Abstract

Aim: Nigella sativa oil has been shown to improve metabolic syndrome-associated dyslipidemia and oxidative stress. Effects of N. sativa oil on letrozole-induced polycystic ovary syndrome (PCOS)-associated hormonal, metabolic, redox, and lipid dysregulation in rats were investigated.
Methods: Female Sprague-Dawley rats were randomly assigned into four groups (n=10 per group): control, PCOS, and PCOS treated with N. sativa oil (5 mL/kg/day or 10 mL/kg/day) once daily p.o. starting at day 7 after the commencement of letrozole (1mg/kg) until day 56. Body weight and estrous cycle were recorded starting from days 7 and 28 respectively until day 56. Rats were dissected and serum and ovaries were collected for biochemical and histomorphological assessments.
Results: N. sativa oil (10 mL/kg/day) treatment significantly increased: number of rats undergoing regular cycle (80% vs 20%; p< 0.05), average number of regular cycles (5.00±0.59 vs 0.20±0.42; p< 0.05), appearance of corpus luteum; but reduced number of cystic follicles (7.60±1.51 vs 6.10±0.19; p< 0.05) in PCOS rats. Body weight was also reduced by the oil in PCOS rats. However, ovarian weight, granulose and theca cells layers showed no significant change. The oil also restored altered circulating levels of gonadotropins, steroids and reduced fasting blood glucose. The ovarian total cholesterol, triglycerides, low density lipoprotein-cholesterol, malondialdehyde were markedly reduced while insulin sensitivity and ovarian high density lipoprotein-cholesterol, superoxide dismutase and glutathione peroxidase activities were greatly increased.
Conclusion: N. sativa oil improved polycystic ovarian-morphology and metabolic disorders via its anti-androgenic and insulin-sensitizing actions to ameliorate PCOS-associated dyslipidemia and redox disturbances.

Key words: Dyslipidemia; Letrozole; Nigella sativa oil; PCOS; Redox. Redox.