189 THE EFFECTS OF RESVERATROL ON PORCINE OOCYTES IN VITRO MATURATION AND SUBSEQUENT DEVELOPMENT AFTER PARTHENOGENETIC ACTIVATION AND IN VITRO FERTILIZATION

Abstract

The present study investigated the effects of resveratrol (a phytoalexin with various pharmacological activities) during in vitro maturation (IVM) of porcine oocytes on nuclear maturation, intracellular glutathione (GSH) and reactive oxygen species (ROS) levels, gene expression in matured oocytes and subsequent embryonic development after parthenogenetic activation (PA) and IVF. Data were analyzed with SPSS 17.0 using Duncan's multiple range test. In experiment 1, a total of 1146 cumulus–oocyte complexes (COC) were divided into 5 groups (0, 0.1, 0.5, 2.0 and 10.0 μM resveratrol). In the nuclear maturation after 44-h IVM, the groups of 0.1, 0.5 and 2.0 μM (83.0, 84.1 and 88.3%, respectively) had no significant difference compared to the control group (84.1%). The group of 10.0 μM decreased the nuclear maturation (75.0%) significantly (P < 0.05). In experiment 2, a total of 300 matured oocytes were examined for the effects of different resveratrol concentrations (0, 0.5, 2.0 and 10.0 μM) on porcine oocyte intracellular GSH and ROS levels. The groups of 0.5 and 2.0 μM showed a significant (P < 0.05) increase in intracellular GSH levels (1.3 and 1.3, respectively) compared with the control and 10.0 μM groups (1.0 and 1.0, respectively). The intracellular ROS level of oocytes matured with 2.0 μM resveratrol (0.4) was significantly (P < 0.05) decreased compared to other groups (control: 1.0; 0.5 μM: 0.6; and 10.0 μM: 0.7). In experiment 3, lower expression of apoptosis-related genes (Bax, Caspase-3 and Bak) was observed in matured oocytes treated with 2.0 μM resveratrol when compared with that of the control (P < 0.05). In experiment 4, a total of 728 oocytes were divided into 4 groups (control, 0.5, 2.0 and 10.0 μM) and examined subsequent to embryonic development after PA. Oocytes treated with 2.0 μM resveratrol during IVM had a significantly higher cleavage (CL) rate, blastocyst (BL) formation rate and total cell numbers (TCN) after PA compared with those of the control (2.0 μM: 96.6%, 62.1% and 49.1 vs control: 88.3%, 48.8% and 41.4, respectively) and the 10.0 μM groups (87.3%, 41.4% and 40.9, respectively). Oocytes treated with 0.5 μM resveratrol (87.2%, 50.5% and 48.6, respectively) during IVM had significantly higher TCN, but there were no differences in CL and BL formation rates. In experiment 5, a total of 935 oocytes in 3 groups (control, 2.0 and 10.0 μM resveratrol) were conducted in IVF. The BL formation rate and TCN were significantly higher in the group of 2.0 μM resveratrol (20.5% and 54.0, respectively) than the control (11.0% and 43.4, respectively) and 10.0 μM group (11.7% and 45.0, respectively), but there was no significant difference in CL rate. In conclusion, 2.0 μM resveratrol supplementation during IVM improved the developmental potential of PA and IVF in porcine embryos by increasing the intracellular GSH concentration, decreasing the ROS level and decreasing apoptosis-related gene expression during oocyte maturation. This work was supported by a grant from the Next-Generation BioGreen 21 Program (No. PJ008121), Rural Development Administration, Republic of Korea.