N-acetyl-L-cysteine pre-treatment protects cryopreserved bovine spermatozoa from reactive oxygen species without compromising the invitro developmental potential of intracytoplasmic sperm injection embryos

摘要

Excess of reactive oxygen species (ROS) on invitro embryo production systems negatively affects the quality and developmental potential of embryos, as result of a decreased sperm quality and increased DNA fragmentation. This issue is of major importance in assisted fertilisation procedures such as intracytoplasmic sperm injection (ICSI), because this technique does not allow the natural selection of competent spermatozoa, and therefore, DNA-damaged spermatozoa might be used to fertilise an egg. The aim of this study was to investigate a new strategy to prevent the potential deleterious effect of ROS on cryopreserved bovine spermatozoa. We evaluated the effect of a sperm pre-treatment with different concentrations of N-acetyl-L-cysteine (NAC) on ROS production, viability and DNA fragmentation and assessed the effect of this treatment on the invitro developmental potential and quality of embryos generated by ICSI. The results show a strong scavenging effect of 1 and 10 mm NAC after exposure of spermatozoa to a ROS inducer, without compromising the viability and DNA integrity. Importantly, invitro developmental potential and quality of embryos generated by ICSI with spermatozoa treated with NAC were not affected, confirming the feasibility of using this treatment before an ICSI cycle.