Vitexin attenuates autoimmune hepatitis in mouse induced by syngeneic liver cytosolic proteins via activation of AMPK/AKT/GSK-3ß/Nrf2 pathway.

Autoimmune hepatitis (AIH) is a chronic progressive liver disease that currently does not have a successful therapeutic option. Vitexin, a bioflavonoid isolated from various medicinal plants, possesses a variety of activities; however, whether vitexin protects against AIH remains unclear. Therefore, the current study aims to investigate the hepatoprotective effects and mechanism of action of vitexin in both an experimental autoimmune hepatitis (EAH) mouse model and in D-galactosamine/lipopolysaccharide (D-GalN/LPS)-induced hepatocyte injury. Syngeneic liver antigen S100 was used to establish EAH. Vitexin treatment significantly decreased the infiltration of inflammatory and CD4+ T cells in the liver, reduced ALT and AST levels in the serum and attenuated hepatic injury due to oxidative stress. Moreover, vitexin mitigated the upregulation of Bax and cleaved caspase-3 and the downregulation of Bcl-2 in the livers of AIH mice. These regulations were accompanied by not only increased phosphorylation of AMPK, AKT and GSK-3ß but also activation of Nrf2. Furthermore, vitexin inhibited apoptosis and the overexpression of inflammatory cytokines in D-GalN/LPS-treated AML12 cells. In addition, vitexin enhanced the phosphorylation of AMPK, AKT and GSK-3ß. When AML12 cells were treated with an inhibitor of AMPK/AKT or specific siRNA targeting Nrf2, vitexin did not further induce the activation of Nrf2/HO-1. A molecular docking study confirmed that vitexin could interact with AMPK through hydrogen bonding interactions. In conclusion, vitexin ameliorated hepatic injury in EAH mice through activation of the AMPK/AKT/GSK-3ß pathway and upregulation of the Nrf2 gene.

Dietary Copper Plays an Important Role in Maintaining Intestinal Barrier Integrity During Alcohol-Induced Liver Disease Through Regulation of the Intestinal HIF-1α Signaling Pathway and Oxidative Stress.

Impaired intestinal barrier function and oxidative stress injury play critical roles in the pathogenesis of alcoholic liver disease (ALD), and recent investigations have revealed a role for dietary copper in the liver and intestinal barrier function. Therefore, the current study investigates the mechanisms and role of dietary copper in alcohol induced liver diseases. C57BL/6 mice were used to create an alcoholic liver disease model with a Lieber-DeCarli diet containing 5% alcohol and were fed with different concentrations of dietary copper of adequate (6 ppm, CuA), marginal (1.5 ppm, CuM), or supplemental (20 ppm, CuS) amounts. Caco-2 cells were also exposed to ethanol and different concentrations of copper. Damages of the liver and intestine were evaluated by transaminases, histology staining, and protein and mRNA level, as well as cell proliferation, oxidative stress, and mitochondrial membrane potential. In animal experiments, the results indicate that an alcohol diet causes liver injury and disruption of intestinal barrier function as well as decreasing the expression of genes such as HIF-1α, occludin, SOD1, and GPX1. Supplemental dietary copper can revert these changes except for SOD1, but marginal dietary copper can worsen these changes. The in vitro cell experiments showed that proper copper supplementation can promote cell growth and reduce reactive oxygen species (ROS) production. In conclusion, supplemental dietary copper has beneficial effects on alcohol-induced intestine and liver injury, and marginal dietary copper shows detrimental effects on these parameters.

Sodium butyrate ameliorates S100/FCA-induced autoimmune hepatitis through regulation of intestinal tight junction and toll-like receptor 4 signaling pathway.

BACKGROUND AND AIM: Recent investigation revealed that dysbiosis in the gut flora and disruption of permeability of intestinal barrier are possible causes for the development of autoimmune hepatitis. Supplementation of sodium butyrate has been suggested to protect liver injury from disrupted permeability of small intestine. In current study, we employed S100/Freund's complete adjuvant induced autoimmune hepatitis to investigate therapeutic efficacy of sodium butyrate and its mechanism in the liver and upper small intestine. METHODS: C57BL/6 mice were employed and divided into three groups - control group (n=8), autoimmune hepatitis group (n=12) and autoimmune hepatitis with treatment of sodium butyrate group (n=12). Histological staining and western blot analyses were employed to evaluate liver and upper small intestine morphology and gene expression respectively. RESULTS: The findings revealed that S100/Freund's complete adjuvant caused liver injury and disruption of upper small intestine villi. Sodium butyrate attenuated the injuries and prevented migration of Escherichia coli into the liver. Moreover, the effect of sodium butyrate on protection of injuries of the liver and upper small intestine could be due to inhibition of toll-like receptor 4 signaling pathway, as well as its down-regulation of inflammatory cytokines - interleukin-6 and tumor necrosis factor-a. CONCLUSIONS: Sodium butyrate can prevent liver injury by maintaining the integrity of small intestine and inhibiting inflammatory response in S100/Freund's complete adjuvant induced autoimmune hepatitis.

Plumbagin Ameliorates CCl 4 -Induced Hepatic Fibrosis in Rats via the Epidermal Growth Factor Receptor Signaling Pathway.

Epidermal growth factor (EGF) and its signaling molecules, EGFreceptor (EGFR) and signal transducer and activator of transcription factor 3 (STAT3), have been considered to play a role in liver fibrosis and cirrhosis. Plumbagin (PL) is an extracted component from the plant and has been used to treat different kinds of cancer. However, its role in regulation of EGFR and STAT3 during liver fibrosis has not been investigated. In this study, the effects of PL on the regulation of EGFR and STAT3 were investigated in carbon tetrachloride (CCl4) induced liver fibrosis and hepatic stellate cells (HSC-T6). PL significantly attenuated liver injury and fibrosis in CCl4 treated rats. At concentrations of 2 to 6 µM, PL did not induce significant cytotoxicity of HSC-T6 cells. Moreover, PL reduced phosphorylation of EGFR and STAT3 in both fibrotic liver and heparin-binding EGF-like growth factor (HB-EGF) treated HSC-T6 cells. Furthermore, PL reduced the expression of α-SMA, EGFR, and STAT3 in both fibrotic liver and HB-EGF treated HSC-T6 cells. In conclusion, plumbagin could ameliorate the development of hepatic fibrosis through its downregulation of EGFR and STAT3 in the liver, especially in hepatic stellate cells.

A cardiovascular drug rescues mice from lethal sepsis by selectively attenuating a late-acting proinflammatory mediator, high mobility group box 1.

The pathogenesis of sepsis is mediated in part by bacterial endotoxin, which stimulates macrophages/monocytes to sequentially release early (e.g., TNF, IL-1, and IFN-gamma) and late (e.g., high mobility group box 1 (HMGB1) protein) proinflammatory cytokines. The recent discovery of HMGB1 as a late mediator of lethal sepsis has prompted investigation for development of new experimental therapeutics. We found that many steroidal drugs (such as dexamethasone and cortisone) and nonsteroidal anti-inflammatory drugs (such as aspirin, ibuprofen, and indomethacin) failed to influence endotoxin-induced HMGB1 release even at superpharmacological concentrations (up to 10-25 microM). However, several steroid-like pigments (tanshinone I, tanshinone IIA, and cryptotanshinone) of a popular Chinese herb, Danshen (Salvia miltiorrhiza), dose dependently attenuated endotoxin-induced HMGB1 release in macrophage/monocyte cultures. A water-soluble tanshinone IIA sodium sulfonate derivative (TSNIIA-SS), which has been widely used as a Chinese medicine for patients with cardiovascular disorders, selectively abrogated endotoxin-induced HMGB1 cytoplasmic translocation and release in a glucocorticoid receptor-independent manner. Administration of TSNIIA-SS significantly protected mice against lethal endotoxemia and rescued mice from lethal sepsis even when the first dose was given 24 h after the onset of sepsis. The therapeutic effects were partly attributable to attenuation of systemic accumulation of HMGB1 (but not TNF and NO) and improvement of cardiovascular physiologic parameters (e.g., decrease in total peripheral vascular resistance and increase in cardiac stroke volume) in septic animals. Taken together, these data re-enforce the pathogenic role of HMGB1 in lethal sepsis, and support a therapeutic potential for TSNIIA-SS in the treatment of human sepsis.

Pathogenic role of HMGB1 in SARS?

High mobility group box 1 protein (HMGB1) is released by necrotic cells or activated macrophages/monocytes, and functions as a late mediator of lethal systemic and local pulmonary inflammation. Passive immunization with anti-HMGB1 antibodies confers significant protection against lethal endotoxemia, sepsis, and acute lung injury, even when antibodies are administered after the onset of these diseases. In light of observations that three Chinese herbal formulations recommended for treatment of severe acute respiratory syndrome (SARS) specifically inhibited the release of HMGB1 from innate immune cells, we hypothesize that HMGB1 might occupy a pathogenic role in SARS by mediating an injurious pulmonary inflammatory response.

Lifespan is prolonged in autoimmune-prone (NZB/NZW) F1 mice fed a diet supplemented with indole-3-carbinol.

Dietary modulation has the potential to prevent or ameliorate systemic lupus erythematosus (SLE). Indole-3-carbinol (I3C), which is abundant in cruciferous vegetables, was evaluated in a murine model of SLE because of its antiestrogenic activities. Female (NZB x NZW) F1 mice, which develop SLE, were fed an AIN76A diet without or with 0.2 g/kg I3C, starting soon after weaning or at 5 mo of age. At 12 mo of age, 80% of mice fed the I3C-supplemented diet soon after weaning were alive compared with only 10% of controls. When experimental diets were initiated at 5 mo of age, 100% of I3C fed mice and 30% of controls were alive at 12 mo of age. Anti-double-stranded DNA (dsDNA) antibodies developed in all groups, although at several time points, the levels produced in I3C-fed mice were significantly lower. Renal disease (proteinuria, histologic changes, IgG immune complex deposition, subepithelial deposits and diffuse epithelial cell foot process effacement) was more severe in controls with both protocols. The estrogen urinary metabolite ratio of 2- to 16alpha-hydroxyestrone was increased in I3C-fed mice. These findings demonstrate a profound effect of dietary I3C in experimental SLE.

n-6 Polyunsaturated fatty acids increase skin but not cervical cancer in human papillomavirus 16 transgenic mice.

Using a mouse with transgenes for the highly oncogenic human papillomavirus type 16, we asked whether a diet high in fat, namely, the n-6 polyunsaturated fatty acid linoleic acid, would influence the development of skin or cervical cancer. Virgin female keratin 14-human papillomavirus 16 transgenic mice were fed control diet or diet with 20% corn oil. The effect of these diets was compared in mice implanted or not implanted with 0.125 mg/60 day release of estradiol. More precancers and cancers of the skin developed faster in mice fed the high-fat diet. Estrogen had no effect on the development of skin cancers. In contrast, estrogen was necessary for the development of cervical cancer, and a high-fat diet had no effect on the development of cervical cancer.