Medicinal plants in homegardens of four ethnic groups in Thailand.

ETHNOPHARMACOLOGICAL RELEVANCE: Homegardens are important habitats for medicinal plants and traditional knowledge, especially among indigenous groups in remote areas. In homegardens, medicinal plants and traditional knowledge are well conserved through human management and ease of access. AIM OF THE STUDY: To understand the drivers of diversity and the composition of homegardens with focus on medicinal plants, including exotic species, and their uses. We compare the homegardens of four ethnic groups in northern Thailand (Thai Yuan, Lahu, Karen, and Lisu). METHODS: We inventoried all medicinal species in 195 homegardens from four villages belonging to the four ethnic groups. The owners were asked to point out all useful species in their homegardens. For any medicinal species, they were then interviewed about their main and secondary uses, medicinal properties, plant part used, preparation methods, and route of administrations. RESULTS: We recorded 95 medicinal homegarden plant species ranging from 20-59 species per village and ethnic group. Most of the medicinal plants had a primary use as food plants, which demonstrated the close relationship between local food and medicine in the lives of these ethnic groups. Many of the medicinal plants were also used as food additives, ornamentals, or materials, showing that medicinal plants are not an exclusive category in the homegardens. The number of homegarden plants varied almost four-fold from 58 species in one village to 211 in the most species rich village. The number of medicinal homegarden plants varied accordingly from 20 to 59 in the poorest and the richest villages. Five medicinal species were found in all villages, but 70% of the medicinal plants were found in only one village. Infection & infestation, Nutritional disorders, and Digestive system disorders were the three most important medicinal use categories for plants in the homegardens, and all three categories were found in most of the studied homegardens. Of the 95 species with medicinal uses, 26 (27%) were exotic, which shows that local people amplify the spectrum of alternative ways to treat their illnesses. CONCLUSION: Homegardens are an important source of ethnomedicinal species and knowledge. These species are beneficial for treating acute and common ailments; they are easy to access and can be prepared by simple methods, which are suitable for treating disorders, such as infections or any digestive system ailments. Medicinal plants in homegardens have been important in improving health, at least, at the family level.

Ethnomedicinal plant diversity in Thailand.

ETHNOPHARMACOLOGICAL RELEVANCE: Plants have provided medicine to humans for thousands of years, and in most parts of the world people still use traditional plant-derived medicine. Knowledge related to traditional use provides an important alternative to unavailable or expensive western medicine in many rural communities. At the same time, ethnomedicinal discoveries are valuable for the development of modern medicine. Unfortunately, globalization and urbanization causes the disappearance of much traditional medicinal plant knowledge. AIM OF THE STUDY: To review available ethnobotanical knowledge about medicinal plants in Thailand and to estimate its diversity. METHODS: Information about ethnomedicinal uses of plants in Thailand was extracted from 64 scientific reports, books, and theses produced between 1990 and 2014. Plant identifications in the primary sources were updated to currently accepted names following The Plant List website and the species were assigned to family following the Angiosperm Phylogeny Website. Use Values (UV) were calculated to estimate the importance of medicinal plant species (UVs) and families (UVf). Medicinal use categories, plant parts used, preparations of the medicine, and their applications were noted for each use report. RESULTS: We found 16,789 use reports for 2187 plant species in 206 families. These data came from 19 ethnic groups living in 121 villages throughout Thailand. The health conditions most commonly treated with medicinal plants were in the categories digestive system disorders, infections/infestations, nutritional disorders, muscular-skeletal system disorders, and genitourinary system disorders. Plant families with very high use values were Fabaceae, Asteraceae, Acanthaceae, Lamiaceae, and Zingiberaceae and species with very high use values were Chromolaena odorata (L.) R.M.King & H.Rob., Blumea balsamifera (L.) DC., and Cheilocostus speciosus (J.Koenig) C.D.Specht. Stems and leaves were the most used plant parts, but also other parts of the plants were used in medicinal recipes. The most common way of using the medicinal plants was as a decoction in water. CONCLUSION: We found 2187 plant species that were used in traditional medicine in Thailand. Of these a few hundred had high use values, suggesting that they may produce bioactive compounds with strong physiological effects.

Ethnobotanical study of medicinal plants used by Tai Yai in Northern Thailand.

ETHNOPHARMACOLOGICAL RELEVANCE: We studied traditional knowledge of medicinal plants used by Tai Yai people in Northern Thailand. We documented traditional medical practices and determined importance among the Tai Yai. This paper reports on knowledge in usage of medicinal plants of the Tai Yai people in Northern Thailand. MATERIALS AND METHODS: Interviews were conducted in 4 Tai Yai villages in Mae Hong Son and Chiang Mai provinces whose inhabitants immigrated from Myanmar at different times. Discussions and interviews were held with 126 key-informants (56 males and 70 females) ranging in age from 16 to 80 years in three age groups (age 16-40, 41-60, and 61-80). We calculated the informant consensus factor (ICF) for use category, use value index (UV) for use report of plant. We tested differences between the knowledge of different age groups and locations using principal component analysis (PCA). RESULTS: These Tai Yai people used of 141 medicinal plants belonging to 59 families. Of the medicinal plant species, the highest percentage was in the family Euphorbiaceae: Croton acutifolius and Croton roxburghii. The highest number of Informant consensus factor was for metabolic system disorders. Overall, Tai Yai people use medicinal plants to cure many sicknesses such as hypertension, lumbago, wounds, puerperium, kidney disorders, kidney stones, coughs, fevers, hemorrhoids, flatulence and malaria. There were no significant differences in knowledge of plants usage among villages of different ages. In addition, the knowledge of the plants was not significantly different between men and women. However, we found that the younger had less experience with and knowledge of medicinal plants than older people. CONCLUSIONS: The result indicates loss of accumulated knowledge of medicinal plants and traditional use. Although, the medicinal plant knowledge was passed from one generation to the next by word of mouth, the detailed documentation of medicinal plants and their use may effectively prevent the knowledge-loss through time.

Karen and Lawa medicinal plant use: uniformity or ethnic divergence?

ETHNOPHARMACOLOGICAL RELEVANCE: We here tease apart the ethnopharmacological knowledge of plants in two Thai villages to determine to which degree the uses are particular to individual ethnic groups and to which degree they are part of a generalized and uniform set of widespread medicinal plants used over a large geographic range. We compared Karen and Lawa knowledge of medicinal plants in the Mae Cheam watershed of northern Thailand, where both ethnic groups have settled and share ecological conditions for resource extraction. We were interested in documenting the degree to which these two ethnic groups use the same or different medicinal plant species. The use of the same plant species by the two groups was considered a sign of uniform and cross-cultural local knowledge, whereas the use of different medicinal plants by each group was considered a sign of culturally specific local knowledge that developed within each ethnic group. MATERIALS AND METHODS: We inventoried the plant species in different habitats around one Karen village and one Lawa village using stratified vegetation plots and using semi-structured questionnaires we interviewed 67 key informants regarding their use of plants for medicine. We then calculated the Fidelity level FL (FL values near 100% for a species indicate that almost all use reports refer to the same way of using the species, whereas low FL values indicate that a species is used for many different purposes) and cultural importance index CI (the sum of the proportion of informants that mention each of the use categories for a given species) to estimate the variation in medicinal plant use. We used Jaccard's Index JI (This index relates the number of shared species to the total number of species) to analyze the similarity of medicinal plant use between the two villages. RESULTS: A total of 103 species of medicinal plant species in 87 genera and 41 families were identified and they were used to cure 35 ailments. The FL of the medicinal plant species varied from 10% to 100%, was different for each ailment, and differed between the two ethnic groups. The most important medicinal plant species, those with the highest CI value, were not the same in the two villages. Costus speciosus, which is used to treat urinary infections and wounds in animals, had the highest CI value in the Karen village, whereas Sambucus javanica, which is used to treat wounds, fractures, bloat, and edema in humans, had the highest CI value in the Lawa village. Only 17 medicinal species (16.5%) were shared between the two villages. Methods of preparation and application were significantly different between the two villages, whereas the plant parts used, habit, and route of administration were similar. CONCLUSION: Our study demonstrates that ethnic groups that live in the same geographic area can have significantly different traditional knowledge systems for medicinal plants, at least when it comes to the species used and their preparation and medicinal application. We assume that differences in cultural history and background in the two villages led to differences in medicinal plant use, preparation, and application.