Free radical scavenger effect of rebamipide in sperm processing and cryopreservation

AIM: To study the effect of rebamipide added to semen samples and cryoprotectant on reactive oxygen species (ROS) production. METHODS: Semen samples from 30 fertile and healthy volunteers were collected by masturbation after 2 days approximately 3 days of abstinence. After liquefaction, the specimens were diluted with sperm wash media to a uniform density of 20 x 10(6)/mL. Rebamipide was added to semen samples and cryoprotectant to a final concentration of 10 micromol/L, 30 micromol/L, 100 micromol/L or 300 micromol/L. Specimens were incubated at 37 degree C in a 0.5 % CO(2) incubator for 1 h or cryopreserved at -196 degree C LN(2) for 3 days. The sperm motility and viability and the levels of ROS and lipid peroxidation of sperm membrance were assessed before and after incubation and cryopreservation by means of computer assisted semen analyzer, eosin-nigrosin stain, chemiluminescence and thiobarbituric acid assay, respectively. RESULTS: The sperm motility was significantly increased after incubation with 100 micromol/L and 300 micromol/L rebamipide (P<0.05). After cryopreservation, the sperm motility was significantly decreased in all concentrations (P<0.05), but the decrease was less with 100 micromol/L and 300 micromol/L rebamipide than that with other concentrations. The sperm viability showed no significant difference before and after incubation (P>0.05). The levels of ROS and lipid peroxidation in semen were significantly decreased in proportion to the concentrations of rebamipide both after incubation and cryopreservation (P<0.05). CONCLUSION: Rebamipide is an effective free radical scavenger in semen in vitro.