Experimental Study On The Protective Effect Of Grape Procyanidins On Proliferation And Apoptosis Of Hepatocytes And Thymus Cells

Objective: Grape procyanidins(GPC) are natural polyphenols extracted from grapes. It was reported that GPC have a lot of bioactivities such as antioxidation, antiradical and antitumor effects. In this study we investigated whether GPC can protect oxidative injury of cells induced by free radicals in vitro and vivo. Methods:1.Hepatocytes(1) In vitro it takes a model of hepatocytes oxidative damage induced by CCL4, alcohol and H202repectively. MTT assay was used to test the influence of GPC on free radicals induced inhibition of cell proliferation. Meanwhile the proliferation of normal cells was also tested.(2) Healthy Kunming mice were divided into 5 groups such as normal control, alcohol and GPC bred continuously for one week. MTT assay was used to test effect of GPC on the acute damage of hepatocytes.2.Thymus cell: Thymus cells of mouse were cultured in vitro. Flow cytoraetry was used to analysis apoptosis and mitochondrial transmembrane potential of thymus cells damaged by H2O2.Results: 1. GPC can promote the proliferation of normal hepatocytes in vitro. The cell proliferation was 0.621 ±0.015 and 0.671 ± 0.022 after normalhepatocytes were cultured with 50 and 100 ug/ml GPC for 36h, much higher than2. In positive groups damaged by CCL4, alcohol and H202respectively, cell proliferation decreased in different degrees. While after pretreatment of GPC, cell proliferation damages lowed obviously. The proliferation of cells damaged by 10mol/L CCL4, was 0.287±0026, much lower than the group prtreated by 50ug/ml GPC. The proliferation of 100ul/ml alcohol group was 0. 365±0.024. After pretreatment of 50ug/ml GPC, cell proliferatin was 0.541±0.026. The difference between two groups is obvious. The proliferation of 1mmol/l H202 was 0.367±0.033. It is lower than the group pretreated by 50ug/ml GPC (0.568 ±0.042).3. In vivo, GPC can decrease the acute damage of hepatocytes obviously. The proliferation rate of the positive group was 0.064 ± 0.022. While after pretreated by 150mg/ml GPC, the proliferation rate was 0.119±0.015, much higher than the positive group.4. The result of flow cytometry shows apoptosis rate and mitochondrial transmembrane potential of posive group were 29. 53% and 27.24 repectively. After pretreatment of 50ug/ml GPC, the apoptosis rate decreased by 22.02% and the mitochondrial transmembrane potential increased by 60. 31. Conclusion: GPC can lesson proliferation inhibition of hepatocytes and thymus cells induced by oxygen-derived free radicals both in vitro and in vivo. It decreased lipid peroxidation products in cells and increased activities of antioxidation enzyme. Furthermore GPC can also promote proliferation of normal hepatocytes.Lilei(Medical Nutrition)Directed by Professor Zhong jinyi...