Objective/Background: Cisplatin (CP) is an effective chemotherapeutic drug, but generation of reactive oxygen species (ROS) has limited its usefulness due to its toxicity to normal cells including testis cells. Methylene blue (MB) is a reducing agent that can act as a powerful antioxidant and also as an enhancer of the electron transport chain preventing formation of mitochondrial oxygen free radicals. This research was designed to investigate the protective effect of MB on CP-induced toxicity on reproductive system of male rats. Materials & Methods: in this study, 35 male rats were divided into 5 groups: control, CP (5 mg/kg) given intraperitoneal as single dose), CP+ MB (4 mg/kg by Subcutaneous injection), CP+MB (2 mg/kg) and MB (4 mg/kg). Experimental period was 7 days. After treatment, serum from all groups were collected for biochemical analysis. Histological examination and sperm parameter inclouding: sperm count, viability and motility were evaluated. Results: our data indicate a significant reduction in the sperm count, motility, viability in cisplatin group but MB ameliorate this reduction in CP+MB group. The MB treated group showed an improved histological appearance in compared to CP group. In addition, serum testestrone level in CP group reduced significantly and MB with high and low dose prevent this reduction. Conclusion: In conclusion, our study showed that MB can correct the histological damages caused by cisplatin, improve the sperm parameters and the amount of testosterone hormone.
