Protective Effect Of Green Tea Polyphenols On Damages Of HUVEC-12 Induced By Formaldehyde

Objective: To study the injury and mechanism of formaldehyde on the Human Umbilical Vein Endothelial Cells and the protective effect of green tea polyphenols.Methods: Human umbilical vein endothelial cells(HUVEC-12) were cultured with DMEM in vitro and selected the cells in the exponential phase of growth to experiment. The cells were treated with different formaldehyde concentrations(0 mmol/L, 0.05 mmol/L, 0.1 mmol/L, 1.0 mmol/L) for 4h. To determine the time-dependent effect, 0.1 mmol/L formaldehyde concentration was utilized to treat the cells for 0, 2, 4, 6, and 8h. To investigate the protective effect of green tea polyphenols(GTP) on damages of human umbilical vein endothelial cells induced by formaldehyde, the cells were divided into control group, 0.1 mmol/L formaldehyde group and four GTP groups(2.5 mg/L, 5 mg/L, 10 mg/L, 20 mg/L). Various concentrations GTP were preincubated with cells for 12h, then detected indexes mentioned below. The cell morphology was observed by transmission electron microscope(TEM). The concentrations of malondialdehyde(MDA) were determined by thiobarbiturif acid reactive substance method. The activity of superoxide dismutase(SOD) was determined by xianthine-xanthine oxidase method. The transudation contents of lactate dehydrogenase(LDH) were measured by colorimetry. Intracellular reduced glutathione(GSH) level were measured to evaluate the oxidative damage degree. The level of nitric oxide(NO) was determined by nitrate reductase method. The activation of nuclear factor-κB was investigated by immunocytochemistry (SP kit). Statistical analyses were performed with SPSS 11.5 statistical software. Data for each experimental group were subjected to analysis of variance(ANOVA). The data are expressed as the mean ± standard deviation. The level of statistical significance employed in all cases was P< 0.05.Results: Formaldehyde could induce cell membrane injury. The level of LDH,MDA and NO in FA groups were significantly increased in dose- and time-dependent manner,...