Taxifolin: A flavonoid in the freezing medium augments post-thaw semen quality and in vivo fertility potential of buffalo bull spermatozoa

This comprehensive study was carried out to investigate the effects of taxifolin in the freezing medium on post-thaw semen quality, and fertility potential of buffalo bull spermatozoa. Taxifolin was also evaluated for radical scavenging activity through DPPH (2, 2-diphenyl-1-picrylhydrazyl), and Nitric oxide (NO) inhibition (%) during in vitro conditions. Collected semen samples from four buffalo bulls were initially evaluated (consistency, volume, motility, and concentrations); the accepted samples were pooled, and diluted in extenders containing different doses of taxifolin (0 μM [control], 2 μM, 5 μM, 10 μM, and 20 μM). Diluted semen was gradually cooled (2 h, 4 °C), equilibrated (4 h, 4 °C), and then frozen in liquid nitrogen (−196 °C). Data analysis revealed that taxifolin supplementation (10 μM) displayed the highest DPPH-scavenging ability, and NO inhibition compared to the control (% DPPH, 67.31 vs. 13.50; and % NO, 78.25 vs. 21.25) respectively. Moreover, taxifolin supplementation (10 μM) significantly (P < 0.05) improved progressive motility (%), average path velocity (μm/sec), straight-line velocity (μm/sec), and seminal plasma glutathione peroxidase (μM), and superoxide dismutase (U/mL) of buffalo bull spermatozoa than control. Sperm plasma membrane integrity, mitochondrial transmembrane potential, acrosome integrity (%) and seminal plasma adenosine triphosphate (nmol/million), and total antioxidant capacity (μM/L) were enhanced significantly with taxifolin (10 and 20 μM) supplementing group. Lastly, taxifolin supplementation significantly improved the fertility rate (%, 69.09 vs. 40.38) compared to the control. Further studies to assess mechanisms by which taxifolin improves semen quality and fertility of buffalo spermatozoa are warranted.