Photobiomodulation therapy reverses spermatogenesis arrest in hyperthermia-induced azoospermia mouse model.

Testicular heat stress leads to impairment of spermatogenesis in mammals. Involved mechanism in this vulnerability to heat-induced injury remains unclear, and research is being conducted to find an approach to reverse spermatogenesis arrest caused by hyperthermia. Recently, different studies have utilized photobiomodulation therapy (PBMT) therapy for the improvement of sperm criteria and fertility. This study aimed at evaluating the effect of PBMT on the improvement of spermatogenesis in mouse models of hyperthermia-induced azoospermia. A total of 32 male NMRI mice were equally divided into four groups consisting of control, hyperthermia, hyperthermia + Laser 0.03 J/cm2, and hyperthermia + Laser 0.2 J/cm2. To induce scrotal hyperthermia, mice were anesthetized and placed in a hot water bath at 43 °C for 20 min for 5 weeks. Then, PBMT was operated for 21 days using 0.03 J/cm2 and 0.2 J/cm2 laser energy densities in the Laser 0.03 and Laser 0.2 groups, respectively. Results revealed that PBMT with lower intensity (0.03 J/cm2) increased succinate dehydrogenase (SDH) activity and glutathione (GSH)/oxidized glutathione (GSSG) ratio in hyperthermia-induced azoospermia mice. At the same time, low-level PBMT reduced reactive oxygen species (ROS), mitochondrial membrane potential, and lipid peroxidation levels in the azoospermia model. These alterations accompanied the restoration of spermatogenesis manifested by the elevated number of testicular cells, increased volume and length of seminiferous tubules, and production of mature spermatozoa. After conducting experiments and analyzing the results, it has been revealed that the use of PBMT at a dosage of 0.03 J/cm2 has shown remarkable healing effects in the heat-induced azoospermia mouse model.

The potential chemoprotective effects of melatonin against genotoxicity induced by diazinon in human peripheral blood lymphocytes.

The protection afforded by melatonin (MLT) against diazinon (DZN)-induced micronucleus formation, an index of DNA damage, in human blood lymphocytes was investigated. Whole blood samples were collected from five volunteers and were incubated with MLT at different concentrations (100, 200, 300, and 400 µM final concentration) for 1 h. The samples were then incubated with 750 µM DZN for 1 h. Subsequently, the lymphocytes were cultured with a mitogenic stimulant to evaluate micronucleus formation in cytokinesis-blocked binucleated cells. The incubation of lymphocytes with DZN induces additional genotoxicity. Pretreatment with MLT at these doses significantly reduced the micronucleus frequency in cultured lymphocytes (p < 0.05-p < 0.0001). The maximum decrease in the frequency of micronuclei was observed at 400 µM of MLT, which caused a reduction of 87%. MLT also exhibited an excellent and dose-dependent radical-scavenging activity against 1,1-diphenyl-2-picrylhydrazyl free radicals. Our study revealed that MLT has a potent antigenotoxic effect against DZN-induced DNA damage, which may be due to the scavenging of free radicals and increased antioxidant status. Because MLT is a natural compound and is considered safe, it can be used as a supplement to protect people exposed to chemical or environmental hazards.