Yews (Taxus) along the Hindu Kush-Himalayan region: Exploring the ethnopharmacological relevance among communities of Mongol and Caucasian origins

ETHNOPHARMACOLOGICAL RELEVANCE: Three species of yews Taxus contorta Griff., Taxus mairei (Lemée & Lév.) S.Y. Hu ex T.S. Liu and Taxus wallichiana Zucc. distributed in the Hindu Kush-Himalayan (HKH) region have been commercially exploited in recent decades to extract an anticancer chemotherapeutic drug 'Taxol'. Additionally, indigenous people of this region are using yews for several other purposes including gastro-intestinal disorders, respiratory problems, skeletal system disorders, and as edible fruit, fodder, fish poison, traditional veterinary medicine, among others. AIM OF THE STUDY: The study was designed to document and evaluate knowledge concerning uses of yews among indigenous communities of Mongol and Caucasian origins. MATERIALS AND METHODS: Ethnobotanical knowledge from 10 major ethnic/caste groups of Mongol and Caucasian origins in the Nepal Himalayas was documented in 2010 and 2011 from 27 sites covering the extant distribution range of the three species of Taxus. A total of 72 key informants (60 men, 12 women), recommended by the majority of people in informal group discussions at each study site, were interviewed to collect information on the importance of yews. RESULTS: This study reports multidimensional uses of yews commonly practiced by different indigenous communities of Nepal and compared those with published uses along the HKH region. The key informants cited a total 45 uses under 21 categories. A greater use diversity and high consensus value for use types were recorded for medicinal uses (gastro-intestinal ailments, cough and cold, skeleto-muscular system problem and others medicinal importance) followed by fruit consumption, household tools, agriculture implements and timber. A decline of yew populations and associated traditional knowledge among the younger generations of indigenous people was found. CONCLUSION: The present study shows a strong agreement of ethnobotanical knowledge on yews between communities of Mongols and Caucasian origins. Our findings further revealed the potential for additional therapeutic applications in yews of the HKH region, besides cancer treatment. To compensate the low yield of 'Taxol', and the fact that three yew species are involved, the reported species-specific curative properties need to be validated scientifically and evaluated clinically. Moreover, initiatives should be taken immediately to stop further degradation of yew populations and the associated indigenous knowledge in the HKH region.