Indigenous Use and Bio-Efficacy of Medicinal Plants in the Rasuwa
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Uprety et al. Journal of Ethnobiology and Ethnomedicine 2010, 6:3 http://www.ethnobiomed.com/content/6/1/3 JOURNAL OF ETHNOBIOLOGY AND ETHNOMEDICINE RESEARCH Open Access Indigenous use and bio-efficacy of medicinal plants in the Rasuwa District, Central Nepal Yadav Uprety1,4*, Hugo Asselin2, Emmanuel K Boon1, Saroj Yadav3, Krishna K Shrestha3 Abstract Background: By revealing historical and present plant use, ethnobotany contributes to drug discovery and socioeconomic development. Nepal is a natural storehouse of medicinal plants. Although several ethnobotanical studies were conducted in the country, many areas remain unexplored. Furthermore, few studies have compared indigenous plant use with reported phytochemical and pharmacological properties. Methods: Ethnopharmacological data was collected in the Rasuwa district of Central Nepal by conducting interviews and focus group discussions with local people. The informant consensus factor (FIC) was calculated in order to estimate use variability of medicinal plants. Bio-efficacy was assessed by comparing indigenous plant use with phytochemical and pharmacological properties determined from a review of the available literature. Criteria were used to identify high priority medicinal plant species. Results: A total of 60 medicinal formulations from 56 plant species were documented. Medicinal plants were used to treat various diseases and disorders, with the highest number of species being used for gastro-intestinal problems, followed by fever and headache. Herbs were the primary source of medicinal plants (57% of the species), followed by trees (23%). The average FIC value for all ailment categories was 0.82, indicating a high level of informant agreement compared to similar studies conducted elsewhere. High FIC values were obtained for ophthalmological problems, tooth ache, kidney problems, and menstrual disorders, indicating that the species traditionally used to treat these ailments are worth searching for bioactive compounds: Astilbe rivularis, Berberis asiatica, Hippophae salicifolia, Juniperus recurva, and Swertia multicaulis. A 90% correspondence was found between local plant use and reported plant chemical composition and pharmacological properties for the 30 species for which information was available. Sixteen medicinal plants were ranked as priority species, 13 of which having also been prioritized in a country-wide governmental classification. Conclusions: The Tamang people possess rich ethnopharmacological knowledge. This study allowed to identify many high value and high priority medicinal plant species, indicating high potential for economic development through sustainable collection and trade. Background Globally, millions of people in the developing world Ethnobotany reveals historical and present plant use to rely on medicinal plants for primary health care, income fulfil a wide variety of human needs [1,2]. Documenting generation and livelihood improvement [6]. Indigenous indigenous knowledge through the ethnobiological people living on their traditional territory largely rely on approach is important for species conservation and sus- medicinal plants for healthcare and they are therefore tainable resource use [3]. Furthermore, such studies are rich in ethnopharmacological knowledge. The interest in often significant in revealing locally important plant spe- phytomedicine has been renewed over the last decade cies, sometimes leading to the discovery of crude drugs and several medicinal plant species are now being [4,5], or contributing to economic development. screened for pharmacological potential. According to Laird and Pierce [7], the world market for herbal reme- dies was worth 19.4 billion US$ in 1999. The global * Correspondence: [email protected] demand for medicinal plants is increasing and, in India 1Human Ecology Department, Vrije Universiteit Brussel, Laarbeeklaan 109, B- 1090 Brussels, Belgium alone, the market is expanding at an annual rate of 20% © 2010 Uprety et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Uprety et al. Journal of Ethnobiology and Ethnomedicine 2010, 6:3 Page 2 of 10 http://www.ethnobiomed.com/content/6/1/3 [8,9]. Scientific research is needed to determine the Tamang indigenous people, which comprises 98% of the active principles of traditional medicinal recipes and to total Chilime VDC population [23]. People from the evaluate their effectiveness, so that benefits could be Tamang ethnic group have a rich culture and possess equally shared among local peoples in the spirit of the sound traditional knowledge. However, they are eco- Convention on Biological Diversity [10]. nomically and socially marginalized and far from having Medicinal plants play vital roles in the Nepalese liveli- their basic needs fulfilled. hood [11] and the use of medicinal plants is frequent in several Nepalese regions [12-14]. It is estimated that Methods only 15-20% of the population of Nepal - living in and Ethnopharmacological data was collected by conducting around urban areas - have access to modern medicinal interviews and focus group discussions with local people facilities, whereas the rest depend on traditional medi- (50% > 40 years old), from July to September 2007. A cines [11]. Nepal is a natural storehouse of medicinal total of 50 household heads (56% male and 44% female) plants [12,15,16]. Each year thousands of tons of raw from the Chilime VDC of the Rasuwa district partici- material are exported, mostly to India, but also to Asia, pated in the study. Participants were purposively Europe and America [17]. The government of Nepal selected to include key informants [24] like plant collec- aims to promote medicinal plant use and conservation tors, medicinal plant cultivators, traditional healers, and programmes for livelihood improvement and poverty traders. Respondents were all from the Tamang ethnic alleviation through various policies [11]. However, the group, predominant (65%) in the Rasuwa district. The contribution of this sector to the national economy is majority (62%) of the respondents had no formal educa- still nominal. tion, 18% had primary school education, 12% had sec- Several ethnopharmacological studies have been con- ondary education, and 8% had university level ducted in Nepal [13,15,16,18,19], but many parts of the education. Prior informed consent was obtained with country remain unexplored. Few studies have attempted the help of community workers [25] that also facilitated to estimate use variability of Nepalese medicinal plants interviews and discussions with the local people. Con- or to evaluate their bio-efficacy [20,21]. Therefore, this sent was granted by the local people for the dissemina- study was conducted in order to achieve the following tion of their traditional knowledge. objectives: Guidelines for the interviews and group discussions 1. Document the medicinal plants used in the tradi- were developed to facilitate the collection of informa- tional healthcare delivery system of the Chilime Village tion. Interviews and group discussions were conducted Development Committee (VDC) of the Rasuwa district to gather information on plant uses, parts used, and of Central Nepal, modes of utilization. A checklist was developed and 2. Estimate use variability of medicinal plants, indicat- used to determine what species were used to treat what ing informant agreement, kinds of diseases/disorders. Herbarium specimens were 3. Evaluate the bio-efficacy of medicinal plants by collected for those species for which field identification comparing local use with findings from published phyto- was not certain and brought back to the lab to facilitate chemical and pharmacological studies, identification using reference collections [26-29] and 4. Identify priority medicinal plant species for the expert knowledge. The specimens are deposited at the Rasuwa district. Tribhuvan University Central Herbarium (TUCH). The informant consensus factor (FIC) was calculated Study area to estimate use variability of medicinal plants [30,31]. A field study was carried out in the Chilime VDC of the FIC values range from 0.00 to 1.00. High FIC values are Rasuwa district of Central Nepal. The district lies obtained when only one or a few plant species are ’ ’ ’ ’ between 27° 2 and 27° 10 N and 84° 45 and 85° 88 E, reported to be used by a high proportion of informants with altitude ranging from 792 to 7245 m a.s.l. The to treat a particular ailment, whereas low FIC values Rasuwa district presents some of the best examples of indicate that informants disagree over which plant to graded climatic conditions in Central Himalaya. Pro- use [30]. High FIC values can thus be used to pinpoint nounced altitudinal gradients, coupled with complex particularly interesting species for the search of bioactive topography and geology, have resulted in a rich biodi- compounds [31]. FIC is calculated using the following versity and unique vegetation patchwork [22]. Therefore, formula [30,31]: the district harbours a rich diversity of medicinal plants. =− − The Chilime VDC lies in the northern part of the dis- FNNNIC ur t/( ur 1 ) trict, bordering the Tibetan part of China, and com- prises temperate to alpine climates within 2000-4700 m where Nur is the number of individual plant use altitude (Fig. 1). The local