C Fullerenes Suppress Reactive Oxygen Species Toxicity Damage in Boar Sperm.

We report the carboxylated C improved the survival and quality of boar sperm during liquid storage at 4 °C and thus propose the use of carboxylated C as a novel antioxidant semen extender supplement. Our results demonstrated that the sperm treated with 2 μg mL carboxylated C had higher motility than the control group (58.6% and 35.4%, respectively; P ˂ 0.05). Moreover, after incubation with carboxylated C for 10 days, acrosome integrity and mitochondrial activity of sperm increased by 18.1% and 34%, respectively, compared with that in the control group. Similarly, the antioxidation abilities and adenosine triphosphate levels in boar sperm treated with carboxylated C significantly increased (P ˂ 0.05) compared with those in the control group. The presence of carboxylated C in semen extender increases sperm motility probably by suppressing reactive oxygen species (ROS) toxicity damage. Interestingly, carboxylated C could protect boar sperm from oxidative stress and energy deficiency by inhibiting the ROS-induced protein dephosphorylation via the cAMP-PKA signaling pathway. In addition, the safety of carboxylated C as an alternative antioxidant was also comprehensively evaluated by assessing the mean litter size and number of live offspring in the carboxylated C treatment group. Our findings confirm carboxylated C as a novel antioxidant agent and suggest its use as a semen extender supplement for assisted reproductive technology in domestic animals.