Morin mitigates cadmium-induced testicular impairment by stimulating testosterone secretion and germ cell proliferation in mice

Cadmium (Cd) is one of the heavy metal pollutants present in the environment due to human intervention. It is well known that Cd causes toxicological effects on various organs, including the testes. Morin hydrate is a plant-derived bioflavonoid with antioxidant, anti-inflammatory, and anti-stress properties. Thus, the question can be raised as to whether Morin has an effect on Cd-intoxication-induced testicular impairment. Therefore, the aim of this study was to investigate the role of Morin on Cd-mediated disruption of testicular activity. Mice were divided into three groups: group 1 served as the control group, group 2 was given Cd (10 mg/kg) orally for 35 days, and group 3 was given Cd and Morin hydrate (100 mg/kg) for 35 days. To validate the in vivo findings, an in vitro study on testicular explants was also performed. The results of the in vivo study showed that Cd-intoxicated mice had testicular disorganization, reduced circulating testosterone levels, decreased sperm density, and elevated oxidative stress and sperm abnormality. The expression of the germ cell proliferation marker, germ cell nuclear acidic protein (GCNA), and adipocytokine visfatin were also downregulated. It was observed that Morin hydrate upregulated testicular visfatin and GCNA expression in Cd-intoxicated mice, along with improvement in circulating testosterone, testicular histology, and sperm parameters. Furthermore, the in vitro study showed that Cd-mediated downregulation of testicular visfatin and GCNA expression, along with the suppressed secretion of testosterone from testicular explants, was normalized by Morin treatment, whereas visfatin expression was not. Overall, these data indicate that environmental cadmium exposure impairs testicular activity through downregulation of visfatin and GCNA expression, and Morin might play a protective role against Cd-induced testicular toxicity.