ABSTRACT
Phytoestrogens are natural estrogenic agents present in plants. Phytoestrogens are any plant compounds structurally and/or functionally similar to ovarian and placental estrogens and their active metabolites. Sesamumindicum is one of the phytoestrogen containing seeds used by man for food and medicinal purposes. Researches have shown that phytoestrogens present in plants might have both fertility-enhancing and anti-fertility effects. Present studies evaluated the mean lethal dose of the hydroethanolic seed extract of sesame and the effects of the extract on some reproductive parameters of female albino rats. Cycling female rats weighing 120-140g were used for the studies. For the ovulation study, twenty (20) female rats were divided into four (4) groups of five (5) rats groups II, III and IV received 100, 300 and 500 mg/kg of seeds extract of S. indicumorally respectively. The animals were dosed at 4 hourly interval for 24 hours. Animals were sacrificed the following morning. For the hormonal level study, the extract was administered orally to three (3) experimental groups of five (5) female rats at doses of 100, 300 and 500 mg/kg once daily while control group received distilled water at dose of 1ml/kg for 30 days. The animals were subsequently sacrificed in the morning of the day after the last administration. For studies on pregnancy outcome, the extract was administered orally four (4) groups of five (5) pregnant rats each. Administration was done once daily from day 1-7 of pregnancy as follows: group I: distilled water (1 ml/kg), group II: 100 mg/kg, group III: 300 mg/kg and group IV 500 mg/kg respectively, with seeds extract of S. indicum. The number of ovarian follicles was significantly higher (p < 0.05) in group IV than control rats (31.40 + 3.20 vs 22.80 + 4.22), while groups II and III had lower number of follicles than control rats (14.80 + 2.40, 19.80 + 3.40 vs 22.80 + 4.22). 7 The values of gonadosomatic index were similar in group III and control rats (0.83 + 0.12% vs 0.83 + 0.11%). However, the gonadosomatic indices in groups II and IV were significantly lower (p < 0.05) than control rats (0.66 + 0.03, 0.75 + 0.14 vs 0.83 + 0.12, respectively). The mean (+ SEM) serum estrogen concentration was significantly lower (p<0.05) in group III than in groups II, IV and control rats (349.60 + 10.20 pg/ml vs 422.40 + 28.19 pg/ml, 414.17 + 17.49pg/ml, 431. 80 + 9.47 pg/ml respectively). The mean serum progesterone followed a similar pattern, with relatively lower values in group III than groups II, IV and control rats (14.70 + 1.39 ng/ml vs 15.10 + 0.74 ng/ml, 19.12 + 1.91 ng/ml and 17.22 + 4.22, respectively). The number of fetuses delivered by pregnant rats was not significantly different (p < 0.05) between treated and control rats (group I: 6.0 + 0.71, group II: 7.00 + 0.90, group III: 6.20 + 1.07 and group IV: 7.40 + 1.78, respectively; p<0.05). It is therefore concluded that hydroethanolic seeds extract of S. indicum possess both anti- and pro-estrogenic properties in a dose-dependent fashion in adult female albino rats.