Cytotoxicity of plants from Malaysia and Thailand used traditionally to treat cancer

The SRB cytotoxicity assay was used to screen extracts and isolated constituents of some traditional medicinal plants from Malaysia and Thailand against two human cancer cell lines, COR L23 lung cancer cell line and MCF7 breast cancer cell line and the non-cancer MCF5 cell line. Five out of the seven species tested, i.e. Thai Alpinia galanga, Alpinia officinarum, Cayratia japonica, Physalis minima, Tabernaemontana divaricata, exhibited interesting cytotoxicity activity and this is the first report of cytotoxicity from any Cayratia species. Following bioassay-guided fractionation, 1′-acetoxychavicol acetate (48 h exposure against COR L23 cells, IC50 7.8 μM against MCF7 cells, IC50 23.9 μM) was isolated as the major cytotoxic component of the Alpinia species, physalin F as the major cytotoxic component of Physalis minima (48 h exposure against COR L23 cells IC50 0.4 μM against MCF7 cells, IC50 0.59 μM). The Malaysian Alpinia galanga showed weak activity compared with the Thai sample and this was shown to be due to the relatively high amounts of 1′-acetoxychavicol acetate present in the Thai sample.