Neuropeptide W protects against ovarian oxidative injury and reinforces ovarian steroidogenic activity via the upregulation of ERα expression

The aim of this study was to investigate the protective effect of neuropeptide W (NPW) on ovarian ischemia-reperfusion-induced oxidative injury and ovarian steroid metabolism. Rats were randomly divided into control and ischemia groups that received either saline or NPW (0.1 or 5 μg/kg/day). Bilateral ovarian ischemia was performed for 3 h followed by a 72-h reperfusion. Blood, ovary, and uterus samples were collected for biochemical and histological assessments. Treatment with either dose of NPW alleviated oxidative injury of the ovaries with a significant suppression in free radical formation and decreased histopathological injury in both the ovarian and uterine tissues, along with reduced lipid peroxidation and neutrophil accumulation in the uterus. Moreover, NPW treatment reversed the decrease in aromatase expression with a concomitant reduction in the expression of the inactivity enzyme estrogen sulfotransferase. Also, downregulation of estrogen receptor-α (ERα) expression in the injured ovarian tissue was abolished by NPW treatment, which implicates that the protective effect of NPW on the female reproductive system may involve the upregulation of the ERα-mediated signaling pathway. Our study demonstrated for the first time that NPW protects against ovarian oxidative injury and reinforces ovarian steroidogenic activity, which is accompanied by the upregulation of ERα expression in the ovaries.