Melatonin promotes embryonic development and reduces reactive oxygen species in vitrified mouse 2‐cell embryos

Abstract

Two-cell embryos of mouse were vitrified by the open-pulled straw (OPS) method. The vitrified embryos were warmed and introduced into M16 medium for culture that contains melatonin at different concentrations (10(-3), 10(-5), 10(-7), 10(-9), 10(-11) m). This process caused reactive oxygen species (ROS) formation and jeopardized the development of the embryos. Melatonin, at different concentrations, significantly suppresses ROS production and promotes embryonic development in vitrified embryos compared with untreated ones. The mechanistic studies indicated that the beneficial effects of melatonin on vitrified 2-cell embryos of mouse were melatonin receptor (MT1 and MT2) independent. The direct free radical scavenging activity, the enhancement of endogenous glutathione levels, and the anti-apoptotic capacity of melatonin may account for its protective effects on vitrified embryonic development.

Melatonin modulates the expression of BCL-xl and improve the development of vitrified embryos obtained by IVF in mice

“…It has been shown that intracellular GSH protects embryo from ROS [12]. Previous study has shown that the level of GSH decreased after vitrification and addition of melatonin increases the GSH levels [14]. The results of present study showed that the intracellular levels of GSH in 10 −9 and 10 −12 M groups were significantly improved relative to the control group.…”

“…Ishizuka et al [21] suggested that the concentration of melatonin in mouse embryo development has a positive effect on 10 −6 M while Rodriguez-Osorio et al [15] claimed no significant difference in the cleavage stage of porcine embryo or blastocyst development in 10 −6 M concentration. Gao et al [14] vitrified two-cell mouse embryos obtained in vivo via OPS method, and found that melatonin at concentrations of 10 −5 to 10 −11 shows significant differences in the development of two-cell vitrified embryos to the blastocyst and increases the number of cells. Survival of frozen embryos is usually determined by growth in medium after warming.…”

“…Tian and colleaguse [26] demonstrated that melatonin at 10 −9 M concentrations leads to an increase in porcine blastocysts blastomeres, which is related to the antioxidant and anti-apoptotic properties of this indole. Antioxidant and anti-apoptotic activity of melatonin and the supportive role of this molecule were studied in preimplantation embryo culture by Reiter et al [41] and Gao et al [14]. Mitochondrial DNA is a major target of free radicals.…”

“…Intracellular GSH levels were determined by previously reported methods [14,32]. Briefly, cell tracker blue CMF2HC (4-chloromethyl-6, 8-difluoro-7-hydroxycoumarin; Molecular probe, Life technology) was used to detect intracellular GSH level by blue fluorescence.…”

“…Attention has been focused on addition of antioxidants to the culture medium of preimplantation embryos as a means of protecting ROS [2]. Various systems of free radical scavengers have been studied for in vitro culture of mammalian embryos, of which melatonin is one of the most important scavengers [14,15].…”