Effect of phenobarbital on hepatic injury induced by chronic carbon tetrachloride treatment

Rats were given 1 ml CCl4 per kg body weight subcutaneously 2 times a week, for 16 weeks. The effects of simultaneous phenobarbital (PB) treatment (0.05% in drinking water) on the hepatotoxicity of CCl4 was studied during 16 weeks of treatment. The retardation of growth, the increase in liver weight and mortality were greater in animals receiving both PB and CCl4 than those given CCl4 alone. Cirrhosis was apparent only in animals treated by PB + CCl4. The potentiating effect of PB on CCl4 hepatotoxicity was also seen in hexobarbital sleeping time, the rate of hexobarbital metabolism, and the cytochrome P-450 content in liver microsomes. The inducing effect of PB alone decreased with time both in vivo and in vitro, which suggests an adaptation or some kind of exhaustion of liver to the effects of PB.     

Danshensu-mediated protective effect against hepatic fibrosis induced by carbon tetrachloride in rats

The culprit of hepatic fibrosis (HF) is linked to suprathreshold deposition of collagen. Thus, collagen reduction by improved metabolism contributes to HF management. In this study, we aimed to investigate the hepatoprotective effects of Danshensu (DSS) against carbon tetrachloride (CCl₄)-induced HF rats. The results showed that DSS-administrated rats resulted in decreasing in hepatosomatic indexes, and lowering serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Meanwhile, the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) were increased, while the content of malonaldehyde (MDA) was lessened in liver tissue of DSS administration group. In addition, the pro-fibrotic markers of hydroxyproline (Hyp), type III procollagen (PCIII) and hyaluronic acid (HA) contents were decreased. Histopathological examination confirmed that the hepatotoxicity in CCl₄-injured rats was alleviated following the DSS administration. Furthermore, intrahepatic protein expressions of alpha-smooth muscle actin (α-SMA), phosphorylated JAK2 (p-JAK2) and phosphorylated STAT3 (p-STAT3) were effectively down-regulated, respectively. Overall, this work demonstrates that DSS played the protective effect against CCl₄-induced cytotoxicity in liver tissue, which the probable mechanism is associated with attenuation of lipid peroxidation, collagen accumulation and enhancement of anti-oxidative defense capability, as well as regulation of intrahepatic JAK/STAT pathway for maintaining collagenic homoeostasis.     

The effect of serotonin reuptake inhibitors on hepatic injury induced by carbon tetrachloride

The aim of the present study was to investigate the effect of several drugs acting on serotonergic neurotransmission on the development of hepatocellular injury caused by carbon tetrachloride (CCl₄) in rats. Liver damage was induced in rats by administration of CCl₄ (2.8 ml/kg in olive oil, orally). Sertraline, citalopram, or fluvoxamine were administered orally once daily in association with CCl₄ and for 1 week thereafter. Sibutramine was administered 1 week prior to the toxic agent and for 3 days thereafter. Liver damage was assessed by determining serum enzyme activities and hepatic histopathology. In CCl₄-treated rats, sertraline (10, 20 mg/kg) reduced serum alanine aminotransferase (ALT) levels by 41.8% and 53.4%, respectively, compared to controls. Serum aspartate aminotransferase (AST) levels decreased by 37.4% and 58.2%, respectively, while alkaline phosphatase (ALP) decreased by 40.5% and 59.3%, respectively. Treatment with citalopram (5, 10, 20 mg/kg) reduced serum ALT levels by 29.8%, 35.6%, and 43.8%, AST levels by 24.2%, 29.9%, and 43%, and ALP by 17.8%, 35%, and 48.9%, respectively. Fluvoxamine (5, 10, 20 mg/kg) dose-dependently reduced the elevation of ALT levels by 42.6%, 49.9%, and 51.9%, AST levels by 40.2%, 44.6%, and 61.6%, and ALP by 8.3%, 46.8%, and 52.7%, respectively. Given as a pretreatment, sibutramine (5, 10, 20 mg/kg) reduced serum ALT levels by 52.1%, 52.2%, and 57.5%, AST levels by 53.6%, 58.4%, and 59.4%, and ALP by 46.8%, 67.6%, and 72.2%, respectively. Histopathological and histochemical examinations also indicated that CCl₄-induced liver injury was less severe after treatment with the test drugs than in the CCl₄ control groups. It is concluded that the administration of drugs with serotonin reuptake inhibitory properties is associated with a reduction in experimental liver injury induced by CCl₄.     

柴芪益肝颗粒防治四氯化碳诱导大鼠肝纤维化的作用

目的观察柴芪益肝颗粒治疗四氯化碳诱导的大鼠肝纤维化的疗效及其对Leptin、TGF—β1和IL-13因子的影响。方法将50只SD大鼠随机分为模型组、柴芪益肝颗粒组、复方鳖甲软肝片组、秋水仙碱组和空白对照组,每组10只。大鼠腹腔注射四氯化碳诱导肝纤维化,光镜观察肝组织病理学改变,放射免疫分析法检测肝纤四项,液相芯片检测血清细胞因子。结果与模型组比较,柴芪益肝颗粒组肝脏病理变化显著减轻,肝小叶结构基本清晰,细胞索、肝窦无明显异常;与模型组比较,透明质酸（P=0．001）、层粘连蛋白（P=0．005）和Ⅳ型胶原（P=0．000）水平显著降低,瘦素（P=0．012）、转化生长因子131（TGF-β1）（P=0．000）和白介素13（IL-13）（P=0．016）水平亦显著降低,差异均有统计学意义。结论柴芪益肝颗粒显著改善肝纤维化,可能与其通过降低瘦素、TGF—β1和IL-13水平,抑制细胞外基质沉积有关。     

LPS预处理减轻CCl4诱导的慢性肝损伤

目的:探讨脂多糖(LPS)预处理对四氯化碳(CCl4)诱导的肝损伤的影响及相关的信号转导分子的变化。方法:雄性Wistar大鼠随机分为正常对照组、肝损伤组和LPS预处理组。肝损伤组和LPS预处理组经皮下注射CCl4并同时饲以高脂饮食造模,于实验第4周末处死动物,取血浆测定内毒素水平和ALT活性;取肝组织测定TNF-α水平;Western blotting测定肝组织中TLR4、p38、p-p38、IκΒ、NF-κΒp65表达;制备肝脏切片,观察肝脏病理改变。结果:LPS预处理可明显减轻CCl4所致肝损伤,经LPS预处理动物血浆ALT活性显著低于肝损伤组（P<0.01）;肝匀浆的TNF-α测定结果表明,LPS预处理组TNF-α含量明显低于肝损伤组（P<0.01）。LPS预处理组TLR4、p-p38、NF-κΒ的表达显著低于肝损伤组,而IκΒ表达显著高于肝损伤组。结论:LPS预处理可以减轻CCl4诱导的肝损伤, LPS预处理引起相关信号转导通路发生了改变,致使致炎因子分泌减少可能是其作用机制。     

Sesamin ameliorates oxidative liver injury induced by carbon tetrachloride in rat

Sesamin is naturally occurring lignan from sesame oil with putative antioxidant property. The present study was designed to investigate the protective role of sesamin against carbon tetrachloride induced oxidative liver injury. Male Wistar albino rats (180-200 g) were divided in to 5 groups (n=6). Hepatotoxicity was induced by the administration of CCl₄ (0.1 ml/100 g bw., 50% v/v with olive oil) intraperitoneally. Sesamin was administered in two different dose (5 and 10 ml/kg bw) to evaluate the hepatoprotective activity. Sesamin significantly reduced the elevated serum liver marker enzymes (P<0.0001). Reduction of TBARS (P<0.01 and P<0.001) followed by enhancement of GSH., SOD and catalase (P<0.0001) in liver homogenate in sesamin treated groups shows the amelioration of oxidative stress induced by CCl₄. Histopathological report also supported the hepatoprotection offered by sesamin. Sesamin effects in both the dose were in comparable to reference standard drug silymarin. From these above findings it has been concluded that sesamin ameliorate the oxidative liver injury in terms of reduction of lipid peroxidation and enhancement of liver antioxidant enzymes.     

外源性一氧化碳抗大鼠肢体缺血再灌注所致肺损伤的实验研究

目的：观察外源性一氧化碳（CO）对大鼠肢体缺血再灌注（IR）所致肺损伤的作用及机制。 方法： 32只SD大鼠，随机分为4组(每组n=8)：对照组（control）、control+CO、IR和IR+CO组。复制大鼠双后肢缺血及再灌注后肺损伤模型。IR+CO和control+CO组在再灌注前1 h或相应时点置含2.5×10-8 CO的空气中，其余两组呼吸正常空气。观察大鼠肺组织学、肺组织中中性粒细胞（PMN）数目、丙二醛(MDA)含量、肺组织湿重和干重之比(W/D)以及动物生存情况等。应用一氧化碳血氧分析仪监测动脉血中碳氧血红蛋白(COHb)水平的变化；应用Western blotting检测肺组织中细胞间粘附分子-1（ICAM-1）表达的变化。 结果： IR组动物死亡率、肺组织中PMN数目、W/D、MDA含量和ICAM-1表达均显著高于control组；IR+CO组血内COHb水平显著高于IR组，而上述指标则均显著低于IR组、肺损伤减轻。 结论： 外源性CO可减轻肢体IR所致肺损伤，其机制可能与下调ICAM-1表达、抑制PMN在肺内聚集有关。     

Cannabis sativa exacerbates hepatic injury caused by acetaminophen or carbon tetrachloride in rats

The effect of Cannabis sativa extract on acute liver injury caused by acetaminophen or carbon tetrachloride (CCl₄) was studied in rats. Cannabis sativa was given at doses of 5 or 10 mg/kg (expressed as Δ⁹-tetrahydrocannabinol) once daily intraperitoneally (i.p.) for 2 days and simultaneously with acetaminophen or CCl₄. Rats were killed 24 h after acetaminophen or CCl₄ administration. Reduced glutathione (GSH), lipid peroxidation (malondialdehyde; MDA) and nitric oxide (nitrite/nitrate) concentrations were measured in the liver. Alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) were determined in serum. Hepatic injury was also determined via histological examination of liver sections. The administration of only cannabis for 2 days had no significant effect on serum liver enzymes or on the hepatic levels of GSH, MDA or nitric oxide. However, in rats intoxicated with acetaminophen, Cannabis sativa at 5 or 10 mg/kg resulted in a significant increase in serum GOT by 17.6% and 19.5%, respectively, compared with the acetaminophen control group. In the CCl₄-induced acute liver injury, the levels of AST, ALT and ALP in serum were significantly elevated by Cannabis sativa extract in a dose-dependent manner by 23.7–29.1%, 14.4–21.3% and 17.6–22.1%, respectively. In both models of hepatic injury, Cannabis sativa resulted in a significant increase in the level of liver MDA and nitric oxide and a significant decrease in GSH compared with the corresponding acetaminophen or CCl₄ control group. These changes were dose dependent. Histological examination showed an increase in centrilobular necrotic areas in acetaminophen or CCl₄-treated rats administered with Cannabis sativa. Histochemical investigation revealed a decrease in intracellular protein contents caused by CCl₄ or acetaminophen, and these were further decreased by Cannabis sativa. It is concluded that short-term administration of Cannabis sativa enhances acute hepatic damage caused by CCl₄ or acetaminophen in rats.     

Manganese induced hepatic lesions in carbon tetrachloride pretreated rats.

Manganese sulphate (6 mg/kg) was administered intraperitoneally daily for 30 days in carbon tetrachloride pretreated rats. Histological and histochemical studies in liver tissue revealed extensive damage to hepatic parenchyma in these rats as compared to lesions produced by manganese sulphate alone. These findings suggest that workers, with liver dysfunction ergated in manganese industry may be more susceptible to the toxic effects of this metal.     

Evaluation of the antioxidant and hepatoprotective effect of Majoon-e-Dabeed-ul-ward against carbon tetrachloride induced liver injury

The present study was designed to demonstrate the antioxidant and hepatoprotective effect of Majoon-e-Dabeed-ul-ward, a Unani herbal formulation. The Majoon-e-Dabeed-ul-ward (MD) at the doses of 250, 500 and 1000 mg/kg, p.o. was administered after carbon-tetrachloride (CCl₄; 1.5 ml/kg, i.p. once only) intoxication. Treatment with MD at three doses brought the levels of aspartate transaminase, alanine transaminase, albumin and urea in dose dependent manner. Signification reduction was found in TBARS content and restored the level of reduced glutathione, adenosine triphosphatase, and glucose-6-phosphatase in liver. Therapy of MD showed its protective effect on biochemical and histopathological observation at all the three doses in a dose dependent manner. The study conducted showed that MD possesses strong hepatoprotective activity as decrease the hexobarbitone sleep time and improvement in physiological parameter, excretory capacity (BSP retention time) was seen. DPPH and H₂O₂ scavenging effects indicated its potent antioxidant activities. The results revealed that MD could afford significant dose-dependent protection against CCl₄ induced hepatocellular injury.     

Effect of cholinergic denervation on hepatic fibrosis induced by carbon tetrachloride in rats

Various factors involved in the development of liver fibrosis, including hepatic stellate cells (HSCs), cholinergic nervous activity and fibrogenetic cytokines. The present study aims to investigate the role of cholinergic regulation in the promoting of liver fibrogenesis relating to bone morphogenetic protein-6 (BMP-6) and/or transforming growth factor-beta1 (TGFbeta1). We treated carbon tetrachloride (CCl(4)) into rats for eight weeks to induce liver fibrosis and arranged these rats for cholinergic denervation, hepatic branch vagotomy or atropine administration. Acetylcholinesterase (AChE) staining showed the distribution of cholinergic nerve around fibrosis scaring septa. The immunohistochemical staining for alpha smooth muscle actin (alphaSMA) indicated the less HSCs in CCl(4) treated rat liver with cholinergic denervation as compared to the sham-operated CCl(4) treated rats. It seems that cholinergic nerve not only innervates around the fibrosis area but also promotes HSCs. We also detected TGFbeta1 and BMP-6 expressions using RT-PCR and immunohistochemistry. The obtained results show that cholinergic denerveration decreases BMP-6 and TGF-beta1 expressions in CCl(4) induced liver fibrosis of rats. In conclusion, cholinergic nerve may influence HSCs in addition to the lowering of BMP-6 and TGF-beta1 gene expressions to modify liver fibrosis.     

含硒藻蓝蛋白抗小鼠实验性肝损伤的作用

目的:观察含硒藻蓝蛋白(Se-SPC)对四氯化碳(CCl₄)致小鼠急性肝损伤的拮抗作用。方法:以2%CCl₄油灌胃复制小鼠急性肝损伤模型,各组分别腹腔注射Se-SPC、藻蓝蛋白(SPC)、无机硒(Se)7d,测定血及肝组织中Se、谷胱甘肽过氧化物酶(GPx)、超氧化物歧化酶(SOD)、丙二醛(MDA)、谷丙转氨酶(ALT)、一氧化氮(NO)水平,分析Se-SPC、SPC、无机Se对上述指标的影响。结果:Se-SPC组比CCl₄组血和肝中Se、GPx、SOD水平显著增高(P<0.05),血ALT、血和肝中MDA及NO₂^-/NO₃^-水平显著降低(P＜0.05),高剂量Se-SPC组对Se含量、GPx、MDA、NO₂^-/NO₃^-等指标的影响更为显著(P＜0.01),在相同蛋白或硒剂量下,Se-SPC组比SPC组和无机Se组对上述指标作用更大。相关分析发现小鼠血Se水平与GPx活性呈显著正相关(r=0.705),血GPx活性与MDA、NO₂^-/NO₃^-、ALT水平呈明显负相关(r=－0.629,r=－0.336,r=－0.457),血ALT活性与MDA及NO₂^-/NO₃^-呈显著正相关(r=0.519,r=0.641)。结论:Se-SP可能结合增高硒酶活性及抗炎双重功效,对CCl₄致小鼠肝脏的氧化损伤具有拮抗作用。     

Liver precursor cells increase hepatic fibrosis induced by chronic carbon tetrachloride intoxication in rats

Hepatic fibrosis, the major complication of virtually all types of chronic liver damage, usually begins in portal areas, and its severity has been correlated to liver progenitor cells (LPC) expansion from periportal areas, even if the primary targets of injury are intralobular hepatocytes. The aim of this study was to determine the potential fibrogenic role of LPC, using a new experimental model in which rat liver fibrosis was induced by chronic carbon tetrachloride (CCl(4)) administration for 6 weeks, in combination with chronic acetylaminofluorene treatment (AAF), which promotes activation of LPC compartment. Treatment with CCl(4) alone caused a significant increase in serum transaminase activity as well as liver fibrosis initiating around central veins and leading to formation of incomplete centro-central septa with sparse fibrogenic cells expressing α-smooth muscle actin (αSMA). In AAF/CCl(4)-treated animals, the fibrogenic response was profoundly worsened, with formation of multiple porto-central bridging septa leading to cirrhosis, whereas hepatocellular necrosis and inflammation were similar to those observed in CCl(4)-treated animals. Enhanced fibrosis in AAF/CCl(4) group was accompanied by ductule forming LPC expanding from portal areas, αSMA-positive cells accumulation in the fibrotic areas and increased expression of hepatic collagen type 1, 3 and 4 mRNA. Moreover, CK19-positive LPC expressed the most potent fibrogenic cytokine transforming growth factor-β (TGFβ) without any expression of αSMA, desmin or fibroblast-specific protein-1, demonstrating that LPC did not undergo an epithelial-mesenchymal transition. In this new experimental model, LPC, by expressing TGFβ, contributed to the accumulation of αSMA-positive myofibroblasts in the ductular reaction leading to enhanced fibrosis but also to disease progression and to a fibrotic pattern similar to that observed in humans.     

四氯化碳致小鼠急性肝损伤的性别差异及其与雄激素受体表达的关系

目的比较CCl4对不同性别小鼠急性肝损伤的诱导作用及其对肝脏雄激素受体(AR)表达的影响。方法健康成年昆明小鼠70只,随机分为CCl4雄性组、CCl4雌性组、雄性对照组,雌性对照组。50%CCl4-粟米油溶液皮下注射,0.6ml/100g体重,1周2次,诱导小鼠急性肝损伤。造模第7天处死各组动物取材固定,常规HE染色比较不同组别小鼠肝组织病理变化;免疫组织化学法检测各组小鼠肝脏AR的表达,根据阳性细胞反应强度及百分比设定0级(阴性)及1-3级(阳性)标准,双盲计分法统计各组AR表达分值。结果实验组CCl4造模过程中雄性组小鼠死亡率为60%(15/25),明显高于雌性组(12%,3/25),对照组小鼠无死亡(0/10,0/10)。肝组织HE染色结果可见CCl4诱导的急性肝损伤主要部位为肝小叶周围的门管区及界板区,损伤部位肝细胞出现脂肪变,少数肝组织出现点状坏死。免疫组化显示雄性及雌性对照组小鼠肝细胞AR呈弱阳性表达,不同性别小鼠肝细胞AR表达差别无统计学意义;实验组各组别肝小叶周围受损肝细胞出现较强的AR表达,其中CCl4雄性组AR表达分值明显高于CCl4雌性组小鼠(P<0.01)。结论雄性小鼠对急性肝损伤的耐受性低于雌性小鼠,其中AR的高表达与CCl4诱导的急性肝损伤性别差异密切相关。