Addition of ellagic acid improved the immune ability and delayed the apoptosis of ovarian granulosa cells of Guizhou black goat

Context Follicular development plays an important role in the growth and reproduction of female mammals. Ellagic acid (EA), as a natural antioxidant, has been used in freezing protection of pig semen. However, the effects of EA on immunity and the anti-apoptotic ability of ovarian granulosa cells (GCs) are still unclear. Aims The aim of this study was to analyse the effects of different concentrations of EA on the immune and anti-apoptotic ability of ovarian GCs of Guizhou black goats. Methods In this study, different concentrations of EA (0, 50, 100, 150, 200 μmol/L) were added to the culture of ovarian GCs in vitro, and Cell-Counting Kit 8 (CCK8) assay, cell wound scratch assay, and real-time fluorescence quantitative polymerase chain reaction (RT–qPCR) assay were used to detect the effects of different concentrations of EA on the proliferation, migration, and reproductive marker genes of ovarian GCs. Then the optimal addition concentration of EA was selected and the effects of EA supplementation on immune factors, cytochrome P450 family 19 subfamily A member 1 gene (CYP19A1), estradiol concentrations, intracellular reactive oxygen species concentrations, and apoptosis-related protein expression were detected by RT–qPCR, enzyme-linked immunosorbent assay (ELISA), ROS, and western blotting on the basis of the optimal addition concentration. Key results The CCK8 test and cell scratch test showed that the addition of EA could significantly inhibit the proliferation and migration ability of ovarian GCs compared with the control group, and a dose effect was observed with the increase in concentration. RT–qPCR results showed that different concentrations of EA significantly increased the expression of genes associated with reproduction, including bone morphogenetic protein 15 (BMP15), bone morphogenetic protein receptor 1B (BMPR-1B), growth differentiation fFactor 9 (GDF9), and follicle-stimulating hormone β subunit (FSHβ), and the maximum increase was observed at 150 μmol/L EA. Further analyses using 150 μmol/L EA as the optimal concentration showed significantly increased expressions of CYP19A1, interleukin-10 (IL-10), and superoxide dismutase (SOD2) after EA supplementation, while the expression of IL-8 was significantly decreased compared with those of the control group. ELISA and ROS showed that both intracellular and extracellular estradiol concentrations were higher, while ROS concentrations were significantly lower than those in the control group. Western blotting results showed that 150 μmol/L EA significantly decreased the expression of Caspase-3 and Caspase-9 and the ratio of BCL2-associated X:B-cell lymphoma-2. Conclusions The supplementation of 150 μmol/L EA had significant effects on improving GC immunity and delaying GC apoptosis in goats. The addition of EA also increased the expression of BMP15, BMPR-1B, GDF9, FSHβ, and CYP19A1 and promoted the secretion of estradiol in GCs. Implications These results provided a preliminary lead for further research on the effect of EA on the maturation and development of goat oocytes in vitro.