Effect of tea polyphenols on formaldehyde-induced damage of human umbilical vein endothelial cells

ObjectiveTo observe the effect of tea polyphenols(TP)on formaldehyde-induced oxidative damage of human umbilical vein endothelial cells.MethodsHuman umbilical vein endothelial cells were cultured with Dulbeccos modified Eagles medium in vitro and selected for exponential phase of growth for the experiment.Three groups were established as nomal group,formaldehyde injured group(0.1 mmol/L),and TP protection groups(2.5,5,10,and 20 mg/L),in which the tea polyphenols was firstly preincubated with the cells for 12hr before adding formaldehyde,followed by culturing for 4hr in CO₂ incubator.The activity of superoxide dismutase(SOD)in cell culture solution,the level of lactate dehydrogenase(LDH),malondialdehyde(MDA),nitric oxide(NO)in the culture,and glutathione(GSH)and the activity of nuclear factor-kappa B(NF-κB)in the cells were detected.ResultsThere were statistical differences in the levels of LDH, MDA,and NO between TP protection groups and formaldehyde-injured group,with the LDH levels of 2 021.02,1 878.17,1 748.56,and 1 625.72 U/L,MDA of 3.50,3.30,2.99,and 2.68 nmol/mL,and NO of 79.09,75.07,66.79,and 60.59 μmol/L for the TP group of 2.5,5,10,and 20 mg/L,respectively.Although the activity of NF-κB was significantly lower than that of formaldehyde group,the activity of SOD,GSH of the TP protection group were different from that of formaldehyde-injured group(P<0.01),with the SOD activity of 24.16,24.67,25.56,and 26.02 U/mL,GSH of 0.334,0.364,0.445,and 0.449μmol/mg,all higher than those of formaldehyde-injured group(SOD=23.72 U/ml and GSH=0.325 μmol/mg).ConclusionTea polyphenols can increase the activity of antioxidant enzymes in endothelial cells and reduce oxidative damage caused by formaldehyde.Tea polyphenols can lower generation of NO and ease intracellular lipid peroxidation by inhibiting the expression of NF-κB.