[Chinese herbal medicine Lingqi Huangban Granule protects retinal pigment epithelial cells against oxidative stress-induced injury in vitro].

OBJECTIVE

To observe the protective effects of drug-contained serum of Lingqi Huangban Granule (LQHBG), a compound traditional Chinese herbal medicine, on oxidative stress-induced injury in rabbit retinal pigment epithelial (RPE) cells in vitro.

METHODS

The oxidative stress of rabbit RPE cells in vitro was induced with hydrogen peroxide (500μmol/L) and different concentrations of LQHBG were administered to rats to prepare medicated serum. RPE cells were randomized into normal control group (no hydrogen peroxide), model group (hydrogen peroxide), model plus serum group (hydrogen peroxide and 10% control serum), model plus low-dose LQHBG group (hydrogen peroxide and low-dose LQHBG-medicated serum) and model plus high-dose LQHBG group (hydrogen peroxide and high-dose LQHBG-medicated serum). Teminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay and flow cytometry (FCM) were used to measure apoptosis of cultured rabbit RPE cells. Protein expressions of caspase-3 and Bcl-X(L) were observed by Western blot method.

RESULTS

FCM results showed that the apoptotic rates of the normal control group, model group, control serum group and serum containing low- and high-dose LQHBG groups were (4.85±0.26)%, (20.02±1.37)%, (21.84±0.94)%, (13.56±0.55)%, and (8.58±0.39)%, respectively; compared with the model group, the apoptotic rates of RPE cells in the low- and high-dose LQHBG groups were obviously reduced in a dose-related manner (P<0.05). TUNEL results showed that nuclei of apoptotic cells were stained brown; the number of apoptotic cells in the low- and high-dose LQHBG groups was obviously less than that in the model group. The protein expression of caspase-3 was up-regulated in the model and control serum groups, which was higher than that in the high-dose LQHBG group (P<0.05). The protein expression of Bcl-X(L) was down-regulated in the model and control serum groups, which was lower than that in the low- and high-dose LQHBG groups (P<0.01).

CONCLUSION

Drug-contained serum of LQHBG obviously reduces apoptosis and partly protects rabbit RPE cells from oxidative stress-induced injury. The protective function is due to an improvement in antioxidant abilities, down-regulation of the expression of caspase-3 and up-regulation of the expression of Bcl-X(L).