Comparative Antioxidant Capacity of Two Different Forms of Selenium and their Molecular Impact on Cryopreserved Rabbit's Sperm

Cryopreservation lessens the amount of sperm's antioxidants and makes them more sensitive to damage caused by oxidative stress. The purpose of the current study was to assess the effects of selenium addition to rabbit buck semen on the post-thaw quality parameters that were either supplemented in normal or nano form. Sixteen mature New Zealand white bucks were provided for semen collection. Semen samples were examined, and supplemented with selenium in normal or nano form at the recommended level of 2 µg/ml. Our findings demonstrated that supplementing either normal or nano selenium to the semen extender had a positive effect on post-freezing physical characteristics. Moreover, the post-freezing profile of spermatozoa antioxidant enzymes (TAC and GPX1) and the expression of defence genes (NFR2, GPX1, and SOD1) were greater (p ≤0.05) in the groups supplemented with normal and nano selenium than in the control group. Our results concluded that supplementing rabbit sperm extender with Se in normal or in nanoparticles form improved the percentage of viable spermatozoa and enhance acrosomal intactness, in addition to sperm antioxidant status. This action of selenium was fulfilled by lowering MDA levels, increasing levels of key antioxidant spermatozoa enzymes (SOD1, CAT, and GPx), that was accompanied by upregulating transcription levels of antioxidant genes (NRF2, GPX1, TXN, SOD1, and CAT).