Leung HY, Cheung KC, Ko KM,
Division of Life Science, The Hong Kong University of Science & Technology, Clear Water Bay, Hong Kong SAR, China.
In the present study, two cell-based systems for assessing Yang and Yin activities were for the first time used to investigate the effect of ursolic acid (UA) and oleanolic acid (OA). The results indicated that while UA was only active in the Yang assay, OA produced activity in the Yin assay. The Yang/Yin activity of UA/OA may be attributed to their distinct molecular structures, which confer their differential ability to interact with mitochondrial membrane or cellular membrane lipids, with resultant membrane fluidization and potentiation of biological responses.