Coenzyme Q10 and α‐Tocopherol Prevent the Lipid Peroxidation of Cooled Equine Semen

Abstract

Biotechnology applied for equine semen increases the levels of reactive oxygen species and reduces the natural antioxidant defence, by both dilution and removal of seminal plasma. Therefore, the aims of this study were to evaluate the effect of adding coenzyme Q10 (CoQ10) and α-tocopherol (α-TOH) to the cooling extender, singly or in combination, on sperm parameters, and their effectiveness in preventing lipid peroxidation (LPO) of equine semen during cooling at 5°C for 72 h. Ten adult stallions of proven fertility were used, using two ejaculates each, subjecting them to the treatments with the following concentrations: α-TOH: 2 mm; CoQ10: 40 μg/ml; and CoQ10 + α-TOH: 40 μg/ml + 2 mm for control (C) without the addition of antioxidants and for vehicle control (EtOH) with 100 μl ethanol. The CoQ10 group had a higher percentage of total motility (69.1 ± 16.2%) compared to control (62.1 ± 16.2%) and EtOH (58.1 ± 18.6%). CoQ10 + α-TOH and α-TOH groups were most effective in preventing LPO compared to controls (1765.9 ± 695.9, 1890.8 ± 749.5, 2506.2 ± 769.4 ng malondialdehyde/10(8) sptz, respectively). In conclusion, CoQ10 and α-TOH were effective during the cooling process of equine semen at 5°C for 72 h, providing increased levels of total motility, as well as lower LPO.

Effects of Feeding Coenzyme Q10-Ubiquinol on Plasma Coenzyme Q10 Concentrations and Semen Quality in Stallions

“…By preventing the oxidation of lipids in spermatozoal membranes, the integrity of the plasma membrane is maintained, and the spermatozoa survive. Similarly, previous studies in humans [28,29], bulls [30], and horses [19,31,32] have shown that CoQ10 acts as an excellent tool in repairing damage to the spermatozoal plasma membrane.…”

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

“…Our results are in contrast with those obtain by Yousefian et al (2014) and Nogueira et al (2015). Our difference value measured at 48 h (Figure 4) between CRT and CRT þ Q for motility can be explained with a possible negative effect due to the high amount of antioxidant used.…”

Effects of cashew gum and nanoparticles on cooled stallion semen

“…Previous studies have shown that the addition of the antioxidant α-tocopherol to semen extender may improve cryopreservation or cooling of stallion semen [2,29]; this antioxidant avoids the peroxidation of lipids in the plasma membrane, thus contributing to sperm preservation [30]. Gums provide protection against cold shock because of their physicochemical characteristics since they can retard or minimize the following processes: crystallization of water or sugar; gravitational sedimentation of suspended particles; loss of small molecules or ions due to the formation of an impermeable film; and syneresis in the gels, i.e.…”

“…The solvent was evaporated in a rotavapor at 35 °C, followed by the lyophilization process. The concentration of α-tocopherol in the experimental group TOC (10%) was chosen from previous studies [2].…”

“…Cooled stallion semen is widely used for equine artificial insemination since fertility rates are higher than frozen semen [1], even when the semen is used 36 h after collection [2]. The plasma membrane in stallion spermatozoa has a low ratio of cholesterol to phospholipids, resulting in susceptibility to cold shock during storage at low temperatures [3]; thus cooling the semen results in better sperm survival than cryopreservation.…”