Cell growth inhibitory action of an unusual labdane diterpene, 13-epi-sclareol in breast and uterine cancers in vitro.

In the course of our studies on the isolation of bioactive compounds from the roots of Coleus forskohlii, a traditional herb in India, rare 13-epi-sclareol has been isolated, and its structure determined by extensive 2D NMR. This is the first report of isolation from this plant. The isolated compound showed antiproliferative activity in breast and uterine cancers in vitro. The antiproliferative activity of 13-epi-sclareol is comparable to Tamoxifen in terms of IC50 and also showed concentration dependent increased apoptotic changes in the breast cancer cell line, MCF-7.