槲皮素拮抗酒精性肝损伤中胆红素的介导效应

目的探讨槲皮素诱导Ⅰ型血红素氧合酶(heme Oxygenase-1,HO-1)及其代谢产物胆红素对肝细胞酒精性氧化损伤的保护效应。方法二步胶原酶灌注技术分离培养SD大鼠原代肝细胞,在孵以200 mmol乙醇建立酒精性肝细胞氧化损伤模型的同时,加入槲皮素(100μmol)、hemin(20μmol)等及不同剂量(2-100μmol)的胆红素干预24 h后,检测细胞内超氧化物歧化酶(SOD)活力及谷胱甘肽(GSH)、丙二醛(MDA)及氧自由基(ROS)水平及培养基中总胆红素水平。结果槲皮素明显抑制了乙醇孵育后细胞MDA和ROS水平的升高,有效维持了细胞内GSH水平和SOD活力;加入外源性胆红素也显示出相同的保护效应,且具有一定的剂量依赖性;锌原卟啉IX(ZnPP-IX)则明显抑制了上述槲皮素的保护效应。结论槲皮素诱导HO-1对酒精所致大鼠原代肝细胞氧化损伤具有保护作用,其机制与HO-1的代谢产物之一胆红素有关。

THE MEDIATE EFFECT OF BILIRUBIN INVOLVED IN QUERCETIN AGAINST ETHANOL-INDUCED HEPATOCYTES INJURY

Objective To investigate the protective effect of hemeoxygenase-1(HO-1) and its metabolite bilirubin induced by quercetin on ethanol-induced oxidative damage in hepatocytes.Methods Primary hepatocytes were isolated from Sprague-Dawley rat using two-step collagenase perfusion technique.The oxidative damage model was established through ethanol(200 mmol/L) incubation for 24 h.Meanwhile,the ethanol-intoxicated hepatocytes were treated with quercetin(100 μmol/L),hemin(20 μmol/L) or different dose of bilirubin(2-100 μmol/L),etc.The activities of superoxide dismutase(SOD),as well as the levels of malondialdehyde(MDA),glutathione(GSH),total bilirubin and reactive oxygen species(ROS) were detected following 24 h incubation.Results Quercetin inhibited the increase of MDA and ROS,the GSH depletion and SOD inactivation in heaptocytes induced by ethanol.Exogenous bilirubin,however,manifested the similar protective effect in dose-dependent manner to some extent.Znpp-IX,HO-1 inhibitor,abolished the protective effect of quercetin.Conclusion Quercetin prevented rat primary hepatocytes from ethnol-induced oxidative damage through the effect of bilirubin,one of the HO-1 metabolites.