槲皮素对LPS诱导的体外培养肝细胞损伤的影响及机制

目的： 通过体外观察槲皮素对脂多糖（LPS）所致肝细胞损伤和肿瘤坏死因子（TNF-α）表达的影响,探讨槲皮素的作用及其机制。方法：胶原酶灌流分离培养大鼠肝细胞,40 mg/L LPS诱导损伤,同时用0.5-10 μmol/L浓度槲皮素进行干预,作用24 h后,四甲基偶氮唑盐比色法（MTT）、PI-AnnexinV染色检测肝细胞的增殖凋亡比例、测定上清液乳酸脱氢酶含量,ELISA、RT－PCR方法检测TNF-α表达。结果：40 mg/L LPS作用于原代培养大鼠肝细胞24 h后,与对照组相比,细胞生长抑制率达27%,细胞总凋亡率30.2%,培养上清液LDH含量增加20倍,TNF-α mRNA和蛋白表达明显增加（P<0.05）。给予0.5-10 μmol/L槲皮素后,各项指标有明显下降,且呈量效关系。结论：0.5-10 μmol/L槲皮素拮抗LPS所致的肝细胞损伤,其保护作用的机制可能与抑制TNF-α的表达有关。

Effects of ouercetin on lipopolysaccharide induced hepatocyte injury in vitro

AIM: To study the effects of quercetin on lipopolysaccharide (LPS) induced hepatocyte injury and the expression of TNF-α in vitro. METHODS: Hepatocytes were isolated from male Sprague-Dawley rats by collagenase perfusion. LPS at concentration of 40 mg/L was used to induce injury to the cultured cells, and 0.5-10 μmol/L quercetin was added at the same time. After 24 h of incubation, the cell apoptosis rates were detected by MTT and PI-AnnexinV. LDH and TNF-α were measured by kits. RESULTS: 40 mg/L LPS caused a 27% growth inhibition. The apoptosis rate was 30.2%. LDH leakage was 20 folds higher than normal. TNF-α expression significantly increased. Treated with quercetin at doses of 0.5-10 μmol/L, the apoptosis rate, LDH leakage and TNF-α expression in hepatocytes were attenuated in a dose dependent manner. CONCLUSION: 0.5-10 μmol/L of quercetin protects hepatocytes from injury induced by LPS, which is associated with suppression of the inflammatory cytokine TNF-α.