2.1. Metabolism
An in vitro study assessing the estrogenicity of compounds in Pueraria Mirifica noted that concentrations of the herb between 0.025ng/mL and 2.5mcg/mL failed to induce an estrogenic response yet in an MCF-7 (breast cancer cell) assay a dose-dependent increase was seen with 250-2500ng/mL being as effective as 25nM estradiol while in HepG2 cells it outperformed estradiol.[22] These results suggest that the estrogenic activity seen with Pueraria Mirifica is not due to a compound found in the herb per se, but due to a cellular metabolite when one of the compounds is subject to metabolism (to form a more potent metabolite than the parent molecule).[22]
Plant extracts that are known to have such a relationship can be bioactivated in vitro with S9,[23] which has been used in some studies with Pueraria Mirifica.[24]