Correlation between sperm motility and sperm chromatin/DNA damage before and after cryopreservation and the effect of folic acid and nicotinic acid on post-thaw sperm quality in normozoospermic men

Background: Cryopreservation exposes sperm to physical and chemical stresses due to the overexposure of reactive oxygen species and reduced efficacy of existing antioxidants.Objective: We aimed in this experiment to study the association between sperm motility and sperm chromatin/DNA damage before and after cryopreservation. Then, we investigated the possible protective effects of nicotinic acid and folic acid on sperm quality.Materials and Methods: Semen samples were collected randomly from 30 normozospermic males with age range of 25-45 yr. Each sample was divided into 5 groups: fresh, cryopreserved without treatment (control), with nicotinic acid or folic acid, and combination of folic acid and nicotinic acid. In each group to assess sperm viability and motility we used eosin-nigrosin staining and computer aided sperm analysis (CASA), and for chromatin and DNA quality we used aniline blue and toluidine blue staining, sperm chromatin dispersion test and acridine orange staining.Results: Sperm quality after cryopreservation showed statistically significantly reduced in comparison to fresh sample groups (p<0.05). Before and after cryopreservation, sperm chromatin/DNA damage was negatively correlated with percentage of progressively motile cells. After addition of folic acid or nicotinic acid in cryopreservation medium found to significantly improved sperm parameters and DNA and chromatin quality when compared with the control groups (p<0.05), the combination of folic acid and nicotinic acid showed best cryoprotective effect on semen.Conclusion: In conclusion, significant reduction in progressive motility in post-thaw sperm can be indicator of significant chromatin/DNA damage and folic acid and nicotinic acid showed to have cryoprotective effect on sperm quality.

Keywords:

Cryopreservation , Sperm , DNA , Chromatin , Folic Acid , Nicotinic Acid