Protective Effect And Mechanism Of "Lingqi Huangban Granula" On Oxidative Stress-induced Injury In Rabbit Retinal Pigment Epithelial Cells

Objective: To observe the protective effect and Mechanism of drug-contained serum of"Lingqi Huangban Granula"(LQHB) on rabbit retinal pigment epithelial (RPE) cells of oxidative stress induced injury in vitro.Methods: The oxidative stress model of cultured rabbit RPE cells was induced with hydrogen peroxide (500μmol/L) and different concentrations drug-contained serum of LQHB were administered. RPE cells were randomized into normal control group (NC group), model group (M group), model + normal serum group (MS group), model + low-dose LQHB group (ML group) and model + high-dose LQHB group (MH group). The level of cell proliferation was measured by the MTT method, TUNEL and Flow Cytometer (FCM) methods were used to measure the apoptosis of cultured rabbit RPE cells. The level of malondialdehyde (MDA) and the activity of total superoxide dismutase (T-SOD) in the cell were determined to reflect the oxidant-antioxidant status. The protein expression of Caspase-3 and Bcl-XL were observed by western blot and immunohistochemistry methods. (Data were analysed by statistic software of SAS 6.12)Result: MTT: the drug-contained serum of LQHB could significantly accelerate cell proliferation and reduce the inhibition rate of cell growth induced by H2O2. FCM: the apoptosis rates of NC, M, MS, ML and MH group were 4.85%±0.46%, 20.02%±1.37%, 21.84%±1.53%, 13.56%±0.87%, 8.58%±0.74% respectively, and compared with M group, the apoptosis rate in ML and MH group was obviously reduced. TUNEL: there were major apoptotic cells in M and MS group which cell nuclei were stained yellow, while a few were found in ML and MH group. The MDA levels of RPE cells in M and MS group were significantly higher than that in NC group, lower levels were found in ML and MH group; the activities of T-SOD in ML and MH group were significantly higher than those in M and MS group, and also higher than that in NC group. The protein expression of Caspase-3 was upregulated in M and MS group, which was higher than that in ML and MH group. The protein expression of Bcl-XL was downregulated in M and MS group, which was lower than that in ML and MH group.Conclusion: drug-contained serum of LQHB could obviously reduce apoptosis and partly protect rabbit RPE cells from oxidative stress-induced injury, and represented dose-dependent trend. The protection maybe via improve the antioxidant ability, downregulated the expression of Caspase-3 and upregulated Bcl-XL.