Background and Aim: Sperm cryopreservation is an important assisted reproductive technique. However, due to increased production of reactive oxygen species and oxidative stress, it can impair sperm function and reduce quality of fertility. The aim of this study was to investigate the effects of nicotinic acid and folic acid on maintenance of sperm function during cryopreservation by evaluation of sperm parameters and chromatin concentration.

Material and Methods: Thirty samples were collected from normozoospermic men and examined for chromatin quality, viability, membrane integrity, morphology and motility. The samples were frozen and placed in 4 groups: control, folic acid (50 nM), nicotinic acid (10 mM) and a combination of both. After cryopreservation, the four groups were compared with one another in regard to the sperm parameters. Also the sperm parameters were compared before and after freezing in every group. We assessed chromatin quality by TB staining, viability by eosin-nigrosin staining, membrane integrity by hypo osmotic swelling test, and morphology and movement by CASA software.

Results: Before cryopreservation chromatin quality, membrane integrity, normal morphology, sperm motility were lower and immotile sperms were higher in all groups compared to those after cryopreservation (p <0.001). The highest chromatin quality was detected in the folic acid, folic acid + nicotinic acid groups and the lowest chromatin quality was observed in the control group (p</05). The rates of sperm viability and normal morphology were lowest in the control group and highest in the folic acid and other groups (p <0.05). percentage of membrane integrity was highest in the folic acid group followed by nicotinic acid + folic acid, nicotinic acid and control groups, respectively (p <0.05). Folic acid played an important role in maintaining sperm parameters.
Conclusion: Nicotinic acid and folic acid have a positive effect on maintaining sperm function during cryopreservation