The effect of epigallocatechin-3-gallate on caspase-3, BCL-2, NRF-2 and NF-kB protein expression in rats with carbon tetrachloride-induced liver damage

Epigallocatechin-3-gallate (EGCG) is a polyphenol that is effective in preventing tissue damage, cancer formation and increasing metabolism. In this thesis, 28 Wistar albino rats (n = 28, 8 weeks old) used. Animals were divided into four groups, and 7 rats involved in each group. The groups were: (i) Control Group: Standard diet; (ii) EGCG Group (50 mg/kg Live Weight (LW), ip): Standard diet + EGCG; (iii) CCl4 Group (1,5 ml/kg LW, ip): Standard diet + CCl4; (iv) CCl4 + EGCG Group: Standard diet + CCl4 (1,5 ml/kg LW, ip) + EGCG (50 mg/kg LW, ip). The animals were decapitated after 4 weeks and liver tissues were examined. Expression levels of caspase-3, bcl-2, Nrf-2 and NF-kB in the liver were determined by western blot technique, lipid peroxidation MDA (malondialdehyde) analysis by spectrophotometer. EGCG application, in the CCl4 + EGCG group, when compared to the CCl4 group, caspase-3, bcl-2, Nrf-2 and NF-kB expressions and MDA level create a significant difference (p<0.05). Caspase-3 and Nrf-2 expression level increased, MDA level decreased but bcl-2 and NF-kB expression level was decreased, through the application of EGCG. The rate of apoptotic index was observed decrease in the CCl4 + EGCG group than the CCl4 group at TUNEL assay examinations. These results shows that EGCG reduce the rate of liver damage at Wistar albino rats and these findings will be guiding in research of inhibitory effect of liver damage of humans like rats.