Regulation of Reproductive Disorders Associated with Letrozole-Induced Polycystic Ovarian Syndrome in Rats by Ethanolic Extract of Parquetina nigrescens (Afzel.) Leaves

Abstract

Polycystic ovarian syndrome (PCOS) is one of the common causes of female infertility. Parquetina nigrescens is a plant used in the treatment of various ailments including menstrual disorders. This work investigated the regulation of ethanolic extracts of Parquetina nigrescens leaves on oestrous cyclicity and lipid profile in letrozole-induced PCOS rats. After the induction of letrozole (1mg/kg/day), normal (n=4), and PCOS (n=15; distributed into 4 groups of 4 animals/group) rats were treated orally for 14 days with distilled water (1m/kg/day), clomiphene citrate (2mg/kg/day), metformin (500mg/kg/day), and ethanolic extract of P.nigrescens (50 and 100mg). Oestrous cyclicity, body weight and fasting blood glucose levels were measured. They were letrozole-induced PCOS characterised by irregular oestrous cyclicity, elevated (p>0.05) triglycerides, low density lipoprotein cholesterol (LDL), total cholesterol, insulin, testosterone, and luteinising hormone concentration (LH). Low (p>0.05) progesterone, follicle stimulating hormone (FSH), high density lipoprotein cholesterol (HDL) and fasting blood glucose concentration compared to that of the control group. PCOS rats had altered oestrous cycle compared to that of the control. These reproductive, biochemical and structural alterations were alleviated by the administration of ethanolic extract of P. nigrescens leaves (50mg/kg) restored the oestrous cycle after 14 days of treatment. However, the ethanolic extracts of P.nigrescens (100mg/kg) significantly increased (p>0.05) FSH, HDL and progesterone concentrations, but decreased the LH, progesterone, and total cholesterol. Ethanolic extracts of P.nigrescens leaves alleviated regulated the reproductive, hormonal and structural alterations of PCOS rats. The ethanolic extract of this P.nigrescens leaves can therefore be used in the management/treatment of the reproductive and metabolic disorders related to PCOS.