Antioxidant effect of Epigallocatechin gallate on bovine IVM and IVF

Abstract

The present study examined the effect of epigallocatechin gallate (EGCG) during In-vitro maturation (IVM) and In-vitro fertilization (IVF) of bovine oocytes. Cumulus-oocyte complexes (COCs) were aspirated from the ovaries derived from slaughter house and cultured in Tissue culture medium-199 supplemented with 5, 10 or 15 µM of epigallocatechin gallate for 24 h. Oocytes of a control group were matured in a maturation medium without EGCG. After IVM, COCs were coincubated with frozen-thawed spermatozoa for 15–18 h. In comparison with the absence of EGCG, treatment with EGCG at 10 and 15 µM showed a significant increase in the proportion of cumulus cell expansion, 1st polar body and 2nd polar body. However, compared to control, the presence of 10 and 15 µM EGCG during IVM significantly (P < 0.01) increased the proportion of In-vitro maturation and fertilization rate. However, a further decrease to 5 µM EGCG reduced (P < 0.01) the In-vitro maturation and fertilization rate. The results suggest that at certain concentrations of EGCG (10 and 15 µM) in IVM medium has beneficial effects on In-vitro maturation and subsequent In-vitro fertilization of bovine oocytes.