Potential dual protective effects of melatonin on spermatogonia against hexavalent chromium

Overview of biological effects of melatonin on testis: A review

“…Chromium VI however is a strong oxidising agent and one of the strongest carcinogens (Chen, Murphy, et al, 2019). Chromium VI can have major adverse effects on spermatogenesis by stimulating oxidative stress (Aruldhas et al, 2005) and suppressing phosphorylation of ATM-p53 and the mitogenactivated protein kinase (MAPK) pathway (Li et al, 2022). Melatonin also modulates PDC-induced increase in TNF-α and IL-6 levels and can be effective in reducing testicular damage due to PDC-induced oxidative stress (Ebaid et al, 2021).…”

“…It has been shown that exposure to PDC decreases the levels of sex hormones, glutathione, superoxide dismutase, catalase and carnitine and the number of motile sperms and increases the level of MDA and NO in rat testicles, but administration of melatonin to mice reduces the MDA level and restores the activity of antioxidant enzymes and levels of sex hormones. The results of a study conducted in 2022 by Li et al showed that melatonin protects spermatogonial stem cells from chromium‐induced damage via elimination reactive oxygen species and suppressing phosphorylation of ATM‐p53 and the mitogen‐activated protein kinase (MAPK) pathway (Li et al, 2022). Melatonin also modulates PDC‐induced increase in TNF‐ α and IL‐6 levels and can be effective in reducing testicular damage due to PDC‐induced oxidative stress (Ebaid et al, 2021).…”

The Role of Melatonin to Ameliorate Oxidative Stress in Sperm Cells

“…Generally, in the male reproductive system, an essential role of melatonin is the prevention of testicular damage, and it is effective in maintaining the blood-testis barrier in testes [239]. Concerning heavy metals, it is likely that melatonin plays an essential role in the reduction of negative impacts caused by Cadmium (Cd) in the male reproductive system, improving the DNA damage and suspending autophagy in sperm through the ATM/AMPK/mTOR signaling pathway [240].…”

“…Based on several studies carried out in recent years on the use of melatonin against metal-induced cytotoxicity, it appears that melatonin has a protective role against OS by counteracting free radicals and enhancing the antioxidant enzyme activity [239].…”

“…According to Li and colleagues [239], melatonin can be effective in toxicity reduction, induced by metals such as copper, iron, and molybdenum, due to its high lipophilicity, low toxicity, and ability to penetrate fast into cells [239]. The same research group studied the exposure of haexavalent chromium in spermatogonia and the role of melatonin in the protection against haexavalent chromium toxicity.…”