Administration of metformin ameliorates endocrine abnormalities associated with mouse model of PCOS by increasing Cyp19a1 expression

A number of reproductive aged women often suffer from polycystic ovarian syndrome (PCOS). This study attempted to determine how metformin affects the genes involved in folliculogenesis and steroidogenesis in mice with PCOS. Eighteen adult Parkes strain mice (4–5 weeks) with body weight of 16–21 g were divided into three groups at random with six animals each as follows: group I (control) received water and normal diet for 51 days, group II received by oral gavage 6 mg/kg of letrozole (LETZ) which was dissolved in 0.9% NaCl solution for 21 days for the induction of PCOS, group III received by oral gavage 6 mg/kg of LETZ for 3 weeks, followed by the administration of metformin (METF) (150 mg/kg daily by oral gavage) for 30 days. The study revealed that mice with PCOS had irregular oestrous cycle and increase in LH/FSH and oestrogen level with decrease in expression of Kitl, Bmp, Cyp11a1, Has2, Cyp19a1, Ar, lhr, Fshr and Esr2 in ovarian tissue. Additionally, expression of Cyp17a1 and testosterone level increased. All these changes were reversed after the administration of metformin in PCOS mice. Metformin treatment, therefore, reversed the functional, molecular, morphological and reproductive abnormalities caused by letrozole-induced PCOS.