中文摘要：

目的：通过对乙酰氨基酚体内体外实验建立急性肝损伤模型,观察虎眼万年青总皂苷的肝保护作用。方法：体内实验,小鼠预先口服给予虎眼万年青总皂苷（300,200,100mg·kg-1）或N-乙酰-L-半胱氨酸（300mg·kg-1）3次,每次间隔24小时,末次给药后2小时腹腔注射对乙酰氨基酚。体外实验,张氏肝细胞培养在含有虎眼万年青（50,100,200mg·mL-1）或N-乙酰-L-半胱氨酸（10mmol·L-1）的培养基中,同时加入对乙酰氨基酚（10mmol·L-1）培养24小时。结果：虎眼万年青总皂苷在对乙酰氨基酚诱导肝损伤12小时后具有较强的肝保护作用,抑制了血清中谷草转氨酶和谷丙转氨酶的活性,减少了脂质过氧化物的生成,提高了过氧化氢酶、超氧化物歧化酶和谷胱甘肽过氧化物酶的活性,抑制了细胞凋亡蛋白酶caspase-3和缺氧诱导因子-1α的表达。体外实验结果显示虎眼万年青总皂苷显著减少了对乙酰氨基酚代谢过程中关键酶细胞色素P4502E1的活性及环氧化酶2的表达。结论：虎眼万年青总皂苷对对乙酰氨基酚诱导的肝损伤具有保护作用其肝保护作用机制可能与抗氧化,抑制细胞色素P4502E1的活性和减少缺氧诱导因子1α的生成有关。

英文摘要：

AIM：To investigate the hepatoprotective effect of total saponin from Ornithogalum saundersiae Ait（Liliaceae）（OC）against acetaminophen（APAP）-induced acute liver injury in vivo and in vitro.METHODS：Mice were pretreated with OC（300,200 or100 mg·kg-1,body weight） or N-acetyl-L-cysteine（NAC）（300 mg·kg-1,body weight） for 3 times at 24 h intervals.APAP was administered2 h after OC last dose.Chang liver cells were incubated with the medium containing OC（50,100,200 mg·mL-1） or NAC（10mmol·L-1） with the presence or absence of APAP（10 mmol·L-1） for 24 h.RESULTS：OC showed remarkable hepatoprotective effect12 h after APAP administration by decreased aspartate aminotransferase and alanine aminotransferase levels,reduced the products oflipid peroxidation,improved the activity of catalase,superoxide dismutase and glutathione peroxidase,inhibited the caspase-3 cleavageand hypoxia inducible factor-1α accumulation in vivo.In vitro,OC significantly decreased the activities of metabolism enzyme cytochromeP450 2E1（CYP2E1） and cyclooxygenase-2（COX-2） induced by APAP.CONCLUSION：OC possesses the ability to protecthepatocyte from APAP-induced liver damage,suggesting that the hepatoprotective mechanism of OC might be related to antioxidationvia blocking the CYP2E1,and mediating reactive oxygen species scavenging and accumulation of hypoxia-inducible factor（HIF）-1α.