The main alkaloids of sophora (kushen), namely oxymatrine and matrine, have been used in China as an herbal drug for more than 25 years. The alkaloids are reported to prevent leukopenia during cancer therapy and to inhibit cancer cell growth; both the crude herb and the alkaloids are therefore used in cancer therapy. Sophora subprostrata (shandougen), another source of the alkaloids, is a ....