Survival of buffalo bull spermatozoa: effect on structure and function due to alpha-lipoic acid and cholesterol-loaded cyclodextrin.

Sperm survival depending upon integral membranes and function is imperative for fertilization. This study was designed to augment survival of buffalo spermatozoa using alpha-lipoic acid (ALA) and cholesterol-loaded cyclodextrin (CLC) during cryopreservation. Semen was frozen using 0, 0.5, 1, 1.5, 2 and 2.5 mmol L-1 ALA (experiment 1) and ALA or CLC separately or together (experiment 2). Semen was assessed for post-thaw motility, plasma membrane integrity (PMI), intact acrosome and plasma membrane (IACR-IPM) and DNA integrity at 0, 1.5, 3 and 4.5 hr of incubation. In experiment 1, use of 0.5 mmol L-1 ALA enhanced the sperm cryosurvival and post-thaw longevity than other groups up to 4.5 hr of incubation, and this concentration of ALA was used in second experiment with CLC. The results revealed higher (p < .05) sperm survival function and time of sperm attributes due to use of ALA than CLC and control. However, the sperm quality did not improve (p > .05) when ALA was combined with CLC. In conclusion, survival of buffalo bull spermatozoa during freeze-thawing and post-thaw incubation can be enhanced more with ALA than CLC or control, followed by CLC than control. However, there is no synergistic effect on survival of buffalo bull spermatozoa due to ALA and CLC.