The effect of astaxanthin (AXA) on oxidative stress in sperm post-cryopreservation

Abstract

Reactive oxygen species (ROS) is one of the leading causes of oxidative stress in sperm (Lamirander 2008), which can lead to DNA damage and loss of motility. Historically, a solution to this has been low-molecular-weight antioxidants such as vitamin C. Astaxanthin (AXA) is an antioxidant with anti-cancer and anti-inflammatory properties (Dona 2013), and has been shown to be 65 times stronger than vitamin C and 50 times stronger than vitamin E in protecting against damage from free radicals. While the effects of AXA have been studied in oral, liver, and colorectal cancers, little research has been done on the effects of AXA on bull sperm following cryopreservation. To test whether AXA has the same effects in sperm as it does in cancer cells, four concentrations of AXA (0 µM, 50 µM, 75 µM, 100 µM) were added to frozen-thawed bull sperm for 30 minutes. Acrosomal integrity, motility, viability, and mitochondrial membrane potential were measured following AXA incubation. Despite an overall decrease in sperm health post-incubation for all groups, sperm incubated in AXA showed a trend for improved function compared to the control. Sperm incubated in 50 µM AXA demonstrated the most improvement regarding motility and acrosomal integrity. In conclusion, evidence from this study suggests that AXA has the potential to benefit sperm function and reduce oxidative stress following cryopreservation. Further research is necessary to clarify the role of AXA in sperm oxidative stress and mitochondrial membrane potential.