Background: Sperm cryopreservation is an important compo- nent of fertility management and much of its successful applica- tion seems to affect the reproductive outcome of assisted repro- duction technologies (ART): appropriate use of cryoprotectants before and sperm selection technologies after cryopreservation seem to have the greatest impact on preventing DNA fragmen- tation, thus improving sperm cryosurvival rates. Quercetin is a flavonoid with high reactive oxygen species (ROS) scavenging and ion chelating activity. We were interested in testing the ef- fect of quercetin, as an antioxidant, in preventing sperm dam- age during the freeze - thawing process. Materials and Methods: Spermatozoa from 20 patients with asthenospermia were incubated in vitro with 50 µM quercetin or phosphate-buffered saline as a control for 1 hours. After this incubation period and administration of these compounds dur- ing freezing process, sperm progressive motility, sperm mor- phology, viability and DNA integrity were assessed before and after freezing/thawing process. Sperm motility and count were assessed according to WHO criteria, eosin nigrosin assay to assess sperm viability and the acridan orange assay to assess sperm DNA integrity, and papanicolaou assay to assess sperm morphology. Statistical analysis was performed by the student's t test. Results: Data showed that supplementation of the cryopreser- vation medium with quercetin induced a significant improve- ment in post thaw sperm parameters, compared to those of con- trol, regarding sperm morphology (P=0.05), viability (P=0.001) and DNA integrity (P=0.05). Conclusion: Quercetin could have protective effect during cry- opreservation and improves the quality of cryopreserved human semen but further research is needed to confirm this effect.
