Abstract Onion (Allium cepa) contains many vitamins, minerals and antioxidants which are used in the prevention and treatment of some diseases. The aim of this study was to investigate the effects of red onion on the pituitary-gonadal axis of Balb /C female mice. Mice were divided into five groups after regulating the sexual cycle (control, placebo and the extract in of 50, 100, 200 mg/kg amounts). The extract was injected intraperitoneally every other day for 20 days. The control group received no medication and the placebo group received only physiological serum. At the end of the injections, blood samples were taken from all groups. Hormonal assays including FSH, LH, estradiol and progesterone were performed using ELA method. Obtained data were analyzed using SPSS program, one-way variance analysis and Duncan test at 5% probability level. Results showed significant increases in estradiol level of third experimental group and progesterone level of second experimental group. However, FSH and LH levels remained unchanged in all groups. However, FSH and LH levels remained unchanged in all groups. These results may indicate the phytoestrogenic properties of red onion at dose of 200 mg/kg and its phytoprogesterone properties at dose of 100 mg / kg. According to the results, onion can be a good alternative to estrogen deficiency in postmenopausal women with diabetes or hypertension. Also, onion extract at a dose of 100 mg / kg can be effective in the treatment of hyperinsulinemia and diabetes.
Keywords Red onion, FSH, LH, Progesterone, Estradiol, Mice.