ABSTRACT
AIM:To study the effect of Lycium barbarum polysaccharides (LBP) on oxidative stress injury of human endothelium-like EA. Hy926 cells induced by hydrogen peroxide (H2O2). METHODS:The EA. Hy926 cell model of oxidative stress injury was established by H2O2 treatment. The EA. Hy926 cells were divided into 5 groups:control group, damage (H2O2 at 50 mmol/L) group, LBP (100 mg/L) group, anti-damage groups (LBP at 50 mg/L, 100 mg/L or 200 mg/L+50 mol/L H2O2), and LY294002 (20 μmol/L) group. The effect of LBP at different concentrations on the cell viability of EA. Hy926 cells was measured by CCK-8 assay, and the optimum concentration of LBP was screened out. The apoptotic of EA. Hy926 cells was analyzed by flow cytometry. Acridine orange/ethidium bromide ( AO/EB) staining was used to observe the morphological characteristics of the apoptotic cells. The cell migration ability was detected by scratch method. The levels of nitric oxide (NO) and vascular endothelial growth factor (VEGF) in the cell culture medium were examined. The protein levels of cleaved caspase-3, Bax, Bcl-2, endothelial NO synthase (eNOS), p-eNOS and p-Akt were determined by Western blot. RESULTS:LBP at concentration of 100 mg/L significantly attenuated the injury of EA. Hy926 cells induced by H2O2, as indicated by improved cell viability ( P <0.05 ) and decreased apoptosis ( P <0.05). Pretreatment with LBP elevated the levels of NO and VEGF (P<0.05), and promoted the migration ability of EA. Hy926 cells. LBP also increased the Bcl-2/Bax ratio, down-regulated the protein level of cleaved caspase-3, and up-regulated the protein levels of eNOS and p-eNOS. The protective effect of LBP were abolished by pretreatment of the EA. Hy926 cells with the inhibitor of PI3K (P<0.05). As a result, the protein level of p-Akt was down-regulated, and the level of NO was also significantly reduced. CONCLUSION:LBP has protective effect on H2O2-induced EA. Hy926 cells by attenuating apoptosis of the cells. The mechanism is closely related to the activation of PI3K/Akt/eNOS signaling pathway.
ABSTRACT
The opening of laboratories in universities is one of important parts in teaching reform and it is necessary for bringing up high-qualified students.Combined with the practical teaching,we have a primary discussion with the problems of the laborato- ry opening and put forward some suggestions and measures.