Antitumor activity of pisosterol in mice bearing with S180 tumor.

It has been reported that pisosterol was active against cancer cells but lacked activity on the development of sea urchin eggs. Recently, it was reported that pisosterol induces differentiation in leukemia cell line. The present study evaluated the in vivo antitumor activity of pisosterol a triterpene isolated from Pisolithus tinctorius. Histopathological and morphological analyses of the tumor and the organs, including liver, spleen and kidney, were performed in order to evaluate toxicological aspects associated with pisosterol treatments. Antitumor activity of pisosterol (50 or 100 mg/m2) was confirmed in mice bearing Sarcoma 180 tumor cells. The tumor growth inhibition ratios were 43.0% and 38.7% for mice treated with pisosterol at 50 and 100 mg/m2, respectively. Histopathological analysis of liver, kidney and spleen was also evaluated. Liver and kidney were the major affected organs by pisosterol, although the observed alterations can be considered reversible.