Field/Research Interest

Traditional/Herbal Medicine Research including Phytochemistry, Bioactivity-guided Fractionation, Toxicology and Standardization of Medicinal Herbs. Bioequivalent & Pharmacokinetic Studies

There has been resurgence in the use of nutraceuticals for the prevention and treatment of diseases, despite the lack of scientific and clinical evidence to support their use.  Many of these, especially those from herbal origin have failed to fulfill the regulatory requirements as to their quality, safety and efficacy.  While it is generally assumed that most nutraceuticals are safe, adverse effects have been reported for a number of these products not only from contamination by microbes, toxic metals or chemicals but also from indiscriminate adulteration with potent drugs.  Some herbs contain intrinsically toxic chemical constituents and their limitation is necessary so as not to present a health hazard.  Of primary concern is the lack of quality control and reliability of the products available in the marketplace today. These medicinal herbs may pose potential adverse health effects for consumers especially with their extended or high dose use. Against this background, it is important that the isolation, purification and characterization or identification of the bioactive or toxic constituents of the herbal raw materials through bioactivity-guided fractionation be conducted to obtain markers or reference standards.  For example, the chemical profile of the chosen extract including the concentration of the major bioactive molecules has to be developed.  Once the standardization protocols have been established, pre-clinical studies can then be conducted on the bioactivity and safety of these herbs. Concurrently, the bioavailability and pharmacokinetics of the biomolecules on the formulated bioactive extract have to be studied prior to clinical evaluation so that the correct and reproducible doses of the bioactive molecules are known in the herbal extract or mixtures.

Consultation

Research and Development on Medicinal Herbs for Pharmaceutical and Herbal Industries

Selected Publications

1. Vikneswaran, M. and Chan K. L. (2007). Determination of four lignans in Phyllanthus niruri by a simple high-performance liquid chromatography method with fluorescence detection. J. Chromatography A, 1154, 198-204. 

2. Vikneswaran, M. and Chan K. L. (2007). Analysis of lignans from Phyllanthus niruri L. in plasma using a simple HPLC method with fluorescence detection and its application in a pharmacokinetic study. J. Chromatography B, 852, 138-144. 

3. Vikneswaran, M. and Chan K. L. (2006).  Antihyperuricemic lignans from the leaves of Phyllanthus niruri L. Planta Medica, 72 (14), 1262-1267.              

4. Chan, K. L., Choo, C. Y. and Noor Rain Abdullah (2005). Semisynthetic 15-O-acyl- and 1,15-di-O-acyleurycomanones from Eurycoma longifolia  as potential antimalarials. Planta Medica 71, 967-969.

5. Low, B. S., Ng, B. H., Choy, W. P. Yuen, K. H. and Chan, K. L. (2005). Bioavailability and Pharmacokinetic Studies of Eurycomanone from Eurycoma longifolia Jack.  Planta Medica 71, 803-807.

6.  Chan, K. L., Choo, C. Y., Noor Rain Abdullah and Zakiah Ismail (2004).  Antiplasmodial Studies of Eurycoma longifolia Jack using the Lactate Dehydrogenase Assay of Plasmodium falciparum.  J. Ethnopharmacol 92, 223-227.

7. Tan, S., Yuen, K. H. and Chan, K. L. (2002):  HPLC Analysis of Plasma 9-Methoxycanthin-6-one from Eurycoma longifolia Jack and its Application in Bioavailability/Pharmacokinetic Study.  Planta Medica 68(4), 355-358.

8.      Chan, K. L. and Choo, C. Y. (2002):  The Toxicity of Some Quassinoids from Eurycoma longifolia Jack. Planta Medica 68(7), 662-664.                 

9.      Chan, K. L., Choo, C. Y., Morita, H. and Itokawa, H. (1998): High Performance Liquid Chromatography in Phytochemical Analysis of Eurycoma longifolia. Planta Medica, 64, 741-745.

10.   Chan, K. L., Yuen, K. H., Takayanagi, H., Jinadasa, S., Peh, K. K. and Lim, L.Y. (1997). Artemisia annua: Polymorphism of Artemisinin.  Phytochemistry, 46(7), 1209-1214.                                                                                                             Home