Ellagic acid maintains post-thaw goat sperm quality via protecting mitochondrial function from ROS damage

Abstract

This study aimed to investigate the effects of ellagic acid (EA), an antioxidant, on goat sperm quality after freezing and thawing. Goat semen was frozen using Tris-citric acid-glucose (TCG) extender containing 0, 1.25, 2.5, 5, and 10 μM of EA. Egg yolk represented 20 % (v/v) and glycerol represented 5 % (v/v) of the extender's final concentration. Goat sperm post-thaw motility, acrosome integrity, plasma membrane integrity, mitochondrial activity, ATP content, NADH/NAD⁺ levels, and NADH-CoQ activity were evaluated. Moreover, to elucidate how EA enhanced the goat sperm characteristics, the post-thaw sperm mitochondrial reactive oxygen species (ROS) level, malondialdehyde (MDA) level, oxidative DNA damage, apoptosis, levels of NADH dehydrogenase 1 (MT-ND1) and NADH dehydrogenase 6 (MT-ND6) proteins, and the 4-hydroxynonenal (4-HNE) level were also measured after thawing. The results demonstrated that motility, plasma membrane integrity, and acrosome integrity rates were enhanced in the group treated with 5 μM of EA compared to the other concentrations (0 μM, 1.25 μM, 2.5 μM, 5, and 10 μM). Moreover, mitochondrial activity and ATP content were notably superior in the 5 μM EA group compared to all other treatment groups, along with a considerable decrease in ROS and MDA levels. The 4-HNE level and oxidative DNA damage in sperm were also reduced by EA supplementation. Additionally, it was found that EA (5 μM) significantly (p < 0.05) decreased sperm apoptosis levels. Furthermore, the addition of 5 μM EA maintained the post-thaw sperm MT-ND1 and MT-ND6 levels and reduced the negative impact of ROS on MT-ND1 and MT-ND6, thereby sustaining mitochondrial function for ATP generation. These results suggest that ellagic acid supplementation could maintain goat post-thaw sperm quality by reducing ROS damage and maintaining mitochondrial function for ATP generation. Antioxidant treatments, such as ellagic acid are a useful tool for maintaining frozen-thawed sperm quality.