Traditional herbal medicine for the control of tropical diseases.

Throughout history, traditional herbal medicine has afforded a rich repository of remedies with diverse chemical structures and bioactivities against several health disorders. A common issue of herbal medicine is the limitation of information on their pharmacological activities and their active constituents. Traditionally, the use of herbal medicine has been based on empirical treatment and passed on from generation to generation with information available only in local journals. This prevents several herbal medicines from being developed to their full potential. The presentation will focus on research and development of Atractylodes lancea (Thunb) DC. (AL: family Compositae) as a potential chemotherapeutic for cholangiocarcinoma (CCA), the bile duct cancer commonly found in Southeast Asia. The dried rhizome of AL is a medicinal plant used in Chinese ("Cang Zhu"), Japan ("So-jutsu") and Thai ("Khod-Kha-Mao") traditional medicine for its various pharmacological properties including anticancer, anti-inflammation and antimicrobial activities, activities on central nervous, cardiovascular, and gastrointestinal systems. The major constituents in the essential oils from AL rhizome are β-eudesmol, hinesol and atractylon. Preliminary investigation has demonstrated its promising anti-CCA activity both in vitro and animal (Opisthorchis viverrini/dimethylnitrosamine-induced CCA in hamsters and CCA-xenografted nude mice) models with high selectivity index comparing with the standard drug, 5-fluorouracil. It also showed virtually no toxicity with only minimal CNS effects on locomotor activity at the maximum dose of 5,000 mg/kg body weight. Studies are underway to identify active constituent(s) which contribute to anti-CCA activity as well as its pharmacokinetic and pharmacodynamic properties. The main research interest of my research group is the discovery and development of traditional herbal medicine for the treatment of two important tropical diseases, cholangiocarcinoma and malaria. As the time is quite limited, I am going to give you the summary of the conceptual framework and highlight some important findings which will illustrate how different approaches have been used or applied for the discovery of the promising candidates for these two diseases.