Preventive and therapeutic mechanism of ginkgo biloba extract on liver injury poisoned by xylene / 天津医药

@#Objective To investigate the potential effect and molecular mechanism of ginkgo biloba extract (GBE) on the expression of inflammatory factors in liver tissue of mice poisoned by xylene. Methods A total of 30 clean grade healthy Kunming mice were randomly divided into normal control group, model group and ginkgo biloba extract intervention group (GBE group). Mice of three groups were granted free access to food and water. The concentration of xylene inhalation was 110-130 mg/m3 (the air samples were collected in the box, and the gas chromatogram was measured by direct injection method) in model group and GBE group. The mice in control group inhaled air. GBE group was intraperitoneally injected with 50 mg/(kg·d) of GBE. Control and model groups were intraperitoneal injected with same amount of normal saline. After 8 weeks, mice were sacrificed, and serum and liver tissues were retained. The serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), alkaline phosphatase (ALP) and glutamyl transpeptidase (GGT) were measured. Haematoxylin and Eosin staining was used to observe pathological changes of liver tissue. RT-PCR and Western blot assay were used to detect the expression levels of nuclear factor kappa B (NF-κB), tumor necrosis factor alpha (TNF-α) mRNA and protein in liver tissue. Results Compared with the control group, the liver tissue was damage seriously in the model group. The blood biochemical indexes (ALT, AST, TBIL, ALP and GGT) were significantly increased (P＜0.05), and the NF-κB, TNF-α mRNA and protein were significantly increased in the model group (P＜0.05). Compared with the model group, the liver tissue damage was reduced, the blood biochemical indexes (ALT, AST, TBIL, ALP and GGT) were significantly decreased (P＜0.05) and the NF-κB, TNF-α mRNA and protein were significantly down-regulated in the GBE group (P＜0.05). Conclusion Ginkgo biloba extract can reduce hepatic inflammatory response of mice poisoned by xylene through inhibiting the expression of NF-κB and TNF-α inflammatory factors.

Activation of Fas/FasL and its downstream signaling pathway promotes development of alcoholic steatohepatitis and liver fibrosis in mice / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To explore the role and mechanism of the Fas/Fas ligand (FasL) system and its downstream signaling pathway related to the progression of alcoholic steatohepatitis and liver fibrosis.</p><p><b>METHODS</b>Eighteen C57BL/6J mice were randomly divided into three groups: controls; alcoholic steatohepatitis model, given four-weeks of a 4% ethanol-containing Lieber-DeCarli liquid diet; alcoholic steatohepatitis and liver fibrosis model, given the four-week alcohol diet followed by twice weekly intraperitoneal injections of carbon tetrachloride (5% olive oil solution; 2 mL/kg dose) during the fifth to eighth weeks. Mice in the model groups were sacrificed at the end of week 4 and 8, respectively, along with control mice for comparative analyses. Liver tissue sections were evaluated for hepatocellular apoptosis by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay. The mRNA expression of Fas, FasL, cysteine aspartate-specific proteases 3 (caspase 3), and cytochrome P450 2E1 (CYP 2E1) in liver tissues was detected by reverse transcription (RT)-PCR, visualized by ethidium bromide staining, and normalized to the gray-value of GAPDH expression. The protein expression of Fas and caspase 3 were detected by western blotting (b-actin normalized), and of FasL and CYP 2E1 by immunohistochemistry staining. Intergroup differences and statistical significance were evaluated by single factor analysis of variance and the least squares difference-t test or the Kruskal-Wallis H test and the Mann-Whitney U test.</p><p><b>RESULTS</b>The number of apoptotic cells in the liver sections was significantly higher in both model groups with alcoholic steatohepatitis (vs. controls) and the amount in the alcoholic steatohepatitis plus liver fibrosis model was significantly higher than that in the model with only alcoholic steatohepatitis. In addition, activation of Fas, FasL and its downstream signaling pathway showed an increasing trend with extent of liver injury. The hepatic mRNA (by RT-PCR) and protein (by western blotting) normalized expression levels in the controls, alcoholic steatohepatitis models, and alcoholic steatohepatitis plus liver fibrosis models were, respectively: Fas mRNA: 0.50+/-0.05, 0.61+/-0.10, 0.76+/-0.03 (H=12.137, P less than 0.05), protein: 0.52+/-0.14, 0.86+/-0.10, 0.99+/-0.09 (F=12.758, P less than 0.01); FasL mRNA: 0.31+/-0.03, 0.53+/-0.02, 1.02+/-0.04 (F=153.260, P less than 0.01); caspase 3 mRNA: 0.86+/-0.11, 0.85+/-0.05, 1.33+/-0.16 (F=8.740, P less than 0.01), protein: 0.40+/-0.03, 0.69+/-0.06, 1.02+/-0.10 (F=90.785, P less than 0.01); CYP 2E1 mRNA: 0.72+/-0.14, 1.00+/-0.15, 1.30+/-0.20 (H=4.713, P less than 0.01). The changes in hepatic FasL and CYP 2E1 expression detected by immunohistochemistry were consistent with the mRNA expression.</p><p><b>CONCLUSION</b>Activation of Fas/FasL and its downstream signaling pathway, which induces hepatocellular apoptosis, contributes to the development of alcoholic steatohepatitis and liver fibrosis.</p>

Establishment of a complex alcoholic liver fibrosis mouse model and investigation of OPN and TGF-beta1 hepatic expression / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To create a convenient method to establish an alcoholic liver fibrosis model in mice and use it to explore the putative pathogenic mechanisms involving the immunomodulatory proteins osteopontin (OPN) and transforming growth factor-betal (TGF-beta1).</p><p><b>METHODS</b>Forty C57BLI6J mice were fed the Lieber-DeCarli 4% ethanol-containing liquid diet for four weeks, followed by an additional four weeks of the 4% ethanol diet combined with intraperitoneal injection of carbon tetrachloride (CC14 5% solution in olive oil; 2ml/ kg body weight, 2 times/week) to induce alcoholic liver fibrosis. Control groups (n = 6 each) included: normal diet; normal diet plus CCl4 injections; ethanol diet alone; ethanol diet plus solvent (olive oil) injections. Model establishment was monitored by sacrificing six mice at model inception (week 0), and weeks 4, 5, 6, 7, and 8 of modeling to collect liver tissues and blood for histological and biochemical analyses. Extent of hepatic steatosis, inflammation, and fibrosis was assessed by hematoxylin-eosin and Masson staining. Liver function markers, serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, were tested by automated enzymatic assays. Alpha-smooth muscle actin (alpha-SMA) expression was detected by immunohistochemistry. The mRNA and protein expression of OPN and TGF-beta1 was detected by real-time quantitative reverse transcription-PCR and western blotting, respectively. Significance of differences between multiple groups was assessed by one-way ANOVA analysis followed by least significant difference t-test or Kruskal-Wallis H test followed by the Mann-Whitney U test.</p><p><b>RESULTS</b>Compared to the control groups, the group of mice administrated ethanol and CCl4 developed mild to moderate hepatic steatosis at week 4 of modeling, progressive necroinflammation and perisinusoidal and portal fibrosis from weeks 5-8, and irregular necrosis and bridging fibrosis at week 8. In addition, the model group showed progressive up-regulation of a-SMA expression in the activated hepatic stellate cells (HSCs) and fibrotic areas from weeks 5-8. Both hepatic OPN and TGF-beta1 showed significantly increasing trends in mRNA and protein expressions from weeks 5-8 (OPN mRNA: 1.83 +/- 0.25, 2.94 +/- 0.19, 3.45 +/- 0.31, and 5.99 +/- 0.17 (F= 476.27, P < 0.001); OPN protein: 0.52 +/- 0.06, 1.02 +/- 0.10, 1.52 +/- 0.11 and 1.50 +/- 0.08 (F= 298.03, P< 0.001); TGF-beta1 mRNA: 13.19 +/- 0.40, 3.31 +/- 0.28, 1.58 +/- 0.18 and 2.08 +/- 0.26 (F= 85.55, P < 0.001); TGF-P31 protein: 1.26 +/- 0.16, 0.96 +/- 0.12, 1.09 +/- 0.25 and 1.10 +/- 0.20 (F = 43.64, P < 0.001).</p><p><b>CONCLUSION</b>Feeding C57BL/6J mice the Lieber-DeCarli ethanol-containing liquid diet combined with CCl4 intraperitoneal injection is a convenient method to establish a model of alcoholic liver fibrosis within a relatively short amount of time (eight weeks). Progression of alcoholic liver fibrosis is accompanied by increased hepatic expression of OPN and TGF-beta1, which may contribute to the pathogenic mechanism of this disease and may be targets of future molecular therapies.</p>