Role of coenzyme Q and vitamin E on stallion semen motility evaluated both in frozen and cooled-stored semen

Abstract

Several studies reveal that coenzyme Q (CoQ) and vitamin E (Vit. E) act against oxidative deterioration, and that CoQ restores the active and antioxidant form of Vit. E. These two antioxidants, acting against lipid peroxidation, seem to be able to improve motility parameters of spermatozoa. The objective of this study is to evaluate the addition of CoQ and Vit. E to semen extender for equine spermatozoa in order to evaluate possible effects on semen motility. First, immediately after collection, semen samples were diluted with 1mM of CoQ and 1mM of CoQ plus 1mM of Vit. E and prepared for frozen storage in liquid nitrogen. After thawing (37 °C/30 s), samples were maintained at 37 °C and subjected to analysis after 0, 2 and 4 h for motility parameters with CASA (Computer-Assisted Sperm Analysis) method. In a second experiment, after the collection, semen samples were diluted with 1mM of CoQ, in presence or absence of seminal plasma where Vit. E is normally present, and prepared for cooled storage at 4 °C. The effects on motility parameters were determined with CASA at 0, 24, 31 and 48 h after collection. During the analysis, samples were kept at 4 °C. The CASA variables were examined with a mixed linear model. No improvement (p > .05) in motility parameters results from the addition of CoQ and Vit. E in frozen or cooled-stored equine semen when compared to control group.

Keywords

• Equine semen
• coenzyme Q
• α-tocopherol
• vitamin E
• oxidative stress