To preserve and protect spermatozoa against any possible oxidative damage the addition of natural antioxidants might be the ideal solution which has been investigated worldwide. The composition of the diluents is as follows: 50 µM/L vitamin C with 0.5% DMSO (dimethyl sulfoxide, Sigma, St. Louis, USA); 50 µM/L vitamin E with 0.5% ethanol; each added separately to the spermatozoa with the aim to determine its effect on post-thaw quality of spermatozoa. 20 samples from each control and experimental group were analysed. Semen was thawed at 37°C for 70 seconds. The sperm motility parameters were analysed immediately after thawing used Sperm Vision CASA (Computer Assisted Semen Analysis) system. The viability of the cells was evaluated by metabolic activity MTT assay and the nitroblue-tetrazolium (NBT) test was used to assess the intracellular formation of the superoxide radicals. Motility was observed with highest statistical differences (P<0.001) with vitamin E. Even though, the motility was significantly lower (P>0.05) with the samples containing vitamin C, however, higher percentage (54%) of motility was observed in comparison to the control group (51.61%). Based on MTT assay, viability was also improved with the supplementation of vitamin C with the highest significance (P<0.001) impact. Only vitamin E was observed significantly lower (P>0.05). however, had higher percentage of viable spermatozoa (105.8%) when compare to the control group (100.1%) which did not contain vitamin E. All of the mentioned substances used – vitamin C, vitamin E – prevented the intracellular overproduction of free radicals within the sperm mitochondrial membrane with the statistical significance (P<0.01), (P<0.05), respectively, resulted from NBT Test. Thus, the addition of vitamin C, vitamin E, in the semen extender could improve the frozen-thawed quality of bovine spermatozoa.
Vitamin C, Vitamin E, motility, viability, oxidative stress