RESUMO
Background: Polycystic ovarian syndrome (PCOS) is one of the known causes of anovulatory fertility in the world. Previous research has linked oxidative stress could contribute to PCOS, and vanillic acid has shown antioxidant potential. Hence, the present study evaluated the effect of vanillic acid on letrozole-induced polycystic ovarian syndrome in female rats. Materials and methods: PCOS was induced in Wistar female rats with letrozole (1 mg/kg, orally) in carboxymethoxycellulose (1 % w/v), administered for 21 days. After induction, the standard group received clomiphene citrate (1 mg/kg, orally) while other treatment groups were administered with vanillic acid at doses 25, 50, and 100 mg/kg, orally for 15 days, and without treatment was considered a negative control group. Different parameters studied were body weight, ovary weight, blood glucose, lipid profile, hormonal levels [luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone], markers for oxidative stress (superoxide dismutase, reduced glutathione, catalase, and malonaldehyde), and histopathology of the ovary. Statistical analysis was done for the results and p < 0.05 was considered to indicate the significance. Results: Vanillic acid-treated animals showed a concentration-dependent activity on the tested parameters. The highest tested dose (100 mg/kg) produced a more prominent effect in significantly (P < 0.001) decreasing the body weight, and ovary weight and improving the hormonal imbalance. Also, vanillic acid significantly (P < 0.01) reduced elevated blood sugar and lipid levels. Additionally, vanillic acid reduced oxidative stress significantly (P < 0.001) in the ovaries of female rats. Histopathological reports showed a reduction in cystic follicles and appearance of normal healthy follicles at different stages of development after the administration of vanillic acid. Furthermore, these effects were observed to be comparable with those recorded for standard drug, clomiphene. Conclusion: The current study data suggests that vanillic acid has protected the letrozole-induced polycystic ovarian syndrome. In the event of several side effects associated with conventional treatments used for PCOS, the findings of this study suggest the promising role of vanillic acid. More research in this direction might identify the true potency of vanillic acid in the treatment of PCOS.