Protective effect of oridonin against the injuries in endothelial cells

Abstract

Objective To investigate the protective role of oridonin in the vascular endothelial cells dysfunction induced by high glucose and lipid. Methods The optimum concentration of oridonin on human umbilical vein endothelial cells(HUVECs)were determined by MTT assay.The model of HUVECs was established and divided into 3 groups:control group,oridonin group(oridonin treated for 24 h,with high glucose and high palmitic),high glucose and palmitic acid group 33.3 mmol/L glucose.HUVECs were pretreated with oridonin under the condition of 33.3 mmol/L glucose and 500 μmol/L palmitic acid,while other groups received 33.3 mmol/L glucose and 500 μmol/L palmitic acid and dimethyl sulfoxide(DMSO). After 48 h treatment,the concentration of tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6)in the supernatant was detected by the enzyme-linked immunosorbent assay (ELISA) to observethe inflammation state while flow cytometry was used to detect the cell apoptosis of each group,the mRNA expression of TAp63 and Silent information regulator 1 (Sirt1) in HUVECs was detected by the real time polymerase chain reaction(real time PCR). And the protein expression of TAp63,Sirt1,phosphorylated extracellular regulated protein kinases (p-ERK) and B-cell lymphoma 2(Bcl-2) were determined by Western-blotting. Result The optimum concentration of oridonin treating on HUVECs was 5 μmol/L when effect for 24 h. Compared with the control group,the apoptosis rate,the protein expression of phosphated ERK, and the concentration of inflammation factors(TNF-α and IL-6) in the supernatant were significantly higher(t=14.34,12.59,17.37, 17.90, P<0.05 all above)while the expression of TAp63 mRNA and protein,Sirt1 mRNA and protein,Bcl-2 protein was significantly lower in the HUVECs in the high glucose and palmitic acid group(t=-22.50,-6.02,-16.22,-6.72,-7.71,all P<0.05).But in the oridonin group which were treated with 33.3 mmol/ L glucose and 500 μmol/L palmitic acid, the pretreatment with oridonin significantly induced the expression of TAp63 mRNA and protein(t=5.85,5.06,all P<0.05),Sirt1 mRNA and protein level(t=4.55,3.04, all P<0.05)and Bcl-2 protein(t=5.81,P<0.05).Furthermore, the apoptosis rate,the protein expression of phosphated ERK, and the concentration of TNF-α and IL-6 in the supernatant were significantly reduced(t=-7.11,-7.81,- 10.51,-10.36,all P<0.05). Conclusion Oridonin could protect vein endothelial cells from the damage induced by high glucose and palmitic acid,which may be related to the inhibition inflammation induced by high glucose and palmitic acid,or to increasing the expression of TAp63,Sirt1,Bcl-2 and decreasing the expression of p-ERK. Key words: Oridonin; V ascular endothelial cells; TAp63; Silent information regulator 1; Inflammation