Semen cryopreservation and use of vitamins in the extender medium: literature review

Abstract

The objective of this review was to present the main difficulties encountered in cryopreservation of semen, with oxidative stress being the most impacting of them, and to demonstrate the antioxidant potential of Vitamins C and E, as well as its use in cryopreserved semen dilution media. Semen cryopreservation is a technology of great impact in the national livestock industry and has been increasingly emphasized due to the advances of animal breeding biotechnologies, being the use of cryopreserved semen in artificial insemination, an important tool for the genetic improvement of several animal species and which has many advantages of its application, such as the ease of commercialization and transportation, control of sexually transmitted diseases, and mainly, the expressive genetic gain. Different media and additives are used in cryopreservation of the semen, seeking to confer greater cryoresistance to the spermatozoa during the freeze / thaw cycle. However, despite numerous research in the field, approximately 50% of sperm cells become unviable after the process. Despite the great advances made since the discovery of glycerol, studies on cryoprotectants and other additives such as antioxidants, in order to improve sperm viability, aiming to increase the yield of ejaculated doses and pregnancy rates are of great importance. As antioxidants used in seminal freezing media, stand out Vitamins C and E, which are non-enzymatic antioxidants. These vitamins are substances of low molecular weight, which act as possible removers of the agents that cause oxidative damage, or as repairers of the already initiated lesion, and have the potential to aid in the improvement of seminal viability after thawing.

Keywords

• oxidative stress, reactive oxygen species, antioxidant, tocopherol, ascorbic acid