Henrik Balslev

Background: Diabetes is a metabolic disorder and a serious global health problem. Over 400 million people suffer from diabetes and it is estimated that the number will dramatically increase in the future. The cost of diabetes treatment for individual patients is very high. However, traditional knowledge could be used to support conventional diabetes treatments. Here, we identify medicinal plants that have been used as treatments for diabetes based on Thai ethnobotanical knowledge. Methods: We present a literature review of data for the use of ethnomedicinal plants for diabetes treatments used by people in Thailand. The data were obtained from 31 original references including theses, reports, journal articles, and books published from 1992–2015. Results: In total, 187 reports of 123 plants species that had been used traditionally to treat diabetes in Thailand were identified. Tinospora crispa (L.) Hook. f. & Thomson, Morinda citrifolia L. and Phyllanthus amarus Schumach. & Thonn were the three most commonly used species. There were also numerous reports of the use of Leguminosae, Lamiaceae, Phyllanthaceae, Rubiaceae, and Acanthaceae for the treatment of diabetes. Interestingly, the grass family (Poaceae), for which there were otherwise few medicinal use reports, ranked third in our data. Stems, roots, and leaves were most commonly used in diabetesmedicinal recipes. For preparation and administration of the diabetes medicines, decoction and oral ingestion were most common. Conclusions: Thailand has a vast number of plant species that have been used by ethnic minority groups and rural Thai communities in traditional medicines to treat diabetes. These plants constitute a potentially important natural resource to provide inexpensive treatment of a disease commonly affecting the population of Thailand. The plants used for diabetes treatment should be tested for pharmacological efficacy to help select the most useful for traditional medicines.