The antioxidant/anti-inflammatory protective effects of rutin against ethanol-induced testicular perturbation in rats: Involvement of the immunosuppressive indoleamine 2,3-dioxygenase

This study investigated the influence of rutin against EtOH-induced testicular impairment in rats and the involvement of the indole-aminergic pathway. Four groups of eight rats each were orally exposed to drinking water (Group 1), EtOH (5 g/kg bwt, Group 2), R (5 g/kg bwt, Group 3), and EtOH + R (5 g/kg bwt + 50 mg/kg bwt, Group 4) via gavage for 15 days. Results showed that exposure to EtOH significantly (p < 0.0001) reduced the testicular antioxidant system and increased lipid peroxidation (LPO) relative to control. We observed a significant (p < 0.0001) increase in the inflammatory biomarkers, with attendant disruption in the testicular histological structure and concomitant elevation in the activities of indoleamine 2,3-dioxygenase (IDO), in comparison with control and no noticeable effects in tryptophan 2,3-dioxygenase (TDO) activity across the groups. Rutin-only exposed group did not show any alteration in the measured parameters when compared with the control. Rutin co-exposure augmented the antioxidant system, prevented histological damage, reduced LPO and inflammation, and thus, lowered EtOH-mediated increase in IDO activity, compared with control. Overall, these findings reveal the involvement of the indole-aminergic pathway in rutin's protective influence against EtOH-induced testicular impairment in rats.