the effects of taurine antioxidant on standard parameters, dna fragmentation, protamine deficiency and oxidative stress on freezing human semen

objective: evaluation of the effects of different doses of antioxidant taurine on oxidative stress and human sperm parameters following cryopreservation. materials and methods: the semen of 20 fertile men were divided to 5 aliquot, one part considered as a fresh after analysis of standard semen parameters (motility, abnormal morphology, viability) and protamine deficiency, dna damage and measurement of ros and rns. the other part was loaded on to a 80% and 40% allgrad gradient and centrifuged. the pellet was washed and divided into 4 separate fractions for control (non-frozen) and cryopreservation groups in absence or presence of 0.25 and 50 mm taurine. the frozen specimen were thawed and then examined. sperm motility evaluated using a casa software. the viability of spermatozoa was assessed by the trypan-blue stain method. levels of ros determined by spectroflorometry assay using dcfh-da. dna fragmentation examined by scd test and protamine deficiency examined by cma3+ staining. at the end results were analyzed using anova test. result: cryopreservation procedure increased the amount of ros and adding 25 mm of taurine improved post-thaw motility, progressive motility and sperm protamine deficiency. however, different doses of taurine (25 and 50 mm) had no significant effects in total abnormalities, viability, dna fragmentation and ros reduction. conclusion: antioxidant taurine has no significant effects on ros production following human sperm cryopreservation. but with dose of 25mm could improve the quality of spermatozoa due to the assessment of motility and protamine deficiency.