Possible Interaction: Tamoxifen and Genistein

“ Genistein also shows synergistic behavior with well-known anticancer drugs, such as adriamycin, docetaxel, and tamoxifen , suggesting a potential role in combination therapy.”

“ GE treatment also re-sensitized ERα-dependent cellular responses to activator 17β-estradiol (E2) and antagonist TAM.”

“The soybean isoflavone, genistein (GE), has been shown to prevent and inhibit breast cancer and recent studies have suggested that GE can enhance the anticancer capacity of an estrogen antagonist, tamoxifen (TAM), especially in ERα-positive breast cancer cells.”

“We have demonstrated that dietary GEN can negate the inhibitory effect of tamoxifen.”

“In addition, genistein and TAM combination synergistically delayed the growth of breast tumor via decreased estrogen level and activity, and down-regulation of EGFR expression.”

“The combination of TAM with genistein or SPC, especially at the lower dose of TAM, had synergistic effects on delaying the growth of MCF-7 tumors.”

“Interestingly, coadministration of TAM with either daidzein or genistein produced tumors of greater size than with TAM alone.”

“In vitro studies of human and mouse mammary tumor cell lines confirm that low doses of genistein , co-administered with tamoxifen , promote cell proliferation.”

“ Genistein acts synergistically with drugs such as tamoxifen , cisplatin, 1,3-bis 2-chloroethyl-1-nitrosourea (BCNU), dexamethasone, daunorubicin and tiazofurin, and with bioflavonoid food supplements such as quercetin, green-tea catechins and black-tea thearubigins.”

“We hypothesized that weakly estrogenic genistein negate/overwhelm the inhibitory effect of TAM on the growth of E-dependent breast tumors.”

“At high concentrations, genistein inhibited tumor growth and enhanced the effect of tamoxifen in vitro.”

“In micromolar concentrations (0.1-10 μM) genistein decreased the cytotoxic effects of cisplatin and tamoxifen.”

“It is shown that the half maximal inhibitory concentration (IC50) value of genistein (0.2 mM) for the growth inhibition of HeLa cells is at least ten times higher than that one of tamoxifen and cisplatin--drugs, used in cervical cancer treatment.”