Evaluation of the mutagenic, cytotoxic, and antitumor potential of triptolide, a highly oxygenated diterpene isolated from Tripterygium wilfordii

Triptolide, a highly oxygenated diterpene isolated from Tripterygium wilfordii Hook f. (Celastraceae), has been shown to demonstrate potent antileukemic activity in rodent models at remarkably low treatment doses. A variety of other physiological responses are known to be mediated by this compound, including immunosuppressive and antifertility effects. We currently report that triptolide was not mutagenic toward Salmonella typhimurium strain TM677, either in the presence or absence of a metabolic activating system. Relatively potent but non-specific cytotoxicity was observed with a panel of cultured mammalian cell lines, and modest antitumor activity was observed when an i.p. dose of 25 μg was administered three times weekly to athymic mice carrying human breast tumors. Treatment regimens involving higher doses of triptolide (e.g. 50 μg/mouse three times weekly) were lethal.