Improving the quality of ram epididymal sperm by adding rutin antioxidant during storage 48 hours after cooling

The sperm membrane is rich in unsaturated fatty acids, which is very sensitive to the damage caused by ROS as a result of lipid peroxidation. Using suitable antioxidants in semen extenders can reduce the level of ROS. Rutin is a naturally occurring antioxidant polyphenolic flavonoid with powerful radical scavenging and lipid peroxidation inhibition properties. However, no studies have investigated the potential impact of rutin supplementation in cooling preservation of ram epididymal sperm. The current research was aimed to compare different concentrations of rutin antioxidant in the cooling process.

In this experimental study, testes of mature rams were collected from a local slaughterhouse and transferred to the laboratory within 1 hours in saline (0.9% NaCl) solution. In the laboratory, the epididymis was separated from the testis and cleaned from any connective tissues and blood vessels. For sperm recovery, the cauda epididymis was trimmed with a scalpel and epididymal sperm was obtained by cutting into small pieces in 5 ml of tris base extender pre-warmed at 37°C and incubated for 10 min to allow sperm swim out. The diluted sperm samples were divided into five equal experimental groups including: 1) tris base extender (Control), 2) extender containing 0.5 mM rutin, 3) extender containing 0.75 mM rutin, 4) extender containing 1 mM rutin, and 5) extender containing 1.25 mM rutin. The sperm samples were cooled gradually from 37°C to 4°C in 2 hours and held at 4°C. Sperm motility, viability, membrane integrity and lipid peroxidation were evaluated after extension (0 h) and at 24 and 48 hours of storage. The motility, viability, membrane integrity and morphology of sperm samples were evaluated immediately after extension (0 h) and at 24 and 48 h of storage at 4°C. The sperm motion kinematics were objectively evaluated by using the computer-assisted sperm analysis (CASA) system. The eosin-nigrosin staining technique was applied to evaluate viability. The hypo-osmotic swelling test (HOST) was performed to assess membrane integrity. Sperm morphology was determined by staining sperm smears with Hancock’s solution. Lipid peroxidation was evaluated by measuring malondialdehyde (MDA) concentration.

The data obtained from this experiment show that after 24 and 48 hours of cooling, the addition of rutin antioxidant at a concentration of 0.75 and 1 mM causes a significant increase in total motility, progressive motility and straight path velocity. The results of the present study show that experimental treatments at 0, 24 and 48 hours after cooling have no effect on VAP, VCL and STR. The results of this experiment show that after 24 and 48 hours of cooling, the addition of rutin antioxidants at concentrations of 0.75 and 1 mM significantly increases the viability and integrity of the membrane. Also, the results show that the experimental treatments reduce the amount of MDA. The results show that the applied treatments have no effect on sperm morphology.

The results show that using rutin antioxidant in concentrations of 0.75 and 1 mM improves the quality of ram sperm.