Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0019158 (hepatitis)
 30,205 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Furazolidone produces a dilative cardiomyopathy and hepatitis in turkeys exposed to this drug in their diets. The ability of furazolidone to enhance free radical reactions when incubated with turkey cardiac or hepatic membranes was determined to evaluate if free radical reactions might contribute to the pathology. Furazolidone (0.135 mM) incubated with NADPH and hepatic microsomes increased oxygen consumption 350% over control incubations. Superoxide dismutase and catalase attenuated the furazolidone-mediated stimulation of oxygen consumption, indicating that the drug promoted the formation of superoxide and hydrogen peroxide. Lipid peroxidation was also stimulated by furazolidone incubated with microsomes, NADPH, and ferric chloride. At concentrations as low as 0.017 mM, lipid peroxidation was more than doubled by furazolidone. Incubation of cardiac sarcosomes with NADPH and furazolidone (0.135 mM) increased oxygen consumption 72% the rate of cytochrome c reduction 72%, and epinephrine oxidation 238% over control. Epinephrine oxidation was enhanced by concentrations of furazolidone as low as 0.017 mM (69% increase over control). This effect of furazolidone was blocked by superoxide dismutase or incubation in an argon atmosphere. These data establish the potential for furazolidone to enhance free radical reactions in cardiac, as well as hepatic tissue. Free radical reactions are therefore potential determinants of furazolidone-mediated hepatic and cardiac toxicities.
 ...
PMID:Furazolidone-enhanced production of free radicals by avian cardiac and hepatic microsomal membranes. 253 46

Caspase-3 is essential for Fas-mediated apoptosis in vitro. We investigated the role of caspase-3 in Fas-mediated cell death in vivo by injecting caspase-3-deficient mice with agonistic anti-Fas Ab. Wild-type controls died rapidly of fulminant hepatitis, whereas the survival of caspase-3-/- mice was increased due to a delay in hepatocyte cell death. Bcl-2 expression in the liver was dramatically decreased in wild-type mice following anti-Fas injection, but was unchanged in caspase-3-/- mice. Hepatocytes from anti-Fas-injected wild-type, but not caspase-3-/-, mice released cytochrome c into the cytoplasm. Western blotting confirmed the lack of caspase-3-mediated cleavage of Bcl-2. Presumably the presence of intact Bcl-2 in caspase-3-/- hepatocytes prevents the release of cytochrome c from the mitochondria, a required step for the mitochondrial death pathway. We also show by Western blot that Bcl-xL, caspase-9, caspase-8, and Bid are processed by caspase-3 in injected wild-type mice but that this processing does not occur in caspase-3-/- mice. This study thus provides novel in vivo evidence that caspase-3, conventionally known for its downstream effector function in apoptosis, also modifies Bcl-2 and other upstream proteins involved in the regulation of Fas-mediated apoptosis.
 ...
PMID:In vivo evidence that caspase-3 is required for Fas-mediated apoptosis of hepatocytes. 1052 93

Correcting action of vitamin E and it's short chain derivative on the activity of some mitochondria electron transport chain enzymes were investigated on models of acute and chronic toxic hepatitis. Inhibition of NADH- and succinate-cytochrome c oxidoreductase complexes activity was established in short term action of xenobiotics. Treatment of rats with CCl4 during 60 days lowered activity of NADH-cytochrome c oxidoreductase complex and significantly increased activity of succinate-cytochrome c oxidoreductase complex and succinate dehydrogenase. Obviously, as a result of long term influence of hepatotoxic agents switching over in rat mitochondria electron transport from NAD-dependent way of substrate oxidation to succinate-dependent way took place. This event could be a part of the body adaptation mechanisms. Vitamin E and its short chain analogue corrected activities of investigated enzymes of mitochondria liver in the animals with acute and chronic hepatitis.
 ...
PMID:[Correction of the activity of certain enzymes in the rat liver mitochondrial electron transport chain by derivatives of alpha-tocopheryl acetate in toxic damage to the liver]. 1079 Oct 53

The Bcl-2 family proteins consist of both antiapoptosis and pro-apoptosis members that regulate apoptosis typically at the mitochondrial level, mainly by controlling the release of cytochrome c and other mitochondrial apoptotic events. However, death signals mediated by Fas/TNF-R1 receptors can usually activate caspases directly, bypassing the need for mitochondria and escaping the regulation by Bcl-2 family proteins. Bid is a novel pro-apoptosis Bcl-2 family protein that is activated by Caspase 8 in response to Fas/TNF-R1 death receptor activation. Activated Bid is translocated to mitochondria and induces cytochrome c release, which in turn activates the downstream caspases. This Bid-mediated pathway is critical in hepatocyte apoptosis induced by Fas/TNF-R1 engagement, where direct activation of cytosolic caspase cascade seems inefficient. The dependence on Bid, and thus on the mitochondrial cytochrome c release, of hepatocyte apoptosis induced by the death receptors also renders it sensitive to the inhibitory regulation by the anti-apoptosis members of the Bcl-2 family proteins, such as Bcl-2 and Bcl-xL. Moreover, the revealing of this death pathway in hepatocytes is important to the understanding of the pathogenesis of a number of hepatic diseases such as hepatitis or endotoxemia-related hepatic failure.
 ...
PMID:Bid, a critical mediator for apoptosis induced by the activation of Fas/TNF-R1 death receptors in hepatocytes. 1093 82

Xanthine oxidase inhibitors are known to be therapeutically useful for the treatment of hepatitis and brain tumor. Baicalein, baicalin and wogonin, isolated from Scutellaria rivularis, have been reported to exhibit a strong activity on xanthine oxidase inhibition. In this study, their antioxidant activity was evaluated by modified xanthine oxidase inhibition and cytochrome c reduced methods. The results showed that the order of activity on xanthine oxidase inhibition was baicalein > wogonin > baicalin, IC50 = 3.12, 157.38 and 215.19 microM, respectively, whereas the activity on cytochrome c reduction was baicalin > wogonin > baicalein (IC50 = 224.12, 300.10 and 370.33 microM, respectively). In another study, an electron spin resonance (ESR) technique was used to further confirm the direct free radical scavenging activity. Both baicalein and baicalin demonstrated a strong activity on eliminating the superoxide radical (.O2-) (baicalein: 7.31 x 10(4) u/g; baicalin: 1.19 x 10(5) u/g). The IC50 of baicalein was 2.8 fold higher than that of baicalin. However they had no significant effect on scavenging hydroxyl radical (.OH). The present results demonstrated that baicalein and baicalin posed a different pathological pathway. The antioxidant function of baicalin was mainly based on scavenging superoxide radical whilst baicalein was a good xanthine oxidase inhibitor.
 ...
PMID:Antioxidant and free radical scavenging effects of baicalein, baicalin and wogonin. 1106 94

Previous studies showed that following acute carbon tetrachloride (CCl(4)) treatment, interleukin-6 null (IL-6-/-) mice develop increased hepatocellular injury, defective regeneration, delayed wound healing, and increased hepatocyte apoptosis. Pretreatment with IL-6 prior to CCl(4) reduces injury, hepatocyte apoptosis, and accelerates regeneration in both IL-6-/- and +/+ livers. To demonstrate whether IL-6 can prevent liver injury that involves direct stimulation of hepatocyte apoptosis, IL-6-/- and +/+ mice were treated with the Fas agonist, Jo-2 mAb. At low Fas agonist doses, IL-6+/+ mice developed mild hepatic injury and survived, whereas IL-6-/- mice developed severe apoptotic hepatitis within 12 h and died. Pretreatment with IL-6 improved survival in IL-6-/- mice and reduced injury in both IL-6-/- and +/+ livers. The direct anti-apoptotic effects of IL-6 were demonstrated in vitro as IL-6 decreased Fas-mediated apoptosis in both IL-6-/- and +/+ primary hepatocyte cultures, and suggested that IL-6-/- hepatocytes have a pre-existing defect in anti-apoptotic pathways. After Fas activation, IL-6-/- livers demonstrated evidence of both proximal and distal alterations in the apoptotic pathways including elevated caspase 8 and 3 activation-associated fragments, and loss of cytochrome c staining. IL-6-/- livers had reduced pre-existing protein expression of the anti-apoptotic factors Bcl-2 and Bcl-xL as well as more rapid degradation of FLIP following Fas treatment that appeared to be post-transcriptionally regulated. FLIP is a crucial proximal inhibitor of caspase 8 activation in Fas, tumor necrosis factor, and DR3/DR4-mediated apoptosis, and Bcl-2 and Bcl-xL more downstream anti-apoptotic regulators. IL-6 may function as a critical anti-apoptotic factor in the liver by its ability to establish and maintain an adequate level of FLIP and downstream anti-apoptotic factors.
 ...
PMID:Interleukin-6 protects against Fas-mediated death by establishing a critical level of anti-apoptotic hepatic proteins FLIP, Bcl-2, and Bcl-xL. 1134 25

Thioredoxin (Trx) is a small redox-active protein with antioxidant and antiapoptotic effects. Trx transgenic (Tg) mice are more resistant to cerebral infarction and survive longer than wild-type (WT) C57BL/6 mice. The aim of the present study was to investigate the protective role of Trx in acute hepatitis models. The expression of endogenous Trx was decreased in thioacetamide (TAA)-induced acute hepatitis. TAA (100 microg/g) was injected intraperitoneally in WT and Tg mice. Survival rate after TAA injection was higher in Tg mice than in WT mice. The level of oxidative stress was significantly less in Tg mice than in WT mice, as shown by the protein carbonylation assay and lipid peroxidation assay. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL)-positive cells were less in Tg mice than in WT mice, which was consistent with DNA laddering assay. Caspase-3 and caspase-9 activities and cytochrome c release were significantly inhibited in Tg mice compared with those in WT mice. In addition, lipopolysaccharide (LPS) plus d-galactosamine (GalN), or anti-Fas antibody (Jo2) were injected. Survival rate after LPS plus GalN injection was much higher in Tg mice than in WT mice. In contrast, there was no difference in survival rate after Jo2 injection between WT and Tg mice. In conclusion, transgene of Trx attenuated TAA- or LPS-induced acute lethal hepatitis. In addition to an antioxidant effect, Trx has the potential to protect acute liver injury via an antiapoptotic effect, which mainly inhibits mitochondria-mediated apoptosis signaling.
 ...
PMID:Overexpression of thioredoxin prevents acute hepatitis caused by thioacetamide or lipopolysaccharide in mice. 1271 82

We compared the biological mechanism of cell death during hepatotoxicity induced by ligation of the Fas receptor in wild-type and liver-specific bcl-2 transgenic mice. Transgenic overexpression of Bcl-2 in mouse hepatocytes can prevent lethal hepatitis induced by agonistic anti-Fas antibodies. In contrast, Fas ligand (FasL)-induced death cannot be overcome in bcl-2 transgenic mice, indicating that anti-Fas antibodies do not reliably mimic the more physiological ligand. Different apoptotic parameters, viz. caspase activation, cytochrome c release and nuclear DNA degradation were analysed. No differences, however, could be observed between wild-type and bcl-2 transgenic mice after injection with a lethal dose of soluble FasL, indicating that apoptosis by FasL-dependent ligation is not modulated by Bcl-2 in vivo. These results demonstrate that the stimulus determines the outcome between type I mitochondria-independent apoptosis, in the case of FasL, or type II mitochondria-dependent and Bcl-2-inhibitable apoptosis, in the case of anti-Fas antibodies.
 ...
PMID:A Bcl-2 transgene expressed in hepatocytes does not protect mice from fulminant liver destruction induced by Fas ligand. 1284 4

The Bcl-2 family of proteins regulates apoptosis chiefly by controlling mitochondrial membrane permeability. It has previously been shown that the BH4 domain of Bcl-2/Bcl-xL is essential for the prevention of apoptotic mitochondrial changes, including the release of cytochrome c and apoptotic cell death. We have previously reported that BH4 peptide fused to the protein transduction domain of HIV-1 TAT protein (TAT-BH4) significantly inhibits etoposide-induced apoptosis in a cell line. This time, we investigated whether TAT-BH4 peptide was cytoprotective in ex vivo and in vivo rodent models. Intraperitoneal injection of TAT-BH4 peptide greatly inhibited X-ray-induced apoptosis in the small intestine of mice and partially suppressed Fas-induced fulminant hepatitis. In addition, this peptide markedly suppressed heart failure after ischemia-reperfusion injury in isolated rat heart, probably by preventing mitochondrial dysfunction. These findings demonstrate that TAT-BH4 peptide exerts anti-apoptotic activity both in vivo and ex vivo, and imply that it may be a useful therapeutic agent for diseases involving mitochondrial dysfunction and apoptosis.
 ...
PMID:BH4-domain peptide from Bcl-xL exerts anti-apoptotic activity in vivo. 1462 84

Physalis species is a popular folk medicine used for treating cancer, leukemia, hepatitis and other diseases. Studies have shown that the ethanol extract of Physalis peruviana (EEPP) inhibits growth and induces apoptotic death of human Hep G2 cells in culture, whereas proliferation of the mouse BALB/C normal liver cells was not affected. In this study, we performed detailed studies to define the molecular mechanism of EEPP-induced apoptosis in Hep G2 cells. The results further confirmed that EEPP inhibited cell proliferation in a dose- and time-dependent manner. At 50 microg/ml, EEPP significantly increased the accumulation of the sub-G1 peak (hypoploid) and the portion of apoptotic annexin V positive cells. EEPP was found to trigger apoptosis through the release of cytochrome c, Smac/DIABLO and Omi/HtrA2 from mitochondria to cytosol and consequently resulted in caspase-3 activation. Pre-treatment with a general caspase inhibitor (z-VAD-fmk) prevented cytochrome c release. After 48 h of EEPP treatment, the apoptosis of Hep G2 cells was found to associate with an elevated p53, and CD95 and CD95L proteins expression. Furthermore, a marked down-regulation of the expression of the Bcl-2, Bcl-XL and XIAP, and up-regulation of the Bax and Bad proteins were noted. Taken together, the present results suggest that EEPP-induced Hep G2 cell apoptosis was possibly mediated through the CD95/CD95L system and the mitochondrial signaling transduction pathway.
 ...
PMID:Physalis peruviana extract induces apoptosis in human Hep G2 cells through CD95/CD95L system and the mitochondrial signaling transduction pathway. 1548 39


1 2 3 4 Next >>