Comparative analysis of oral and local intraovarian administration of metformin and nanoparticles (NPs11) in alleviating testosterone-induced polycystic ovary syndrome in rats

Polycystic ovary syndrome (PCOS) is an endocrine and metabolic dysfunction. This study aims to compare the oral and local treatments of metformin or its nanoparticles (NPs11) for ameliorating PCOS in rats. Rats were divided into 4 groups: the control group with no drug treatment; the PCOS group, where subcutaneous testosterone was given (10 mg/kg/day) for 28 days; the MET group, where metformin was administered orally or locally; and the NP group, where metformin NPs11 were also administered orally or locally. Oral administrations were for 21 days, while local injection was performed once surgically. After 7 weeks, all rats were sacrificed; blood glucose and serum hormonal levels and lipid profile were estimated, and the ovaries were assessed by histopathological, Ki-67 immunohistochemical, and histomorphometric evaluations. Blood glucose levels were significantly decreased in groups of orally administered metformin or NPs11 only, while the most efficient option for modulating PCOS-induced hormonal and lipid profile changes was intraovarian injection of NPs11. The ovaries of PCOS rats demonstrated large follicular cysts, massive collagen depositions, and attenuated Ki-67 immunoexpression. Also, the PCOS group revealed a significant decrease in the count of all stages of growing follicles, corpora lutea, granulosa cell layer thickness, and surface area of corpora lutea, in addition to an increase in the number of atretic follicles and follicular cysts, theca cell layer thickness, and surface area of the follicular cysts. All these parameters were recovered with metformin or their NPs11 treatments in different degrees, while local injection of NPs11 was the best option. •Polycystic ovary syndrome (PCOS) affects endocrine and ovarian functions.•Metformin and their nanoparticles (NPs) treatments ameliorate PCOS-induced changes.•Local injection of metformin-NPs is the best option to improve PCOS alterations.