Abstract

Natural products have traditionally provided a rich source of drugs for many diseases, including cancer, and plants are an important source of novel natural products. Only a fraction of the diversity of the biosphere has been tested for biological activity and novel cancer therapeutics remains to be discovered. The present study was undertaken to evaluate the cytotoxic activity of the crude ethanolic extracts of 300 species of herbal plants traditionally used in China for the treatment of a variety of diseases. MMT assay was used to examine in vitro cytotoxic activity of these extracts on human gastric adenocarcinoma SGC-7901 cells and splenocytes (normal cells). Extracts which exhibited cytotoxicity at 100 µM were considered active. 33 of these raw ethanolic extracts demonstrated growth inhibitory activity on SGC-7901 cells. Interestingly, of the 33 active extracts on cancer cells, nine showed less toxicity against the normal spleen cells. Furthermore, four hundred natural compounds were screened against SGC-7901 cells. Of the 400 natural compounds, 18 significantly inhibited proliferation of SGC-7901 cells. These results indicate the potential use of traditional Chinese medicinal herbs as antineoplastic agents and suggest that further studies evaluating their mechanism(s) of action and the isolation of active anti-tumor compounds are warranted.

Key words: Traditional Chinese medicines (TCM), SGC-7901 cells, natural compounds, cytotoxic activity.