Epigallocatechin gallate attenuated non-alcoholic steatohepatitis induced by methionine- and choline-deficient diet.

Nonalcoholic fatty liver disease (NAFLD) and its progressive form, nonalcoholic steatohepatitis (NASH), are the most common causes of chronic liver disease. In this study, we evaluated the effects of Epigallocatechin gallate (EGCG) on methionine- and choline-deficient (MCD) diet-induced NASH. Our data showed that EGCG significantly prevented MCD diet-induced liver and body weight loss. Histological analysis showed that EGCG inhibited MCD diet-induced steatohepatitis including fat accumulation and inflammatory cells infiltration. Biochemical analysis data showed that EGCG significantly reduced the elevation of plasma ALT and AST levels but increased plasma triglyceride and cholesterol contents. However, EGCG significantly inhibited hepatic triglyceride and cholesterol content in MCD diet fed mice. Consistent with histology results, EGCG treatment significantly inhibited MCD diet-induced IL-1β, IL-6, TNF-α and MCP-1 mRNA expression. As an antioxidant, EGCG treatment significant inhibited hepatic MDA contents and increased hepatic SOD contents. In addition, transforming growth factor (TGF)-β, collagen I-α1, tissue inhibitor of metalloproteinase 1 (TIMP-1) and α-smooth muscle actin (SMA) mRNA expression, which are markers of hepatic fibrosis, were markedly inhibited by EGCG treatment. Western blot data showed that EGCG inhibited Smad2 and Smad3 phosphorylation in the liver and LX-2 cells which were involved in TGF-β-induced pathway. Taken together, EGCG attenuated NASH induced by MCD diet associated with ameliorating fibrosis, oxidative stress, and hepatic inflammation. Our results indicate that EGCG has beneficial roles in the development of MCD diet-induced NASH.

Ding Y ，Sun X ，Chen Y ，Deng Y ，Qian K ... -  《-》

S-Propargyl-cysteine Exerts a Novel Protective Effect on Methionine and Choline Deficient Diet-Induced Fatty Liver via Akt/Nrf2/HO-1 Pathway.

Li W ，Ma F ，Zhang L ，Huang Y ，Li X ，Zhang A ，Hou C ，Zhu Y ，Zhu Y ... -  《-》

Dynamics of oxidative/nitrosative stress in mice with methionine-choline-deficient diet-induced nonalcoholic fatty liver disease.

Insulin resistance, oxidative stress, and proinflammatory cytokines play a key role in pathogenesis of nonalcoholic fatty liver disease (NAFLD). The aim of our study was to investigate the dynamics of oxidative/nitrosative stress in methionine-choline-deficient (MCD) diet -induced NAFLD in mice. Male C57BL/6 mice were divided into following groups: group 1: control group on standard diet; group 2: MCD diet for 2, 4, and 6 weeks (MCD2, MCD4, and MCD6, respectively). After treatment, liver and blood samples were taken for histopathology, alanine- and aspartate aminotransferase, acute phase reactants, and oxidative/nitrosative stress parameters. Liver malondialdehyde level was higher in all MCD-fed groups versus control group (p < 0.01), while nitrites + nitrates level showed a progressive increase. The activity of total superoxide dismutase and its isoenzymes was significantly lower in all MCD-fed groups (p < 0.01). Although catalase activity was significantly lower in MCD-fed animals at all intervals (p < 0.01), the lowest activity of this enzyme was evident in MCD4 group. Liver content of glutathione was lower in MCD4 (p < 0.05) and MCD6 group (p < 0.01) versus control. : Ferritin and C-reactive protein serum concentration were significantly higher only in MCD6 group. Our study suggests that MCD diet induces a progressive rise in nitrosative stress in the liver. Additionally, the most prominent decrease in liver antioxidative capacity is in the fourth week, which implies that application of antioxidants would be most suitable in this period, in order to prevent nonalcoholic steatohepatitis but not the initial NAFLD phase.

Jorgačević B ，Mladenović D ，Ninković M ，Prokić V ，Stanković MN ，Aleksić V ，Cerović I ，Vukićević RJ ，Vučević D ，Stanković M ，Radosavljević T ... -  《-》

Alpha-lipoic acid attenuates methionine choline deficient diet-induced steatohepatitis in C57BL/6 mice.

Non-alcoholic steatohepatitis (NASH) is a liver disease that causes fat accumulation, inflammation and fibrosis. Increased oxidative stress contributes to hepatic inflammation and fibrosis by upregulation of Cytochrome P450 2E1 (CYP2E1), endoplasmic reticulum (ER) stress and mitogen-activated protein kinase (MAPK) activity. This study examined whether alpha-lipoic acid (ALA), a naturally occurring thiol antioxidant, prevents steatohepatitis through the inhibition of several pathways involved in hepatic inflammation and fibrosis. C57BL/6 mice were fed an MCD diet with or without ALA for 4weeks. Liver sections from mice on control or MCD diets with or without ALA were stained with hematoxylin-eosin, oil red O, and anti-4-HNE antibody. The effects of ALA on methionine-choline deficient MCD-diet induced plasma AST and ALT as well as tissue TBARS were measured. The effects of ALA on CYP2E1 expression, ER stress, MAPK levels, and NF-κB activity in MCD diet-fed mice liver were measured by northern and western blot analysis. Dietary supplementation with ALA reduced MCD diet-induced hepatic lipid accumulation, hepatic inflammation, TBARS, 4-HNE, and plasma ALT and AST levels. These effects were associated with a reduced expression of CYP2E1 and reduced ER stress and MAPK and NF-κB activity. Taken together, the results of the present study indicate that ALA attenuates steatohepatitis through inhibition of several pathways, and provide the possibility that ALA can be used to prevent the development and progression of non-alcoholic fatty liver disease in patients who have strong risk factors for NASH.

Min AK ，Kim MK ，Kim HS ，Seo HY ，Lee KU ，Kim JG ，Park KG ，Lee IK ... -  《-》

The indole derivative NecroX-7 improves nonalcoholic steatohepatitis in ob/ob mice through suppression of mitochondrial ROS/RNS and inflammation.

Nonalcoholic steatohepatitis (NASH) is associated with cirrhosis and hepatocellular carcinoma. Reactive oxygen species (ROS) and reactive nitrogen species (RNS) play key roles in the development of the disease. However, the therapeutic target of NASH has not been fully defined and new treatments are needed. We investigated the protective effects of the antioxidant indole-derived NecroX-7 in a NASH mouse model using leptin-deficient ob/ob and methionine- and choline-deficient (MCD) diet-fed ob/ob mice. Six-week-old male mice were divided into three groups: ob/+ mice, ob/ob mice treated with vehicle and ob/ob mice treated daily with NecroX-7 (20 mg/kg) for 4 weeks. To study the effects of NecroX-7 in a fibrosis model, NASH was induced by feeding ob/ob mice an MCD diet. The effects of NecroX-7 on NASH progression were evaluated using biochemical, histological and molecular markers. NecroX-7-treated ob/ob mice had a marked decrease in serum aspartate aminotransferase and alanine transaminase compared with vehicle-treated controls. Interestingly, hepatic steatosis and lipid peroxidation were significantly improved by NecroX-7 treatment. NecroX-7 inhibited tert-butylhydroperoxide- and H2 O2 -induced mitochondrial ROS/RNS in primary hepatocytes and attenuated mitochondrial dysfunction in vitro and in vivo. Furthermore, NecroX-7-treated mice exhibited fewer infiltrating macrophages and reduced hepatic tumour necrosis factor-alpha expression. Hepatic fibrosis in MCD-fed ob/ob mice was significantly decreased by NecroX-7 treatment. NecroX-7 treatment improved hepatic steatosis and fibrosis in murine NASH models. These effects occurred through the suppression of whole-cell ROS/RNS and inflammatory responses and suggest that NecroX-7 has a potential therapeutic benefit in steatohepatitis.

Chung HK ，Kim YK ，Park JH ，Ryu MJ ，Chang JY ，Hwang JH ，Lee CH ，Kim SH ，Kim HJ ，Kweon GR ，Kim KS ，Shong M ... -  《-》