Effects of Resveratrol‐Loaded Nanoparticles on Follicular Survival, Stromal Integrity and Activity of Endogenous Free‐Radical Scavengers in Bovine Ovarian Cortical Slices Cultured In Vitro

The aims of this study were to assess the effects of resveratrol-loaded nanoparticles (RLNP) on follicular survival, stromal integrity and activity of endogenous free-radical scavengers in bovine ovarian tissues cultured in vitro. Ovarian cortical slices were incubated in α-MEM+ alone or supplemented with 0.2, 2.0 or 20.0 μM RLNP, blank nanoparticles (BNP) or free resveratrol (20.0 μM) for 6 days at 38.5°C and 5% CO2. Follicular integrity, number of stromal cells, density of collagen fibres, levels of thiol and activity of free-radical scavengers (glutathione peroxidase GPX, superoxide dismutase SOD and catalase CAT) were evaluated in tissues cultured in the different treatments. The data showed that ovarian cortex cultured with 20.0 μM free resveratrol or RLNP, in all tested concentrations, had a reduced rate of morphologically intact follicles in relation to uncultured controls (p < 0.05). The RLNP (0.2, 2.0 or 20.0 μM) and BNP increased the proportion of growing follicles and stromal cell numbers (p < 0.05). Collagen fibre levels decreased in tissues cultured with 0.2 or 2.0 μM RLNP compared to uncultured controls, but remained greater than those seen in ovarian cortex cultured in other treatments (p < 0.05). Free resveratrol increased CAT and GPX activity, while RLNP reduced activity of SOD and GPX (p < 0.05). In conclusion, RLNP improved follicle survival and growth, preserved stromal tissue and modulated the activity of free-radical scavengers in bovine ovarian slices cultured in vitro.