Objective: The aim of this study was to evaluate the effects of Trifolium pratense and Cimicifuga racemosa upon the endometrium of castrated female Wistar rats, comparing these results with a placebo and estradiol valerate.
Methods: Thirty-two adult castrated female Wistar rats were divided into four groups (eight rats per group) that receiving either tap water, estradiol valerate, isoflavones from T. pratense or deoxyactein from C. racemosa daily. The doses used were equivalent to normal doses used in humans. The results were analyzed by endometrial histology and the expression of alpha-estrogen receptor and protein Ki67. Both alpha-receptor and Ki67 expressions were determined by immunohistochemical and morphometric analysis.
Results: Endometrium histology stayed atrophic with both herbal extracts, but T. pratense supplementation increased the expression of alpha-estrogen receptors when compared to the placebo group, without protein Ki67 expression enhancement. Both herbal extracts presented a lower Ki67 expression when compared to the placebo group.
Conclusion: T. pratense presented alpha-estrogen receptor stimulation in the endometrium without increasing cell proliferation. Both herbal extracts reduced endometrial proliferation in comparison to the placebo group.