Documentation and quantitative analysis of the local knowledge on medicinal plants among traditional Siddha healers in Virudhunagar district of Tamil Nadu, India

ETHNOPHARMACOLOGICAL RELEVANCE: India has a population with high degree of medical pluralism. Siddha system of Indian traditional medicine is practiced dominantly by the people in Tamil Nadu. The traditionally trained Siddha healers still play an important role in the rural health care. Their knowledge is comparatively more vulnerable than the documented traditional knowledge. Thus, the present study was aimed to document and quantitatively analyze the local knowledge of the traditional Siddha healers in Virudhunagar district of Tamil Nadu, India. MATERIALS AND METHODS: The results presented in this paper are the outcome of series of interviews conducted between January and August, 2010 consisting of 196 field days. After getting prior informed consent, interviews were conducted and successive free-listing was used in the interviews in order to make informants cite the medicinal plants that they have used. By this way 96 healers were interviewed and their data were quantitatively analyzed using various indices such as Informant Consensus Factor (Fᵢc), Fidelity Level (FL), Informant Agreement on Remedies (IAR) and Cultural Importance Index (CII). RESULTS: This study recorded the ethno-medicinal usage of 227 species which were used to prepare 611 formulations for the treatment of 36 illness categories. The knowledge holders had the experience of minimum 20 years. There was unevenness in male–female ratio. Regarding the medicinal plants, easily available plants were holding significantly high number of citations, IAR and CII values. Nine illness categories had a high Fᵢc value, compared to others. Species with high citations in these groups were Moringa oleifera (aphrodisiacs), Acalypha indica (dermatological ailments), Dodonaea viscosa (musculo-skeletal disorders), Solanum trilobatum (pulmonary ailments), Phyllanthus amarus (jaundice), Piper nigrum (adjuvant) Allium cepa (hemorrhoids), Azadirachta indica (antiseptic) and Tribulus terrestris (urinary ailments). CONCLUSION: Quantitative analysis of the data had revealed that the easily available species hold a high consensus and cultural importance. Future biomedical studies using the medicinal plants enumerated in this study, particularly those with high number of citations and high Fᵢc values might yield some novel prototypes. Such studies will also be useful to assess the efficacy and safety of these herbal treatments to take decisions on the health care of rural India.