THE EFFECT OF GREEN TEA EXTRACT - EPIGALLOCATECHIN GALLATE (EGCG) ON BASIC OVARIAN FUNCTIONS IN PORCINE OVARIAN GRANULOSA CELLS

Abstract

Epigallocatechin gallate (EGCG) is the major catechin found in green tea (Camellia sinensis), but there is only little data of its influence on reproductive processes. The aim of this „in vitro“study was to examine the effects of green tea extract - epigallocatechin gallate (GT-EGCG) on proliferation, apoptosis and steroidogenesis of ovarian cells. Granulosa cells isolated from porcine ovaries were cultured without (control) or with GT-EGCG (0, 1, 10, 100 μg.ml-1of medium). Markers of proliferation (PCNA) and apoptosis (bax) were detected by immunocytochemistry. Secretion of steroid hormones (progesterone and testosterone) was measured by RIA. It was found, that GT-EGCG supplement significantly diminished percentage of cells containing PCNA (proliferation) at all used doses. Proportion of bax-positive cells (apoptosis) was increased after addition of GT-EGCG at the highest dose. Addition of GT-EGCG increased progesterone release by addition at 10 μg.ml-1 dose and inhibited testosterone secretion at the lowest dose. In conclussion, we demonstrated that GT – EGCG has potent dose-dependent effect on proliferation and apoptosis of ovarian granulosa cells, as well as secretory activity of these cells to produce steroid hormones. It was shown, that green tee GT-EGCG can be an inhibitor of porcine ovarian functions. These direct effect on the ovary could be taken into account by green tee consumption and its application for control of animal and human reproductive procrsses.