Resveratrol compares with melatonin in improving in vitro porcine oocyte maturation under heat stress

Background: Resveratrol, an important phyto-antioxidant commonly found in grapes, mulberry, and other plants, has a variety of functions including anti-aging, anti-cancer and anti-inflammatory activities. In the current study, we investigated the beneficial effects of resveratrol on in vitro porcine oocyte maturation under heat stress (HS). The effect of resveratrol, melatonin and their combination on alleviating HS was compared according to the maturation rate of oocytes and the development competence of embryos after parthenogenetic activation (PA). Results: Supplementation with resveratrol (2.0 mu mol/L) not only improved the nuclear maturation but also raised the blastocyst rate of porcine embryos' PA from oocytes that underwent HS by increasing their glutathione (GSH) level, reducing reactive oxygen species (ROS) and up-regulating the expression of Sirtuin 1 (SIRT1). It was also found that melatonin (10(-7) mol/L) and the combination of resveratrol (2.0 mu mol/L) plus melatonin (10(-7) mol/L) exhibited more potent effects than resveratrol alone regarding their protective activities on oocyte maturation under HS. Conclusions: This study compared the efficiencies of resveratrol, melatonin and their combination for protecting porcine oocytes from heat stress. The mechanisms are attributed to the fact that each treatment may have different ability to regulate the synthesis of steroid hormones and the expression of mature related genes.