The beneficial effect of antioxidant supplementation in maturation culture media of sow oocytes was evaluated by the expression quantification of apoptotic genes and the genes that ensure stability of germ cells during fertilization. The oocytes were cultivated for 44 h in conventional medium (C) or in medium supplemented with 105 µM rosmarinic acid (R) and 0.5 mM ascorbic acid (A) and classified into three quality classes by morphological observation from which the total RNA was isolated. The gene expression of Ptx3 and the apoptotic regulator p53, Bax and BCL-2 were evaluated by quantitative PCR technique. The decreased expression of the Bax gene in the A and R groups, compared to the control, indicates a protective role of antioxidants in the cells. Cell homeostasis was maintained, as reflected in the ratio of Bax/Bcl-2 in class I COCs (cumulus-oocyte complex) regardless of the experimental group, indicating minimum cellular stress. The expression of p53 genes was higher in all class III COC, but in A1 and R1 the expression was lower than in C1, and a similar Ptx-3 gene decreased significantly in groups A1, A2, A3 and R1 compared with control groups. Antioxidant supplementation showed beneficial effects on all morphological classes of pig COCs.
Keywords: antioxidants; apoptosis; in vitro maturation; oocytes; sow.