The reproductive system has been increasingly implicated as a sensitive target of microwave radiation. Oxidative stress plays a critical role in microwave radiation -induced reproductive damage, though precise mechanisms are obscure. Metformin, a widely used antidiabetic drug, has emerged as an efficient antioxidant against a variety of oxidative injuries. In the present study, we hypothesized that metformin can function as an antioxidant and protect the reproductive system from microwave radiation. To test this hypothesis, rats were exposed to 2.856 GHz microwave radiation for 6 weeks to simulate real-life exposure to high-frequency microwave radiation. Our results showed that exposure to 2.856 GHz microwave radiation elicited serum hormone disorder, decreased sperm motility, and depleted sperm energy, and it induced abnormalities of testicular structure as well as mitochondrial impairment. Metformin was found to effectively protect the reproductive system against structural and functional impairments caused by microwave radiation. In particular, metformin can ameliorate microwave-radiation-induced oxidative injury and mitigate apoptosis in the testis, as determined by glutathione/-oxidized glutathione (GSH/GSSG), lipid peroxidation, and protein expression of heme oxygenase-1 (HO-1). These findings demonstrated that exposure to 2.856 GHz microwave radiation induces obvious structural and functional impairments of the male reproductive system, and suggested that metformin can function as a promising antioxidant to inhibit microwave-radiation-induced harmful effects by inhibiting oxidative stress and apoptosis.

Researches have shown that microwave radiation could cause oxidative stress injury in male reproductive system, and blueberry anthocyanins had excellent oxidation resistance. Our study aimed to investigate the protective effect of blueberry anthocyanins (100, 200 and 400 mg/kg/d) on testicular tissue damage in Wistar rats exposed to 2.856 GHz microwave and the optimal dose. We found that blueberry anthocyanins could ameliorate the decrease of sperm motility and sex hormone levels and testicular tissue structure damage caused by microwave radiation, increase SIRT1 expression and decrease FoxO1 expression, increase GSH/GSSG, SOD and inhibit MDA. The LDH, SDH and ATP synthase were increased, and Caspase-3 expression was decreased, and the high-dose of blueberry anthocyanins (400 mg/kg/d) had the best protective effect. These results suggested that blueberry anthocyanins could inhibit oxidative stress injury induced by 2.856 GHz microwave radiation in rat testicular tissue by regulating SIRT1/FoxO1 pathway, enhance energy metabolism and reduce cell apoptosis.