[Protective effect of Salidroside on oxidative damage to human lens epithelial cells]

The aim of the experiment was to investigate the effects of salidroside (Sal) on oxidative damage to human lens epithelial cells (HLEC).

Experimental study. The cultured HLECwas intervened with hydrogen peroxide (H2O2) which created oxidative damage model to observe the effect of Sal on HLECs. The cultured cells during the logarithmic phase were interposed by different concentrations Sal (0 µmol/L, 10 µmol/L, 30 µmol/L, 50 µmol/L, 100 µmol/L, 200 µmol/L) for 24 h. Then the viability of cells was detected by cell counting Kit-8 (CCK-8) assay. The cells were divided into 5 groups:control group, H2O2 group, Sal low dose group (30 µmol/L Sal+ H2O2 group), Sal middle dose group (50 µmol/L Sal+H2O2 group), Sal high dose group (100 µmol/L Sal+ H2O2 group). The effects of Sal on the apoptosis of the HLEC were determined by Hoechst 33258 staining and flow cytometry assay.Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to detect B cell lymphoma-2 associated X protein (Bax), B-cell lymphoma-2 (Bcl-2) and Cysteinyl aspartate specific proteinase 3 (Caspase-3) expression. Data between groups were analyzed using one-way analysis of variance (ANOVA), while LSD-t test was used for further comparison between every two groups.

CCK-8 result showed that when the concentration of H2O2 was 200 µmol/L, the survival of HLEC inhibition rate was 49.56% ± 7.07%, which was close to the half of the cell survival inhibition rate (IC50). So 200 µmol/L was chosen as the concentration of H2O2 in follow-up experiments. Different concentrations of Sal had no inhibitive influence on HLEC viability. After 24 hours cultivated with Sal (10 µmol/L, 30 µmol/L, 50 µmol/L, 100 µmol/L, 200 µmol/L), the survival rate of HLEC were 100.24% ± 2.07%, 101.18% ± 2.14%, 101.32% ± 2.48%, 101.76% ± 1.93% and 99.28% ± 1.74% correspondingly. There was no significant difference comparing with that of the control group 99.84% ± 2.21% (F = 1.044, P = 0.415; all P > 0.05). Hoechst 33258 staining showed that the chromatin of H2O2 group aggregated and concentrated obviously. And Sal could reduce the aggregation of chromatin of HLEC obviously. FCM results indicated that the apoptosis rate of HLEC was 2.26% ± 0.29% in control group and 44.56% ± 4.28% in H2O2 group. After interposal with Sal (30 µmol/L, 50 µmol/L, 100 µmol/L), the apoptosis rate of HLEC reduced to 31.52% ± 3.05%, 24.06% ± 4.25% and 17.16% ± 2.75%. The differences of apoptosis rates had statistical significance between the five groups (F = 117.082, P < 0.001). The HLEC apoptosis rate decreased with higher Sal concentreations (F = 117.082, P < 0.01). The expression of Bax and Caspase-3 in H2O2 group were higher and the expression of Bcl-2 were lower than that in the control group (P < 0.01). Compared with the control group, the expression of Bcl-2 in three Sal dose groups was higher and the expression of Bax, Caspase-3 was lower, especially the high dose Sal group (Bax:F = 493.554, P < 0.01; Bcl-2:F = 827.820, P < 0.01; Caspase-3:F = 537.237, P < 0.01).

The Sal takes the protective effect on the oxidative damage to HLEC.It could decrease the apoptosis of HLEC.