Estrogenicity of outer scales of onion on uteri of immature mice.

We aimed to investigate the estrogen-like activities of the outer scales of onion and garlic on the uteri of immature mice. This work compared the estrogenic effects induced by estradiol with the effects of plant extract (onion, garlic) in models of immature mice (n = 72). The animals were divided into 6 groups, with 12 animals in each group, as follows: Group I (control group), Group II (estradiol-treated group), Group III (onion extract treated group), Group IV (onion extract treated group after blockage of estrogen receptors), Group V (garlic extract treated group), and Group VI (garlic extract treated group after blockage of estrogen receptors). Uterine wet weight/body mass ratios were determined. Uterotrophic bio-assay, immunohistochemical assay for estrogen receptor and proliferative marker Ki67, uterine contractility, and serum estrogen levels were investigated. Onion extract induced proliferative changes in the uterus, it also increased the uterine mass and epithelial cell height. Also, the frequency and amplitude of myometrial contractility were significantly increased in the group treated with onion extract. This estrogenic activity could be attributed to the quercetin and daidzein content, and activation of estrogenic receptors, as these effects disappeared after blockage of E2 receptors. Our results support the possible estrogenic properties of the onion extract, which could be attributed to quercetin and daidzein, but not that of garlic extract.