Excessive caffeine intake inhibits steroidogenesis, folliculogenesis and disrupts utero-ovarian tissue histomorphology integrity in experimental rats, and precipitates polycystic ovary syndrome in Sprague-Dawley rats

•Polycystic ovarian syndrome (PCOS) is characterized by a variety of anovulation and hyperandrogenism symptoms.•Caffeine (CAF) is popularly consumed and it is a legal psychoactive substance.•CAF disrupts utero-ovarian histomorphology integrity.•CAF promotes a hormonal imbalance in PCOS and infertility.•CAF precipitates PCOS. Polycystic ovarian syndrome (PCOS) is characterized by anovulation and hyperandrogenism symptoms. Caffeine is popularly consumed and it is a legal psychoactive substance. This study evaluated the effect of excessive caffeine intake on utero-ovarian tissue in polycystic ovary syndrome rats. Twenty-four female rats randomized into group A control received 2 ml of normal saline. Group B received 4 mg/kg body weight (bwt) i.p of estradiol valerate (EV) on the first day, Group C received 100 mg/kg bwt of caffeine orally, and Group D received i.p 4 mg/kg bwt EV and 100 mg/kg bwt of caffeine orally. The experiment lasted 30 days. Histology of the ovary and uterus, oxidative and antioxidant, reproductive hormone, lipid profile, inflammatory markers, and apoptosis markers were evaluated. The ovarian histoarchitecture revealed degeneration of the theca cells, granulosa, and corpus luteum, and loss of mucin granules in the uterine tissues in PCOS, CAF, and PCO+CAF. The estrous cycle became irregular, with prolonged diestrous and proestrus phases. Marked rise in oxidative markers and decline in the activities of ovarian enzymatic antioxidants, inflammatory response, caspase-dependent apoptosis, and hormonal imbalance. Excessive caffeine consumption, therefore impaired utero-ovarian integrity, hormones, inflammatory indicators, oxidant and antioxidant parameters, apoptotic markers, and the estrous cycle.