In vitro maturation(IVM)is considered a potential assisted reproductive technology that is a safer and simpler alternative to conventional in vitro fertilization.It is primarily used in patients with impaired oocyte m...In vitro maturation(IVM)is considered a potential assisted reproductive technology that is a safer and simpler alternative to conventional in vitro fertilization.It is primarily used in patients with impaired oocyte maturation and for the treatment of infertile women who are at risk of fertility loss.In addition,IVM is currently used mainly in polycystic ovarian syndrome patients with a high ovarian response and is stll considered an experimental option in fertility preservation.Producing highly competent oocytes during IVM is considered a key step in the success of in vitro production(IVP)of embryos.Some factors,such as culture medium conditions and other supplements,have a significant impact on oocyte IVM performance.One of the known disruptors of oocyte developmental competence in IVP is oxidative stress(Os),which is caused by an imbalance between the production and neutralization of reactive oxygen species(ROS).In vitro conditions induce supraphysiological ROS levels due to exposure to an oxidative environment and the isolation of the oocyte from the follicle protective antioxidant milieu.Given the importance of Os in oocyte competence,the establishment of standardized antioxidant IVM systems is critical for improving the overall success of IVP.This review focuses on the main antioxidants tested to protect oocytes against OS in IVM.展开更多
Mammalian gametes and embryos are particularly vulnerable to oxidative stress-induced damage, which is mainly caused by reactive oxygen species（ROS） originating from normal metabolism and/or the external environment...Mammalian gametes and embryos are particularly vulnerable to oxidative stress-induced damage, which is mainly caused by reactive oxygen species（ROS） originating from normal metabolism and/or the external environment. Several researchers have implicated the role of oxidative stress in the activation of apoptosis, causing peroxidative damage to sperms/oocytes and inducing embryo fragmentation, arrest, or demise. Melatonin is a tryptophan derivative that is known for its powerful free radical-scavenging activity and broad-spectrum antioxidant property. Numerous studies have shown that melatonin and its metabolic derivatives can sequentially detoxify ROS in an antioxidant cascade, and modulate various antioxidant enzymes via its receptors to prevent radical-mediated damage. The identification of melatonin receptors in cumulus/granulosa cells, oocytes, and epididymal tissues implies that melatonin has protective actions on gametes and embryos. Enriching the semen extender or culture medium with melatonin significantly benefits sperm characteristics, improves oocyte maturation potential and quality, and enhances the developmental competence of preimplantation embryos. Certainly, further comparative studies are needed to show the unique antioxidant role and the advantage of melatonin in this field. This review summarizes the harmful effects of ROS and the beneficial role of melatonin against oxidative damage of gametes and embryos.展开更多
基金financially supported by the Abadan University of Medical Sciences,Abadan,Iran(1401U-1467).
文摘In vitro maturation(IVM)is considered a potential assisted reproductive technology that is a safer and simpler alternative to conventional in vitro fertilization.It is primarily used in patients with impaired oocyte maturation and for the treatment of infertile women who are at risk of fertility loss.In addition,IVM is currently used mainly in polycystic ovarian syndrome patients with a high ovarian response and is stll considered an experimental option in fertility preservation.Producing highly competent oocytes during IVM is considered a key step in the success of in vitro production(IVP)of embryos.Some factors,such as culture medium conditions and other supplements,have a significant impact on oocyte IVM performance.One of the known disruptors of oocyte developmental competence in IVP is oxidative stress(Os),which is caused by an imbalance between the production and neutralization of reactive oxygen species(ROS).In vitro conditions induce supraphysiological ROS levels due to exposure to an oxidative environment and the isolation of the oocyte from the follicle protective antioxidant milieu.Given the importance of Os in oocyte competence,the establishment of standardized antioxidant IVM systems is critical for improving the overall success of IVP.This review focuses on the main antioxidants tested to protect oocytes against OS in IVM.
基金supported by the grants from the Agricultural Science and Technology Innovation Program, China (ASTIPIAS06)the earmarked fund for China Agriculture Research System (CARS-36)
文摘Mammalian gametes and embryos are particularly vulnerable to oxidative stress-induced damage, which is mainly caused by reactive oxygen species（ROS） originating from normal metabolism and/or the external environment. Several researchers have implicated the role of oxidative stress in the activation of apoptosis, causing peroxidative damage to sperms/oocytes and inducing embryo fragmentation, arrest, or demise. Melatonin is a tryptophan derivative that is known for its powerful free radical-scavenging activity and broad-spectrum antioxidant property. Numerous studies have shown that melatonin and its metabolic derivatives can sequentially detoxify ROS in an antioxidant cascade, and modulate various antioxidant enzymes via its receptors to prevent radical-mediated damage. The identification of melatonin receptors in cumulus/granulosa cells, oocytes, and epididymal tissues implies that melatonin has protective actions on gametes and embryos. Enriching the semen extender or culture medium with melatonin significantly benefits sperm characteristics, improves oocyte maturation potential and quality, and enhances the developmental competence of preimplantation embryos. Certainly, further comparative studies are needed to show the unique antioxidant role and the advantage of melatonin in this field. This review summarizes the harmful effects of ROS and the beneficial role of melatonin against oxidative damage of gametes and embryos.
