Student Graduate School of Science, Kyoto University Kyoto-shi, Kyoto, Japan
Abstract Authors: Post-Thaw Treatment with Astaxanthin Enhances Sperm Function Following Cryopreservation
Kaya Weiner1., Halli S. Weiner1.
1. First-Year Innovation and Research Experience, University of Maryland, College Park, USA
Abstract Text: During cryopreservation, sperm suffer from oxidative stress caused by the production of reactive oxygen species, which can lead to DNA damage and loss of motility. Historically, low-molecular-weight antioxidants, such as vitamins C and E, have been used to mitigate these effects in cryopreserved sperm. Astaxanthin (AXA) is a powerful antioxidant that is shown to be 65 times stronger than vitamin C and 50 times stronger than vitamin E in protecting against oxidative damage. Recent studies using human sperm report that post-thaw parameters (motility, viability, DNA integrity, and mitochondrial membrane potential) improve significantly when sperm are exposed to AXA before cryopreservation. To test whether AXA can rescue cells from oxidative damage following cryopreservation, commercially-sourced bull sperm frozen in an egg-yolk-based cryopreservation medium (n=7) were thawed and incubated for 30 minutes in DPBS (Sigma D4031) with AXA (0 μM, 50 μM, 75 μM, and 100 μM, described as control, low, medium, and high, respectively). Motility (% motile), viability (% live), acrosomal integrity (%intact), and intracellular ATP concentration (μM) were measured immediately after thawing and after AXA incubation. Statistical significance was measured using a Student T-Test, and data are expressed as mean ± SD. Analysis showed a significant decrease in motility after 30 minutes in the control medium (71.58 ± 7.36, p< 0.01) compared to post-thaw (93.24 ± 3.33). Additionally, AXA treatment did not significantly affect viability (p >0.05) or acrosomal integrity (p >0.05) at any concentration, indicating no detrimental effect on the health of each sample during incubation. However, when compared to the control, sperm motility was significantly improved following treatment with 50 μM AXA (87.4 ± 4.38, p< 0.05), 75 μM AXA (86.36 ± 3.82, p< 0.05), and 100 μM AXA (90.06 ± 3.51, p< 0.05). Intracellular ATP (n=2) was significantly reduced in sperm incubated with high concentrations of AXA (0.3 ± 0.1, p< 0.05) compared to low (0.53 ± 0.08) or medium (0.54 ± 0.09) treatment groups. These data suggest that AXA could be used as a therapy to preserve sperm health following cryopreservation, with applications for samples collected in suboptimal field conditions and from endangered wildlife species.
