Estrogenic effects of the ethyl-acetate extract of the stem bark of Erythrina lysistemon Hutch (Fabaceae)

The stem bark of Erythrina lysistemon, one of the traditionally used “women remedies”, has been assessed for its estrogenic activity. The ethyl-acetate extract of the stem bark of E. lysistemon showed estrogenic activities in vitro either in a yeast-based estrogen receptor assay or on the estrogen-dependent stimulation of alkaline phosphatase activity in the human endometrial carcinoma cell line Ishikawa. The estrogenic activity was investigated in vivo in young ovariectomized Wistar female rats after a 7-day treatment. The estrogenicity was evaluated through the proliferative status of target sex organs such as uterus and vagina. The results obtained showed that oral administration of 200 mg/kg BW/d of E. lysistemon extract in comparison to untreated ovariectomized rats significantly increased the vaginal epithelial height by 47.23% (from 8.71±0.47 to 12.34±1.31 μm); and induced a weak increase of uterine epithelial height by 6.76% (from 5.42±0.52 to 5.84±0.91 μm). Both were not as pronounced as those elicited in the positive control of 100 μg/kg BW/d of ethinylestradiol given orally. Overall our results suggest that the extract of E. lysistemon contains secondary metabolites endowed with estrogenic activity.