has a long history of therapeutic uses as it is credited with a variety of important beneficial properties. It is considered as one of the golden resources with immense export potential as medicine, beauty aid, cooking spice, and as a dye to color products, such as tanned leather, cotton cloth, thread and palm fibers to a golden yellow. Turmeric products are also used as a cheap and more environmentally friendly alternative to chemical pesticides already used. The medicinal values of turmeric are known and used by medical practitioners of Siddha, Ayurveda, and Indian systems of medicine and traditional Chinese medicine. It is also used as a home remedy for many disorders. Different forms of preparations, such as stick, powder, paste, liquid, and so on, are available.1-6

C. longa rhizomes are being the source of a bright yellow spice and dye with various medicinal applications. Turmeric’s finger-like underground rhizomes are dried and used as a spice or taken as a powder in capsule form. The use of the yellow color of turmeric rhizome and other plant derivatives as dyes is on the increase toward replacing synthetic additives with natural compounds. This yellow color is due to the presence of three main curcuminoids in the rhizome namely, curcumin, demethoxycurcumin and bis-demethoxycurcumin. Rhizomes are used in Africa and Asia as a cosmetic for body and face. In Asia, turmeric is widely used as an important constituent of curry powder containing up to 25% turmeric. In Western countries, ground turmeric rhizome is widely used in food industry, in particular as a coloring agent in processed foods and sauces.1-6

Rhizomes of C. longa are part of numerous traditional medicines used as stomachic, stimulant and blood purifier and to treat liver complaints, biliousness and jaundice for arthritic, muscular disorders, biliary disorders, anorexia, cough, diabetic wounds, hepatic disorders, rheumatism and sinusitis. Mixed with warm milk, they are used to cure common cold, bronchitis, and asthma. Juice from fresh rhizomes is applied against many skin infections, whereas a decoction is effective against eye infections. It has promising pharmaceutical activity against cancer, dermatitis, AIDS, inflammation, high cholesterol levels, and dyspeptic conditions. C. longa also has also insecticidal, fungicidal, and nematicidal properties.1-6

Turmeric can be regarded as a drug for the management of many diseases, such as cancer, inflammations, microbial infections, diabetes, arthritic, muscular disorders, biliary disorders, anorexia, cough, diabetic wounds, hepatic disorders and sinusitis. Curcumin also displayed various pharmacological activities including antioxidant, antineoplastic, antiviral, anti-inflammatory, anti-bacterial, anti-fungal, anti-diabetic, anticoagulant, antifertility, cardiovascular protective, hepatoprotective and immunostimulant activities in animals. Growing evidence shows that an active component of turmeric, curcumin, may be used medically to treat a variety of dermatologic diseases such as acne, alopecia, atopic dermatitis, facial photoaging, oral lichen planus, pruritus, psoriasis, radiodermatitis and vitiligo.1-6

Literature Review

There is no scientometric study on Curcuma longa research till today. However, few scientometric studies are available which quantitatively analyze global literature on individual medicinal plants, such as Glycyrrhiza glabra,7 Aloe Vera,8 Artemisinin,9 Azadirachta indica10 and Phonix dactyl lifra.11-12

OBJECTIVES

The main objectives of this study are to study the performance and status of global Curcuma longa research during the last 20 years (1997-2016), based on publications indexed in Scopus database. The study focuses on the objectives, such as the characteristics of Curcuma longa, including growth rate, publication distribution and citation impact by countries, distribution of global research output by broad subject areas and identification of subject trends using keywords, productivity and citation impact of 20 most productive organizations and authors, important medium of communication and prominent journals and the characteristics of its top 340 highly cited papers

METHODOLOGY

Using the Scopus international database (http://www.scopus.com), the present study retrieved and downloaded 20-year (1997-2016) global publication data in Curcuma longa research. Keywords, such as “Curcuma longa” or “curcumin” or “turmeric”’ were searched in ‘Title, Abstract and Keyword” tag for the time period ‘2007-16’. Finally, this search string was applied for searching global publication data on Curcuma longa research. When the main search string with restricted to individual top 12 most productive country name in “country tag”, the publication data on the individual country in Curcuma longa was obtained. 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 18 May 2018. For the present study, the search on Curcuma longa research was carried out on 22 January 2018. A number of select bibliometric indicators have been used to study the performance of global Curcuma longa research.

TITLE-ABS-KEY (Curcuma longa or curcumin or turmeric) AND PUBYEAR > 1996 AND PUBYEAR < 2017

ANALYSIS RESULTS

The total research output of the world in field of Curcuma longa cumulated to 5351 publications in 20 years during 1997-2016. The annual output of the world in Curcuma longa research increased from 54 in the year 1997 to 532 publications in the year 2016, registering 13.40% growth per annum. The cumulative world output in Curcuma longa research in 10 years 1997-2006 increased from 1181 to 4170 publications during succeeding ten-year period 2007-16, registering 253.09% growth. Of the total global publications output, 80.3% (4297) appeared as articles, 13.77% (737) as reviews, 2.49% (133) as conference papers, 1.14% (61) as book chapters, 0.73% (39) as notes, 0.52% (28) as letters, 0.43%(23) as editorials, 0.41% (22) as short surveys, 0.15% (8) as erratum, 0.02%(1) each as book, conference review and article in press. The citation impact of global publications on Curcuma longa research in 20 years averaged to 29.04 citations per publication (CPP) during 1997-2016; ten-yearly impact averaged to 59.60 CPP for the period 1997-2006, which sharply declined to 20.39 CPP in the succeeding five-year 2007-2016 (Table 1)

Table 1

World Output in Curcuma longa Research, 1997-16.

Publication PeriodWorldWorld
TPTCCPPTPTCCPP
199754222541.2020093531037329.39
199854363067.222010388978525.22
1999699074131.512011441936721.24
200067319247.642012439736516.78
200189796889.532013472779416.51
2002111692662.402014461546511.85
2003139746353.69201549737147.47
2004152792652.14201653216243.05
20052151265058.841997-200611817038259.60
2006231932840.382007-201641708500720.39
20072721297447.701997-2016535115538929.04
20083151654652.53

TP=Total Papers; TC=Total Citations; CPP=Citations Per Paper

Top 12 Most Productive Countries in Curcuma longa research

The global research output in the field of Curcuma longa research had originated from as many as 105 countries in the world during 1997-2016, of which, 64 published 1-10 papers each in 20 years, 21 countries 11-50 papers each, 5 countries 51-100 papers each, 11 countries 101-300 papers each, 3 countries 301-800 papers each and 1 country 1661 papers. The top 15 most productive countries in Curcuma longa research contributed 102 to 1661 publications each during 1997-2016 (Table 2). The top 15 most productive countries in Curcuma longa research accounted for 92.66% global publication share and 96.84% citation share during 1997-2016. Their ten-yearly output accounted for 89.25% global publication share during 1997-2006 which increased to 93.62% during succeeding ten-year period 2007-16. Country-wise, the global publication shares of top 15 countries varied widely 1.91% to 31.04% during 1997-16, with India accounting for the highest publication share (31.04%), followed by USA (13.96%), China (11.55% share), South Korea, Japan and Thailand (from 4.47% to 5.81%), Iran, Brazil, Malaysia, Germany, Italy and U.K. (from 2.28% to 2.90%), Taiwan, Egypt and Pakistan (from 1.91% to 1.98%) during 1997-2016. The global publication share registered an increasing publication share varying from 0.28% to 3.30% in 10 countries namely China, Iran, Malaysia, Egypt, Italy, Pakistan, South Korea, Thailand, Taiwan and India, as against decrease from 0.51% to 4.58% in 5 countries, namely Brazil, German, U.K., USA and Japan in ten years period (1997-2006 and 2007-16). Only five of top 15 countries scored relative citation index above the world average of 1.05: USA (2.29), U.K. (2.08), Taiwan (1.81), Italy (1.23) and South Korea (1.10) during 1997-2016. India has though emerged as one of the world leaders in Curcuma longa research, its performance in terms of relative citation index has below the world average (0.71).

Table 2

Global Publication Share of Top 15 Most Productive Countriesin Curcuma longa during 1997-2016.

S.NoName of the CountryNumber of PapersShare of PapersTCCPPHIICP%ICPRCI
1997-20062007-20161997-20161997-20062007-20161997-2016
1India3641297166130.8231.1031.043418520.588717410.480.71
2USA19155674716.1713.3313.964959266.3911329539.492.29
3China1065126188.9812.2811.551149618.605112420.060.64
4South Korea592523115.006.045.81993031.93496520.901.10
5Japan981552538.303.724.73758529.98478935.181.03
6Thailand461932393.904.634.47528922.13397129.710.76
7Iran61491550.513.572.90282218.21313421.940.63
8Brazil361061423.052.542.65257618.14254430.990.62
9Malaysia91291380.763.092.58196614.25244633.330.49
10Germany43891323.642.132.47396830.06386851.521.04
11Italy141141281.192.732.39458135.79336046.881.23
12U.K.46761223.901.822.28736060.33405343.442.08
13Taiwan19871061.612.091.98555852.43352220.751.81
14Egypt8961040.682.301.94187017.98214341.350.62
15Pakistan9931020.762.231.91170816.75213736.270.58
Total10543904495889.2593.6292.6615048630.3543.6122524.711.05
World11814170535115538929.04
Share of 15 Countries in World Total89.2593.6292.6696.84

TP=Total Papers; TC=Total Citations; CPP=Citations Per Paper; HI=h-index; ICP=International Collaborative Papers; RCI=Relative Citation Index

International Collaboration

The international collaborative output of top 15 most productive countries in Curcuma longa research as a national share in the country-wise output varied widely from 10.48% to 51.52%, with average share of 23.97% during 1997-2016. The highest international collaborative publication share comes from Germany (51.52%), followed by Italy (46.88%), U.K. (43.44%), Egypt (41.35%), USA (39.49%), Pakistan (36.27%), Japan (35.18%), Malaysia (33.33%), Brazil (30.49%) and other countries share between 10.48% to 29.71% during 1997-16. Most surprisingly, India’s international collaborative share in its national output in Curcuma longa research has been comparatively small and lowest, 10.48.

Subject-Wise Distribution of Research Output

The global Curcuma longa research output published during 1997-16 is distributed across nine sub-fields (as identified in Scopus database classification), with medicine accounting for the highest publications share (37.38%), followed by pharmacology, toxicology and pharmaceutics (32.07%), biochemistry, genetics and molecular biology (31.68%), agricultural and biological sciences (25.53%), chemistry (12.78%), and other 4 sub-fields contribution varying from 2.15% to 5.53% during 1997-16. Its activity index, which computes change in research activity in the discipline over time 1997-2006 to 2007-16 (world average activity index of a given subject is taken as 100), witnessed increase in medicine (from 98.77 to 100.35), pharmacology, toxicology and pharmaceutics (from 93.73 to 101.77), agricultural and biological sciences (from 93.87 to 101.74), immunology and microbiology (from 67.35 to 109.25), neuroscience (from 66.63 to 109.45), and veterinary science (from 86.68 to 103.77), as against decline of research activity in biochemistry, genetics and molecular biology (from 101.58 to 99.55), chemistry (from 107.97 to 97.74) and environmental science (from 109.84 to 97.21) from 1997-2006 to 2007-16. Neuroscience, among various subjects registered the highest citations impact per paper of 53.22 CPP, followed by biochemistry, genetics and molecular biology (42.50), immunology and microbiology (33.84), chemistry (31.35), medicine (31.31), pharmacology, toxicology and pharmaceutics (30.14), environmental science (24.42), agricultural and biological sciences (21.06) and veterinary science (11.03) during 1997-2016 (Table 3).

Table 3

Subject-Wise Breakup of Global Publications in Curcuma longa Research during 1997-2016.

S.NoSubject*Number of Papers (TP)Activity IndexTCCPP%TP
2007-112012-162007-162007-112012-162007-162007-162007-16
1Medicine4361564200098.77100.356261831.3137.38
2Pharmacology, Toxicology and Pharmaceutics3551361171693.73101.775172330.1432.07
3Biochemistry, Genetics and Molecular Biology38013151695101.5899.557203842.5031.68
4Agricultural and Biological Sciences2831083136693.87101.742876321.0625.53
5Chemistry163521684107.9797.742144431.3512.78
6Immunology and Microbiology4425229667.35109.251001833.845.53
7Environmental Science48150198109.8497.21483524.423.70
8Neurosciences2011613666.63109.45723853.222.54
9Veterinary Science229311586.68103.77126811.032.15
World Output4361564200098.77100.356261831.3137.38

• There is overlapping of literature covered under various subjects

TP=Total Papers; TC=Total Citations; CPP=Citations Per Paper

Profile of Top 20 Most Productive Global Organizations

One thousand five hundred and three (1503) organizations participated in global research on Curcuma longa during 1997-2016, of which 1370 organizations contributed 1-10 papers each, 98 organizations 11-20 papers each, 19 organizations 21-30 papers each, 13 organizations 31-50 papers each and 3 organizations 51-57 papers each.

The productivity of top 20 most productive global organizations in Curcuma longa Research varied from 28 to 57 publications and together they contributed 13.89% (743) publication share and 20.75% (32237) citation share during 1997-2016. The scientometric profile of these top 20 organizations is presented in Table 4.

Table 4

Scientometric Profile of Top 20 Most Productive Global Organizationsin Curcuma longa Research during 1997-2016.

S.NoName of the OrganizationTPTCCPPHIICP%ICPRCI
1Central Food Technological Research Institute, Mysore, India57347761.002958.772.10
2Chiang Mai University, Thailand55204037.09212240.001.28
3University of Texas, M.D.Anderson Cancer Centre, USA5413022241.15441425.938.30
4Mahidol University, Thailand5096419.28201632.000.66
5Annamalai University, India43155636.191849.301.25
6Universiti Putra Malaysia4054013.5013922.500.46
7Indian Institute of Spices Research, Calicut, India3951713.2613410.260.46
8Chulalongkorn University, Thailand3776020.5414821.620.71
9Banaras Hindu University, Varanasi362667.391025.560.25
10Mashhad University of Medical Science, Iran3390327.36171442.420.94
11Ministry of Education, China3360918.4512824.240.64
12Bhabha Atomic Research Centre, Mumbai, India32154248.1918412.501.66
13Shenyang Pharm University, China3162820.2617412.900.70
14Universiti Kebang saan Malaysia3036612.2010723.330.42
15Universitidade desao Paulao-USP, Brazil3047015.6714620.000.54
16VA Medical Centre, University of Michigan Medical School, USA30171157.0318516.671.96
17Kyung Hee University, South Korea2955819.241200.000.66
18Yonsei University, South Korea28170360.8214932.142.09
19Kasetsart University, Thailand2841714.8911932.140.51
20Siksha o Anusandhan University, Bhubaneshwar, India281886.71827.140.23
Total of 20 organizations7433223743.3916.6515220.461.49
Total of World535115538929.04
Share of top 20 organizations in World output13.8920.75

TP=Total Papers; TC=Total Citations; CPP=Citations Per Paper; HI=h-index; ICP=International Collaborative Papers; RCI=Relative Citation Index

  • Seven of these organizations registered publications output greater than the group average of 37.15: Central Food Technological Research Institute, Mysore, India (57 papers), Chiang Mai University, Thailand (55 papers), University of Texas, M.D. Anderson Cancer Centre, USA (54 papers), Mahidol University, Thailand (50 papers), Annamalai University, India (43 papers), Universiti Putra Malaysia (40 papers) and Indian Institute of Spices Research, Calicut, India (39 papers) during 1997-2016;

  • Five organizations registered impact above the group average of 43.35 citations per publication during 1997-16: University of Texas, M.D. Anderson Cancer Centre, USA (241.15), Central Food Technological Research Institute, Mysore, India (61.0), Yonsei University, South Korea (60.82), VA Medical Centre, University of Michigan Medical School, USA (57.03) and Bhabha Atomic Research Centre, Mumbai, India (48.19) during 1997-2016;

  • Ten organizations contributed international collaborative publications share above the group average of 20.46%: Mashhad University of Medical Science, Iran (42.42%), Chiang Mai University, Thailand (40.0%), Yonsei University, South Korea and Kasetsart University, Thailand (32.14% each), Mahidol University, Thailand (32.0%), University of Texas, M.D.Anderson Cancer Centre, USA (25.93%), Ministry of Education, China (24.24%), Universiti Kebang saan Malaysia (23.33%), Universiti Putra Malaysia (22.50%) and Chulalongkorn University, Thailand (21.62%) during 1997-2016;

  • Five organizations registered the relative citation index above the group average (1.49) of all organizations: University of Texas, M.D. Anderson Cancer Centre, USA (8.30), Central Food Technological Research Institute, Mysore, India (2.10), Yonsei University, South Korea (2.09), VA Medical Centre, University of Michigan Medical School, USA (1.96) and Bhabha Atomic Research Centre, Mumbai, India (1.66) during 1997-2016

Profile of Top 20 Most Productive Authors

Three thousand and eighty-three (3083) authors participated in global research on Curcuma longa during 1997-2016, of which 2914 authors contributed 1-5 papers each, 153 authors 6-10 papers each and 16 authors 11-47 papers each.

The research productivity in the field of Curcuma longa research of top 20 most productive authors varied from 10 to 47 publications. Together they contributed 5.59% (299) global publication share and 14.52% (22566) citation share during 1997-2016. The scientometric profile of these 20 authors is presented in Table 5.

Table 5

Scientometric Profile of Top 20 Most Productive Authorsin Curcuma longa Research during 1997-2016.

S.NoName of the AuthorAffiliation of the AuthorTPTCCPPHIICP%ICPRCI
1B.B.AggarwalUniversity of Texas, M.D.Anderson Cancer Centre, USA4712430264.47411225.539.11
2A. SahebkarMashhad University of Medical Science, Iran2076438.20151470.001.32
3S. NayakSiksha o Anusandhan University, Bhubaneshwar, India171106.47615.880.22
4B. SasikumarIndian Institute of Spices Research, Calicut, India1730718.06915.880.62
5J.G.ChungChina Medical University, Taiwan1568845.8711320.001.58
6W.JunChonam National University, South Korea151228.13600.000.28
7K.KomatuUniversity of Toyama, Japan1544229.4711853.331.01
8A. SuksamrarnRkhamhaeng University, Thailand1526017.3310320.000.60
9J.K. HwangYonsei University, South Korea1336127.7712646.150.96
10L. PariAnnamalai University, India1351939.921117.691.37
11K. SrinivasanCentral Food Technological Research Institute, Mysore, India13109284.001300.002.89
12G.B.MaruTata Memorial Hospital, Mumbai1253144.251100.001.52
13S.MohantySiksha o Anusandhan University, Bhubaneshwar, India12917.58600.000.26
14R.KuttanAmala Cancer Research Centre, Trichur, Kerala, India1133630.55700.001.05
15J.LeeKyung Hee University, South Korea11918.27600.000.28
16P. LimtrakulChiang Mai University, Thailand11100591.3610436.363.15
17M.RahmatullahUniversity of Development Alternatives, Dhaka, Bangladesh1129927.18600.000.94
18Y.J.SurhSeoul National University, South Korea112832257.451019.098.87
19R.K. JoshiSiksha o Anusandhan University, Bhubaneshwar, India10545.404110.000.19
20B.T.KurienUniversity of Oklahoma Health Services CentreUSA1023223.206110.000.80
  Total of 20 authors2992256675.4710.555618.732.60
  Total of World535115538929.04
  Share of top 20 authors in World total output5.5914.52

TP=Total Papers; TC=Total Citations; CPP=Citations Per Paper; HI=h-index; ICP=International Collaborative Papers; RCI=Relative Citation Index

  • Eight authors registered publications output above the group average of 14.95: B.B. Aggarwal (47 papers), A. Sahebkar (20 papers), S. Nayak and B. Sasikumar (17 papers each), J.G.Chung, W. Jun, K. Komatu and A. Suksamrarn (15 papers each) during 1997-2016;

  • Four authors registered impact above the group average of 75.47 citations per publication: B.B. Aggarwal (264.47), Y.J. Surh (257.45), P. Limtrakul (91.36) and K. Srinivasan (84.0) during 1997-2016;

  • Seven authors contributed international collaborative publications share above the group average of 18.73% of all authors: A. Sahebkar (70.0%), K. Komatu (53.33%), J.K. Hwang (46.15%), P. Limtrakul (36.26%), B.B. Aggarwal (25.53%), J.G. Chung and A. Suksamrarn (@0.0% each) during 1997-2016;

  • Four authors registered the relative citation index above the group average (2.60) of all authors: B.B.Aggarwal (9.11), Y.J. Surh (8.87), P. Limtrakul (3.15) and K. Srinivasan (2.89) during 1997-2016.

Medium of Research Communication

Of the total world output on Curcuma longa research, 96.37% (5157) appeared in journals, 1.68% (90) in book series, 1.08% (58) in books, 0.47% (25) in trade publications, 0.36%(19) as conference proceedings and 0.02% (1 each) as multivolume reference work and unidentified during 1997-2016. 5157 journal papers appeared in 2216 journals, of which 1780 journals published 1-5 papers each, 344 journals, 62 journals 11-20 papers each 17 journals 21-30 papers each, 9 journals 31-50 papers each and 4 journals 51-89 papers each during 1997-2016.

The top 20 most productive journals reported 16 to 64 papers each on Curcuma longa research; together they accounted for 15.92% (558 papers) share of total Curcuma longa output published in journals during 1997-16. Curcuma longa research being reported increasingly in journals is gradually becoming a trend; for example, the top 20 most productive journals in ten years has shown decline in their Curcuma longa output from 17.75% to 15.45% share between 1997-2006 and 2007-16. The top ranking journal is Journal of Ethnopharmacology (with 89 papers), followed by Journal of Agricultural and Food Chemistry (63 papers), Food Chemistry (61 papers), Phototherapy Research (60 papers each), International Journal of Pharmacy and Pharmaceutical Sciences and Zhongguo Zhongyao Zachi (46 papers each), etc. during 1997-2016 (Table 6).

Table 6

Top 20 Most Productive Journals in Curcuma longa Research during 1997-2016.

S.NoName of the JournalNumber of Papers
2007-112012-162007-16
1Journal of Ethnopharmacology206989
2Journal of Agricultural and Food Chemistry204363
3Food Chemistry65561
4Phototherapy Research213960
5International Journal of Pharmacy and Pharmaceutical Sciences04646
6Zhongguo Zhongyao Zachi232346
7Zhong Yao Cai Zhongyaocai. Journal of Chinese Medicinal Materials123345
8PLOS One43539
9Acta Horticulurae63238
10Phytomedicine63238
11Evidence-based Complementary and Alternative Medicine23335
12Food and Chemical Toxicology82735
13Planta Medica122335
14Biochemical and Biophysical Research Communication102232
15International Journal of Pharma and Bio Sciences03030
16Pharmaceutical Biology91827
17MBC Complementary and Alternate Medicine32326
18Cancer Letters141226
19Biological and Pharmaceutical Bulletin131225
20Indian Drugs151025
Total of 20 journals204617821
Total global journal output114940085157
Share of top 20 journals in global journal output17.7515.3915.92

Significant Keywords

Around 46 significant keywords having potential to identify comparative research trends in Curcuma longa research studies including pharmacological properties and medicinal uses were discovered from the global literature on Curcuma longa. These keywords are listed in Table 7 in the decreasing order of the frequency of their occurrence in the literature during 2007-2016.

Table 7

List of Significant Keywords in Literature on Curcuma longa Research during 2007-16.

S.NoKeywordFrequencyS.NoKeywordFrequency
1Curcuma Longa347625Gene Expression203
2Curcumin244226Drug Isolation189
3Curcuma142127Curcuminoids188
4Medicinal Plant76228Diabetes Mellitus188
5Drug Effect68629Drug Formulation186
6Antioxidant Activity63830Cancer Inhibition184
7Metabolism59731Antibacterial Activity172
8Apoptosis54632Liver168
9Rhizome51033Spice158
10Drug Mechanism49334Chinese Medicine157
11Drug Efficacy49035Genetics157
12Antineoplastic Activity42236Alzheimer Disease145
13Oxidation Stress41537Flavonoids142
14Enzyme Activity33438Neoplasms142
15Herbal Medicine29339Antimicrobial Activity140
16Tumor Cell Line28740Breast Cancer135
17Inflammation27141Placebo134
18Drug Structure25842Diarrhea126
19Drug Safety23843Cancer124
20Drug Screening23744Abdominal Pain120
21Pathology23745Bacteria109
22Essential Oils23346Bacterial Infection26
23Traditional Medicine220
24Phytochemistry213

Highly Cited Papers

A total of 340 highly cited papers in Curcuma longa research were identified each having 100 to 83869 citations (232 papers each in citation range 100-199, 53 papers each in 200-299 citations range, 18 papers each in 300-399 citations range, 24 papers each in 400-699 citations range, 7 papers each in 700-999 citations range and 6 paper each 1085-3869 citations range) in 20 years during 1997-16. Together 340 papers cumulated a total of 81274 citations, averaging 239.04 citations per paper. Of the 340 highly cited papers, 150 resulted from the participation of research organizations in their role as stand-alone (non-collaborating) institutional authors and remaining 190 from two or more research organizations working in their role as collaborating partners per paper (92 national collaborative and 98 international collaborative). Among 340 highly cited papers, the largest participation was seen from USA (142 papers), followed by the India (68 papers), South Korea (19 paper), China and Japan (18 papers each), U.K. and Taiwan (13 papers each), Thailand (11 papers), Germany and Italy (9 papers each), Paistan (4 papers), Brazil (3 papers), Iran and Malaysia (2 papers each) etc. These 340 highly cited papers involved the participation of 813 personal authors and 548 research organizations in total across globe. The leading organizations participating in high cited papers were University of Texas, M.D. Anderson Cancer Centre, USA (34 papers), Central Food Technological Research Institute, Mysore, India (11 papers), V.A.Medical Centre, University of Michigan Medical School, USA (8 papers), Chiang Mai University, Thailand (7 papers), Bhabha Atomic Research Centre, Mumbai, India (6 papers), Annamalai University, India (4 papers), China Medical University, Taichung, Taiwan, Chinese University of Hong Kong, Panjab University, Chandigarh, India and Peking University, China (3 papers each), Central Drug Research Institute, Lucknow, India, China Medical University Hospital, Taichung, Taiwan, Jamia Hamdard, Delhi and University of Arizona, USA (2 papers each), etc. The leading authors participating in high cited papers were B.B. Aggarwal (32 papers), A.B. Kunnumakkara (7 papers), Y.J.Surh (6 papers), S.Prasad (5 papers), K. Srinivasan, P. Limtrakul, S.C.Gupta, B. Sung, P. Anand and A. Goel (4 papers each), J.G. Chung, M. Dicato, M.Diederich, J.S. Yang, Y.S. Keum and S.S.Han (3 papers each), etc. Of the 340 highly cited papers, 214 were published as articles, 107 as reviews papers, 14 as conference papers, 3 as short surveys and 2 as letters. These 340 highly cited papers were published in 204 journals, with 10 papers in Journal of Ethnopharmacology, 9 papers in Biochemical Pharmacology, 8 papers each in Cancer Letters, Food and Chemical Toxicology and Journal of Agricultural and Food Chemistry, 6 papers in Planta Medica, 5 papers each in Cancer Research, Journal of Natural Products, Molecular Cancer and Therapeutics, Phytotherapay Research and Phytomedicine, 4 papers each in Advances in Experimental Medicine and Biology, Anticancer Research, Biofactors, Biochemistry and Behavior, Bioorganic and Medicinal Chemistry, Biochemical and Biophysical Research Communication, Carcinogenesis, Food Chemistry, Journal of Biological Chemistry, Molecular Nutrition and Food Research, Pharmacology and Journal of Nutrition, 3 papers each in Alternative Medicine Review, Annals of New York Academy of Sciences, Clinical Cancer Research, European Journal of Pharmacology, Free Radical Biology and Medicine, International Journal of Biochemistry and Cell Biology, International Journal of Pharmaceutics, Journal of Chromatography A, Life Sciences, Mutation Research and Oncogene, 2 papers each in AAPS Journal, Antioxidants and Redox Signaling, Atherosclerosis, Biochemica et Biophysica Acta-General Subjects, Biomaterials, Bioorganic and Medicinal Chemistry Letters, Bio resource Technology, Brain Research, Chemical-Biological Interactions, FEBS Letters, Fitoterpia, Frontier in Biosciences, International Journal of Food Science and Nutrition, International Journal of Medical Research, Journal of Cellular Biochemistry, Journal of Alternate and Complimentary Medicine, Journal of Chromatography B, Malaria Journal, Medicinal Research Review, Nutrition and Cancer, Neurochemical Research, Nutrients and Wound Repair and Regeneration and 1 paper each in 153 other journals.

CONCLUSION

Research publications data on Curcuma longa sourced from the Scopus database was analysed in this study to provide a quantitative and qualitative description of its global research output covering 20 years period (1997-2016). The study showed that annual and ten-year cumulative global output of Curcuma longa research registered 13.40% and 253.09% growth. Its global citation impact averaged to 29.04 citations per paper during 1997-2016, which decreased from 59.60 during 1997-2006 to 20.39 during 2007-16.

More than 57% (between 12.28% to 31.04%) of global Curcuma longa research output share was mainly from India, USA and China and USA, 9 others top ranking countries accounted for global share of 30.28% (between 2.28% and 5.81%) and 3 other countries contributed global share of 5.83% (between 1.91% to 1.98%) during 1997-2006. The top 15 most productive countries in Curcuma longa research together accounted for a high of 92.66% global share during 1997-2016, which increased from 89.25% to 93.62% from 1997-2006 to 2007-16. Top ranking Asian countries in Curcuma longa research dominate in quantity of research whereas American and western countries in the ranking list dominate more in quality of research. For example, India, China, South Korea, Japan, Thailand Iran, Brazil, Malaysia, Egypt, Pakistan and Taiwan mainly from Asia together accounted for 72.119% global share and citation impact (averaging 23.92 citations per paper) and comparatively the USA, Germany, Italy and the U.K. account for only 20.47% global share and citation impact (averaging 52.17 citations per paper) during 1997-2016. The global publication share registered an increasing publication share varying from 0.28% to 3.30% in 10 countries namely China, Iran, Malaysia, Egypt, Italy, Pakistan, South Korea, Thailand, Taiwan and India, as against decrease from 0.51% to 4.58% in 5 countries, namely Brazil, German, U.K., USA and Japan in ten years period (1997-2006 and 2007-16). Only five of top 15 countries scored relative citation index above the world average of 1.05: USA (2.29), U.K. (2.08), Taiwan (1.81), Italy (1.23) and South Korea (1.10) during 1997-2016. The international collaborative publication share of American and western countries in Curcuma longa was greater (39.49% to 51.52% share) compared to that of major Asian countries (10.48% to 36.27% share).

Medicine was the most sought after subject area of Curcuma longa research, accounting for (37.38%) the highest publications share, followed by pharmacology, toxicology and pharmaceutics (32.07%), biochemistry, genetics and molecular biology (31.68%), agricultural and biological sciences (25.53%), chemistry (12.78%), etc. during 1997-16. Among broad subjects, the research activities registered increase in medicine, pharmacology, toxicology and pharmaceutics, agricultural and biological sciences, immunology and microbiology, neuroscience and veterinary science, as against decline of research activity in biochemistry, genetics and molecular biology, chemistry and environmental science from 1997-2006 to 2007-16.

The top 20 most productive research organizations and the authors on Curcuma longa research collectively contributed 13.89% and 5.59% global publication share and 20.75% and 14.25% global citation share respectively during 1997-16. The leading organizations in terms of publication productivity were: Central Food Technological Research Institute, Mysore, India (57 papers), Chiang Mai University, Thailand (55 papers), University of Texas, M.D.Anderson Cancer Centre, USA (54 papers), Mahidol University, Thailand (50 papers), Annamalai University, India (43 papers), Universiti Putra Malaysia (40 papers) and Indian Institute of Spices Research, Calicut, India (39 papers) during 1997-2016. The leading organizations in terms of citation impact per paper were University of Texas, M.D.Anderson Cancer Centre, USA (241.15), Central Food Technological Research Institute, Mysore, India (61.0), Yonsei University, South Korea (60.82), VA Medical Centre, University of Michigan Medical School, USA (57.03) and Bhabha Atomic Research Centre, Mumbai, India (48.19) during 1997-2016;

The journals medium accounted for 96.37% global share in Curcuma longa research with top 20 most productive journals accounting for 15.92% of total publications output in journals during 1997-2016. Journal of Ethnopharmacology contributed the largest number of papers (89), Journal of Agricultural and Food Chemistry (63 papers), Food Chemistry (61 papers), Phototherapy Research (60 papers each), International Journal of Pharmacy and Pharmaceutical Sciences and Zhongguo Zhongyao Zachi (46 papers each), etc.

Of the total Curcuma longa global research output, 340 publications registered high citations, in the range of 100 to 3869 citations per paper, and collectively these highly cited papers received a total of 81274 citations, averaging to 239.04 citations per paper. These 340 highly cited papers involved the participation of 813 personal authors and 548 research organizations in total across globe and were published in 204 journals, with 10 papers in Journal of Ethnopharmacology, 9 papers in Biochemical Pharmacology, 8 papers each in Cancer Letters, Food and Chemical Toxicology and Journal of Agricultural and Food Chemistry, 6 papers in Planta Medica, 5 papers each in Cancer Research, Journal of Natural Products, Molecular Cancer and Therapeutics, Phytotherapay Research and Phytomedicine etc.

Conclusively, this research study reveals that developing countries mainly from (India, China, South Korea, Japan, Thailand, Iran, Brazil, Malaysia, Egypt, Pakistan and Taiwan) dominate in Curcuma longa research more in terms of quantity of research, whereas western countries (USA, Germany, Italy and the U.K) dominate instead more in terms of quality of research. It is concluded that the developing countries need to put much more efforts in investment (both financial and manpower) in R & D to increase their output and also to perform better in terms of quality of research. In addition, the developing countries need to give higher priority to plant based research and encourage leading academic and research organizations to participate in international collaboration with counterparts from western countries.

REFERENCES

1. 

Omosa LK, Midiwo JO, Kuete V , authors. Curcuma longa Chapter 19 ”. In. Victor Kuete, ed. Medicinal Spices and Vegetables from Africa: Therapeutic Potential Against Metabolic, Inflammatory, Infectious and Systemic Diseases. 2017. p. 425–35. Academic Press. https://doi.org/10.1016/B978-0-12-809286-6.00031-5.

2. 

Kumar A, Dora J, Singh A , authors. A review on spice of life Curcuma longa (Turmic). International Journal of Applied Biology and Pharmaceutical Technology. 2011;2(4):371–9

3. 

Vasavi RA, Suresh JY, Hemant KS, Singh A , authors. A review on Curcuma longa research. Journal of Pharmacy and Technology. 2012;5(2):158–65

4. 

Akram M, Shahab-Uddin A, Afzal K, Usmanghani HA, Mohiuddin E, Asif M , authors. Curcuma longa and Curcumin. A review article. Romanian Journal of Biology-Plant Sciences. 2010;55(2):65–70

5. 

Witkin JM, Li X , authors. Curcumin, an active constituent of the ancient medicinal herb Curcuma longa L.: some uses and the establishment and biological basis of medical efficacy. CNS Neurol Disord Drug Targets. 2013;12(4):487–97

6. 

Vaughn AR, Branum A, Sivamani RK , authors. Effects of Turmeric (Curcuma longa) on skin health: A systematic review of the clinical Evidence. Phytotherapy Research. 2016;30(8):1243–64

7. 

Ram S , author. A bibliometric assessment of the liquorice (Glycyrrhiza glabre) research trends. Annals of Library and Information Studies. 2015;62(1):27–32

8. 

Gupta BM, Mueen AKK, Dhawan SM, Gupta R , authors. Aloe Vera (Medicinal Plant) research: A scientometric assessment of global publications output during 2007-16. Pharmacognosy Journal. 2018;10(1):1–8

9. 

Yao Q, Chen J, Lyu PH, Zhang SJ, Ma FC, Fang JG , authors. Knowledge map of artemisinin research. Journal of Vector Borne Diseases. 2012;49:205–16

10. 

Singh N , author. Scientific output on Azadirachta indica (Neem): A bibliometric study. SRELS Journal of Information Management. 2016;53(6):479–85

11. 

Anwar MA, Phonix DL , authors. A bibliometric study of the literature on Date Palm. Malaysian Journal of Library and Information Science. 2006;11(1):41–60

12. 

Alhaider I, Ahmed MKK, Gupta BM , authors. Global research output on date palm (Phonix dactyl lifra): A 12 years scientometric perspective. Scientometrics. 2013;94(3):157–71