Highlight on the studies of anticancer drugs derived from plants in China.

Recent progress on the study of anticancer drugs originating from plants in China is reviewed in this paper. Guided by the experience of traditional Chinese medicine, several new drugs have been found. Indirubin from Indigofera tinctoria is useful for the treatment of chronic myelocytic leukemia. Irisquinone from Iris latea pallasii and 10-hydroxy camptothecin from Camptotheca accuminata have exhibited definite activity on rodent tumors. Recent studies indicate that ginsenoside Rh2 is an inducer of cell differentiation in melanoma B-16 cells in vitro. Pharmacological studies have demonstrated that curcumin from Curcuma longa is an antimutagen as well as an antipromotor for cancer. Daidzein and acetyl boswellic acid have been shown to be effective inducers of cell differentiation in HL-60 cells. Guided by the chemotaxonomic principle of plants, harringtonine and homoharringtonine isolated from Cephalotaxus hainanesis have exhibited significant antileukemia activity and are widely used in clinics in China. Taxol from Taxus chinensis has been shown to be an important new anticancer drug with unique chemical structure and mechanism of action. The continuous search for new anticancer drugs from plants will be a fruitful frontier in cancer treatment and chemoprevention.