探讨茯砖茶乙醇提取物（FTE）对H₂O₂诱发猪肾近曲小管LLC-PK1上皮细胞氧化损伤的保护作用。以不同质量浓度（10~200μg/mL）的FTE预培养LLC-PK1细胞24h后,换用含500μmol/L H₂O₂的DMEM细胞培养液继续培养4h建立细胞氧化损伤模型。MTT法检测细胞生存率,硫代巴比妥酸比色法测定细胞内丙二醛（malondialdehyde, MDA）含量,比色法测定细胞内过氧化氢酶（catalase, CAT）,超氧化物歧化酶（superoxide dismutase, SOD）和谷胱甘肽过氧化物酶（glutathione peroxidase, GSH-px）含量。经不同浓度FTE预处理24h后,受损细胞的生存率上升,细胞内MDA生成量减少。同时,细胞内主要抗氧化酶（CAT、SOD和GSH-px）含量也较对照组增加,并呈剂量效应关系。结果提示,预先经FTE的保护可有效地对抗H₂O₂诱发的LLC-PK1细胞氧化损伤。

The aim of this study is to investigate the protective effect of ethanolic extract from Fuzhuan brick tea (FTE) on H₂O₂-induced oxidative damage in LLC-PK1 cells. Various concentration (10~200μg/mL) of FTE were pre-incubated with LLC-PK1 cells for 24h, and then exposed to H₂O₂ (500μmol/L) for 4h. The cell viability was determined by MTT assay, contents of malondialdehyde (MDA) were determined by thiobarbituric acid reactive substances (TBARS) assay. Intracellular antioxidant enzyme activities, including catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) were determined by colorimetric assay according to the protocols of the commercial kit. The cell viabilities of H₂O₂ treated LLC-PK1 cells were increased, and the contents of MDA were decreased after 24h pre-incubated with different concentrations of FTE. In addition, the antioxidant enzymes (CAT, SOD and GSH-px) levels were also increased in FTE compared with H₂O₂ treated group. There was statistical significant difference between the FTE treated groups and untreated H₂O₂ treated groups (all P<0.05). Those results suggested that pre-incubated with FTE showed a protective effect against H₂O₂-induced oxidative damage in LLC-PK1 cells.