ANTIOXIDANT EFFICIENCY OF RESVERATROL ON OXIDATIVE STRESS-INDUCED DAMAGE IN BOVINE SPERMATOZOA

Substantial reports suggest that biologically active compounds isolated from natural sources may offer protection to semen against the incidence of free radical producers, improvement of semen quality, prevention of cryodamage and DNA fragmentation, as well as a general promotion of spermatozoa metabolism. This study was therefore designed to assess the impact of resveratrol (RES), a natural polyphenol and phytoalexin with potential antiviral, anti-inflammatory and antioxidant properties on bovine spermatozoa subjected to oxidative stress induced by ferrous ascorbate during a short-term cell culture (6h). Fresh bovine semen samples were centrifuged, the seminal plasma was removed, the sperm pellet was washed out and the resulting cells were diluted in 2.90% sodium citrate, divided into equal fractions and subjected to treatment based on a specific concentration of RES (50, 25, 10, 5, 0 mu mol/L) in the presence of an oxidative stress inducer, i.e. ferrous ascorbate (FeAA) containing 150 mu mol/L FeSO4 and 750 mu mol/L ascorbic acid. After 6h, the spermatozoa motility (using the Computer-aided sperm analysis/CASA system) and superoxide production (via the NBT test) were assessed in each sample. Furthermore, the sperm cells were collected, lysed and examined for the activity of superoxide dismutase and catalase, as well as glutathione and malondialdehyde concentrations. The addition of RES into the culture medium was able to significantly (P<0.001) slow down the deleterious effects of in vitro-associated free radical production. Concentrations of 25 - 50 mu mol/L RES were able to significantly (P<0.05) prevent the decline of spermatozoa physiology, functional activity and antioxidant capacity as a consequence of FeAA-associated oxidative stress development. Above all, this natural substance showed remarkable effects in stabilizing the activities of enzymatic antioxidants. Finally, we may suggest that resveratrol may be a suitable supplement for the in vitro management and preservation of male gametes.