银杏叶提取物对对乙酰氨基酚诱导的小鼠急性肝损伤的保护作用

目的：探究银杏叶提取物（GBE）对对乙酰氨基酚（APAP）诱导的小鼠急性肝损伤的保护作用及其机制。方法：30只小鼠随机分为对照组、模型组、GBE低、中、高剂量组（50,100,and 200 mg·kg^-1）,每组6只。除对照组外,剩余小鼠腹腔注射APAP （300 mg/kg）一次,随后GBE低、中、高剂量组按照相应剂量灌胃给药,治疗2 d后取材。观察各组肝脏大体情况和肝组织的病理组织学变化;取血测定各组小鼠血清中ALT、AST的活性和TNF-α、IL-6的水平;取肝检测各组肝组织中SOD、MPO的活性和GSH、MDA的含量;通过Western blot检测各组肝组织中Nrf2、HO-1蛋白的表达量。结果：与对照组相比,模型组肝脏明显肿大,病理表现差,血清中ALT、AST、TNF-α、IL-6的水平显著升高（P<0.01）,肝组织中GSH的含量和SOD的活性显著降低（P<0.01）,MDA的含量和MPO的活性显著升高（P<0.01）,Nrf2、HO-1蛋白表达明显下调（P<0.01）。与模型组相比,GBE组肝脏肿大减轻,病理表现有所改善,血清中ALT、AST、TNF-α、IL-6的水平显著降低（P<0.01）,肝组织中GSH的含量和SOD的活性显著提高（P<0.01）,MDA的含量和MPO的活性显著降低（P<0.01）,Nrf2、HO-1蛋白表达上调（P<0.05）,其中高剂量GBE组治疗效果最明显。结论：GBE可对APAP诱导的小鼠急性肝损伤具有保护作用,其作用机制可能是通过Nrf2/HO-1抗氧化途径发挥作用。     

对乙酰氨基酚诱导的小鼠药物性肝损伤的模型研究

改良对乙酰氨基酚（acetaminophen,APAP）单独诱导小鼠急性肝损伤的模型和致死模型。随机将小鼠分为4组：空白对照组、APAP3h组、APAP6h组和APAP12h组,每组5只。饥饿15h后用对乙酰氨基酚诱发小鼠肝损伤。测定各组血清ALT、AST及胆红素含量,HE染色观察各组肝组织损伤情况。观察生存率时,小鼠随机分为对照组、禁食＋APAP（500mg／kg）组、禁食＋APAP（300mg／kg）组和不禁食＋APAP（500mg／kg）组,四组同时给药,然后记录各组小鼠的生存情况,绘制四组小鼠的生存曲线。小鼠注射APAP后,随时间的延长,ALT、AST水平逐渐升高,均明显高于空白对照组（P〈0．05）。小鼠肝脏HE染色可见,APAP中毒组小鼠肝细胞坏死及炎性细胞浸润。禁食＋APAP（500mg／kg）组小鼠自16h开始出现死亡,72h时全部死亡,死亡率明显高于不禁食组和禁食＋APAP（300mg/kg）组小鼠。该研究对APAPI起的C57／BL6小鼠药物性肝损伤模型进行改良,使其更加稳定和便于研究,为进一步探究APAP诱导肝毒性的机制及防治措施奠定了基础。     

蓑衣莲酮硫酸酯对对乙酰氨基酚诱导小鼠急性肝损伤的保护作用

蓑衣莲酮硫酸酯(Auriculatone sulphate,AS)是天然保肝活性化合物蓑衣莲酮的前药。为评估AS的保肝作用,课题采用小鼠腹腔注射300 mg/kg的对乙酰氨基酚(APAP)复制小鼠急性肝损伤模型,通过静脉注射给予25 mg/kg的AS,测定给药后小鼠血清中的谷草转氨酶(AST)、谷丙转氨酶(ALT)和乳酸脱氢酶(LDH)的含量变化,从肝损伤水平初步了解AS对肝脏的保护作用;通过测定肝组织中丙二醛(MDA)和谷胱甘肽(GSH)的水平以及超氧化物歧化酶(SOD)活性的变化,了解AS对氧化损伤的保护作用;通过小鼠肝组织的病理学检查,直观评价AS通过静脉注射给药后对肝脏的保护作用。研究结果显示,静脉注射AS能够显著降低血清中ALT、AST和LDH的水平,使其趋近于正常水平(P0.001)。与模型组相比,AS不但可以显著降低肝脏中MDA的水平(P0.001),而且显著增加GSH水平和SOD的活性(P0.001)。病理学检查显示,AS能显著改善APAP对肝组织的破坏,使肝组织的结构趋近于正常。综上,静脉注射AS可有效保护小鼠免受APAP诱导小鼠急性肝损伤,其保护作用可能与抑制肝脏氧化损伤有关。     

金线风总黄酮对四氯化碳致急性肝损伤小鼠的保护作用及机制研究

研究金线风总黄酮(TFC)对四氯化碳(CCl4)致急性肝损伤小鼠的保护作用,并从氧化应激、炎症反应和TLR-4/NF-κB信号通路探讨其作用机制。60只小鼠随机分为正常组、模型组、水飞蓟素组(150 mg/kg)、TFC低、中、高剂量组(100、200、400 mg/kg)、连续灌胃给药10 d。末次给药2 h后,除正常组外,各组腹腔注射0.1%的CCl4花生油溶液(10 m L/kg),建立小鼠急性肝损伤模型,16 h后,收集血清和肝组织。血清指标检测表明,与模型组比较,TFC能够显著降低肝脏指数、ALT和AST活性(P0.05),并减少ALP、TBIL和γ-GT含量(P0.05),且降低MDA含量(P0.05),同时增强T-SOD和GSH-Px活性(P0.05)。ELISA法检测肝组织指标结果表明,与模型组比较,TFC能够显著下调TNF-α、IL-1β和IL-6含量(P0.05)。Western blot检测结果显示,与模型组比较,TFC能够明显降低肝组织中TLR-4和NF-κB蛋白表达(P0.05)。HE染色分析肝组织病理学变化结果表明,TFC能够有效改善肝组织损伤程度。综上所述,TFC对CCl4诱导的急性肝损伤小鼠具有保护作用,其保肝作用机理可能与抑制氧化应激、炎症反应以及TLR-4/NF-κB信号通路有关。     

金边桑叶多酚提取物抗氧化及肝保护作用研究

本实验以金边桑叶为研究对象,通过水提法制得粗提物AWE,后经大孔树脂分离纯化制得金边桑叶多酚提取物AWF,在探讨AWE和AWF体外抗氧化(清除自由基)能力的基础上,进一步探究了AWF对乙酰氨基酚(APAP)诱导的小鼠急性肝损伤的保护作用及其作用机制。AWE和AWF多酚含量分别为224.9±1.5和608.7±16.4μg GAE/mg extract,且AWF对DPPH和ABTS自由基具有较强的清除能力,其IC50值分别为4.46和41.25μg/m L。中、高剂量AWF(200和400 mg/kg·bw)灌胃处理能显著改善APAP诱导的小鼠急性肝损伤,使肝损伤小鼠血清中ALT、AST和LDH活性及MDA含量降低(P0.05或P0.001),血清中SOD和CAT及肝脏中GSH-Px活性升高(P0.01或P0.001),免疫组化结果也显示肝脏组织损伤情况明显减轻。此外AWF可显著抑制损伤肝脏组织中MAPKs及促凋亡蛋白caspase-3/9的活化,下调促凋亡蛋白Bax并上调抗凋亡蛋白Bcl2的表达量。实验结果表明,AWF可改善APAP诱导的小鼠急性肝损伤,其作用可能是通过调控MAPKs/apoptosis级联反应,发挥抗氧化和抗凋亡作用来实现的。     

睡莲花总黄酮对四氯化碳致小鼠急性肝损伤的防治作用

探讨睡莲花总黄酮(NCTF)对四氯化碳(CCl4)致小鼠急性肝损伤的保护作用及其机制。60只昆明种小鼠随机分为6组:正常组、模型组、联苯双酯组(150 mg/kg)和NCTF低、中、高剂量组(50、100、200 mg/kg),灌胃给药,连续7 d。末次给药1 h后,除正常组腹腔注射大豆油0.2 m L/10 g外,其余各组均腹腔注射0.12%的CCl4大豆油溶液0.2 m L/kg。禁食8 h后,摘眼球取血,分离血清,检测谷丙转氨酶(ALT)、谷草转胺酶(AST)、白介素-1β(IL-1β)、白介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)、γ-干扰素(IFN-γ);解剖取肝脏、脾脏,计算肝、脾指数,制备肝匀浆,检测超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、丙二醛(MDA)和一氧化氮(NO),留取肝左叶行病理组织学检查。与模型组比较,NCTF(100、200 mg/kg)能显著降低小鼠血清ALT、AST、TNF-α和IL-6水平以及小鼠的肝、脾指数(P0.05);并可明显提高小鼠肝组织匀浆SOD、GSH-Px的活性(P0.05),显著降低MDA和NO水平(P0.05)。病理组织学检查结果显示不同剂量NCTF均可减轻小鼠的肝组织损伤程度。结果说明NCTF对CCl4诱导的小鼠急性肝损伤具有明显的保护作用,其作用机制可能与抗氧化和抑制炎症因子的释放有关。     

芍药苷减轻四氯化碳诱导的急性肝损伤

为研究芍药苷对四氯化碳(CCl_4)诱导的急性肝损伤的保护作用及相关机制。将36只健康雄性C57BL/J小鼠随机分成6组:空白组,芍药苷对照组,CCl_4模型组(0.1%,20 mL/kg),高、中、低剂量芍药苷+CCl_4组(10 mg/kg,30 mg/kg,100 mg/kg),每组6只。24 h后眼球取血收集血清,测定丙氨酸氨基转移酶(ALT),天门冬氨酸氨基转移酶(AST)活性。用苏木精-伊红(HE)染色,观察肝脏的组织学改变;试剂盒测定肝组织中SOD、GSH-PX、CAT的活性及MDA和GSH含量;ELISA法检测血清中TNF-α、IL-6含量;试剂盒检测小鼠肝组织中Caspase-3的活性;q RT-PCR检测肝组织中HO-1 mRNA的表达。实验发现PAE降低小鼠血清ALT、AST水平,改善肝脏的病理形态;芍药苷抑制CCl_4诱导氧化应激,升高肝组织HO-1 mRNA水平;降低TNF-α、IL-6含量;芍药苷减低肝组织中Caspase-3活性,减少肝细胞凋亡。由此可知,芍药苷可保护CCl_4诱导的急性肝细胞损伤,该保护作用可能与抑制脂质过氧化,减少促炎细胞因子产生,减少肝细胞凋亡,促进抗氧化蛋白表达有关。     

基于JNK通路研究老鹳草素对免疫性肝损伤小鼠的影响

为探讨老鹳草素对脂多糖(LPS)所致小鼠免疫性肝损伤的保护作用及可能机制,60只小鼠被随机分为正常组、模型组、水飞蓟素组(180 mg/kg)和老鹳草素低、中、高剂量组(50、100、200 mg/kg),小鼠腹腔注射10 mg/kg的LPS诱导免疫性肝损伤.采取HE染色观察小鼠肝细胞病理改变情况;生化法检测血清中谷丙...     

黔产毛蒟水提物对急性肝损伤小鼠的保护作用

探讨黔产毛蒟水提物(PTE)对四氯化碳(CCl_4)诱导小鼠急性肝损伤的保护作用及其作用机制。本研究中将50只昆明种小鼠随机分为5组,各组10只,分别为空白组、模型组(0.01 g/kg的0.15%CCl_4菜油溶液造模)、PTE组(低剂量组0.5 g/kg和高剂量组1.0 g/kg)和阳性对照组(联苯双酯0.15 g/kg)。检测各组小鼠谷丙转氨酶(ALT)、谷草转氨酶(AST)、肿瘤坏死因子(TNF-α)含量;测定肝组织匀浆中脂质过氧化产物丙二醛(MDA)含量及超氧化物歧化酶(SOD)活性;计算肝脏的湿重指数;HE染色法观察肝脏组织的病理学变化。与空白对照组相比,模型组血清ALT、血清AST、肝脏指数、肝组织MDA含量以及血清TNF-α明显增高(均P0.01),肝组织SOD活性明显降低(P0.01),肝组织病理损伤明显。与模型组相比,PTE高剂量组和阳性对照组血清ALT显著降低(P0.01),PTE低、高剂量组和阳性对照组血清AST、肝脏指数、肝组织MDA含量以及血清TNF-α含量均明显降低(P0.05或P0.01),肝组织SOD活性明显升高(P0.01),并减轻了肝组织病理损害。PTE可减轻CCl_4诱导的急性肝损伤,其机制可能与抗氧化、抑制TNF-α的产生有关。     

基于IL-6/JAK2/STAT3信号通路研究岩白菜素对急性肝损伤大鼠的保护作用

基于IL-6/JAK2/STAT3信号通路探讨岩白菜素对四氯化碳(CCl_4)致大鼠急性肝损伤的保肝作用及其作用机制。60只SD大鼠随机分为正常组、模型组、水飞蓟素(120 mg/kg)组、岩白菜素低、中、高(20、40、80 mg/kg)剂量组,每组10只。水飞蓟素组、岩白菜素各剂量组大鼠按照10 mL/kg灌胃给药,正常组和模型组灌胃相应体积溶剂,每日1次,连续1周。末次给药2 h后,除正常组以外,其余各组腹腔注射25%四氯化碳(CCl_4)橄榄油溶液2 mL/kg,建立急性肝损伤大鼠模型。禁食不禁水,16 h后眼球取血,并收集肝脏。生化法测定血清中谷丙转氨酶(ALT)、谷草转氨酶(AST)、白蛋白(ALB)、丙二醛(MDA)、谷胱甘肽过氧化物酶(GSH-Px)以及超氧化物歧化酶(SOD)的水平或活性。酶联免疫吸附法(ELISA)测定检测肝组织中白细胞介素-6(IL-6)、肿瘤坏死因子(TNF-α)和白细胞介素-1β(IL-1β)的含量。采用HE染色观察肝组织的病理变化程度,免疫组化(IHC)观察肝组织中IL-6的表达水平,蛋白免疫印迹法(Western blot)检测IL-6/JAK2/STAT3通路相关蛋白的表达水平。实验结果表明,与模型组相比,岩白菜素各剂量组和水飞蓟素组大鼠肝组织炎症坏死和IL-6表达不同程度的减轻。岩白菜素可显著降低血清中的ALT、AST、MDA和肝组织中TNF-α、IL-6和IL-1β活性或水平,上调血清中ALB、SOD和GSH-Px的活性或水平,并且抑制IL-6/JAK2/STAT3通路相关蛋白的表达。综上所述,岩白菜素对CCl_4致急性肝损伤大鼠具有保护作用,其保肝机制可能与IL-6/JAK2/STAT信号通路介导的炎症反应和抗氧化有关。     

Enhanced Production of Adenosine Triphosphate by Pharmacological Activation of Adenosine Monophosphate-Activated Protein Kinase Ameliorates Acetaminophen-Induced Liver Injury

The hepatic cell death induced by acetaminophen (APAP) is closely related to cellular adenosine triphosphate (ATP) depletion, which is mainly caused by mitochondrial dysfunction. Adenosine monophosphate (AMP)-activated protein kinase (AMPK) is a key sensor of low energy status. AMPK regulates metabolic homeostasis by stimulating catabolic metabolism and suppressing anabolic pathways to increase cellular energy levels. We found that the decrease in active phosphorylation of AMPK in response to APAP correlates with decreased ATP levels, in vivo. Therefore, we hypothesized that the enhanced production of ATP via AMPK stimulation can lead to amelioration of APAP-induced liver failure. A769662, an allosteric activator of AMPK, produced a strong synergistic effect on AMPK Thr172 phosphorylation with APAP in primary hepatocytes and liver tissue. Interestingly, activation of AMPK by A769662 ameliorated the APAP-induced hepatotoxicity in C57BL/6N mice treated with APAP at a dose of 400 mg/kg intraperitoneally. However, mice treated with APAP alone developed massive centrilobular necrosis, and APAP increased their serum alanine aminotransferase and aspartate aminotransferase levels. Furthermore, A769662 administration prevented the loss of intracellular ATP without interfering with the APAP-mediated reduction of mitochondrial dysfunction. In contrast, inhibition of glycolysis by 2-deoxy-glucose eliminated the beneficial effects of A769662 on APAP-mediated liver injury. In conclusion, A769662 can effectively protect mice against APAP-induced liver injury through ATP synthesis by anaerobic glycolysis. Furthermore, stimulation of AMPK may have potential therapeutic application for APAP overdose.     

Identification of Novel Translational Urinary Biomarkers for Acetaminophen-Induced Acute Liver Injury Using Proteomic Profiling in Mice

Drug-induced liver injury (DILI) is the leading cause of acute liver failure. Currently, no adequate predictive biomarkers for DILI are available. This study describes a translational approach using proteomic profiling for the identification of urinary proteins related to acute liver injury induced by acetaminophen (APAP). Mice were given a single intraperitoneal dose of APAP (0–350 mg/kg bw) followed by 24 h urine collection. Doses of ≥275 mg/kg bw APAP resulted in hepatic centrilobular necrosis and significantly elevated plasma alanine aminotransferase (ALT) values (p<0.0001). Proteomic profiling resulted in the identification of 12 differentially excreted proteins in urine of mice with acute liver injury (p<0.001), including superoxide dismutase 1 (SOD1), carbonic anhydrase 3 (CA3) and calmodulin (CaM), as novel biomarkers for APAP-induced liver injury. Urinary levels of SOD1 and CA3 increased with rising plasma ALT levels, but urinary CaM was already present in mice treated with high dose of APAP without elevated plasma ALT levels. Importantly, we showed in human urine after APAP intoxication the presence of SOD1 and CA3, whereas both proteins were absent in control urine samples. Urinary concentrations of CaM were significantly increased and correlated well with plasma APAP concentrations (r = 0.97; p<0.0001) in human APAP intoxicants, who did not present with elevated plasma ALT levels. In conclusion, using this urinary proteomics approach we demonstrate CA3, SOD1 and, most importantly, CaM as potential human biomarkers for APAP-induced liver injury.     

Melatonin Protects against Apoptosis-Inducing Factor (AIF)-Dependent Cell Death during Acetaminophen-Induced Acute Liver Failure

Acetaminophen (APAP) overdose is the most frequent cause of acute liver failure and is primarily caused by cytochrome P450 (CYP) 2E1-driven conversion of APAP into hepatotoxic metabolites. Several reports showed that melatonin attenuated APAP-induced acute liver failure. Nevertheless, the exact mechanism remains obscure. In the present study, we investigated the effects of melatonin on apoptosis-inducing factor (AIF)-dependent cell death in APAP-induced acute liver failure. Mice were intraperitoneally (i.p.) injected with different doses of melatonin (1.25, 5, 20 mg/kg) 30 min before APAP (300 mg/kg, i.p.). As expected, melatonin significantly alleviated APAP-induced cell death, as determined by TdT-mediated dUTP-biotin nick end labeling (TUNEL) assay. Further analysis showed that melatonin significantly attenuated APAP-induced activation of the serine/threonine kinase receptor interacting protein 1 (RIP1). In addition, melatonin inhibited APAP-induced hepatic c-Jun N-terminal kinase (JNK) phosphorylation and mitochondrial Bax translocation. Correspondingly, melatonin inhibited APAP-induced translocation of AIF from mitochondria to nuclei. Interestingly, no changes were induced by melatonin on hepatic CYP2E1 expression. In addition, melatonin had little effect on APAP-induced hepatic glutathione (GSH) depletion. In conclusion, melatonin protects against AIF-dependent cell death during APAP-induced acute liver failure through its direct inhibition of hepatic RIP1 and subsequent JNK phosphorylation and mitochondrial Bax translocation.     

Protective effects of BML-111 against acetaminophen-induced acute liver injury in mice

The present study was undertaken to investigate the effect of the new formyl peptide receptor 2/lipoxin A₄ receptor agonist BML-111 on acetaminophen (APAP)-induced liver injury in mice and explore its possible mechanism(s). Male Swiss albino mice were intraperitoneally injected with BML-111 (1 mg/kg) twice daily for five consecutive days prior to a single intraperitoneal injection of APAP (500 mg/kg). Results have shown that APAP injection caused liver damage as indicated by significant increase in serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP). Liver histopathological examination revealed marked necrosis and inflammation. Additionally, APAP decreased activities of hepatic glutathione (GSH) and superoxide dismutase (SOD) with significant increase in the hepatic malondialdehyde (MDA) content. Furthermore, APAP increased serum nitrite/nitrate (NO₂ ^?/NO₃ ^? ) level and hepatic tumor necrosis factor alpha (TNF-α). Pretreatment with BML-111 significantly reversed all APAP-induced pathological changes. BML-111 prevented the increase of AST, ALT, and ALP. Also, BML-111 markedly attenuated APAP-induced necrosis and inflammation. It decreased MDA with increase in SOD and GSH. Importantly, BML-111 decreased NO₂ ^?/NO₃ ^? level and TNF-α. These findings suggest that BML-111 has hepatoprotective effects against APAP-induced liver injury in mice. Its protective effect may be attributed to its ability to counteract the inflammatory ROS generation and regulate cytokine effects.     

Protection against paracetamol-induced hepatic injury by prazosin pre-treatment in CD-1 mice

A synergistic depletion of glutathione has been suggested to be one critical factor in the hepatic injury in mice induced by non-toxic doses of paracetamol (APAP) when co-administered with -adrenergic agonists. Prazosin (an -adrenergic antagonist) could confer hepatoprotection following a toxic APAP dose (530 mg/kg) by increasing glutathione levels and enhancing bioinactivation by glucuronidation and glutathione conjugation. The effect of prazosin pre-treatment on APAP-induced gluthathione depletion and bioinactivation in vivo was assessed. Prazosin (15 mg/kg) pre-treatment provided protection against APAP-induced hepatic injury as evidenced by a significant decrease in serum transaminase (ALT) levels after 5 h (p < 0.05). Interestingly, prazosin pre-treatment did not prevent the dramatic depletion of glutathione by high dose APAP and it had no effect on the quantity of the glutathione conjugate formed. However, prazosin pre-treatment caused a significant increase in recovery of the administered dose (530 mg/kg) as the glucuronide metabolite (p < 0.05). UDP-glucuronosyltransferase (UGT) is involved in the bioinactivation of APAP by glucuronidation and we showed that prazosin had no effect on microsomal UGT kinetics. Thus, prazosin had no effect on either APAP-mediated glutathione depletion or the extent of APAP-glutathione conjugate formation and may be affecting other mechanisms to reduce oxidative stress caused by a toxic dose of APAP.     

Role of interleukin-6 in hepatic heat shock protein expression and protection against acetaminophen-induced liver disease

Recent experimental data suggest that the idiosyncratic nature of drug-induced liver disease (DILD) may be due in part to a deficiency of one or more hepatoprotective factors. In this study we have investigated whether interleukin (IL)-6 may also be one of these factors. Following the induction of liver injury with acetaminophen (APAP), a time-dependent increase in liver mRNA expression of IL-6 and its family members IL-11, leukemia inhibitory factor, and oncostatin M was observed in wild type (WT) mice, suggesting a possible hepatoprotective role played by this cytokine family. Indeed, mice lacking IL-6 (IL-6-/-) were more susceptible than were WT mice to APAP-induced liver injury. The increased susceptibility of the IL-6-/- mice was associated with a deficiency in the expression of hepatic heat shock protein (HSP)25, 32, and 40 as well as inducible HSP70 following APAP treatment. These results suggest that IL-6 and possibly other family members may protect the liver from injury, at least in part, by up-regulating the hepatic expression of several cytoprotective HSPs.