Hepatic Nuclear factor-kappaB Research Articles

Galangin Activates Nrf2 Signaling and Attenuates Oxidative Damage, Inflammation, and Apoptosis in a Rat Model of Cyclophosphamide-Induced Hepatotoxicity.

Cyclophosphamide (CP) is a widely used chemotherapeutic agent; however, its clinical application is limited because of its multi-organ toxicity. Galangin (Gal) is a bioactive flavonoid with promising biological activities. This study investigated the hepatoprotective effect of Gal in CP-induced rats. Rats received Gal (15, 30 and 60 mg/kg/day) for 15 days followed by a single dose of CP at day 16. Cyclophosphamide triggered liver injury characterized by elevated serum transaminases, alkaline phosphatase (ALP) and lactate dehydrogenase (LDH), and histopathological manifestations. Increased hepatic reactive oxygen species, malondialdehyde, nitric oxide, and oxidative DNA damage along with declined glutathione and antioxidant enzymes were demonstrated in CP-administered rats. CP provoked hepatic nuclear factor-kappaB (NF-κB) phosphorylation and increased mRNA abundance of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), and tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) both expression and serum levels. Gal prevented CP-induced liver injury, boosted antioxidants and suppressed oxidative stress, DNA damage, NF-κB phosphorylation and pro-inflammatory mediators. Gal diminished Bax and caspase-3, and increased B-cell lymphoma-2 (Bcl-2) in liver of CP-administered rats. In addition, Gal increased peroxisome proliferator-activated receptor gamma (PPARγ) expression and activated hepatic nuclear factor erythroid 2-related factor 2 (Nrf2) signaling showed by the increase in Nrf2, NAD(P)H: quinone acceptor oxidoreductase-1 (NQO-1) and heme oxygenase 1 (HO-1) in CP-administered rats. These findings suggest that Gal prevents CP hepatotoxicity through activation of Nrf2/HO-1 signaling and attenuation of oxidative damage, inflammation and cell death. Therefore, Gal might represent a promising adjuvant therapy to prevent hepatotoxicity in patients on CP treatment.

Diallyl disulfide, an organo-sulfur compound in garlic and onion attenuates trichloromethane-induced hepatic oxidative stress, activation of NFkB and apoptosis in rats

Trichloromethane (TCM) serves as an ingredient in pesticide formulations and fire extinguishers. It is a reported hepato- and renal-toxin. We therefore investigated the chemo-preventive effect of diallyl disulfide (DADS) on TCM-induced hepatotoxicity. Twenty five rats, divided into five groups of five animals each were used. TCM at the dose of 200 mg/kg was orally administered, and concomitantly treated with DADS (50 mg/kg), 5 days per week for 3 weeks. Compared with control, there was a significant increase in hepatic expressions of nuclear factor kappa B (NFkB), TUNEL positive cells (apoptosis), and concentrations of malondialdehyde (MDA), hydrogen peroxide (H2O2), and nitric oxide (NO). Also, a significant decrease in expressions of p53, and activities of catalase (CAT) and glutathione peroxidase (GPx), as well as level of reduced glutathione (GSH) was recorded following TCM administration. Following treatment, DADS intervention significantly reduced the hepatic NFkB expressions, apoptotic positive cells as well as levels of MDA, H2O2, and NO, and also significantly increased the level of GSH, activities of CAT and GPx compared with TCM group, while its effect on expressions of p53 was insignificant. Hepato-protection by DADS against TCM-induced hepatotoxicity may therefore be via suppressions of NFkB activation, apoptosis, and oxidative stress in rats.

Effectiveness of vinpocetine and isosorbide-5-mononitrate on experimental schistosomiasis mansoni: Biochemical and immunohistochemical study

Schistosomiasis is one of the most important tropical and subtropical devastating diseases, where praziquantel is the sole drug of choice. Praziquantel effectively kills the adult worms, however, drug resistance has been repeatedly reported. Moreover, there is currently no efficient anti-fibrotic therapy available for chronic schistosomiasis. So, novel drugs which exert anti-fibrotic efficacy are urgently needed. This research is complementary to our previous work that evaluated the anti-schistosomal effects of the anti-inflammatory vinpocetine, as well as the vasodilator and the anti-oxidant isosorbide-5-mononitrate. In the present study, we assessed the therapeutic efficacies of drugs in Swiss albino female mice experimentally infected with an Egyptian strain of Schistosoma mansoni, using some biochemical and immunohistochemical parameters. Our results revealed that both vinpocetine and isosorbide-5-mononitrate monotherapy significantly decreased hepatic nuclear factor-kappaB, 10 weeks post infection. The best effects were seen in mice administered praziquantel combined with isosorbide-5-mononitrate, as detected by reduction in hydroxyproline and collagen contents of the liver, and significant increase in the hepatic nitric oxide content. The data provides insight into the potential effects of the assessed drugs with isosorbide-5-mononitrate being more superior to vinpocetine, hence it can be used as novel adjuvant to praziquantel to alleviate schistosomal hepatic fibrosis. However, molecular mechanism/s and clinical trials are worthy to be scrutinized.

The efficacy of dietary curcumin on growth performance, lipid peroxidation and hepatic transcription factors in rainbow troutOncorhynchus Mykiss(Walbaum) reared under different stocking densities

Curcumin, derived from Curcuma longa, exerts antioxidant, antibacterial, anticancer and immunomodulatory properties. This study was conducted to determine the effect of dietary water-soluble curcumin (0, 200 or 400 mg kg−1) on growth performance and antioxidant status in rainbow trout (Oncorhynchus mykiss, Walbaum) rearing under normal (20 kg m−3) or high (100 kg m−3) stocking density conditions. A significant increase in body weight (FBW), feed intake (FI) and weight gain (BWG) was observed in fish fed with curcumin-supplemented diet at 200 mg kg−1 of diet levels of high stocking density conditions (P < 0.0001), whereas feed conversion ratio (FCR) was not significant. Also, serum and liver malondialdehyde (MDA) levels were decreased by dietary curcumin in crowded fish (P < 0.01, for both). With curcumin supplementation, expressions of heat shock protein 70 (HSP70; P < 0.0001) and hepatic nuclear factor kappa-B (NF-κB; P < 0.01) decreased, whereas expressions of hepatic nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) (P < 0.001, for both) increased in fish exposed to high stocking density. In conclusion, curcumin supplementation alleviates adverse effects of high stocking density on performance through modulating expressions of stress-related nuclear transcription factors in rainbow trout.

Melatonin Protection against Burn-Induced Hepatic Injury by Down-Regulation and Nuclear Factor Kappa B Activation

Melatonin exhibits a wide variety of biological activity including antioxidant and anti-inflammatory effects. We have previously reported its protective effect on hepatic oxidative hepatic injury in burns. In this study, we investigated the role of nuclear factor kappa B (NF-κB) in melatonin-mediated protection against liver injury by using the burned-rat model. Melatonin (N-acetyl-5-methoxytriptamin, 10mg/kg (-1), i.p.) was administered immediately and 12 hours after thermal skin injury. Hepatic NF-κB expression was determined by Western blotting. TNF-α level in liver homogenate was quantified using enzyme-linked immunosorbent assay (ELISA) kit. Plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were determined to assess liver injury at the 24th hour after burns. Thermal skin injury caused significant elevation of hepatic NF-κB expression by 48 percent, TNF-α level by 55 percent and plasma AST and ALT activities by 2- and 3-fold, respectively, in comparison with normal control rats. Treatment with melatonin decreased significantly elevated hepatic NF-κB activity and TNF-α, maintaining the levels close to the control values Melatonin suppressed the elevation of plasma AST and ALT activities (p less than 0.001), which remained significantly increased compared to controls. In conclusion, thermal skin injury causes hepatic NF-κB activation that may mediate the release of hepatic TNF-α and contribute to liver damage. Melatonin protects against burn-induced hepatic injury as to a certain extent this effect may result from the suppression of NF-κB-mediated inflammatory response.

Lutein decreases oxidative stress and inflammation in liver and eyes of guinea pigs fed a hypercholesterolemic diet

Guinea pigs were fed a hypercholesterolemic diet (0.25 g/100 g cholesterol) and randomly allocated either to a Control group (n = 9) or to a Lutein (0.1 g/100 g) group (n = 10) for 12 weeks to evaluate oxidative stress and inflammation in both liver and eyes. Malondialdehyde (MDA) concentrations and inflammatory cytokines were measured as well as hepatic nuclear factor-kappaB (NF-κB) binding. Lutein concentrations were greater in eyes (P < 0.01) and liver (P < 0.001) in the Lutein group. All guinea pigs had high concentrations of hepatic cholesterol as well as high plasma ALT and AST levels indicative of liver injury. However, the Lutein group had 43% lower hepatic free cholesterol than the Controls (P < 0.05). Hepatic MDA and MDA in the eye were lower in the Lutein compared to the Control group (P < 0.05). Hepatic tumor necrosis factor-α was 32% lower in the Lutein group (P < 0.05). Lastly, the Lutein group presented lower NF-κB DNA binding activity than the Control group (P < 0.001). These results suggest that in the presence of high cholesterol, lutein exerts both antioxidant and anti-inflammatory effects, which can be explained by attenuated NF-κB DNA binding activity. Furthermore, results also suggest that lutein accumulates in the eyes of guinea pigs to protect against oxidative stress.

Bamboo Culm Extract Supplementation Elevates HDL-Cholesterol and Ameliorates Oxidative Stress in C57BL/6 Mice Fed Atherogenic Diet

Previously, we reported that bamboo culms possess a stronger antioxidative capacity than bamboo leaves in vitro. In this study, we investigated whether bamboo culm extract (BCE) supplementation ameliorates oxidative stress and hepatic nuclear factor kappaB (NF kappa B) activation in C57BL/6 mice fed an atherogenic diet. In addition, the effect of BCE supplementation on plasma lipid levels of the animals was tested. The mice were randomly assigned to a normal diet, an atherogenic diet (control), or an atherogenic diet supplemented with 1% (wt/wt) BCE or 3% (wt/wt) BCE for 16 weeks. Atherogenic diet-induced oxidative stress, measured by hepatic thiobarbituric acid-reactive substances and protein carbonyls, was significantly lower in the BCE-supplemented groups than in the control (P < .05). Total antioxidative capacity was elevated in the BCE groups, along with greater activities of antioxidative enzymes such as superoxide dismutase and catalase, compared to the control or normal groups (P < .05). The hepatic NF kappa B binding activities were significantly lower in the BCE groups as well (P < .05). The high-density lipoprotein-cholesterol level was significantly elevated by BCE supplementation (P < .05), whereas the effects of BCE on triglyceride and total cholesterol were inconsistent. Results from this study suggest that BCE supplementation may lessen oxidative stress via a series of changes, including a reinforced antioxidant system, and also suggest that the lowered oxidative stress status may down-regulate the activation of inflammatory mediators.

Toll-Like Receptor-4 Signaling Mediates Hepatic Injury and Systemic Inflammation in Hemorrhagic Shock

Hemorrhagic shock and resuscitation (HS/R) activates inflammatory pathways leading to organ injury after trauma. Toll-like receptors (TLRs), such as TLR4, are required for activation of proinflammatory cellular signaling pathways in response to microbial products, but can also recognize endogenous molecules released from damaged tissues. Using mouse strains deficient in TLR4 protein or signaling, we hypothesized that TLR4 would be important for development of systemic inflammation and hepatic injury after HS/R. We sought to determine the role of lipolysaccharide through use of CD14-/- mice. TLR4-mutant (C[3H]/HeJ), TLR4-deficient (TLR4-/-), CD14-/-, TLR2-/- mice and wild-type (WT) controls were subjected to HS/R or sham procedure (Sham). At 6.5 hours, mice were euthanized for determination of serum interleukin (IL)-6, IL-10, and alanine aminotransferase concentrations. Hepatic nuclear factor-kappaB DNA-binding (electrophoretic mobility shift assay) and tumor necrosis factor, IL-10, and inducible nitric oxide synthase mRNA expression (semiquantitative reverse transcriptase-polymerase chain reaction) were determined. Relative to sham, TLR4-competent (C[3H]/HeOuJ) mice exhibited a significant increase in serum alanine aminotransferase, IL-6, and IL-10 after HS/R (p < 0.05). TLR4-mutant (C[3H]/HeJ) mice were protected from HS/R-induced hepatocellular injury and had lower circulating IL-6 and IL-10 levels than WT (p < 0.05). Similarly, TLR4-/- mice had lower circulating IL-6 and IL-10 levels than WT after HS/R (p < 0.05). Hepatic nuclear factor-kappaB activation and tumor necrosis factor, IL-10, and inducible nitric oxide synthase mRNA expression were lower in TLR4-mutant compared with TLR4-competent mice after HS/R. In contrast, serum ALT concentrations were comparable between CD14-/- and TLR2-/- mice and their WT counterparts after HS/R. These results suggest that TLR4, but not TLR2, signaling is required for initiation of the systemic inflammatory response and development of hepatocellular injury after HS/R. Lack of involvement of CD14 argues for a lipolysaccharide-independent role for TLR4 in this process.

Carbon monoxide inhalation ameliorates cold ischemia/reperfusion injury after rat liver transplantation

Carbon monoxide (CO), a product of heme degradation by heme oxygenase, induces cytoprotection against ischemia/reperfusion (I/R) injury in a variety of organs such as the heart, lung, kidney, and small intestine. We examined whether CO would protect liver grafts against cold I/R injury associated with transplantation. Orthotopic liver transplantation (OLT) was performed in syngeneic Lewis rats with 18 hours preservation in cold University of Wisconsin solution. Recipients were exposed to air or CO (100 ppm) for 1 hour before and 24 hours after OLT. Recipients were sacrificed 0.5 to 48 hours post-transplant. CO inhalation significantly decreased serum aspartate aminotransferase and alanine aminotransferase levels and suppressed hepatic necrosis formation and neutrophil accumulation at 6 to 48 hours after OLT, compared with air control. The expressions of tumor necrosis factor alpha, intercellular adhesion molecule 1, and inducible nitric oxide synthase messenger RNA in the liver graft were significantly inhibited in the CO-treated group at 1 hour after reperfusion. Hepatic nuclear factor-kappaB activation did not differ between the groups. The results demonstrate that exogenous CO treatment suppresses early proinflammatory gene expression and neutrophil infiltration, and efficiently ameliorates hepatic I/R injury. The possible mechanism by which CO protects the liver against cold I/R does not seem to be associated with downregulation of the nuclear factor-kappaB-signaling pathway.

Effect of 2,2',4,4',5,5'-Hexachlorobiphenyl (PCB-153) on Hepatocyte Proliferation and Apoptosis in Mice Deficient in the p50 Subunit of the Transcription Factor NF- B

Polychlorinated biphenyls (PCBs) are a group of synthetic chemicals that induce and promote liver tumors in rodents. We previously showed hepatic nuclear factor kappaB (NF-kappaB) activation and increased hepatocyte proliferation in PCB-treated rats. In this study, the role of NF-kappaB in hepatocyte proliferation and apoptosis after PCB administration was analyzed in wild-type mice and in mice deficient in the NF-kappaB p50 subunit (p50-/-). In a 2-day study, mice received a single intraperitoneal (ip) injection of corn oil or PCB-153. Hepatic NF-kappaB DNA binding activity and cell proliferation were increased by PCB-153 in wild-type mice but not in p50-/- mice. In a 21-day study, mice received six ip injections of corn oil or PCB-153 (twice weekly for 3 weeks) and were euthanized 4 days after the last injection. In this study, NF-kappaB DNA binding activity was not increased after PCB-153 treatment in wild-type or p50-/- mice. Cell proliferation was significantly increased in the wild-type mice treated with PCB-153; in the p50-/- mice treated with PCB-153, cell proliferation was greater than in untreated mice but less than in wild-type mice treated with PCB-153. The livers of p50-/- mice showed greater apoptosis than those of wild-type mice; PCB-153 decreased apoptosis in p50-/- mice, with higher inhibition in the 21-day study than in the 2-day study. RNase protection assays indicated that PCB-153 decreased the mRNA level of cyclin A2, B1, B2, and C in the 2-day study, but not in the 21-day study; however, it did not affect cyclin D1 and D2 mRNA levels at either time point. Cyclin D1 protein levels were not affected by PCB-153. Taken together, these data indicate that the absence of the NF-kappaB p50 subunit alters the proliferative and apoptotic changes in mouse liver in the response to PCB-153.

Cell proliferation, apoptosis, NF-kappaB expression, enzyme, protein, and weight changes in livers of burned rats.

Thermal injury has been shown to alter gut epithelium and heart myocyte homeostasis by inducing programmed cell death. The effect of thermal injury on hepatocyte apoptosis and proliferation, however, has not been established. The purpose of this study was to determine whether a large thermal injury increases liver cell apoptosis and proliferation and whether these changes were associated with alterations in hepatic nuclear factor kappaB (NF-kappaB) expression and changes in liver enzymes and amount of protein. Sprague-Dawley rats received a 40% total body surface area scald burn or sham burn. Rats were killed and livers were harvested at 1, 2, 5, and 7 days after burn. Liver cell apoptosis was determined by terminal deoxyuridine nick end labeling (TUNEL) assay and cell proliferation by immunohistochemistry for proliferating cell nuclear antigen. Hepatic NF-kappaB expression was determined by Western blot, and total hepatic protein content was determined by protein assay. Protein concentration decreased after burn compared with sham controls (P < 0.05). Liver cell apoptosis, proliferation, and NF-kappaB expression in hepatocytes increased in burned rats compared with controls (P < 0.05). It was concluded that thermal injury induces hepatic cell apoptosis and proliferation associated with an increase in hepatic NF-kappaB expression and a decrease in hepatic protein concentration.

Depletion of Hepatic Glutathione Prevents Death Receptor-Dependent Apoptotic and Necrotic Liver Injury in Mice

The activation of the death receptors, tumor necrosis factor-receptor-1 (TNF-R1) or CD95, is a hallmark of inflammatory or viral liver disease. In different murine in vivo models, we found that livers depleted of gamma-glutamyl-cysteinyl-glycine (GSH) by endogenous enzymatic conjugation after phorone treatment were resistant against death receptor-elicited injury as assessed by transaminase release and histopathology. In apoptotic models initiated by engagement of CD95, or by injection of TNF or lipopolysaccharide into galactosamine-sensitized mice, hepatic caspase-3-like proteases were not activated in the GSH-depleted state. Under GSH depletion, also caspase-independent, TNF-R1-mediated injury (high-dose actinomycin D or alpha-amanitin), as well as necrotic hepatotoxicity (high-dose lipopolysaccharide) were entirely blocked. In the T-cell-dependent model of concanavalin A-induced hepatotoxicity, GSH depletion resulted in a suppression of interferon-gamma release, delay of systemic TNF release, hepatic nuclear factor-kappaB activation, and an abrogation of sinusoidal endothelial cell detachment as assessed by electron microscopy. When GSH depletion was initiated 3 hours after concanavalin A injection, ie, after the peak of early pro-inflammatory cytokines, livers were still protected. We conclude that sufficient hepatic GSH levels are a prerequisite for the execution of death receptor-mediated hepatocyte demise.