Prophylaxis with carnosol attenuates liver injury induced by intestinal ischemia/reperfusion

AIM： To investigate the possible protective effects of carnosol on liver injury induced by intestinal ischemia reperfusion （I/R）.
METHODS： Rats were divided randomly into three experimental groups： sham, intestinal I/R and carnosol treatment （n = 18 each）. The intestinal I/R model was established by clamping the superior mesenteric artery for 1 h. In the carnosol treatment group, surgery was performed as in the intestinal I/R group, with intraperitoneal administration of 3 mg/kg carnosol 1 h before the operation. At 2, 4 and 6 h after reperfusion, rats were killed and blood, intestine and liver tissue samples were obtained. Intestine and liver histology was investigated. Serum levels of aspartate aminotransferase （AST）, alanine aminotransferase （ALT） and interleukin （IL）-6 were measured. Liver tissue superoxide dismutase （SOD） and myeloperoxidase （IvIPO） activity were assayed. The liver intercellular adhesion molecule-1 （ICAM-1） and nuclear factor κB （NF-κB） were determined by immunohistochemical analysis and western blot analysis.
RESULTS： Intestinal I/R induced intestine and liver injury, characterized by histological changes, as well as a significant increase in serum AST and ALT levels. The activity of SOD in the liver tissue decreased after I/R, which was enhanced by carnosol pretreatment. In addition, compared with the control group, carnosol markedly reduced liver tissue MPO activity and serum IL-6 level, which was in parallel with the decreased level of liver ICAI-1 and NF-κB expression.
CONCLUSION： Our results indicate that carnosol pretreatment attenuates liver injury induced by intestinal I/R, attributable to the antioxidant effect and inhibition of the NF-κB pathway.     

Nigella sativa relieves the deleterious effects of ischemia reperfusion injury on liver

AIM： To determine whether Nigella sativa prevents hepatic ischemia-reperfusion injury to the liver. METHODS： Thirty rats were divided into three groups as sham （Group 1）, control （Group 2）, and Nigella sativa （NS） treatment group （Group 3）. All rats underwent hepatic ischemia for 45 min followed by 60 min period of reperfusion. Rats were intraperitoneally infused with only 0.9% saline solution in group 2. Rats in group 3 received NS （0.2 mL/kg） intraperitoneally, before ischemia and before reperfusion. Blood samples and liver tissues were harvested from the rats, and then the rats were sacrifi ced. Serum aspartate aminotransferase （AST）, alanine aminotransferase （ALT）, and lactate dehydrogenase （LDH） levels were determined. Total antioxidant capacity （TAC）, catalase （CAT）, total oxidative status （TOS）, oxidative stress index （OSI） and my-eloperoxidase （MPO） in hepatic tissue were measured. Also liver tissue histopathology was evaluated by light microscopy. RESULTS： The levels of liver enzymes in group 3 weresignifi cantly lower than those in the group 2. TAC in liver tissue was significantly higher in group 3 than in group 2. TOS, OSI and MPO in hepatic tissue were signifi cantly lower in group 3 than the group 2. Histological tissue damage was milder in the NS treatment group than that in the control group. CONCLUSION： Our results suggest that Nigella sativa treatment protects the rat liver against to hepatic ischemia-reperfusion injury.     

Melatonin protects against endosulfan-induced oxidative tissue damage in rats

Abstract:  Endosulfan is a chlorinated cyclodiene insecticide which induces oxidative stress. In this study, we investigated the possible protective effect of melatonin, an antioxidant agent, against endosulfan (Endo)-induced toxicity in rats. Wistar albino rats (n = 8) were administered endosulfan (22 mg/kg/day orally) followed by either saline (Endo group) or melatonin (10 mg/kg/day, Endo + Mel group) for 5 days. In other rats, saline (control group) or melatonin (10 mg/kg/day, Mel group) was injected for 5 days, following corn oil administration (vehicle of endosulfan). Measurement of malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity and collagen content were performed in liver and kidney. Furthermore, aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN), and creatinine levels, lactate dehydrogenase (LDH) activity were measured in the serum samples, while tumor necrosis factor-α (TNF-α), interleukin-β (IL-β) and total antioxidant capacity (AOC) were assayed in plasma samples. Endosulfan administration caused a significant decrease in tissue GSH and plasma AOC, which was accompanied with significant rises in tissue MDA and collagen levels and MPO activity. Moreover, the proinflammatory mediators (TNF-α and IL-β), LDH activity, AST, ALT, creatinine and BUN levels were significantly elevated in the endosulfan-treated rats. On the other hand, melatonin treatment reversed all these biochemical alterations induced by endosulfan. Our results suggest that oxidative mechanisms play an important role in endosulfan-induced tissue damage and melatonin, by inhibiting neutrophil infiltration, balancing oxidant–antioxidant status and regulating the generation of inflammatory mediators, ameliorates oxidative organ injury as a result of endosulfan toxicity.     

Continuous intravenous infusion of deleted form of hepatocyte growth factor attenuates hepatic ischemia–reperfusion injury in rats

BACKGROUND/AIMS: Although beneficial roles of hepatocyte growth factor (HGF) and its variants on several hepatic disorders have been reported, their effects on hepatic ischemia-reperfusion (IR) injury remain undetermined. We investigated the action of a deleted form of HGF (dHGF) on hepatic IR injury in rats. METHODS: dHGF or phosphate-buffered saline was continuously infused intravenously for 20 h prior to a 20-min occlusion of hepatic vessels. Samples were taken before and after IR, for measurement of serum dHGF and released enzymes, liver gamma-glutamylcysteinyl glycine (GSH) level, as well as histological and immunohistochemical examinations. RESULTS: After reperfusion, histological injury, as well as increase in the serum activities of aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and creatine kinase-BB were significantly attenuated in the dHGF-treated rats. dHGF maintained a high GSH level and suppressed oxidative stress and intercellular adhesion molecule-1 (ICAM-1) expression on sinusoidal endothelial cells (SECs), on which c-Met was not detected. IR caused activation of c-Met expression, which was milder in the dHGF-treated group, in hepatocytes at the pericentral region. CONCLUSIONS: dHGF attenuated liver injury after IR. It also maintained a higher GSH level, depressed oxidative stress and inhibited ICAM-1 expression on c-Met negative SECs, suggesting a paracrine effect of dHGF.     

缺氧诱导因子1-α在酒精性肝病形成中的表达

目的 研究缺氧诱导因子1-α(HIF1-α)在洒精性肝病动物模型的表达情况,探讨其与酒精性肝病的关系。方法 采用酒精灌胃法建立酒精性肝病动物模型,应用逆转录聚合酶链反应(RT-PCR)法和免疫组织化学染色法检测大鼠肝组织HIF1-α mRNA和蛋白水平。结果 RT-PCR结果显示模型组大鼠HIF1-α mRNA表达阳性率为62.5％(5/8),对照组为16.7％(2/12),x~2=3.94,P<0.05。两组大鼠肝脏HIF1-α多克隆抗体免疫组织化学染色评分分别为3.13±0.83和0.83±1.27,差异有非常显著必,t=4.88,P<0.01。结论 HIF1-α在酒精性肝病动物模型的表达明显增高,缺氧是酒精性肝病的发病机制之一。     

Protective role of supplement with foreign Bifidobacterium and Lactobacillus in experimental hepatic ischemia-reperfusion injury

BACKGROUND AND AIM: Intestinal microflora play a crucial role in some severe liver diseases. The purpose of this study was to evaluate the effects of a Lactobacillus strain and a Bifidobacterium strain on ischemia-reperfusion (I/R) liver injury. METHODS: Rats were divided into six groups. Each group received either Bifidobacterium Catenulatum ZYB0401; Lactobacillus Fermentum ZYL0401; a mixture of these two bacterial strains; gentamicin; or saline by daily gavage for 7 days. On the sixth day, all rats, except those in the control group, were subjected to 20 min of liver ischemia. After 22 h of hepatic reperfusion, liver enzymes and histology, malondialdehyde (MDA), superoxide dismutase (SOD), endotoxemia, serum tumor necrosis factor-alpha (TNF-alpha), intestinal bacteria, intestinal mucosal ultrastructure, and bacterial translocation were studied. RESULTS: All administered bacteria increased intestinal Bifidobacterium and Lactobacillus, decreased endotoxemia (P < 0.01), alanine aminotransferase (ALT) (P < 0.01), and markedly ameliorated liver histology and intestinal mucosal ultrastructure. Only rats treated with Bifidobacterium Catenulatum ZYB0401 and Lactobacillus Fermentum ZYL0401 showed reduced incidence of bacterial translocation to the kidney (P < 0.05), associated with decreased serum TNF-alpha and liver MDA (P < 0.05) and increased liver SOD (P < 0.05) compared to the I/R group. Gentamicin decreased almost all kinds of intestinal bacteria (P < 0.01) and decreased ALT (P < 0.01) and serum TNF-alpha, but failed to reduce both endotoxemia and the incidence of bacterial translocation and had no effects on liver MDA and SOD. CONCLUSION: Bifidobacterium Catenulatum ZYB0401 in combination with Lactobacillus Fermentum ZYL0401 could be useful in restoring intestinal microflora and in preventing liver injury in hepatic I/R of rats.     

益肝颗粒对酒精性肝损伤大鼠保护作用的实验研究

[目的]探讨益肝颗粒对酒精性肝损伤的保护作用。[方法]以56度白酒灌胃（10ml／kg,2次／d,连续8周）的方法建立酒精性肝损伤大鼠模型,50只大鼠随机均分为空白组,模型组,益肝颗粒低剂量组（0．39g／ml益肝颗粒水溶液）,益肝颗粒高剂量组（O．78g／ml益肝颗粒水溶液）,茵栀黄颗粒组（0．012g／ml的茵栀黄颗粒水溶液）,3治疗组均7ml／（kg·次）,1次／d,连续28d。[结果]与模型组相比,益肝颗粒可以显著降低丙氨酸氨基转移酶（ALT）、天冬氨酸转氨酶（AST）、7-谷氨酰转移酶（GGT）、肿瘤坏死因子-α（TNF-α）、丙二醛（MDA）水平（P〈O．01或〈O．05）,提高超氧化物歧化酶（SOD）活性（P〈0．01）,而且,益肝颗粒高剂量组AST、ALT水平及肝组织内MDA水平低于茵栀黄颗粒组（P〈O．01或〈O．05）,SOD水平高于茵栀黄颗粒组（P〈O．05）。[结论]益肝颗粒可以有效降低血清ALT、AST、GGT、TNF-α及MDA水平,提高SOD活性,促进酒精在体内的代谢,保护肝细胞。     

叶下珠对小鼠酒精性肝损伤的保护作用

目的研究叶下珠对小鼠酒精性肝损伤的保护作用。方法将30只小鼠随机分为3组:空白对照组小鼠每日以常规饲料和自来水喂养;酒精损伤组小鼠每日以白酒连续灌胃,常规饲料中拌有白酒;叶下珠保护组小鼠将白酒加浓度70%的叶下珠提取液按酒精损伤组动物灌胃。4周后,处死小鼠,取小鼠血清和肝脏测定ALT、AST、MDA、SOD等指标。结果叶下珠处理能够抑制血清谷草转氨酶(AST)、谷丙转氨酶(ALT)和肝脏的丙二醛(MDA)上升,其AST、ALT和MDA值比酒精损伤组分别下降了52.5%、41.4%和29.3%。同时叶下珠也能提高超氧化物歧化酶(SOD)的活性,处理后SOD值上升了16.3%。结论叶下珠对小鼠酒精性肝损伤有明显的保护作用。     

Protective effect of N2-mercaptopropionylglycine on rats and dogs liver during ischemia/reperfusion process

BACKGROUND: N2-mercaptopropionylglycine is a powerful super oxide synthesis inhibitor and has been tested as a preventive agent of metabolic and structural hepatic damage in the ischemia/reperfusion process. AIM: To analyze some effects of N2-mercaptopropionylglycine administration to animals of two species submitted to normothermic liver ischemia/reperfusion. MATERIAL AND METHODS: Twenty-two rats and 22 dogs were divided into four groups: group I: rats that received intravenous saline 0.9%; group II: rats that received 100 mg/kg of N2-mercaptopropionylglycine; group III: dogs that received saline intravenous 0.9% and group IV: dogs that received 100 mg/kg N2-mercaptopropionylglycine. RESULTS: Ten minutes after the saline or drug administration, each group was submitted to left lobe liver ischemia for 25 minutes followed by reperfusion. Biochemical studies 24 hours after reperfusion revealed a significantly lower elevation of transaminases in animals of groups II (AST = 271 +/- 182; ALT = 261 +/- 161 ) and IV (AST = 101 +/- 45; ALT = 123 +/- 89) when compared to the controls group: I (AST = 2144 +/- 966; ALT = 1869 +/- 1040 00) and III (AST = 182 +/- 76.51; ALT = 277 +/- 219), respectively. Histology study demonstrated a significantly minor aggression to animals of groups II and IV when compared to groups I and III, respectively. CONCLUSION: These results suggest a significant release of free radicals of oxygen in the process and that N2-mercaptopropionylglycine may have a significant protective effect on liver parenchyma when submitted to ischemia/reperfusion.     

温阳解毒化瘀方对肝衰竭大鼠内毒素血症的影响

目的:动态观察温阳解毒化瘀方对肝衰竭大鼠内毒素血症(ITEM)的影响。方法:将85只SD大鼠随机分为正常组、模型组、对照组(予乳果糖+三联活菌溶液)及温阳解毒化瘀颗粒组(实验组),采用D-半乳糖胺(D-gal)腹腔注射致肝衰竭ITEM大鼠模型。正常组在腹腔注射生理盐水12小时后处死,其余各组分别于造模后12小时、24小时各取10只大鼠处死,检测各组大鼠血清转氨酶(ALT、AST)、肝组织病理学、门静脉及结肠内毒素水平。结果:模型组12小时时ALT和AST较正常组升高(P<0.05),24小时时门静脉及结肠内毒素水平明显升高(P<0.01),肝组织大面积坏死;实验组及对照组在造模后12小时各观察指标与模型组比较,差异无显著性意义,造模后24小时两组ALT和AST、门静脉及结肠内毒素水平较模型组降低(P<0.05),肝组织病变减轻。结论:D-gal腹腔注射可建立大鼠肝衰竭ITEM模型,温阳解毒化瘀方可通过降低门静脉及结肠内毒素水平减轻ITEM而达到抗肝衰竭的效应。     

Preventive effect of Qianggan-Rongxian Decoction on rat liver fibrosis

AIM： To study the preventive effects of Qianggan-Rongxian Decoction on liver fibrosis induced by dimethylnitrosamine （DMN） in rats.
METHODS： Male Wistar rats were randomly divided into hepatic fibrosis model group, control group and 3 treatment groups （12 rats in each group）. Except for the normal control group, all the rats received 1% DMN （10 μL/kg body weight, i.p）, 3 times a week for 4 wk. The rats in the 3 treatment groups including a high-dose DMN group （10 mL/kg）, a medium-dose DMN group （7 mL/kg）, and a low-dose DMN group （4 mL/kg） were daily gavaged with Qianggan-Rongxian Decoction, and the rats in the model and normal control groups were given saline vehicle. Enzyme-linked immunosorbent assay （ELISA） was used to determine the changes in serum hyaluronic acid （HA）, laminin （LN）, and type IV collagen levels. Serum alanine aminotransferase （ALT） and aspartate aminotransferase （AST） levels were measured using routine laboratory methods. Pathologic changes, particularly fibrosis, were examined by hematoxylin and eosin （HE） and Sirius red staining. Hepatic stellate cells （HSC） were examined by transmission electron microscopy.
RESULTS： Compared with the model control group, the serum levels of HA, LN, type Ⅳ collagen, ALT and AST were decreased markedly in the other groups after treatment with Qianggan-Rongxian Decoction, especially in the medium-dose DMN group （P 〈 0.05）.Moreover, the area-density percentage of collagen fibrosis was lower in the Qianggan-Rongxian Decoction treatment groups than in the model group, and a more significant drop was observed in the medium-dose DMN group （P 〈 0.05）.
CONCLUSION： Qianggan-Rongxian Decoction can inhibit hepatic fibrosis due to chronic liver injury, delay the development of cirrhosis, and notably ameliorate liver function. It may be used as a safe and effective thera-peutic drug for patients with fibrosis.     

尿激酶型纤溶酶原激活物途径在大鼠酒精性肝纤维化形成中的作用

目的 通过观察尿激酶型纤溶酶原激活物(uPA)及其抑制物(PAI-1)在大鼠酒精性肝纤维化形成中的动态变化,探讨uPA纤溶途径在酒精性肝纤维化形成中的作用.方法 雄性SD大鼠随机分为空白组、四氯化碳(CCl4)组和造模组.采用56度二锅头酒、玉米油、吡唑混合物灌胃联合腹腔注射CCl4橄榄油溶液(CCl4∶橄榄油=1∶3...     

蓝莓对大鼠肝纤维化TGF-β1/Smads信号通路的影响

目的观察蓝莓对大鼠肝纤维化的预防作用及对肝纤维化大鼠肝组织转化生长因子（transforminggrowthfactor,TGF）-β1／Smads信号通路的影响。方法45只健康sD大鼠被随机分为正常对照组、模型组、蓝莓预防组、丹芍化纤胶囊预防组、蓝莓＋丹芍化纤胶囊预防组。每组9只。用四氯化碳（cch）制作大鼠肝纤维化模型,共8周。测定肝脏指数及血清ALT、AST并进行肝组织病理学检查,采用实时荧光定量RT—PCR检测TGF-β1、Smad4mRNA的表达,免疫组织化学法检测肝脏组织TGF-β1、Smad4及Smad7蛋白的表达。结果与正常对照组比较,模型组TGF-β1及Smad4的表达增高（P〈0．05）,而Smad7的表达降低（P〈0．05）。与模型组比较,各预防组血清ALT及AST均明显降低（P〈0．05）,TGF-β1及Smad4的表达均降低（P〈0．05）,而Smad7的表达均增高（P〈0．05）。结论蓝莓对GEL所致大鼠肝纤维化有一定的预防保护作用,其机制可能与蓝莓影响TGF-β1／Smads信号转导通路,从而下调TGF-β1及smad4的表达,同时上调Smad7的表达有关。     

The effects of a cyclooxygenase-2 inhibitor, FK3311, on total hepatic ischemia-reperfusion injury of the rat

BACKGROUND/AIMS: This study was designed to investigate the effects of a selective cyclooxygenase-2 inhibitor, FK3311, on warm ischemia-reperfusion injury of the rat liver. METHODOLOGY: Male Sprague-Dawley rats were used in this experimental study. Total hepatic ischemia was induced with a clamping portal triad. The animals were divided into two groups: the control group and the FK group, in which FK3311 (FK, 1.0 mg/kg) was administered via the penile vein. The serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) were measured 2 h after reperfusion, while those of thromboxane (Tx) B2 and 6-ketoprostaglandin (PG) F1alpha (stable metabolites of TxA2 and PGI2) were measured 30 min after reperfusion. The liver tissue blood flow was measured at preischemia, end-ischemia, and 30, 60, 90, and 120 min after reperfusion. The liver tissues obtained from animals at 2h after reperfusion were excised for histopathology. RESULTS: The serum levels of AST, ALT, and LDH were significantly lower in the FK group than in the control group. Similarly, in the FK group, the serum levels of TxB2 were significantly lower than in the control group. By contrast, the 6-keto-PG F1a levels were not significantly reduced. The liver tissue blood flow at 120 min after reperfusion was significantly higher in the FK group than in the control group. The histopathological study showed that hepatic tissue damage was milder in the FK group than in the control group. CONCLUSIONS: FK has protective effects on hepatic ischemia-reperfusion injury stemming from the marked inhibition of TxA2.     

Simvastatin for rats with thioacetamide-induced liver failure and encephalopathy

Background and Aim:  Nitric oxide (NO) inhibition aggravates hepatic damage and encephalopathy and increases mortality in rats with thioacetamide (TAA)-induced acute liver failure. Statins enhance NO synthase expression beyond their lipid-lowering capability, but the impact on encephalopathy remains unexplored. The aim of this study was to assess the effects of simvastatin on rats with TAA-induced acute liver damage and hepatic encephalopathy.
Methods:  Sprague–Dawley rats received TAA (350 mg/kg/day) or normal saline (NS) by intraperitoneal injection for 3 consecutive days. Two days before injections, each group was divided into three subgroups, taking (i) distilled water; (ii) simvastatin (20 mg/kg/day); or (iii) simvastatin plus N ^G-nitro- l -arginine methyl ester (L-NAME, 25 mg/kg/day) by oral gavage for 5 days. On the fifth day, severity of encephalopathy was assessed and plasma levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin and ammonia were measured.
Results:  The TAA subgroups showed higher ALT, AST, bilirubin and ammonia levels and lower motor activity counts as compared with the NS subgroups. Among the TAA-treated subgroups, rats with simvastatin treatment exerted higher motor activity counts and survival rate ( P  = 0.043), and a trend of lower ALT, AST, bilirubin and ammonia levels than those receiving saline. All rats that underwent simvastatin plus L-NAME treatment died during or after TAA injections.
Conclusions:  Simvastatin improved encephalopathy and survival in TAA-administered rats. The beneficial effect was offset by L-NAME, suggesting the role of NO in liver damage and encephalopathy.     

茶多酚治疗慢性酒精性肝损伤的实验研究

目的 建立酒精性肝病大鼠模型,观察茶多酚对酒精性肝病大鼠血清氨基转移酶活性和肝脏病理变化的影响,探讨茶多酚对酒精性肝损伤的防治作用。 方法 SD大鼠分成3组:酒精组(酒精7g·kg-1·d-1灌胃)、茶多酚组(酒精7g·kg-1·d-1 茶多酚0.25g·kg-1·d-1灌胃)和对照组(等渗盐水灌胃)。各组分别于4周末、12周末和24周末处死大鼠留取肝脏标本,用于HE染色和Masson染色。 结果 酒精组大鼠血清氧基转移酶水平较对照组升高,茶多酚组大鼠与酒精组相比,其值有明显降低,差异有统计学意义(P<0.05)。HE染色显示酒精组大鼠肝细胞浆出现不同程度的脂肪变性,小叶各带可见不同程度的点、灶状或片状坏死,24周大鼠可见桥接坏死。Masson三色染色可见24周大鼠汇管区边缘有绿染胶原纤维包绕增生,肝窦中可见绿染胶原纤维分布。茶多酚组肝脂肪变和炎症程度轻于酒精组,未发现桥接坏死。 结论 茶多酚对酒精性肝损伤具有一定的保护作用。     

Serum carotenoid concentrations are inversely associated with serum aminotransferases in hyperglycemic subjects

Hyperglycemia increases the generation of free radicals by glucose auto-oxidation, and the increment of free radicals may lead to liver cell damage. In this study, we tested the hypothesis that hyperglycemia-induced increases of serum liver enzymes among its physiological concentration would be inversely associated with serum antioxidant carotenoid level. Study subjects were 857 male and female Japanese who had received health examinations in 2003. Those with a history of liver disease and excessive alcohol drinkers were excluded. The associations of serum six-carotenoid concentrations with serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) stratified by glucose tolerance status were evaluated cross-sectionally. Serum AST and ALT concentrations in the groups of impaired fasting glucose (IFG) and diabetes were significantly higher than those in the normal group. The multivariate-adjusted means of the serum AST and ALT concentrations in IFG and diabetes group were significantly low in accordance with the tertiles of the serum beta-cryptoxanthin and beta-carotene concentrations. The most inverse association of serum liver enzyme and carotenoid concentration was observed in beta-cryptoxanthin. Antioxidant carotenoid, especially beta-cryptoxanthin, may act a deterrent substance against increasing the serum aminotransferase in the earlier pathogenesis of liver dysfunction among hyperglycemic subjects.     

维药小茴香抗肝纤维化作用及对TGF-β/smad信号转导通路的影响

目的探讨小茴香提取物抗肝纤维化的作用及其对TGF-β/smad信号转导通路和肝星状细胞活化的影响。方法选择44只SD大鼠给予40%四氯化碳(CCl4)橄榄油溶液4 ml/(kg·体重)皮下注射5周制备肝纤维化模型,成模后随机分成治疗组和模型对照组,同时取6只正常大鼠做空白对照。治疗组给予小茴香提取物灌胃,模型对照组给予生理盐水灌胃,4周末处死大鼠检测血清ALT、AST、HA、LN,肝石蜡切片行Masson染色和抗α平滑肌动蛋白(α-SMA)、TGF-β受体Ⅰ型(TGF-βRⅠ)、TGF-β1免疫组织化学染色,反转录实时荧光定量PCR分析肝组织TGF-β1、smad2 mRNA相对内参基因甘油醛-3-磷酸脱氢酶(GAPDH)的表达量。结果小茴香提取物治疗组血清ALT、AST、HA水平,肝组织内胶原纤维含量、α-SMA、TGF-βRⅠ、TGF-β1表达以及TGF-β1、smad2 mRNA相对表达量均明显低于模型对照组。结论小茴香提取物可通过抑制TGF-β/smad信号转导通路抑制肝星状细胞活化,从而减轻大鼠肝纤维化。     

Melatonin ameliorates experimental hepatic fibrosis induced by carbon tetrachloride in rats

AIM： To investigate the protective effects of melatonin on carbon tetrachloride （CCl4）-induced hepatic fibrosis in experimental rats.
METHODS： All rats were randomly divided into normal control group, model control group treated with CCl4 for 12 wk, CCl4 ＋ NAC group treated with CCl4 ＋ NAC （100 mg/kg, i.p.） for 12 wk, CCl4 ＋ MEL-1 group treated with CCl4 ＋ melatonin （2.5 mg/kg） for 12 wk, CCl4 ＋ MEL-2 group treated with CCl4 ＋ melatonin （5.0 mg/kg） for 12 wk, and CCl4 ＋ MEL-3 group treated with CCl4 ＋ melatonin （10 mg/kg）. Rats in the treatment groups were injected subcutaneously with sterile CCl4 （3 mL/kg, body weight） in a ratio of 2：3 with olive oil twice a week. Rats in normal control group received hypodermic injection of olive oil at the same dose and frequency as those in treatment groups. At the end of experiment, rats in each group were anesthetized and sacrificed. Hematoxylin and eosin （HE） staining and Van Gieson staining were used to examine changes in liver pathology. Serum activities of alanine aminotransferase （ALT）, aspartate aminotransferase （AST） and protein concentration weremeasured with routine laboratory methods using an autoanalyzer. Hydroxyproline （HYP） content in liver and malondialdehyde （MDA） and glutathione peroxidase （GPx） levels in liver homogenates were assayed by spectrophotometry. Serum hyaluronic acid （HA）, laminin （LN）, and procollagen Ⅲ N-terminal peptide （PⅢNP） were determined by radioimmunoassay.
RESULTS： Pathologic grading showed that the fibrogenesis was much less severe in CCl4 ＋ MEL3 group than in model control group （u = 2.172, P 〈 0.05）, indicating that melatonin （10 mg/kg） can significantly ameliorate CCl4-induced hepatic fibrotic changes. The serum levels of ALT and AST were markedly lower in CCl4 ＋ MEL treatment groups （5, 10 mg/kg） than in model control group （ALT： 286.23 ± 121.91 U/L vs 201.15 ± 101.16 U/L and 178.67 ± 103.14 U/L, P = 0.028, P = 0.007; AST： 431.00 ± 166.35 U/L vs 321.23 ± 162.48 U/L and 292.42 ± 126.23 U/L, P = 0.043, P = 0.013）. Similarly, the serum laminin （LN） and hyaluronic acid （HA） levels and hydroxyproline （HYP） contents in liver were significantly lower in CCl4 ＋ MEL-3 group （10 mg/kg） than in model control group （LN： 45.89 ± 11.71 μg/L vs 55.26 ± 12.30 μg/L, P = 0.012; HA： 135.71±76.03 μg/L vs 201.10 ± 68.46 μg/L, P = 0.020; HYP： 0.42 ± 0.08 mg/g tissue vs 0.51 ± 0.07 mg/g tissue, P = 0.012）. Moreover, treatment with melatonin （5, 10 mg/kg） significantly reduced the MDA content and increased the GPx activity in liver homogenates compared with model control group （MDA： 7.89 ± 1.49 noml/mg prot vs 6.29 ±1.42 noml/mg prot and 6.25 ±2.27 noml/mg prot, respectively, P = 0.015, P = 0.015; GPx： 49.13 ±8.72 U/mg prot vs 57.38 ±7.65 U/mg prot and 61.39 ±13.15 U/mg prot, respectively, P = 0.035, P = 0.003）.
CONCLUSION： Melatonin can ameliorate CCl4 -induced hepatic fibrosis in rats. The protective effect of melatonin on hepatic fibrosis may be related to its antioxidant activities,     

甲氰咪呱对非酒精性脂肪性肝炎(NASH)大鼠肝微粒体细胞色素P450的影响

目的研究甲氰咪呱对非酒精性脂肪性肝炎（NASH）大鼠肝微粒体细胞色素P450的影响。方法通过高脂饮食制作非酒精性指肪性肝炎（NASH）动物模型，给予甲氰咪呱灌胃治疗，观察肝组织病理形态变化，进行炎症活动计分，同时测定细胞色素P450（CYP450）和细胞色素2E1（CYP2EI）含量及ALT、AST，并与对照组比较。结果与正常组比较，模型组大鼠ALT、AST及CYP450和CYP2EI含量明显升高；与模型组比较，甲氰咪呱治疗组CYP450和CYP2EI含量均明显下降，（P〈0．05），ALT、AST及炎症活动计分明显低于模型组（P〈0．05）。结论甲氰咪呱能显著改善NASH大鼠肝脏功能及形态损伤，可能通过抑制肝细胞微粒体CYP450和同功酶CYP2EI的表达发挥作用。