Aqueous extract of herba Scutellaria barbatae, a chinese herb used for ovarian cancer, induces apoptosis of ovarian cancer cell lines

Objective. Given the increasingly common use of complementary medicine in cancer patients, we tested the in vitro cytotoxicity of aqueous extracts of 15 traditional Chinese herbs with purported anticancer properties on ovarian and breast cancer cell lines. Methods. Cell viability after treatment with herbal extract was measured by metabolism of a tetrazolium substrate. Apoptosis was measured by nuclear and DNA fragmentation and Annexin V binding. Results. One herb, Herba Scutellaria barbatae, was cytotoxic to 100% (11 of 11) of actively proliferating ovarian lines tested and 50% (2 of 4) of actively proliferating breast cell lines tested. Confluent cultures were resistant to killing by herb, whereas subconfluent cultures were sensitive. Resistant proliferating cell lines expressed higher levels of bc12. Transfection of the most sensitive ovarian cancer cell line (A2780) with bc12 resulted in a noticeable protection against apoptosis, but there was no protection in other transfected lines. Conclusion. These results will be useful in guiding future studies of herbal aqueous extracts, as well as providing information for clinicians when patients are concurrently using these herbs along with conventional cancer therapies. (C) 2003 Elsevier Inc. All rights reserved.