Estrogenic activity of yam via a yeast model and its effects on two cancer cell lines

In our previous study, media milling was found to significantly increase the content of diosgenin in aqueous yam suspensions via size reduction. This study is a continuation to understand the estrogenic activity of the media-milled yam using diosgenin as a reference material. We have examined the effects of the media-milled yam on estrogen level in a yeast strain expressing hERβ and the proliferation of two cancer cell lines (MCF-7 and Ishikawa). As a common form of estrogen, 17β-estradiol exhibited high estrogenic activity, and enhanced the growth of both cancer cell lines. Diosgenin also exhibited estrogenic activity, but inhibited the growth of both cancer cell lines. The media-milled yam yielded an estrogen equivalent of 1.65 × 10−4 g/g with a moderate inhibition on the growth of both cancer cell lines. The data indicated that diosgenin was the major compound for the estrogenic activity and inhibition on cancer cells exerted by the media-milled yam.