紫堇灵、乙酰紫堇灵及原鸦片碱对小鼠实验性肝损伤的保护作用

研究了紫堇灵、乙酰紫堇灵及原鸦片碱对小鼠实验性肝损伤的保护作用及其作用机理。小鼠预先分别ig紫堇灵、乙酰紫堇灵或原鸦片碱50及100mg·kg^-12次,对CCl₄、硫代乙酰胺、扑热息痛所致的小鼠肝损伤均有保护作用,使SGPT显著降低,肝病理损伤程度减轻。此3种成分在体外均能抑制CCl₄引起的肝微粒体脂质过氧化及CCl₄转化为CO。在上述实验中乙酰紫堇灵的作用均强于另外两种成分。另外,此3种成分对肝药酶有先抑制后诱导作用。     

解酒饮对小鼠急性肝损伤的保护作用

目的 探讨解酒饮对小鼠急性四氯化碳（CCl₄）肝损伤的保护作用。方法 将60只小鼠分为正常组、联苯双酯组、模型组（0.3% CCl₄腹腔注射）和解酒饮组（按剂量分为25,12.5,6.25 g·kg^-1组,灌胃25 ml·kg^-1,连续灌胃8 d）,每组各10只。造模12 h后,用全自动生化仪测定血清丙氨酸转移酶（ALT）、天门冬氨酸转移酶（AST）、白蛋白（ALB）、球蛋白（GLB）、总蛋白（TP）的活性。肝组织匀浆测定丙二醛（MDA）含量、超氧化物歧化酶（SOD）和谷胱甘肽（GSH）活性。并对肝组织进行组织形态学检查。免疫组化方法检测肝脏MnSOD、bcl-2、caspase-3的表达情况。结果 解酒饮能降低CCl₄诱导的急性肝损伤小鼠升高的血清ALT、AST水平。解酒饮25 g·kg^-1降低肝匀浆升高的MDA水平,同时升高肝匀浆中的SOD和GSH酶活性,改善肝组织的病理形态。免疫组化结果显示,解酒饮25 g·kg^-1可以上调MnSOD、bcl-2表达水平,下调caspase-3表达水平。结论 解酒饮可能通过提高肝脏抗氧化能力,抑制肝细胞凋亡,对小鼠急性CCl₄肝损伤有一定的保护作用。     

苦参碱联合甘草甜素在四氯化碳慢性肝损伤中的保护作用及机制

摘 要 目的：考察苦参碱联合甘草甜素在四氯化碳（CCl₄）慢性肝损伤中的保护作用,并从能量代谢及CYP酶的角度探讨其保护机制。方法: 建立CCl₄慢性肝损伤模型,通过考察血清ALT、AST观察两药及其联合用药在慢性肝损伤模型中的保护作用;检测血清谷氨酸脱氢酶（GLDH）及肝组织中肝脏腺嘌呤核苷三磷酸（ATP）、二磷酸腺苷（ADP）、腺嘌呤核糖核苷酸（AMP）含量,评价药物对肝脏能量代谢及线粒体功能的调节作用;实时定量PCR及Western Blot法检测肝脏CYP1A2、CYP2E1 mRNA及蛋白水平,评价两药及其联合用药对肝脏CYP酶的调控作用。结果: 苦参碱（72.8 mg·kg^-1）、甘草甜素（43.4 mg·kg^-1）在CCl₄慢性肝损伤模型中均可降低大鼠血清ALT、AST（P<0.05）,两药联合（36.4 mg·kg^-1 苦参碱+21.7 mg·kg^-1 甘草甜素）使用保护作用更加显著(P<0.05);其中苦参碱（72.8 mg·kg^-1）、甘草甜素（43.4 mg·kg^-1）均可降低血清GLDH,并恢复肝脏ATP含量(P<0.05);苦参碱（72.8 mg·kg^-1）对CYP1A2、CYP2E1mRNA表达水平无抑制作用,甘草甜素（43.4 mg·kg^-1）对CYP1A2、CYP2E1mRNA及蛋白表达水平均有抑制作用（P<0.05）。结论: 苦参碱联合甘草甜素在慢性肝损伤模型中具有明显的线粒功能调节和肝保护作用。     

水飞蓟宾自乳化制剂对CCl4所致肝损伤的保护作用

目的 探讨水飞蓟宾自乳化制剂对CCl₄所致急性肝损伤的保护作用。方法 以CCl₄所致小鼠急性肝损伤为模型,以生理盐水为阴性对照,以联苯双酯为阳性对照,以水飞蓟宾混悬剂为参比,以血清中谷丙转氨酶(ALT)、谷草转氨酶(AST)和肝脏中谷胱甘肽过氧化物酶(GSH-PX)活性及肝脏病理组织切片检查为指标,对比研究水飞蓟宾自乳化制剂对CCl₄所致急性肝损伤的保护作用。结果 水飞蓟宾自乳化制剂能显著的抑制CCl₄所致的血清ALT和AST活性升高,使肝脏中的GSH-PX维持在正常水平,保护肝脏并避免其发生严重病变。结论 水飞蓟宾自乳化制剂对CCl₄所致急性肝损伤有保护作用。     

狗肝菜多糖P2B对CCl4致L-02肝细胞损伤的保护作用

摘 要 目的：探讨狗肝菜多糖（P2B）对四氯化碳(CCl₄)诱导的肝L 02细胞损伤的保护作用。方法: 培养人肝L-02细胞,建立CCl₄肝细胞损伤模型,分组实验：正常对照组、CCl₄损伤组和不同浓度的P2B(0.125、0.25和0.5 mg·ml^-1)样品组。采用MTT法检测生化分析培养液中丙氨酸转氨酶（ALT）、天冬氨酸转氨酶（AST）以及细胞内超氧化物歧化酶（SOD）、丙二醛（MDA）含量。结果: 与CCl₄损伤组相比,各P2B样品组细胞活力明显增强,上清液中ALT、AST活性明显降低;细胞内SOD明显升高、MDA含量降低。结论:P2B对CCl₄诱导的体外L 02肝细胞损伤均具有保护作用,随着浓度的增加,作用也随着增强,其机制可能与其抗氧化作用有关。     

基于NF-κB通路探讨延龄草醇提物对急性肝损伤大鼠的保护作用

目的 基于NF-κB通路探讨延龄草醇提取物对CCl₄所致大鼠急性肝损伤的保护作用及机制。方法 把48只SD大鼠,随机分为空白对照组、模型组、联苯双酯组（200 mg·kg^-1）、延龄草醇提取物低、中、高剂量组（100,500,1 000 mg·kg^-1）6组。以CCl₄诱导急性肝损伤模型,造模后灌胃给药,治疗持续一段时间后取材。称重后计算大鼠肝脏脏器系数;检测各组大鼠血清中ALT、AST的活性;利用HE染色切片观察各组肝组织形态学的变化;以RT-PCR法检测各组大鼠肝组织中TNF-α、IL-1β,IL-6的基因表达;通过western blot检测各组肝组织中NF-κB的表达量。结果 与模型组相比,延龄草醇提物各治疗组可降低肝脏脏器系数,高剂量组肝小叶结构完整,肝细胞排列规则,大小均匀;RT-PCR结果显示,延龄草醇提取物能够显著降低TNF-α、IL-1β、IL-6的表达。western blot结果显示,延龄草醇提物显著地降低了NF-κB的表达。结论 延龄草醇提取物能够通过抑制NF-κB的表达,保护CCl₄诱导的大鼠急性肝损伤。     

矮地茶水煎液对四氯化碳致大鼠肝纤维化的保肝作用

摘 要 目的：探讨矮地茶水煎液对四氯化碳（CCl₄）所致肝纤维化的保护作用。方法: 将50只大鼠随机分为5组,即正常组、模型组、联苯双脂组（阳性对照组,200 mg·kg^-1）、矮地茶水煎液高(36 g·kg^-1,以生药材计)、低(18 g·kg^-1,以生药材计)剂量组,每组10只。除正常组外,其余各组用CCl₄诱导肝纤维化模型,造模成功后,每天灌胃给药,连续30 d。测定血清中丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）、血清透明质酸（HA）、肿瘤坏死因子（TNF-α）、层黏蛋白（LN）、Ⅲ型前胶原（PCⅢ）水平及肝组织中羟脯氨酸（Hyp）、超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）、丙二醛（MDA）的含量。结果: 与模型组比较,矮地茶水煎液高、低剂量组能显著降低血清指标ALT、AST、HA、LN、PCⅢ的水平（P<0.05）,降低Hyp、MDA含量（P<0.05）,明显升高SOD、GSH Px含量（P<0.05）。结论:矮地茶水煎液有明显的保肝、抗肝纤维化作用,其作用机制可能与下调HA和TNF-α的表达、保护肝细胞、减轻肝脏炎症和抗脂质过氧化损伤有关。     

姜黄素对四氯化碳诱导大鼠急性肝损害的保护作用

目的 研究姜黄素对四氯化碳诱导的大鼠急性肝损伤的保护作用及其机制。方法 60只健康♂SD大鼠随机分成6组,即正常对照组,肝损伤模型组,阳性药物对照水飞蓟素组（100 mg·kg^-1）,姜黄素低剂量组（25 mg·kg^-1）,姜黄素中剂量组（50 mg·kg^-1）和姜黄素高剂量组（100 mg·kg^-1）。隔天灌胃给药,共30 d;末次给药1 h后,腹腔注射20 mg·kg^-1 CCl₄玉米油溶液（2 mL·kg^-1）造模,禁食不禁水,12 h后乌拉坦麻醉。取下腔静脉血和肝脏后,分别检测大鼠血清中丙氨酸氨基转移酶（AST）及天门冬氨酸氨基转移酶（ASL）的活性,大鼠肝脏组织中血红素加氧酶Ⅰ（HO-1）及静脉血中HbCO的水平,在体外测定姜黄素清除DPPH自由基及ABTS自由基的能力。结果 与正常对照组相比,模型组血清中ALT、AST活性显著升高,肝组织中HO-1活性及静脉血中HbCO的含量显著降低,组织病理检查显示肝组织损伤明显增加。与模型组相比,姜黄素各剂量组可不同程度的降低血清AST及ASL的活性,增加肝脏组织中HO-1的活性及HbCO的水平,组织病理检查显示肝损伤有不同程度减轻。并且姜黄素具有清除DPPH自由基及ABTS自由基的能力。结论 姜黄素对CCl₄诱导的大鼠急性肝损伤具有一定保护作用,其机制可能与其自身抗氧化能力及诱导HO-1及HbCO有关。     

水溶性金属卟啉的合成、表征及其清除有毒活性氧的研究

目的合成并结构表征了4种水溶性金属卟啉配合物［5，10，15，20-四［4-(4′-吡啶-1)丁氧基苯基］金属卟啉溴化盐［锌卟啉(I)、铜卟啉(II)、锰卟啉(III)和钴卟啉(IV)］，作为抗活性氧(O^-₂，H₂O₂，HO·)模拟酶。方法 核黄素-蛋氨酸光照测其清除O^-₂作用，H₂O₂氧化Vit C法测其催化H₂O₂的分解，Fenton-苯甲酸钠荧光法测其对HO·清除作用，小鼠肝匀浆法测其抗脂质过氧化作用。结果1.0×10^-5~1.0×10^-6 mol·L^-1均具有良好的清除O^-₂作用；1.5×10^-6~1.0×10^-6 mol·L^-1均具有分解H₂O₂作用；2.0×10^-8~1.0×10^-8 mol·L^-1均具有清除HO·的功能；1.0×10^-7 mol·L^-1均可使脂质过氧化产物明显减少。结论合成4种水溶性金属卟啉配合物可作为抗多种活性氧(O^-₂，H₂O₂，HO·)模拟酶。     

蕊木宁F对小鼠实验性肝损伤的保护作用

蕊木宁(kopsinine)F(K-F)系自云南蕊木提出的一种吲哚类生物碱。该成分对小鼠因注射CCl₄,硫代乙酰胺,TAA及扑热息痛引起的肝损伤有明显的保护作用,使血清谷丙转氨酶降低,肝脏病理损害减轻。该成分对CCl₄引起的肝微粒体脂质过氧化反应和¹⁴CCl₄与肝微粒体进行的共价结合亦有抑制作用。此外,K-F还能提高小鼠的肝微粒体细胞色素P-450活性。以上结果提示蕊木宁F对小鼠实验性肝损害有保护作用。     

Protection against carbon tetrachloride hepatotoxicity by oleanolic acid is not mediated through metallothionein

Oleanolic acid is a triterpenoid compound that has been shown to protect against liver injury produced by some hepatotoxicants. This study was designed to characterize the protective effects of oleanolic acid on carbon tetrachloride-induced hepatotoxicity, and the role of metallothionein in the protection. Oleanolic acid pretreatment (100–400 μmol/kg, sc) protected Sprague–Dawley rats and mice from carbon tetrachloride-induced liver injury in a dose- and time-dependent manner, as evidenced by serum alanine aminotransferase and sorbitol dehydrogenase activities, as well as by histopathology. The protection against carbon tetrachloride hepatotoxicity was not evident until animals were pretreated with oleanolic acid 12 h, and lasted for 72 h after a single injection. This suggests that the protection might be due to induction of some adaptive mechanisms. Metallothionein (MT), an acute-phase protein proposed to decrease carbon tetrachloride-induced liver injury, was dramatically induced following oleanolic acid treatment. To examine whether oleanolic acid protection is mediated through MT, MT-I and II knock-out (MT-null) mice were utilized. Oleanolic acid pretreatment increased MT levels in control mice (20-fold), but not in MT-null mice, however, it protected equally against carbon tetrachloride-induced hepatotoxicity in both control and MT-null mice. These data indicate that oleanolic acid is effective in protecting rats and mice from the hepatotoxicity produced by carbon tetrachloride, and the protection is not mediated through induction of MT.     

Effects of adenosine on liver cell damage induced by carbon tetrachloride

Adenosine administration delayed the fatty liver and cell necrosis induced by carbon tetrachloride without affecting the action of the hepatotoxin on protein synthesis and liver triacylglycerol release. Adenosine produced a drastic antilipolytic effect accompanied by a decrease in the incorporation of [1-14C]palmitic acid into triacylglycerols and free fatty acids of the liver. Furthermore, a decrease in the serum levels of ketone bodies was observed at early times. The nucleoside also avoided the release of intracellular enzymes and prevented the lipid peroxidation produced by carbon tetrachloride during the 4 hr of treatment. The protective action of adenosine was transient, lasting 3-4 hr, probably the time required to be metabolized. The results suggest that the antilipolytic effect of the nucleoside, the inhibition of hepatic fatty acid metabolism, and the decrease in carbon tetrachloride-induced lipoperoxidation that it produced are involved in the delayed acute hepatotoxicity induced by carbon tetrachloride.     

Inhibition of cytochrome P450 2E1 expression by oleanolic acid: hepatoprotective effects against carbon tetrachloride-induced hepatic injury.

The protective effects of oleanolic acid on carbon tetrachloride-induced hepatotoxicities and the possible mechanisms involved in this protection were investigated in mice. Pretreatment with oleanolic acid prior to the administration of carbon tetrachloride significantly prevented the increase in serum alanine aminotransferase and lactate dehydrogenase activity and liver lipid peroxidation in a dose-dependent manner. Hepatic glutathione levels and glutathione-S-transferase activities were not affected by treatment with oleanolic acid alone but pretreatment with oleanolic acid protects carbon tetrachloride-induced depletion of hepatic glutathione levels. The effects of oleanolic acid on the cytochrome P450 (P450) 2E1, the major isozyme involved in carbon tetrachloride bioactivation were investigated. Treatment of mice with oleanolic acid resulted in a significant decrease of P450 2E1-dependent p-nitrophenol and aniline hydroxylation in a dose-dependent manner. Consistent with these observations, the P450 2E1 expressions were also decreased, as determined by immunoblot analysis. These results show that the protective effects of oleanolic acid against the carbon tetrachloride-induced hepatotoxicity may, at least in part, be due to its ability to block bioactivation of carbon tetrachloride mainly by the inhibition of expression and activities of P450 2E1.     

Hepatoprotective effects of 18beta-glycyrrhetinic acid on carbon tetrachloride-induced liver injury: inhibition of cytochrome P450 2E1 expression.

The protective effects of 18beta-glycyrrhetinic acid (GA), the aglycone of glycyrrhizin (GL) derived from licorice, on carbon tetrachloride-induced hepatotoxicity and the possible mechanisms involved in this protection were investigated in mice. Pretreatment with GA prior to the administration of carbon tetrachloride significantly prevented an increase in serum alanine, aspartate aminotransferase activity and hepatic lipid peroxidation in a dose-dependent manner. In addition, pretreatment with GA also significantly prevented the depletion of glutathione (GSH) content in the livers of carbon tetrachloride-intoxicated mice. However, reduced hepatic GSH levels and glutathione-S-transferase activities were unaffected by treatment with GA alone. Carbon tetrachloride-induced hepatotoxicity was also prevented, as indicated by a liver histopathologic study. The effects of GA on the cytochrome P450 (P450) 2E1, the major isozyme involved in carbon tetrachloride bioactivation, were also investigated. Treatment of mice with GA resulted in a significant decrease of the P450 2E1-dependent hydroxylation of p-nitrophenol and aniline in a dose-dependent manner. Consistent with these observations, the P450 2E1 expressions were also decreased, as determined by immunoblot analysis. GA also showed antioxidant effects upon FeCl(2)-ascorbate-induced lipid peroxidation in mice liver homogenate and upon superoxide radical scavenging activity. These results show that protective effects of GA against the carbon tetrachloride-induced hepatotoxicity may be due to its ability to block the bioactivation of carbon tetrachloride, primarily by inhibiting the expression and activity of P450 2E1, and its free radical scavenging effects.     

Protective role of dietary butylated hydroxyanisole against chemical-induced acute liver damage in mice

Prior consumption of a diet containing the food antioxidant, butylated hydroxyanisole (BHA), by female mice prevented the development of or minimized the acute liver damage caused by monocrotaline, acetaminophen, or bromobenzene. In contrast, neither the incidence nor the severity of carbon tetrachloride-induced hepatotoxicity was affected by dietary BHA. Hepatotoxicity was judged by plasma alanine aminotransferase and aspartate aminotransferase levels, hepatic cytochrome P-450 content, and liver histology. The protective effect of BHA against acetaminophen-induced hepatotoxicity was not demonstrated in male mice. The observed protection by dietary BHA against acetaminophen- and bromobenzene-induced hepatotoxicity was associated with the increase of liver glutathione. It is concluded that the protective action of BHA is dependent upon the nature of the toxic agent.     

Carbon tetrachloride-induced lipid peroxidation of rat liver microsomes in vitro.

Characteristics of carbon tetrachloride-induced lipid peroxidation of rat liver microsomes and effect on microsomal enzymes were studies in vitro. Microsomes isolated from well-perfused livers and washed with EDTA-containing medium exhibited low endogenous lipid peroxidation when incubated in a phosphate buffer (> 0.1 M) in the presence of NADPH, whereas carbon tetrachloride stimulated to a great extent the peroxidation under these conditions. The stimulation was dependent on the concentration of NADPH, neither NADH nor ascorbic acid being replaced. The stimulatory action by bromotrichloromethane was more marked than that by carbon tetrachloride, however chloroform had no stimulatory action. N,N-Diphenyl-p-phenylene diamine, diethyldithiocarbamate and disulfiram inhibited carbon tetrachloride-induced lipid peroxidation in low concentrations. Inhibitions by thiol compounds and EDTA were weaker. Ferricyanide, cytochrome c and vitamine K₃ inhibited the stimulation by carbon tetrachloride while no inhibition was seen with carbon monoxide. An increase in the degree of carbon tetrachloride-induced lipid peroxidation resulted in a coincidental decrease in microsomal cytochrome P-450 content accompanying a parallel loss in aminopyrine demethylase activity, while NADH-ferricyanide dehydrogenase and NAD(P)H-eytochrome c reductase activities, and cytochrome b₅ content remained unaffected. Similar results were obtained when microsomes were peroxidized with NADPH in combination with ferric chloride and pyrophosphate. Regarding the mechanism of hepatotoxic action of carbon tetrachloride, these results support the hypothesis of lipid peroxidation.     

Free radical scavenging and hepatoprotective actions of the medicinal herb, Crassocephalum crepidioides from the Okinawa Islands

Free radical scavenging and protective actions against chemically induced hepatotoxicity of Crassocephalum crepidioides were investigated. A water extract of C. crepidioides strongly scavenged superoxide anion, hydroxyl radical and also stable radical 1,1-diphenyl-2-picrylhydrazyl. Galactosamine (GalN, 400 mg/kg) and lipopolysaccharide (LPS, 0.5 microg/kg) induced hepatotoxicity of rats as seen by an elevation of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and of lipid peroxidation in liver homogenates was significantly depressed when the herbal extract was given intraperitoneally 1 and 15 h before GalN and LPS treatment. Similarly, carbon tetrachloride (CCl4) induced liver injury as evidenced by an increase in AST and ALT activities in serum was also inhibited by the extract pretreatment. Isochlorogenic acids, quercetin and kaempferol glycosides were identified as active components of C. crepidioides with strong free radical scavenging action. These results demonstrate that C. crepidioides is a potent antioxidant and protective against GalN plus LPS- or CCl4-induced hepatotoxicity.     

Hepatoprotective properties of Commiphora opobalsamum ("Balessan"), a traditional medicinal plant of Saudi Arabia

The hepatoprotective activity of an ethanolic extract of Commiphora opobalsamum ("Balessan") was investigated in rats by inducing hepatotoxicity with carbon tetrachloride:liquid paraffin (1:1). This extract has been shown to possess significant protective effect by lowering serum transaminase levels (serum glutamate oxaloacetate transaminase and serum glutamate pyruvate transaminase), alkaline phosphatase and bilirubin. Pretreatment with an extract of Balessan prevented the prolongation of the barbiturate sleeping time associated with carbon tetrachloride-induced liver damage in mice. On the other hand, CCl4-induced low-level nonprotein sulfhydryl concentration in the liver was replenished by the Balessan extract. These data suggest that the plant C. opobalsamum may act as an antioxidant agent and may have a hepatoprotective effect.     

The protective effect of Eclipta alba on carbon tetrachloride-induced acute liver damage

The protective effect of Eclipta alba on carbon tetrachloride-induced acute liver damage was studied using 54 female guinea pigs as experimental animals. Pretreatment of the animals with E. alba gave significant protection from the hepatotoxic action of carbon tetrachloride. This was evidenced by studying the mortality rate, serum aspartate aminotransferase, serum alanine aminotransferase, and serum alkaline phosphatase activity in E. alba-protected and -unprotected groups of animals. The mortality rate at the end of 24 hr was 77.7% in the unprotected group and 22.2% in the protected group. Serum enzyme activities were also significantly lower in the E. alba-protected group. The protective effect was also seen histologically, where centrilobular necrosis, hydropic degeneration, and fatty change of the hepatic parenchymal cells were markedly reduced in the animals receiving E. alba treatment before carbon tetrachloride intoxication.     

Optimization of the dose and route of injection,and characterisation of the time course of carbon tetrachloride-induced hepatotoxicity in the rat

INTRODUCTION: The purpose of this study was to optimize carbon tetrachloride-induced hepatotoxicity in the rat with respect to dose, route of injection, and time course. METHODS: Male Wistar albino rats, 4 to 6 weeks old and weighing 130-180 g were used. Hepatotoxicity was evaluated by measuring the activity of serum enzymes (alkaline phosphatase [ALP], alanine aminotransferase [ALT], and aspartate aminotransferase [AST]) as well as serum total bilirubin level. RESULTS: Intraperitoneal injection of carbon tetrachloride (CCl(4)) increased the activity of ALP (from 64.9 to 137.3 U/l), ALT (from 106.6 to 693.1 U/l), and AST (from 113.8 to 693.9 U/l). Plasma bilirubin level increased (from 0.119 to 0.42 mg/dl). In contrast, subcutaneous injection of CCl(4) had no effect on these variables. The optimum intraperitoneal dose of CCl(4) was found to be 2 ml/kg body weight (dissolved in an equal volume of olive oil), and this increased the level of bilirubin and the activity of the three enzymes significantly, without causing death of the animals. Hepatotoxicity was observed within 2 h of intraperitoneal injection of CCl(4) and reached a peak after 24 h. Bilirubin level and serum enzyme activities declined gradually to normal levels by 3 days after CCl(4) injection. CONCLUSION: It is possible to reliably evoke reversible hepatotoxicity in rats by intraperitoneal injection of 2 ml/kg CCl(4).