ABSTRACT
Breast cancer is a major public health problem and the low effectiveness of conventional therapies to achieve long term survival results in increased mortality associated with advanced breast cancers. Betulinic acid (BA) is a pentacyclic triterpene which can be isolated from number of plants grown in the tropics. It exhibits cytotoxic activity against variety of cancer cell lines. In the present study, the in vitro cytotoxic activity and in vivo antitumor activity of BA was evaluated in athymic nude mice bearing MCF-7 breast adenocarcinoma xenografts. In vitro cytotoxic activity of BA on MCF-7 cells was studied using the MTT assay and BA was cytotoxic towards MCF-7 cells with IC50 value of 13.5µg/mL. The antitumor activity of BA was studied at concentrations of 50 and 100 mg/kg body weight in mice injected with MCF-7 cells. BA treatment delayed tumor formation and statistically significant reduction (P<0.0001) of 52 and 77% in the tumor size at concentrations of 50 and 100 mg, respectively was observed. Histopathological analysis of tumors revealed decreased angiogenesis, proliferation and invasion in BA treated animals. This is one of the first studies demonstrating the in vivo antitumor activity of BA on MCF-7 breast cancer tumors in nude mice. The antitumor effect of BA can further be enhanced by use of combination therapy and novel drug delivery systems, thus making it a promising candidate for management of breast cancer patients.