Cerium oxide nanoparticles improve the post-thaw quality and in-vivo fertility of Beetal buck spermatozoa.

The motility, health quality, and membrane disorders of spermatozoa are adversely affected during the process of semen cryopreservation due to the over-production of reactive oxygen species (ROS). Cerium oxide nanoparticles (CeO 2 NPs) possess properties to scavenge ROS either by mimicking specific antioxidants or by enhancing the activities of antioxidant enzymes. Therefore, we aimed at evaluating the effects of adding the CeO 2 NPs in the TRIS-citrate-yolk extender on in-vitro antioxidant enzyme activities, spermatozoa quality attributes, and in-vivo fertility of post-thaw Beetal buck spermatozoa. The CeO 2 NPs were prepared and characterized (UV-spectrophotometry, FTIR, and XRD). Semen samples, collected from bucks (n = 5), were distributed into five aliquots and diluted in an extender containing increasing concentrations of nanoparticles (0 μg/ml, called the control group, 25 μg/mL, 50 μg/mL, 75 μg/mL, and 100 μg/mL). At post-thaw, spermatozoa were evaluated for the above-mentioned attributes and the pregnancy rate by inseminating Beetal does (n = 252). Results demonstrated that CeO 2 NPs mitigated the detrimental effects of cryopreservation as ROS production and lipid peroxidation were lower (P < 0.001) in the 25, 50, and 75 μg/mL CeO 2 NPs-added groups compared to the control and 100 μg/ml CeO 2 NPs-added group. The addition of 25 μg/mL CeO 2 NPs improved (P < 0.001) the activities of superoxide dismutase, catalase, and peroxidase and the concentration of reduced glutathione (P < 0.001) compared to the other groups. In terms of sperm kinematics and velocity parameters, the groups added with the 25 and 50 μg/mL CeO 2 NPs exhibited higher total motility (P < 0.001), sperm progressive motility (P = 0.003), and rapid velocity (P < 0.001). The group added with the 50 μg/mL CeO 2 NPs had the highest (P = 0.04) average path velocity. The groups added with the 25 and 50 μg/mL CeO 2 NPs also exhibited higher plasma membrane integrity (P = 0.003), acrosomal integrity, and viability (P < 0.001) compared to the control group. The DNA integrity was also higher (P < 0.001) in all the CeO 2 NPs-added groups. The pregnancy rate was higher (P = 0.003) in the 25 (51.92 %) and 50 μg/mL CeO 2 NPs (58.33 %) groups compared to the other groups. Conclusively, our findings suggest that the inclusion of cerium oxide nanoparticles in the TRIS-citrate-yolk freezing extender can reduce the occurrence of cryopreservation-induced damages to Beetal's buck spermatozoa and ultimately enhance the pregnancy rate in does. • Cerium oxide nanoparticles in cryo-diluent, were compared for post-thaw redox potentials, sperm quality and pregnancy in buck spermatozoa. • Five concentrations of cerium oxide nanoparticles (0 μg/ml, 25 μg/mL, 50 μg/mL, 75 μg/mL, and 100 μg/mL) were compared. • Cerium oxide nanoparticles ameliorated the cryopreservation-induced damages to Beetal's buck spermatozoa and ultimately enhanced the pregnancy rate. [ABSTRACT FROM AUTHOR]