Activation of Autophagy Relieves Linoleic Acid-Induced Inflammation in Large Yellow Croaker (Larimichthys crocea).

High levels of soybean oil (SO) in fish diets enriched with linoleic acid (LA, 18:2n-6) could induce strong inflammation. However, the molecular mechanism underlying LA-induced inflammation in the liver of large yellow croaker (Larimichthys crocea) has not been elucidated. Based on previous research, autophagy has been considered a new pathway to relieve inflammation. Therefore, the present study was performed to investigate the role of autophagy in regulating LA-induced inflammation in the liver of large yellow croaker in vivo and in vitro. The results of the present study showed that activation of autophagy in liver or hepatocytes could significantly reduce the gene expression of proinflammatory factors, such as tumor necrosis factor α (TNFα) and interleukin 1ß (IL1ß). The results of the present study also showed that inhibition of autophagy could upregulate the gene expression of proinflammatory factors and downregulate the gene expression of anti-inflammatory factors in vivo and in vitro. Furthermore, autophagy could alleviate LA-induced inflammatory cytokine gene expression in vivo and in vitro, while inhibition of autophagy obtained the opposite results. In conclusion, our study shows that autophagy could regulate inflammation and alleviate LA-induced inflammation in the liver of large yellow croaker in vivo and in vitro for the first time, which may offer considerable benefits to the aquaculture industry and human health.

Glycyrrhizic acid ammonium salt alleviates Concanavalin A-induced immunological liver injury in mice through the regulation of the balance of immune cells and the inhibition of hepatocyte apoptosis.

Glycyrrhizic acid ammonium salt (GAAS) is derived from glycyrrhizic acid, which is an active compound extracted from the Chinese traditional medicine licorice. GAAS is clinically applied to treat immune-mediated liver injury, but its mechanism remains elusive. Therefore, this study aimed to investigate the mechanism in which GAAS alleviates immune-mediated liver injury induced by Concanavalin A (ConA). After ten days of intragastric administration of GAAS, 20 mg/kg ConA was injected via tail vein to establish the immune-mediated liver injury model of BALB/C mice. Then, the concentrations of ALT, AST, and TBIL in the serum of mice were determined. H&E staining was performed to observe the pathological changes in the liver, and the expression of liver cytokines was detected by qPCR. Immunohistochemistry and Western blot analysis was employed to detect the expression of liver-related proteins. The apoptosis in liver tissue was detected by TUNEL. Our results suggest that GAAS demonstrated excellent protective effects in the liver. We found that GAAS down-regulated the mRNA expression of IL-1ß, IL-6, TNF-α, IFN-γ, and IL-17A, and it up-regulated the mRNA expression of IL-4 and TGF-ß. Additionally, GAAS may modulate the balance of four immune cells (Th1, Th2, Th17, and Treg) by regulating the expression of T-bet, GATA3, RORγt, and Foxp3 to alleviate liver injury in mice. Furthermore, GAAS decreased hepatocyte apoptosis by blocking the JAK1/STAT1/IRF1 pathway, suppressing oxidative stress, decreasing p-JNK expression, and regulating the expression of apoptosis-related proteins. In summary, the mechanism of GAAS in liver injury alleviation acts to regulate the balance of Th cells in the liver to inhibit hepatocyte apoptosis. This study may provide a new strategy for the treatment of immune-mediated liver injury.

Yiguanjian decoction enhances fetal liver stem/progenitor cell-mediated repair of liver cirrhosis through regulation of macrophage activation state.

AIM: To investigate whether Yiguanjian decoction (YGJ) has an anti-liver cirrhotic effect and whether it regulates hepatic stem cell differentiation. METHODS: A rat model of liver cirrhosis was established via subcutaneous injection of carbon tetrachloride (CCl4) for 8 wk. From the beginning of the ninth week, the rats received 2-acetylaminofluorene (2-AAF) by oral gavage and a DLK-1+ fetal liver stem/progenitor cell (FLSPC) transplant or an FLSPC transplant in combination with YGJ treatment for 4 wk. In vitro, lipopolysaccharide (LPS)-activated macrophages were co-cultured with WB-F344 cells, and the differentiation of WB-F344 cells was observed in the presence and absence of YGJ treatment. RESULTS: FLSPC transplantation improved liver function and histopathology, and inhibited the activation of the non-canonical Wnt signaling pathway, while activating the canonical Wnt signaling pathway. YGJ enhanced the therapeutic effects of FLSPCs and also promoted the liver regeneration differentiation of FLSPCs into hepatocytes. In vitro, LPS-activated macrophages promoted the differentiation of WB-F344 cells into myofibroblasts, and the canonical Wnt signaling was inhibited while the non-canonical Wnt signaling was activated in WB-F344 cells. YGJ suppressed the activation of macrophages and then inhibited non-canonical Wnt signaling and promoted canonical Wnt signaling. CONCLUSION: YGJ enhances FLSPC-mediated repair of liver cirrhosis through regulation of macrophage activation state, and YGJ in combination with stem cell transplantation may be a suitable treatment for end-stage liver cirrhosis.

Sodium Butyrate Supplementation Alleviates the Adaptive Response to Inflammation and Modulates Fatty Acid Metabolism in Lipopolysaccharide-Stimulated Bovine Hepatocytes.

This study aimed to evaluate whether sodium butyrate (SB) attenuates the hepatic response to LPS-induced inflammation in bovine hepatocytes. Hepatocytes isolated from cows at ∼160 days in milk (DIM) were exposed to 0.5 mmol/L SB for 18 h as pretreatment. Cells pretreated with SB were used for the SB group, and those subjected to 4 µg/mL lipopolysaccharide (LPS) challenge for 6 h were used for the lipopolysaccharide pretreated with SB (LSB) group. The LPS-challenged hepatocytes showed increases in TNF-α and IL-6 production in culture medium (37 ± 11, P < 0.05); these increases were attenuated by pretreatment with SB in the LSB group (267 ± 4, P < 0.05). Compared to that in LPS-treated cells, the phospho-p65 and phospho-IκBα protein expression and nuclear translocation were suppressed when SB was added. Genes ( SREBP1c, SCD1, and DGAT1) and proteins (SREBP1c and SCD1) related to fatty acid metabolism were upregulated in LSB cells compared to those in LPS-treated cells ( P < 0.05). The ratios of phospho-AMPKα to AMPKα (0.32 ± 0.03 vs 0.70 ± 0.07) and phospho-ACCα to ACCα were decreased (0.81 ± 0.06 vs 2.06 ± 0.16) ( P < 0.05) in the LSB group. SB pretreatment reversed the histone H3 deacetylation that was increased by LPS stimulation in bovine hepatocytes (0.54 ± 0.02 vs 1.27 ± 0.11, P < 0.05). Our results suggest that SB pretreatment suppresses the hepatocyte changes that occur during the LPS-induced inflammatory response, which is accompanied by enhanced fatty acid synthesis, downregulated fatty acid oxidation, and histone H3 deacetylation, thus neutralizing the negative effects of infection.

Piperidylmethyloxychalcone improves immune-mediated acute liver failure via inhibiting TAK1 activity.

Mice deficient in the toll-like receptor (TLR) or the myeloid differentiation factor 88 (MyD88) are resistant to acute liver failure (ALF) with sudden death of hepatocytes. Chalcone derivatives from medicinal plants protect from hepatic damages including ALF, but their mechanisms remain to be clarified. Here, we focused on molecular basis of piperidylmethyloxychalcone (PMOC) in the treatment of TLR/MyD88-associated ALF. C57BL/6J mice were sensitized with D-galactosamine (GalN) and challenged with Escherichia coli lipopolysaccharide (LPS, TLR4 agonist) or oligodeoxynucleotide containing unmethylated CpG motif (CpG ODN, TLR9 agonist) for induction of ALF. Post treatment with PMOC sequentially ameliorated hepatic inflammation, apoptosis of hepatocytes, severe liver injury and shock-mediated death in ALF-induced mice. As a mechanism, PMOC inhibited the catalytic activity of TGF-ß-activated kinase 1 (TAK1) in a competitive manner with respect to ATP, displaced fluorescent ATP probe from the complex with TAK1, and docked at the ATP-binding active site on the crystal structure of TAK1. Moreover, PMOC inhibited TAK1 auto-phosphorylation, which is an axis in the activating pathways of nuclear factor-κB (NF-κB) or activating protein 1 (AP1), in the liver with ALF in vivo or in primary liver cells stimulated with TLR agonists in vitro. PMOC consequently suppressed TAK1-inducible NF-κB or AP1 activity in the inflammatory injury, an early pathogenesis leading to ALF. The results suggested that PMOC could contribute to the treatment of TLR/MyD88-associated ALF with the ATP-binding site of TAK1 as a potential therapeutic target.

Effects of water extract of Curcuma longa (L.) roots on immunity and telomerase function.

Background Immunity and Longevity Methods A water extract of Curcuma longa (L.) [vern. Turmeric] roots (TurmericImmune™) standardized for a minimum 20 % of turmeric polysaccharides ukonan A, B, C and D was evaluated for its biological properties in in vitro tissue culture studies. Results The water extract of turmeric (TurP) exhibited induced-nitric oxide (NO) production in RAW264.7 macrophages. These results suggested the immunomodulatory effects of TurP. In addition, the polysaccharides up-regulated function of telomerase reverse transcriptase (TERT) equally to the phenolic compound from turmeric, curcumin. Conclusions The ukonan family of polysaccharides may assist in promoting cellular immune responses, tissue repair and lifespan by enhancing immune response and telomere function.

Hepatic anti-inflammatory effect of hexane extracts of Dioscorea batatas Decne: Possible suppression of toll-like receptor 4-mediated signaling.

The hepatic anti-inflammatory potential of hexane extracts of Dioscorea batatas Decne edible part (EDH-1e) and bark (EDH-2b) were investigated in Western-type diet-fed apolipoprotein E null [ApoE (-/-)] mice and HepG2 cells. EDH-1e and EDH-2b suppressed the increased levels of tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, transforming growth factor beta 1 (TGF-ß1), vascular cell adhesion protein 1 (VCAM-1), and monocyte chemoattractant protein-1 (MCP-1), and reduced infiltration of monocytes into liver tissue. The protein levels of Toll-like receptor 4 (TLR4) were also downregulated by EDH-1e and EDH-2b treatment as were the levels of activator protein 1 (AP-1), c-fos, and c-jun in the livers from Western-type diet-fed ApoE (-/-) mice and in lipopolysaccharide-stimulated HepG2 cells. Taken together, EDH-1e and EDH-2b attenuated hepatic inflammation and fibrosis via suppression of the TLR4-AP1-mediated signaling pathway.

Magnolia officinalis (Hou Po) bark extract stimulates the Nrf2-pathway in hepatocytes and protects against oxidative stress.

ETHNOPHARMACOLOGICAL RELEVANCE: The highly aromatic bark of Magnolia officinalis Rehder and EH Wilson, (magnolia bark) has been widely used in traditional Chinese medicine where it is known as Hou Po. Historically the bark of the tree has been used for treating variety of disorders the most common use of magnolia bark in traditional prescription has been to treat stress and anxiety disorders. Till date it is not clear regarding the fundamental cellular pathway it modulates. NRF2 signaling has emerged as the central pathway that protects cells from variety of stressors this led us to hypothesize that basis for magnolia bark's effects could be via activating NRF2 pathway. MATERIALS AND METHODS: We utilized variety of biochemical procedures like luciferase reporter assay, enzyme induction, gene expression to determine NRF2 inducing activity by magnolia bark extract and its significance. Further we identified the phytochemicals inducing this activity using bio-directed fractionation procedure. RESULTS: In this study, we demonstrate that magnolia bark extract activates Nrf2-dependent gene expression and protects against hydrogen peroxide mediated oxidative stress in hepatocytes. We further identified through HPLC fractionation and mass spectroscopy that magnolol, 4-methoxy honokiol and honokiol are the active phytochemicals inducing the Nrf2-mediated activity. This could be the molecular basis for its numerous beneficial activity.

Protective effects of leucine against lipopolysaccharide-induced inflammatory response in Labeo rohita fingerlings.

The present study investigated the protective effects of leucine against lipopolysaccharide (LPS)-induced inflammatory responses in Labeo rohita (rohu) in vivo and in vitro. Primary hepatocytes, isolated from the hepatopancreas, were exposed to different concentrations of LPS for 24 h to induce an inflammatory response, and the protective effects of leucine against LPS-induced inflammation were studied. Finally, we investigated the efficiency of dietary leucine supplementation in attenuating an immune challenge induced by LPS in vivo. Exposure of cells to 10-25 µg mL(-1) of LPS for 24 h resulted in a significant production of nitric oxide and release of lactate dehydrogenase to the medium, whereas cell viability and protein content were reduced (p < 0.05). LPS exposure (10 µg mL(-1)) increased mRNA levels of the pro-inflammatory cytokines TNF-α, IL-1ß and IL-8 in vitro (p < 0.05). However, pretreatment with leucine prevented the LPS-induced upregulation of TNF-α, IL-1ß and IL-8 mRNAs by downregulating TLR4, MyD88, NF-κBp65, and MAPKp38 mRNA expression. Interestingly, mRNA expression of the anti-inflammatory cytokine, IL-10, which was increased by LPS treatment, was further enhanced (p < 0.05) by leucine pretreatment. The enhanced expression of IL-10 might inhibit the production of other pro-inflammatory cytokines. It was found that leucine pretreatment attenuated the excessive activation of LPS-induced TLR4-MyD88 signaling as manifested by lower level of TLR4, MyD88, MAPKp38, NF-κBp65 and increased level of IκB-α protein in leucine pre-treatment group. In vivo experiments demonstrated that leucine pre-supplementation could protect fish against LPS-induced inflammation through an attenuation of TLR4-MyD88 signaling pathway. Taken together, we propose that leucine pre-supplementation decreases LPS-induced immune damage in rohu by enhancing the expression of IL-10 and by regulating the TLR4-MyD88 signaling pathways.

Chokeberry attenuates the expression of genes related to de novo lipogenesis in the hepatocytes of mice with nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD), which is characterized by steatosis, is a major public health concern. Previous studies have shown that chokeberry has anti-inflammatory, antimutagenic, hepatoprotective, cardioprotective, and antidiabetic effects. In this study, we hypothesized that chokeberry powder can attenuate the expression of genes related to de novo lipogenesis and the triglyceride levels in the hepatocytes of mice with high-fat diet-induced NAFLD. After coadministering chokeberry powder for 8weeks (0.5% and 1% powder) with a high-fat diet, mice that consumed chokeberry powder diets, regardless of the dose, had significantly lower liver triglyceride levels than control mice that were fed a high-fat diet (P=.0145 and P<.0012, respectively). Compared with mice that were fed a high-fat diet, mice that were given 1% chokeberry powder exhibited significantly decreased mRNA expression of sterol regulatory element-binding protein (P=.009) and acetyl-CoA carboxylase (P=.0032) in the liver. Compared with mice in the control group, fatty acid synthase (FAS) expression significantly increased in the mice that were fed a high-fat diet, but both chokeberry powder-treated groups had significantly decreased FAS expression (P=.0157 and P<.0001, respectively). The size of the fat droplets was decreased in the livers of the chokeberry-supplemented groups. In summary, the administration of chokeberry powder may help attenuate high-fat diet-induced NAFLD by regulating the expression levels of sterol regulatory element-binding protein, acetyl-CoA carboxylase, and FAS and by decreasing the size of the fat droplets in the liver.

Gallic acid ameliorates hyperglycemia and improves hepatic carbohydrate metabolism in rats fed a high-fructose diet.

Herein, we investigated the hypoglycemic effect of plant gallic acid (GA) on glucose uptake in an insulin-resistant cell culture model and on hepatic carbohydrate metabolism in rats with a high-fructose diet (HFD)-induced diabetes. Our hypothesis is that GA ameliorates hyperglycemia via alleviating hepatic insulin resistance by suppressing hepatic inflammation and improves abnormal hepatic carbohydrate metabolism by suppressing hepatic gluconeogenesis and enhancing the hepatic glycogenesis and glycolysis pathways in HFD-induced diabetic rats. Gallic acid increased glucose uptake activity by 19.2% at a concentration of 6.25 µg/mL in insulin-resistant FL83B mouse hepatocytes. In HFD-induced diabetic rats, GA significantly alleviated hyperglycemia, reduced the values of the area under the curve for glucose in an oral glucose tolerance test, and reduced the scores of the homeostasis model assessment of insulin resistance index. The levels of serum C-peptide and fructosamine and cardiovascular risk index scores were also significantly decreased in HFD rats treated with GA. Moreover, GA up-regulated the expression of hepatic insulin signal transduction-related proteins, including insulin receptor, insulin receptor substrate 1, phosphatidylinositol-3 kinase, Akt/protein kinase B, and glucose transporter 2, in HFD rats. Gallic acid also down-regulated the expression of hepatic gluconeogenesis-related proteins, such as fructose-1,6-bisphosphatase, and up-regulated expression of hepatic glycogen synthase and glycolysis-related proteins, including hexokinase, phosphofructokinase, and aldolase, in HFD rats. Our findings indicate that GA has potential as a health food ingredient to prevent diabetes mellitus.

Zinc dyshomeostasis during polymicrobial sepsis in mice involves zinc transporter Zip14 and can be overcome by zinc supplementation.

Integrity of the immune system is particularly dependent on the availability of zinc. Recent data suggest that zinc is involved in the development of sepsis, a life-threatening systemic inflammation with high death rates, but with limited therapeutic options. Altered cell zinc transport mechanisms could contribute to the inflammatory effects of sepsis. Zip14, a zinc importer induced by proinflammatory stimuli, could influence zinc metabolism during sepsis and serve as a target for therapy. Using cecal ligation-and-puncture (CLP) to model polymicrobial sepsis, we narrowed the function of ZIP14 to regulation of zinc homeostasis in hepatocytes, while hepatic leukocytes were mostly responsible for driving inflammation, as shown by higher expression of IL-1ß, TNFα, S100A8, and matrix metalloproteinase-8. Using Zip14 knockout (KO) mice as a novel approach, we found that ablation of Zip14 produced a delay in development of leukocytosis, prevented zinc accumulation in the liver, altered the kinetics of hypozincemia, and drastically increased serum IL-6, TNFα, and IL-10 concentrations following CLP. Hence, this model revealed that the zinc transporter ZIP14 is a component of the pathway for zinc redistribution that contributes to zinc dyshomeostasis during polymicrobial sepsis. In contrast, using the identical CLP model, we found that supplemental dietary zinc reduced the severity of sepsis, as shown by amelioration of cytokines, calprotectins, and blood bacterial loads. We conclude that the zinc transporter ZIP14 influences aspects of the pathophysiology of nonlethal polymicrobial murine sepsis induced by CLP through zinc delivery. The results are promising for the use of zinc and its transporters as targets for future sepsis therapy.

A systematic comparison of the impact of inflammatory signaling on absorption, distribution, metabolism, and excretion gene expression and activity in primary human hepatocytes and HepaRG cells.

Inflammatory processes are associated with compromised metabolism and elimination of drugs in the liver, largely mediated by proinflammatory cytokines, such as interleukin-6. The Hepa-RG cell line is an established surrogate for primary human hepatocytes (PHH) in drug metabolism and toxicity studies. However, the impact of inflammatory signaling on HepaRG cells has not been well characterized. In this study, the response of primary human hepatocytes and HepaRG cells to interleukin (IL)-6 was comparatively analyzed. For this purpose, broad-spectrum gene expression profiling, including acute-phase response genes and a large panel of drug-metabolizing enzyme and transporter (DMET) genes as well as their modifiers and regulators, was conducted in combination with cytochrome P450 (P450) activity measurements. Exposure of PHH and HepaRG cells to IL-6 resulted in highly similar coordinated reduction of DMET mRNA, including major ATP-binding cassette transporters (ABCs), P450s, glutathione S-transferases (GSTs), uridine diphosphate glucuronosyltransferases (UGTs), and solute carriers (SLCs). Enzyme activities of CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, and CYP3A4 were reduced upon 48-72 hours exposure to IL-6 in PHH and HepaRG. However, although these effects were not significant in PHH due to large interindividual donor variability, the impact on HepaRG was more pronounced and highly significant, thus emphasizing the advantage of HepaRG as a more reproducible model system. Exposure of HepaRG cells to interleukin-1ß and tumor necrosis factor α resulted in similar effects on gene expression and enzyme activities. The present study emphasizes the role of proinflammatory cytokines in the regulation of drug metabolism and supports the use of HepaRG in lieu of PHH to minimize subject variability.

Dietary fish oil exacerbates concanavalin A induced hepatitis through promoting hepatocyte apoptosis and altering immune cell populations.

The development of hepatitis is associated with the infiltration and activation of immune cells in liver. N-3 polyunsaturated fatty acids (n-3 PUFAs) rich fish oil (FO) is used to prevent and treat inflammatory diseases. But, the effects of dietary FO on autoimmune hepatitis remain largely unknown. In this study, Concanavalin A (Con A) induced hepatitis was used to evaluate the actions of dietary FO. Unexpectedly, 2-week FO treatment had not shown any protection, on the contrary, exacerbated liver injury in this hepatitis model. The levels of alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) statistically increased from 10,501 ± 2,154 and 30,394 ± 2,420 in low fat diet (LFD)/Con A group to 17,579 ± 693 and 49,439 ± 4,628 in FO/Con A group. Simultaneously, FO diet induced more necrotic liver tissues and apoptotic hepatocytes, and up-regulated the hepatic expression of TNF-α and IFN-γ after Con A challenge. Interestingly, FO promoted severe liver injury was accompanied by decreasing the percentage of CD4⁺ T cell, NK1.1⁺ cells and CD8⁺ T cells in CD45⁺ liver non-parenchymal hepatic cells (NPCs) through inducing apoptosis. Further experiments declared 2-week FO diet intake firstly increased the proportion of CD11b⁺Gr-1(hi) neutrophils in liver, but then dramatically expanded CD11b⁺Gr-1(int) inflammatory monocytes population after Con A administration. Collectively, our study indicated that high FO intake not only aggravated liver injury, but also altered the population of immune cells in liver. Thus, these results indicated that when dietary FO was used to benefit health in autoimmune diseases, its potential risks of side effect also need paying close attention.

Hepatoprotective evaluation of the total flavonoids extracted from flowers of Abelmoschus manihot (L.) Medic: In vitro and in vivo studies.

ETHNOPHARMACOLOGICAL RELEVANCE: The decoction of the flowers of Abelmoschus manihot (L.) Medic is traditionally used for the treatment of jaundice and various types of chronic and acute hepatitis in Anhui and Jiangsu Provinces of China. Phytochemical studies have indicated that total flavonoids extracted from flowers of Abelmoschus manihot (L.) Medic (TFA) were the major constituents of the flowers. The present study was designed to investigate the hepatoprotective effect of the plant extracts against carbon tetrachloride (CCl4) induced hepatocyte damage in vitro and liver injury in vivo. MATERIAL AND METHODS: In the in vitro studies, freshly isolated rat hepatocytes were exposed to CCl4 (1%) along with/without various concentrations of TFA (4.5-72mg/L). Cell damage was assessed by the trypan blue exclusion method and alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) in the medium were analyzed. In the in vivo studies, the hepatoprotective activity of TFA (125, 250 and 500mg/kg) were investigated on CCl4-induced liver damages in mice. The levels of ALT, AST and ALP, gamma glutamyltransferase (γ-GT), tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1ß) and nitric oxide (NO) were determined in serum. Hepatic malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and glutathione transferase (GST) were measured in the liver homogenates. Cytokine transcript levels of TNF-α, IL-1ß and inducible nitric oxide synthase (iNOS) in the liver tissues of mice were measured using reverse transcription-polymerase chain reaction (RT-PCR). Livers were dissected out and evaluated for histomorphological changes. RESULTS: A concentration-dependent increase in the percentage viability was observed when CCl4-exposed hepatocytes were treated with different concentrations of TFA. Levels of ALT, AST and ALP in the medium were significantly decreased. In the animal studies, TFA showed significant protection with the depletion of ALT, AST, ALP and γ-GT in serum as was raised by the induction of CCl4. Moreover, TFA decreased the MDA level and elevated the content of GSH in the liver as compared to those in the CCl4 group. Furthermore, activities of antioxidative enzymes, including SOD, GPx, CAT and GST, were enhanced dose dependently with TFA. Meanwhile, the inflammatory mediators (e.g., TNF-α, IL-1ß and NO) were inhibited by TFA treatment both at the serum and mRNA levels. Additionally, histological analyses also showed that TFA reduced the extent of liver lesions induced by CCl4. CONCLUSION: These results suggested that TFA protected mice against CCl4-induced liver injury through antioxidant stress and antiinflammatory effects. This finding justified the use of this plant in traditional medicine for the treatment of liver disease.

Interleukin-6 and lipopolysaccharide modulate hepcidin mRNA expression by HepG2 cells.

Iron homeostasis is controlled by hepcidin (Hpc) as well as other ways. Hpc expression is regulated by iron (Fe) storage and by inflammation, but the joint effect of both stimuli remains unclear. We studied the modulatory role of inflammatory agents (IL6 and LPS) over Hpc and DMT1 mRNA expression in HepG2 cells preloaded with Fe. HepG2 cells were preloaded with different Fe concentrations (holo-Tf or Fe-NTA) and then incubated with IL6 or LPS. We measured intracellular Fe levels by AAS with graphite furnace, transferrin receptor (TfR) by ELISA and mRNA relative abundance of Hpc and DMT1 by qRT-PCR. The maximum effect on Fe uptake was observed in cells incubated with 30 ng/ml IL6 (p < 0.01) and 500 ng/ml LPS (p < 0.05). In HepG2 cells preloaded with holo-Tf or Fe-NTA and challenged with IL6 and LPS, we observed a decreased: (a) Hpc mRNA relative abundance (two-way ANOVA: p < 0.05 and p < 0.001, respectively), (b) DMT1 mRNA relative abundance and TfR1 protein levels (two-way ANOVA: p < 0.001), and (c) intracellular Fe concentration (two-way ANOVA: p < 0.001 and p < 0.01, respectively) compared to control cells incubated only with Fe (holo-Tf or Fe-NTA). Our results support the idea that Fe storage and inflammation act together to regulate Fe homeostasis and suggest a negative regulation in this hepatic cellular model to prevent excessive increases in Hpc.

Fraction from wax apple [Syzygium samarangense (Blume) Merrill and Perry] fruit extract ameliorates insulin resistance via modulating insulin signaling and inflammation pathway in tumor necrosis factor α-treated FL83B mouse hepatocytes.

Inflammation is associated with the development of insulin resistance in Type 2 diabetes mellitus. In the present study, mouse FL83B cells were treated with tumor necrosis factor-alpha (TNF-α) to induce insulin resistance, and then co-incubated with a fraction from wax apple fruit extract (FWFE). This fraction significantly increased the uptake of the nonradioactive fluorescent indicator 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxy-d-glucose (2-NBDG) in insulin resistant cells. Western blot analysis revealed that, compared with the TNF-α-treated control group, FWFE increased the expression of the insulin receptor (IR), insulin receptor substrate-1 (IRS-1), protein kinase B (Akt/PKB), phosphatidylinositol-3 kinase (PI3K), and glucose transporter 2 (GLUT-2), and increased IR tyrosyl phosporylation, in insulin resistant FL83B cells. However, FWFE decreased phosphorylation of c-Jun N-terminal kinases (JNK), but not the expression of the intercellular signal-regulated kinases (ERK), in the same cells. These results suggest that FWFE might alleviate insulin resistance in TNF-α-treated FL83B cells by activating PI3K-Akt/PKB signaling and inhibiting inflammatory response via suppression of JNK, rather than ERK, activation.

The role of dietary fatty acids in the pathology of metabolic syndrome.

Dysfunctional lipid metabolism is a key component in the development of metabolic syndrome, a very frequent condition characterized by dyslipidemia, insulin resistance, abdominal obesity and hypertension, which are related to an elevated risk for type 2 diabetes mellitus. The prevalence of metabolic syndrome is strongly associated with the severity of obesity; its physiopathology is related to both genetics and food intake habits, especially the consumption of a high-caloric, high-fat and high-carbohydrate diet. With the progress of scientific knowledge in the field of nutrigenomics, it was possible to elucidate how the majority of dietary fatty acids influence plasma lipid metabolism and also the genes expression involved in lipolysis and lipogenesis within hepatocytes and adipocytes. The aim of this review is to examine the relevant mechanistic aspects of dietary fatty acids related to blood lipids, adipose tissue metabolism, hepatic fat storage and inflammatory process, all of them closely related to the genesis of metabolic syndrome.

25-Hydroxyvitamin D3 suppresses hepatitis C virus production.

UNLABELLED: Because the current interferon (IFN)-based treatment for hepatitis C virus (HCV) infection has a therapeutic limitation and side effects, a more efficient therapeutic strategy is desired. Recent studies show that supplementation of vitamin D significantly improves sustained viral response via IFN-based therapy. However, mechanisms and an active molecular form of vitamin D for its anti-HCV effects have not been fully clarified. To address these questions, we infected HuH-7 cells with cell culture-generated HCV in the presence or absence of vitamin D(3) or its metabolites. To our surprise, 25-hydroxyvitamin D(3) [25(OH)D(3) ], but not vitamin D(3) or 1,25-dihydroxyvitamin D(3) , reduced the extra- and intracellular levels of HCV core antigen in a concentration-dependent manner. Single-cycle virus production assay with a CD81-negative cell line reveals that the inhibitory effect of 25(OH)D(3) is at the level of infectious virus assembly but not entry or replication. Long-term 25(OH)D(3) treatment generates a HCV mutant with acquired resistance to 25(OH)D(3) , and this mutation resulting in a N1279Y substitution in the nonstructural region 3 helicase domain is responsible for the resistance. CONCLUSION: 25(OH)D(3) is a novel anti-HCV agent that targets an infectious viral particle assembly step. This finding provides insight into the improved efficacy of anti-HCV treatment via the combination of vitamin D(3) and IFN. Our results also suggest that 25(OH)D(3) , not vitamin D(3) , is a better therapeutic option in patients with hepatic dysfunction and reduced enzymatic activity for generation of 25(OH)D(3) .

Pharmacokinetics and pharmacodynamics of pegylated interferon lambda-1 in cynomolgus monkeys.

Type III lambda interferons (IFNs) have activity similar to type I IFNs, but a more restricted receptor distribution. A pegylated human IFN lambda-1 (pegIFNλ) is under development for chronic hepatitis C. Induction of receptor signaling (STAT1 phosphorylation) and expression of interferon-stimulated genes (ISGs) by pegIFNλ were assessed in, respectively, cynomolgus monkey leukocyte subsets and hepatocytes stimulated in vitro. ISG induction by pegIFNλ or IFNα was also assessed in peripheral leukocytes and liver biopsies after single and repeat (x3) dosing of pegIFNλ (0.03, 0.3, 3.0 mg/kg) or unpegylated IFNα-2b (10(7) IU/kg). Single-dose pharmacokinetics of pegIFNλ were evaluated. Strong ISG induction occurred in cultured hepatocytes and liver biopsies with both pegIFNλ and IFNα. However, STAT1 phosphorylation, MHC class 1 upregulation, and ISG induction in leukocytes only occurred with IFNα. Serum neopterin was unaffected by pegIFNλ; however, ß-2-microglobulin was elevated at all doses. The terminal half-life of pegIFNλ was 23 h with a 59 mL/kg volume of distribution, consistent with other pegylated IFNs. Serum exposure was dose-proportional across the dosing range. These data demonstrate the suitability of cynomolgus monkeys for the preclinical evaluation of pegIFNλ. Additionally, the absence of pegIFNλ pharmacologic activity in leukocytes is consistent with its low receptor expression in blood.