Cryoprotective effect of resveratrol on DNA damage and crucial human sperm messenger RNAs, possibly through 5' AMP-activated protein kinase activation.

This work aimed at investigating the effect of resveratrol on (1) DNA integrity and (2) fertilizing capacity of sperm by quantifying the presence of key paternal transcripts considered as markers for male fertility (protamine 1 [PRM1] and protamine 2 [PRM2]) and pregnancy success (adducin 1 alpha [ADD1]) in cryopreserved human spermatozoa through modulation of AMP-activated protein kinase (AMPK). The study populations was drawn from 22 normozoospermic healthy volunteers which were incubated with or without AMPK activator (resveratrol [RSV], 15 µM) or inhibitor (Compound C [CC], 30 µM) for 1 h and were then cryopreserved. Untreated frozen-thawed spermatozoa served as controls. The RSV-induced AMPK activation decreased the level of DNA fragmentation in comparison with the control (21.18 ± 0.92 vs. 22.50 ± 0.40; p < 0.01). The relative mRNA expression levels of protamines (1 and 2) and ADD1 in RSV pretreated frozen-thawed human spermatozoa were also improved significantly compared to the control (p < 0.05). Conversely, the inhibitory effect of CC on AMPK activity deteriorated the deleterious effects of cryopreservation on these parameters (p < 0.01). In conclusion, these results demonstrated the cryoprotective effect of the RSV-induced increase in AMPK activity on DNA integrity and key paternal transcripts of cryopreserved human spermatozoa. These findings are of great importance for improving the available cryopreservation protocols in terms of the number of lesions that produced over key genes and the dramatic effects on sperm DNA fragmentation.