Melatonin Protects Bovine Spermatozoa by Reinforcing Their Antioxidant Defenses

Abstract

Cryopreserved semen is widely used in assisted reproductive techniques. Post-thawing spermatozoa endure oxidative stress due to the high levels of reactive oxygen and nitrogen species, which are produced during the freezing/thawing process, and the depletion of antioxidants. To counteract this depletion, supplementation of sperm preparation medium with antioxidants has been widely applied. Melatonin is a hormone with diverse biological roles and a potent antioxidant, with an ameliorative effect on spermatozoa. In the present study, we assessed the effect of melatonin on thawed bovine spermatozoa during their handling. Cryopreserved bovine spermatozoa were thawed and incubated for 60 min in the presence or absence of 100 μΜ melatonin. Also, the effect of melatonin was assessed on spermatozoa further challenged by the addition of 100 μΜ hydrogen peroxide. Spermatozoa were evaluated in terms of kinematic parameters (CASA), viability (trypan blue staining) and antioxidant capacity (glutathione and NBT assay, determination of iNOS levels by Western blot analysis). In the presence of melatonin, spermatozoa presented better kinematic parameters, as the percentage of motile and rapid spermatozoa was higher in the melatonin group. They also presented higher viability and antioxidant status, as determined by the increased cellular glutathione levels and the decreased iNOS protein levels.

Mangiferin improves early porcine embryonic development by reducing oxidative stress

“…To simulate the maternal environment in vitro, antioxidant drugs are added to the culture medium to reduce or eliminate the embryo blocks caused by environmental stressors. Melatonin (Choi et al, 2024;Lavrentiadou et al, 2023), vitamins (Georgiev et al, 2023;Widgerow et al, 2023), cysteines (Kim et al, 2023), and quercetin (Shi et al, 2023;Zhou et al, 2023) are examples of natural antioxidant substances that have been used in this context. Thus, the identification of novel natural antioxidant drugs is crucial for improving embryonic development and assisted reproductive technologies.…”

Evaluation of Dry Ice for Short-Term Storage and Transportation of Frozen Boar Semen

“…Ultralow-temperature preservation keeps spermatozoa in a relatively quiescent state to achieve a more efficient protection of germplasm resources [1]. Frozen semen has been widely used in assisted reproduction, which has allowed the widespread use and preservation of genetically superior semen [2]. Due to the development of semen banking, which began in 2002, frozen semen was proven to be an effective and safe assisted reproduction technology, and it has a similar fertilization rate to fresh semen [3].…”