Abstract

Nigella sativa (Black seed) is an amazing herb with a rich historical and religious background. N. sativa increases milk production and promotes menstruation in female. The purpose of this study was to assess which extract of N. sativa could improve vaginal epithelial cell in experimentally induced menopause rats. Forty ovariectomized Sprague Dawley rats were used in the study and randomly allotted into one of five experimental groups: treated with supercritical fluid extraction (SFE), methanol extract and hexane extract of N. sativa (300 mg/kg/day) compared to control (Olive oil 1 ml) and estrogen group (0.2 mg/kg conjugated equine estrogen). All groups were treated for 21 consecutive days. Vaginal smears were taken daily to observe the estrogenic effect on vaginal epithelium of rats and serum estradiol was measured on 0, 11 and 21 days The occurrence of vaginal cornification after treatment indicated estrogenic like activity of N. sativa, but this effect was not as much as conjugated equine estrogen (CEE). On the other hand, the most influence of N. sativa in vaginal cornification was observed in methanol extract of N. sativa that was in agreement with serum estradiol of this group. The percent of cornified cells was significantly different compare to control group (p<0.05). These findings suggest that N. sativa posses estrogenic function in the ovariectomized rat model which can be helpful in managing menopausal symptoms as an alternative for hormone replacement therapy.

Key words: Nigella sativa, vaginal cytology assay, ovariectomized rats, estrogenic activity, supercritical fluid extraction, solvent extraction.