Arbutin Preserves Boar Sperm During Storage at 17°C by Enhancing the Antioxidant Capacity via the NRF2/GPX4 Signalling

Arbutin is a naturally present antioxidant derived from plants. The objective of this study was to examine the effect of arbutin on boar sperm during storage at 17°C and the underlying mechanisms. Our results showed that the addition of arbutin to extenders markedly enhanced the sperm (progressive) motility and plasma membrane and acrosomal integrity on Days 9 and 13 of preservation (p < 0.05), with the most pronounced effect of arbutin at the concentration of 100 μmol/L. The addition of 100 μmol/L arbutin also reduced the level of ROS and elevated the levels of ATP and MMP in boar sperm on Days 9 and 13 of preservation (p < 0.05). The subsequent sperm oxidative damage experiment showed that the addition of 100 μmol/L arbutin significantly alleviated the decrease in sperm (progressive) motility and in plasma membrane and acrosomal integrity caused by H₂O₂ (p < 0.05), whereas increased the T-AOC content and the activities of CAT and GPx antioxidant enzymes after 2 h of incubation at 37°C (p < 0.05). Further, the metabolomic analysis revealed that the addition of arbutin principally influenced lipid metabolism, and the Western blot analysis demonstrated that arbutin increased the sperm quality and the antioxidant capacity via the NRF2/GPX4 signalling. Together, arbutin preserves boar sperm during storage at 17°C by enhancing the antioxidant capacity via the NRF2/GPX4 signalling, laying the theoretical foundation for optimisation of the boar semen preservation diluent therefore facilitating the dissemination of superior porcine germplasm resources and improving the economic value.