Effects of Visnagin on Sperm Kinematics and Membrane Integrity in Cryopreserved Ram Semen

The objective of this study was to examine the impact of incorporating visnagin in a ram semen diluent on sperm motility, kinematics, membrane integrity, mitochondrial function and DNA integrity as functional indicators of cryodamage. Eight Tuj breed rams were used in the study. Semen samples were collected from the rams using an artificial vagina, then pooled and divided into five equal volumes. These samples were then diluted in a Tris-egg yolk diluent containing 0, 0.5, 25, 50 or 250 µM visnagin, before being cryopreserved. Following thawing, sperm motility and kinematic parameters were evaluated using computer-assisted sperm analysis (CASA). DNA integrity, acrosomal integrity, mitochondrial membrane potential and plasma membrane integrity were evaluated using standard fluorescence protocols. In the group treated with 25 µM visnagin, plasma membrane integrity was significantly higher, and there was a numerical increase in both total and progressive motility compared to the control group. In the study, visnagin at a dose of 250 µM showed a decrease in VCL, VAP, VSL, ALH, and BCF values. Although there was a numerically higher mitochondrial membrane potential in the group treated with 250 µM of Visnagin compared with the other groups, the rate of acrosomal damage was significantly lower. Consequently, whilst no adverse effects on sperm were observed at low doses of visnagin (0, 0.5, 25 and 50 µM), it was noted that, although the 250 µM dose reduced the rate of acrosomal damage, it also lowered VCL, VAP and BCF levels.