Objective:The in vitro study of different doses of polysaccharides from Curcumae Kwangsiensis Radix on the protective effect and mechanism of H2O2-induced injury of HUVECs. Method:Protective effects of polysaccharides from Curcumae Kwangsiensis Radix on H2O2-induced injury of human umbilical vein endothelial cells (HUVECs) and its mechanism were studied. HUVECs were cultured in vitro

HUVECs were injured with different concentrations of H2O2

and the optimal concentration of H2O2 was 500 μmol·L-1 by cell counting kit-8(CCK-8) method. Then

different concentrations of polysaccharides from Curcumae Kwangsiensis Radix were used to protect the damaged HUVECs. The CCK-8 method was used to determine 62.5

125

250 mg·L-1 as the low

medium and high-dose groups. Effect of CCK-8 method was used to detect the polysaccharides from Curcumae Kwangsiensis Radix H2O2 on the injury of HUVECs cell activity. Lactic dehydrogenase (LDH)

superoxide dismutase (SOD)

glutathione-peroxidase (GSH-Px)

malondialdehyde (MDA) were determined by kit. The levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in cells were detected by enzyme-linked immunosorbent assay (ELISA). Hoechst 33258 fluorescence staining was used to observe the cell apoptosis. The protein expressions of B-cell lymphoma-2 (Bcl-2)

Bcl-2-associated X (Bax) and cysteine aspartate-specific protease-3 (Caspase-3) genes were detected by real-time fluorescence quantitative polymerase chain reaction (Real-time PCR). Result:The result of CCK-8 assay showed after administration for 24 h

polysaccharides from Curcumae Kwangsiensis Radix within the concentration range of 15.625-500 mg·L-1 can promote cell proliferation; as the concentration increased

polysaccharides from Curcumae Kwangsiensis Radix had a certain inhibitory effect on cells. Compared with the model group

polysaccharides from Curcumae Kwangsiensis Radix could significantly reduce the content of LDH

MDA

IL-6

TNF-α(P<0.05

P<0.01)

while significantly increased the contents of SOD and GSH-Px(P<0.05

P<0.01). Hoechst 33258 fluorescence staining results showed that compared with the normal group

the nucleus of HUVECs showed bright blue fluorescence in the model group

dense and dense granular lumps of fluorescence were observed in the cytoplasm

and the cell density was decreased. Compared with the model group

the blue fluorescence intensity decreased

and the typical morphological apoptosis decreased. The Real\|time PCR results showed that compared with the normal group

the model group decreased the expression of Bcl-2 and increased the expression of Bax and Caspase-3(P<0.05

P<0.01). Compared with the model group

polysaccharides from Curcumae Kwangsiensis Radix group could increase the expression of Bcl-2(P<0.05

P<0.01)

while reduce Bax

Caspase-3 expression(P<0.05

P<0.01). Conclusion:polysaccharides from Curcumae Kwangsiensis Radix have a protective effect on human umbilical vein endothelial cells injured by H2O2 by resisting oxidation and inhibiting cell apoptosis.