[Protective Effect of Total Flavonoids from Carya cathayensis Leaf on Cultured H9C2 Cardiomyocytes During Hypoxia / Reoxygenation Injury].

To study the protective effect of total flavonoids from Carya cathayensis leaf on cultured H9C2 cardimyocytes during hypoxia / reoxygenation( H / R) injury.

Co Cl2 was used to induce the H / R injury model in H9C2 cells at different concentrations,different H / R time. Total flavonoids from Carya cathayensis leaf was added into culture medium with final concentration of2. 5,5 and 10 μg / m L before H / R. Lactate dehydrogenase( LDH), Malondialdehyde( MDA) content, Superoxidedimutase( SOD) activity in the bathing medium were assayed for the evaluation of myocardial cell injury. Myocardial cell viability was detected by the MTS assay kit. Apoptotic changes in H9C2 cells were observed by using Hoechst-PI staining and flow cytometry analysis. The expression of HIF-1αprotein was detected by Western blot.

Using 1 200 μmol / L Co Cl2 to hypoxia the cells for 18 h and then reoxygenation for 2 h were the best condition of H / R injury model. Compared with model group,the cells treated with total flavonoids from Carya cathayensis leaf could decrease the activity of LDH and the content of MDA, while increased the activity of SOD. Moreover, they could regulate the expression of HIF-1α protein to normal level.

It is suggested that total flavonoids from Carya cathayensis leaf has a protective effect on H9C2 cardiomyocyte during H / R injury. The mechanism may be relate to enhancing the capability of the cell clearing the oxygen free radial, decreasing the production of lipid peroxidation and reducing apoptosis.