Study On The Protective Effect Of EGCG On Vascular Cells By The Combination With Vardenafil

The incidence of cardiovascular disease has being increased year by year since the change of diet structure and environmental deterioration. It becomes one of the most serious killers that threaten human health. At the same time, the treatment for cardiovascular disease brings physical pain to the patients, and aggravates burdens on their family. As an important bioactive component of green tea,(-)-epigallocatechin gallate (EGCG) shows positive effect on anti-cancer, anti oxidation and cardiovascular disease. But EGCG exhibits low bioavilability which should be improved. The present study aims to improve the bioavilability of EGCG by the combination of EGCG and vardenafil which was previously used in the treatment of cardiovascular diseases. The main investigation include the effect of combination of EGCG and vardenafil on the proliferation of H9C2 cells (rat cardiac myocytes),the effect of the combination of EGCG and vardenafil on the repair of H9C2 cells injured by oxidative damage, and the repair mechanism by analyzing the change of the factors related to cellar apoptosis.The main results are presented as follows:(1) The MTT assay of proliferation H9C2 cells showed that EGCG and vardenafil could promote the proliferation of H9C2 cells and the best treatment concentration for EGCG was 100 μmol/L for EGCG and 2 μmol/L for vardenafil. The proliferative increase rate for EGCG, vardenafil, and the combination of EGCG and vardenafil were 18.74%, 10.77% and 29.17% after 48 h of the treatments respectively,compared to the celles without treatment. Significantly, vardenafil improve the proliferative effect of EGCG on cardiac myocytes.(2) NO concentrations in the cells treated with EGCG, vardenafil, and the combination of EGCG were assayed. The results showed in MTT experimental, detecting the concentration of NO in each group by the method of nitric acid reduction. The results showed that comparing with the blank control group, the concentration of NO increased significantly after treating H9C2 cells with EGCG of 100μmol/L and vardenafil of 2 μmol/L after 48 h.(2) NO concentrations in the cells were assayed. The results showed they were 19.75, 20.87 and 22.47 μmol/L for EGCG, vardenafil, and the combination of EGCG and vardenafil while the cells without treatment gave 17.33 μmol/L of NO, which showed that vardenafil could improve the effect of EGCG on enhancing NO level of the cells.(3) SOD, MDA and GSH-XP were assayed in the injured cells induced by H2O2 by a model of H9C2 cells with a cell survival rate of 50%. The results showed that vardenafil could enhance the inhibition effect of EGCG against oxidative damage indicated by the levels of SOD, MDA and GSH-XP in the cells.(4) The activities of Caspase-3, Caspase-8, Caspase-9, and the expression of Bax, cytochrome C and Bcl-2 in the injured cells induced by H2O2 treated with EGCG, vardenafil, and the combination of EGCG and vardenafil were determined. The results showed that vardenafil enhanced the effects of EGCG on inhibiting the apoptosis of cells induced by H2O2.