Toxicological study of a Chinese herbal medicine, Wikstroemia indica

Wikstroemia indica, a commonly used herbal medicine in China, is thought to be poisonous. However, based on the experience of herbal doctors, it is claimed that the toxicity can be reduced by decocting for 3-5 hours. In this study, the acute toxicities of W. indica (crude drug), and its aqueous and ethanolic extracts were evaluated in mice. The cytotoxicities of both extracts were also assessed using the MTT and LDH assays. Also, in order to evaluate the influence of decoction time on the toxicity of W. indica extracts, the cytotoxicities of W. indica decoctions prepared by boiling the herb for 1, 3, 5, 8, and 10 hours, respectively, were tested. Neither the herb nor its aqueous and ethanolic extracts showed obvious acute toxicity in mice, with maximal tolerance doses higher than 18.7, 11.7, and 25.0 g/kg p.o., respectively. The cytotoxicities of both extracts were low with CC50 values higher than 250 microg/mL. The five W. indica decoctions also showed low cytotoxicity, with CC50 values higher than 1000 microg (crude drug)/mL. Moreover, the result of statistical analysis indicated that the cytotoxicities of the five W. indica decoctions did not exhibit significant differences. The results obtained suggest that W. indica is a relatively nontoxic herb and longer decoction times for reducing the toxicity of the herb seems unnecessary.