Biochemical and histopathological investigation of the protective effects of melatonin and vitamin E against the damage caused by acetamiprid in Balb-c mouse testicles at light and electron microscopic level

The protective effects of melatonin (Mel) and vitamin E (Vit E) against the negative effects of acetamiprid (Acmp) on testicles, reproductive hormones, and oxidative stress parameters were investigated in the present study. A total of 50 Balb-c male mice were used in 7 groups; 6 mice in the control groups (distilled water, corn oil, ethanol), and 8 in other groups (Acmp, Acmp + Mel, Acmp + Vit E, Acmp + Vit E + Mel). After the experiment, which lasted 21 days, hematoxylin eosin (H&E), periodic acid Schiff (PAS), and caspase-3 immunohistochemical (IHC) staining was performed on the testicular tissues. Also, the tissues were examined ultrastructurally with the transmission electron microscopy (TEM). In the Acmp group, there were decreased seminiferous tubule diameter and epithelial thickness, epithelial degeneration, decreased spermatozoa in the lumen, decreased PAS-positive staining in the seminiferous epithelial basement membrane, edema in the interstitial area, and hydropic degeneration in Leydig cells. Caspase-3 immunoreactivity was higher than in the other groups. TEM examination showed degeneration in tubule cells, lysosomal accumulation in cells of the spermatogenic line, vacuolizations with myelin figures, and necrosis. Hydropic degeneration, electron-dense lipid vacuoles, and chromatolysis were evident in the Leydig cell cytoplasm. In Sertoli cells, electron-dense lysosomal deposits were noted. In biochemical terms, there were decreased tissue glutathione (GSH) and total antioxidant status (TAS), and increased malondialdehyde (MDA) and total oxidant status (TOS). Plasma luteinizing hormone (LH), follicular stimulating hormone (FSH), and testosterone levels were decreased. In the groups with melatonin, vitamin E, and both were applied together, tissue damage, and apoptotic cell death were reduced at both light microscopic and ultrastructural levels. In biochemical terms, there were decreased oxidative parameters and increased hormonal parameters. It was found that vitamin E was more effective in decreasing oxidative parameters and increasing antioxidative parameters when compared to melatonin, and hormonal parameters increased at a higher level in the Acmp + Vit E group than in all groups. As a result, it was found that exposure to Acmp caused damage to testicular tissue, induced oxidative stress in testicles, and decreased plasma LH, FSH, and testosterone levels, and although vitamin E is more effective than melatonin in preventing this damage, both are effective.