Estrogenic effects of pomegranate extracts in ovariectomized rats
Pomegranates (Punica granatum L.) have been wildly used for health benefits. They have been found effective in reducing heart disease risk factors  and may be effective against prostate cancer  and osteoarthritis . Recently, their uterotonic effects have been demonstrated . However, their estrogenic effects are not well understood. The aims of the study were to investigate the estrogenic effects of pomegranate seed and peel extracts on ovariectomized rats. We particularly examined the effects of the extracts on vaginal cornification. Pomegranate seeds and peel were collected from local gardens and extracted using methanol. Rats were ovariectomized and treated with distilled water (DW), estradiol valerate (1mg/kg BW), pomegranate seed extract (400, 500mg/kg BW), and pomegranate peel extract (400, 500mg/kg BW) for 14 days. The vaginal cytology was checked daily. The treatments of DW did not influence the vaginal epithelium, but the injection of estradiol valerate induced a vaginal cornification from day 5 to day 14 of treatment period. Interestingly, vaginal cornification was inducible when the rats were fed with either pomegranate seed or peel extract. The occurrence of vaginal cornification during treatment was dependent on types and dosages of the extracts. Thus, the cornification was fist found on day 9 and day 7 with 400 and 500mg/kg BW pomegranate seed extract, respectively. With 400 and 500mg/kg BW pomegranate peel extract, the cornification was fist found on day 10. The effects of both seed and peel extracts lasted until day 14. These data suggest that pomegranates have estrogenic effects in ovariectomized rats and that they could be useful for health benefits in menopause.
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