scholarly journals Behavioral and electroencephalographic manifestations of thioacetamide-induced encephalopathy: Possible mechanisms of neurotoxic effects

2012 ◽  
Vol 64 (3) ◽  
pp. 829-841 ◽  
Author(s):  
D. Mladenovic ◽  
D. Hrncic ◽  
A. Rasic-Markovic ◽  
Olivera Stanojlovic
Keyword(s):  
Oxidative Stress ◽  
Hepatic Encephalopathy ◽  
Liver Failure ◽  
Experimental Model ◽  
Alpha Power ◽  
Dependent Manner ◽  
Chronic Liver Failure ◽  
Toxic Metabolites ◽  
Neurotoxic Effects ◽  
Dose Dependent

Although there is still no ideal experimental model of hepatic encephalopathy, thioacetamide is widely used for the induction of acute and chronic liver failure. Thioacetamide exerts hepatotoxic effects through the formation of toxic metabolites in hepatocytes, oxidative stress and calcium mobilization. An ideal experimental model of hepatic encephalopathy should have similar behavioral and electroencephalographic manifestations as human encephalopathy. Thioacetamide induces motor manifestations in a dose-dependent manner. Milder forms of thioacetamide-induced encephalopathy are associated with an increase in relative alpha power, while more severe forms are followed by a flattening of the electroencephalogram. liver failure-induced hyperammonemia has a pivotal role in the neurotoxic effects of thioacetamide. Hyperammonemia induces brain edema, alterations in neurotransmission, oxidative stress, mitochondrial dysfunction and neuronal death. The aim of this article is to review the behavioral and electroencephalographic manifestations of thioacetamide-induced encephalopathy, as well as to summarize potential mechanisms involved in thioacetamide neurotoxicity.

scholarly journals PDGF Suppresses Oxidative Stress Induced Ca2+Overload and Calpain Activation in Neurons

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Lian-Shun Zheng ◽  
Yoko Ishii ◽  
Qing-Li Zhao ◽  
Takashi Kondo ◽  
Masakiyo Sasahara
Keyword(s):  
Oxidative Stress ◽  
Map Kinases ◽  
Neurological Diseases ◽  
Underlying Mechanism ◽  
Dependent Manner ◽  
Neuroprotective Effects ◽  
Calpain Activation ◽  
Neurotoxic Effects ◽  
Nonapoptotic Cell Death ◽  
Dose Dependent

Oxidative stress is crucially involved in the pathogenesis of neurological diseases such as stroke and degenerative diseases. We previously demonstrated that platelet-derived growth factors (PDGFs) protected neurons from H2O2-induced oxidative stress and indicated the involvement of PI3K-Akt and MAP kinases as an underlying mechanism. Ca2+overload has been shown to mediate the neurotoxic effects of oxidative stress and excitotoxicity. We examined the effects of PDGFs on H2O2-induced Ca2+overload in primary cultured neurons to further clarify their neuroprotective mechanism. H2O2-induced Ca2+overload in neurons in a dose-dependent manner, while pretreating neurons with PDGF-BB for 24 hours largely suppressed it. In a comparative study, the suppressive effects of PDGF-BB were more potent than those of PDGF-AA. We then evaluated calpain activation, which was induced by Ca2+overload and mediated both apoptotic and nonapoptotic cell death. H2O2-induced calpain activation in neurons in a dose-dependent manner. Pretreatment of PDGF-BB completely blocked H2O2-induced calpain activation. To the best of our knowledge, the present study is the first to demonstrate the mechanism underlying the neuroprotective effects of PDGF against oxidative stress via the suppression of Ca2+overload and inactivation of calpain and suggests that PDGF-BB may be a potential therapeutic target of neurological diseases.

scholarly journals Cardiac Remodeling Induced by All-Trans Retinoic Acid is Detrimental in Normal Rats

2017 ◽  
Vol 43 (4) ◽  
pp. 1449-1459 ◽  
Author(s):  
Renata A. C. Silva ◽  
Andréa F. Gonçalves ◽  
Priscila P. dos Santos ◽  
Bruna Rafacho ◽  
Renan F. T. Claro ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Retinoic Acid ◽  
Energy Metabolism ◽  
Cardiac Remodeling ◽  
Citrate Synthase ◽  
Isolated Heart ◽  
Lipid Hydroperoxide ◽  
Dependent Manner ◽  
Heart Study ◽  
Dose Dependent

Background/Aims: This study aimed to discern whether the cardiac alterations caused by retinoic acid (RA) in normal adult rats are physiologic or pathologic. Methods and Results: Wistar rats were assigned into four groups: control animals (C, n = 20) received a standard rat chow; animals fed a diet supplemented with 0.3 mg/kg/day all-trans-RA (AR1, n = 20); animals fed a diet supplemented with 5 mg/kg/day all-trans-RA (AR2, n = 20); and animals fed a diet supplemented with 10 mg/kg/day all-trans-RA (AR3, n = 20). After 2 months, the animals were submitted to echocardiogram, isolated heart study, histology, energy metabolism status, oxidative stress condition, and the signaling pathway involved in the cardiac remodeling induced by RA. RA increased myocyte cross-sectional area in a dose-dependent manner. The treatment did not change the morphological and functional variables, assessed by echocardiogram and isolated heart study. In contrast, RA changed catalases, superoxide dismutase, and glutathione peroxidases and was associated with increased values of lipid hydroperoxide, suggesting oxidative stress. RA also reduced citrate synthase, enzymatic mitochondrial complex II, ATP synthase, and enzymes of fatty acid metabolism and was associated with increased enzymes involved in glucose use. In addition, RA increased JNK 1/2 expression, without changes in TGF-β, PI3K, AKT, NFκB, S6K, and ERK. Conclusion: In normal rats, RA induces cardiac hypertrophy in a dose-dependent manner. The non-participation of the PI3K/Akt pathway, associated with the participation of the JNK pathway, oxidative stress, and changes in energy metabolism, suggests that cardiac remodeling induced by RA supplementation is deleterious.

Cirrhosis and acute on chronic liver failure: is ammonia a predictor of hepatic encephalopathy and mortality?

2017 ◽  
Vol 66 (1) ◽  
pp. S559
Author(s):  
M. Sheikh ◽  
N. Arias ◽  
K. Thomsen ◽  
R. Gallego-Durán ◽  
B. Agarwal ◽  
...  
Keyword(s):  
Hepatic Encephalopathy ◽  
Liver Failure ◽  
Chronic Liver ◽  
Chronic Liver Failure

scholarly journals Protective Effects of Taraxacum officinale L. (Dandelion) Root Extract in Experimental Acute on Chronic Liver Failure

Antioxidants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 504
Author(s):  
Iulia Olimpia Pfingstgraf ◽  
Marian Taulescu ◽  
Raluca Maria Pop ◽  
Remus Orăsan ◽  
Laurian Vlase ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Liver Failure ◽  
Tissue Injury ◽  
Taraxacum Officinale ◽  
Chronic Liver ◽  
Root Extract ◽  
Protective Effects ◽  
Stress Tests ◽  
Chronic Liver Failure

Background: Taraxacum officinale (TO) or dandelion has been frequently used to prevent or treat different liver diseases because of its rich composition in phytochemicals with demonstrated effect against hepatic injuries. This study aimed to investigate the possible preventing effect of ethanolic TO root extract (TOERE) on a rat experimental acute on chronic liver failure (ACLF) model. Methods: Chronic liver failure (CLF) was induced by human serum albumin, and ACLF was induced in CLF by D-galactosamine and lipopolysaccharide (D-Gal-LPS). Five groups (n = 5) of male Wistar rats (200–250 g) were used: ACLF, ACLF-silymarin (200 mg/kg b.w./day), three ACLF-TO administered in three doses (200 mg, 100 mg, 50 mg/kg b.w./day). Results: The in vivo results showed that treatment with TOERE administered in three chosen doses before ACLF induction reduced serum liver injury markers (AST, ALT, ALP, GGT, total bilirubin), renal tests (creatinine, urea), and oxidative stress tests (TOS, OSI, MDA, NO, 3NT). Histopathologically, TOERE diminished the level of liver tissue injury and 3NT immunoexpression. Conclusions: This paper indicated oxidative stress reduction as possible mechanisms for the hepatoprotective effect of TOERE in ACLF and provided evidence for the preventive treatment.

scholarly journals Preclinical Study on the Ameliorating Effect of L-Ascorbic Acid for the Oxidative Stress of Caused by Chronic Administration of Organic Nitrates in Cardiovascular Diseases

2021 ◽  
Author(s):  
Ahmed M Hamdan ◽  
Zuhair M. Mohammedsaleh ◽  
Aalaa Aboelnour ◽  
Sherif M.H. Elkhannishi
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Ascorbic Acid ◽  
Chronic Administration ◽  
Stress Factors ◽  
Male Rats ◽  
Oxidative Stress Marker ◽  
Organic Nitrates ◽  
Dependent Manner ◽  
Dose Dependent

Abstract PurposeThe therapeutic activity of Glyceryl trinitrate (GTN) is mainly regulated by liberating nitric oxide (NO) and reactive nitrogen species (RNS). During this biotransformation, oxidative stress and lipid peroxidation inside the red blood cells (RBCs) occur. The principal objective of our research is to explain the ameliorating effect of L-ascorbic acid for the deleterious effects of chronic administration of nitrovasodilator drugs. MethodsWe studied some biochemical parameters for the oxidative stress using groups of high sucrose/fat (HSF) diet Wistar male rats chronically orally administered ISMN. Afterwards, we evaluated the role of L-ascorbic acid against these biochemical changes. ResultsChronic treatment with organic nitrates caused elevated serum levels of lipid peroxidation, hemoglobin derivatives as methemoglobin and carboxyhemoglobin, rate of hemoglobin autoxidation, the cellular levels of pro-inflammatory cytokines marker (NF-κB) and apoptosis markers (caspase-3) in myocardium muscles in a dose dependent manner. Meanwhile, such exposure caused decline in the enzymatic effect of superoxide dismutase (SOD), glutathione (GSH) and catalase activity (CAT) accompanied with a decrease of in the level of mitochondrial oxidative stress marker (nrf2) in myocardium muscles and decrease in the serum iron and total iron binding capacity (TIBC) in a dose dependent manner. Concomitant treatment with L-ascorbic acid significantly diminished these changes for all examined parameters.ConclusionChronic administration of organic nitrates leads to the alteration of the level of oxidative stress factors in the myocardium tissue due to generation of reactive oxygen species. Using vitamin C can effectively ameliorate such intoxication to overcome the nitrate tolerance.

Liver failure

2020 ◽  
pp. 3089-3100
Author(s):  
Jane Macnaughtan ◽  
Rajiv Jalan
Keyword(s):  
Liver Transplantation ◽  
Liver Disease ◽  
Hepatic Encephalopathy ◽  
Liver Injury ◽  
Liver Failure ◽  
Acute Liver Failure ◽  
Organ Failure ◽  
Clinical Manifestations ◽  
Chronic Liver ◽  
Chronic Liver Failure

Liver failure occurs when loss of hepatic parenchymal function exceeds the capacity of hepatocytes to regenerate or repair liver injury. Acute liver failure is characterized by jaundice and prolongation of the prothrombin time in the context of recent acute liver injury, with hepatic encephalopathy occurring within 8 weeks of the first onset of liver disease. Acute-on-chronic liver failure is characterized by hepatic and/or extrahepatic organ failure in patients with cirrhosis associated with an identified or unidentified precipitating event. The commonest causes of acute liver failure are acute viral hepatitis and drugs. Acute-on-chronic liver failure is most commonly precipitated by infection, alcohol abuse, and superimposed viral infection. The main clinical manifestations are hepatic encephalopathy, coagulopathy, jaundice, renal dysfunction, and haemodynamic instability. Infection and systemic inflammation contribute to pathogenesis and critically contribute to prognosis. Specific therapy for the underlying liver disease is administered when available, but this is not possible for most causes of liver failure. Treatment is predominantly supportive, with particular emphasis on (1) correction or removal of precipitating factors; (2) if encephalopathy is present, using phosphate enemata, nonhydrolysed disaccharide laxatives, and/or rifaximin; (3) early detection and prompt treatment of complications such as hypoglycaemia, hypokalaemia, cerebral oedema, infection, and bleeding. The onset of organ failure should prompt discussion with a liver transplantation centre. The mortality of acute liver failure (without liver transplantation) is about 40%. Patients with acute liver failure who do not develop encephalopathy can be expected to recover completely. Those who recover from an episode of acute-on-chronic liver failure should be considered for liver transplantation because otherwise their subsequent mortality remains high.

Oxidative stress biomarkers in the gills of the bivalve Mactra stultorum exposed to acrylamide

2020 ◽  
Vol 84 (2) ◽  
Author(s):  
Wafa Trabelsi ◽  
Chaima Fouzai ◽  
Imene Chetoui ◽  
Safa Bejaoui ◽  
Khaoula Telahigue ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Ache Activity ◽  
Reduced Glutathione ◽  
Lipid Hydroperoxides ◽  
Dependent Manner ◽  
Advanced Oxidation Protein Products ◽  
Oxidative Stress Biomarkers ◽  
Stress Biomarkers ◽  
The Subject ◽  
Dose Dependent

Acrylamide (ACR) is among the most deleterious pollutants in the environment and presents a serious risk to humans and ecosystems. The purpose of this study was to assess its effects when administered at different concentrations (5, 10 and 20 mg L–1) to evaluate antioxidant status in the gills of Mactra stultorum. Our results showed, after five days of treat­ment, an increase in malondialdehyde (MDA), lipid hydroperoxides (LOOH), advanced oxidation protein products (AOPP), reduced glutathione (GSH), ascorbic acid (Vit C) and metallothionein (MDA) levels in gills of treated clams compared with controls. Moreover, an increase in superoxide dismutase (SOD) and a significant decrease in glutathione peroxidase (GPx) activities were also observed. Acrylamide induced neurotoxicity, as evidenced by the inhibition of acetylcholinesterase (AChE) activity in a dose-dependent manner. Overall, our results indicated that oxidative stress may be considered one of the mechanisms behind acrylamide toxicity in bivalves, although the subject requires more research.

scholarly journals Hepatic Encephalopathy-Associated Cerebral Vasculopathy in Acute-on-Chronic Liver Failure: Alterations on Endothelial Factor Release and Influence on Cerebrovascular Function

2020 ◽  
Vol 11 ◽  
Author(s):  
Laura Caracuel ◽  
Esther Sastre ◽  
María Callejo ◽  
Raquel Rodrigues-Díez ◽  
Ana B. García-Redondo ◽  
...  
Keyword(s):  
Hepatic Encephalopathy ◽  
Liver Failure ◽  
Cerebral Arteries ◽  
Chronic Liver ◽  
Chronic Liver Failure ◽  
Cerebrovascular Function ◽  
Liver Decompensation ◽  
Middle Cerebral Arteries ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

The acute-on-chronic liver failure (ACLF) is a syndrome characterized by liver decompensation, hepatic encephalopathy (HE) and high mortality. We aimed to determine the mechanisms implicated in the development of HE-associated cerebral vasculopathy in a microsurgical liver cholestasis (MHC) model of ACLF. Microsurgical liver cholestasis was induced by ligating and extracting the common bile duct and four bile ducts. Sham-operated and MHC rats were maintained for eight postoperative weeks Bradykinin-induced vasodilation was greater in middle cerebral arteries from MHC rats. Both Nω-Nitro-L-arginine methyl ester and indomethacin diminished bradykinin-induced vasodilation largely in arteries from MHC rats. Nitrite and prostaglandin (PG) F1α releases were increased, whereas thromboxane (TX) B2 was not modified in arteries from MHC. Expressions of endothelial nitric oxide synthase (eNOS), inducible NOS, and cyclooxygenase (COX) 2 were augmented, and neuronal NOS (nNOS), COX-1, PGI2 synthase, and TXA2S were unmodified. Phosphorylation was augmented for eNOS and unmodified for nNOS. Altogether, these endothelial alterations might collaborate to increase brain blood flow in HE.

scholarly journals Salvianolic Acid A Protects the Kidney against Oxidative Stress by Activating the Akt/GSK-3β/Nrf2 Signaling Pathway and Inhibiting the NF-κB Signaling Pathway in 5/6 Nephrectomized Rats

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Hong-feng Zhang ◽  
Jia-hong Wang ◽  
Yan-li Wang ◽  
Cheng Gao ◽  
Yan-ting Gu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Western Blot ◽  
Signaling Pathway ◽  
Kidney Injury ◽  
Dependent Manner ◽  
Salvianolic Acid ◽  
Nrf2 Signaling Pathway ◽  
Antioxidative Effects ◽  
Dose Dependent

Salvianolic acid A (SAA) is a bioactive polyphenol extracted from Salviae miltiorrhizae Bunge, which possesses a variety of pharmacological activities. In our previous study, we have demonstrated that SAA effectively attenuates kidney injury and inflammation in an established animal model of 5/6 nephrectomized (5/6Nx) rats. However, there has been limited research regarding the antioxidative effects of SAA on chronic kidney disease (CKD). Here, we examined the antioxidative effects and underlying mechanisms of SAA in 5/6Nx rats. The rats were injected with SAA (2.5, 5, and 10 mg·kg-1·d-1, ip) for 28 days. Biochemical, flow cytometry, and Western blot analyses showed that SAA significantly increased the activities of total superoxide dismutase (T-SOD), glutathione peroxidase (GPx), and catalase (CAT) and lowered the levels of malondialdehyde (MDA), reactive oxygen species (ROS), and NADPH oxidase 4 (NOX-4) in a dose-dependent manner in 5/6Nx rats and in H2O2-induced HK-2 cells in vitro. Moreover, SAA enhanced the activation of the protein kinase B/glycogen synthase kinase-3β/nuclear factor-erythroid-2-related factor 2 (Akt/GSK-3β/Nrf2) signaling pathway in a dose-dependent manner and subsequently increased the expression of heme oxygenase-1 (HO-1) in the kidney of 5/6Nx rats, which were consistent with those obtained in H2O2-induced HK-2 cells in vitro shown by Western blot analysis. Furthermore, SAA significantly increased the expression of intranuclear Nrf2 and HO-1 proteins compared to HK-2 cells stimulated by LPS on the one hand, which can be enhanced by QNZ to some extent; on the other hand, SAA significantly lowered the expression of p-NF-κB p65 and ICAM-1 proteins compared to HK-2 cells stimulated by H2O2, which can be abrogated by ML385 to some extent. In conclusion, our results demonstrated that SAA effectively protects the kidney against oxidative stress in 5/6Nx rats. One of the pivotal mechanisms for the protective effects of SAA on kidney injury was mainly related with its antioxidative roles by activating the Akt/GSK-3β/Nrf2 signaling pathway and inhibiting the NF-κB signaling pathway.

Antioxidant activity of different extracts of Argentinian medicinal plants against arsenic-induced toxicity in renal cells

2008 ◽  
Vol 27 (4) ◽  
pp. 341-346 ◽  
Author(s):  
EA Soria ◽  
ME Goleniowski ◽  
JJ Cantero ◽  
GA Bongiovanni
Keyword(s):  
Oxidative Stress ◽  
Antioxidant Activity ◽  
Medicinal Plants ◽  
Arsenic Exposure ◽  
Vero Cells ◽  
Lipid Hydroperoxides ◽  
Dependent Manner ◽  
Renal Cells ◽  
Popular Medicine ◽  
Dose Dependent

Chronic toxicity of arsenic resulting from drinking water is a health problem encountered in humans, especially in South America and Asia, where a correlation between oxidative stress, tumor promotion, and arsenic exposure has been observed. Differential solvent extraction (petroleum ether (PE); dichloromethane (DCM); methanol (OL) and water (W)) was performed to compare the protective (antioxidant) activity of five Argentinian medicinal plants on arsenite-induced oxidative stress in Vero cells, assayed by hydroperoxide measurement. The results were analyzed using ANOVA followed by the LSD Fisher test. The data showed that arsenite was a pro-oxidant agent which acts in a time–dose-dependent manner. Extracts from Eupatorium buniifolium (PE), Lantana grisebachii (PE, W), Mandevilla pentlandiana (PE, W), and Sebastiania commersoniana (DCM, OL, W) prevented the formation of both aqueous and lipid hydroperoxides, but Heterothalamus alienus only impeded lipid ones. Therefore, antioxidant extracts are potentially beneficial and may have a protective activity against arsenite-induced renal injury. Among these, the aqueous extract of L. grisebachii may represent the most suitable preparation for humans since the traditional usage of this plant in popular medicine is through consumption of tea.

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