ubiquinone and Chemical-and-Drug-Induced-Liver-Injury

Evidence for in vivo antioxidative activity of reduced CoQ homologs has been presented. This came from studies with experimental endotoxemia in mice, reoxygenation of rat liver following ischemia, and reoxygenation of canine heart following 24-hour cold preservation. In radical-induced injury of hepatocytes, it has been first shown that reduced CoQ9 acts as a potential antioxidant regardless of its cellular concentration, whereas reduced CoQ10 acts in cells containing CoQ10 as the predominant homolog. The antioxidant activity of reduced CoQ homologs appears to be independent of that of alpha-tocopherol under the conditions employed.

Topics: Animals; Antioxidants; Chemical and Drug Induced Liver Injury; Free Radicals; Humans; Liver Diseases; Oxidation-Reduction; Ubiquinone; Vitamin E

The linkage between inflammation and oxidative stress in liver damage has been proven and is undeniable; dexamethasone with some antioxidants can reduce the toxicity of liver tissue. Due to the importance of cancer treatment, glucocorticoids' synergistic effect in inhibiting cancer cell growth is also investigated. Dexamethasone alone and combined with etoposide were tested at concentrations of 1, 5, and 10 μM to evaluate the potency of dexamethasone in inhibiting the growth of A549 cells using oxidative stress factors and DNA damage. Also, intraperitoneal injection of dexamethasone in rats was used to induce liver toxicity. Coenzyme Q10 at different concentrations (1, 10, and 50 mg/kg) was used as an antioxidant to assess the oxidative stress factors and measure Caspase-3 activity. The results showed that dexamethasone combined with etoposide could significantly inhibit the growth of cancer cells and induce apoptosis. Treatment of A549 cells using dexamethasone also inhibits cancer cells' growth by inducing oxidative stress and DNA damage. Dexamethasone also, by inducing oxidative stress and activation of caspase 3, ultimately causes hepatotoxicity. Treatment with different concentrations of CoQ10 showed improved mitochondrial function, antioxidant defense, and liver enzyme. The best effect of coenzyme Q10 on dexamethasone-induced hepatotoxicity is 50 mg/kg. As a result, dexamethasone (alone and combined with etoposide) has an anti-cancer effect by damaging DNA and inducing oxidative stress. Also, CoQ10 has antioxidant effects against dexamethasone-induced hepatotoxicity by improving mitochondrial function and reducing caspase-3 activity.

Topics: Animals; Antioxidants; Caspase 3; Chemical and Drug Induced Liver Injury; Dexamethasone; Etoposide; Glucocorticoids; Oxidative Stress; Rats; Ubiquinone

Mitochondria, a major source of reactive oxygen species (ROS), are intimately involved in the response to oxidative stress in the body. The production of excessive ROS affects the balance between oxidative responses and antioxidant defense mechanisms thus perturbing mitochondrial function eventually leading to tissue injury. Therefore, antioxidant therapies that target mitochondria can be used to treat such diseases and improve general health. This study reports on an attempt to establish a system for delivering an antioxidant molecule coenzyme Q

Topics: Acetaminophen; Antioxidants; Chemical and Drug Induced Liver Injury; Humans; Mitochondria; Oxidative Stress; Reactive Oxygen Species; Scattering, Small Angle; Ubiquinone; X-Ray Diffraction

The mitochondria are the primary source of reactive oxygen species (ROS) under pathological condition, but the significance of mitochondrial ROS in the development of Lipopolysaccharide (LPS)/D-galactosamine (D-Gal)-induced acute liver injury remains unclear. In the present study, the level of mitochondrial ROS in LPS/D-Gal has been determined by MitoSox staining and the potential roles of mitochondrial ROS in LPS/D-Gal-induced liver injury have been investigated by using the mitochondria-targeting antioxidant MitoQ. The results indicated that LPS/D-Gal exposure induced the generation of mitochondrial ROS while treatment with MitoQ reduced the level of mitochondrial ROS. Treatment with MitoQ ameliorated LPS/D-Gal-induced histopathologic abnormalities, suppressed the elevation of AST and ALT, and increased the survival rate of the experimental animals. Treatment with MitoQ also suppressed LPS/D-Gal-induced production of tumor necrosis factor α (TNF-α), inhibited the activities of caspase-3, caspase-8 and caspase-9, decreased the level of cleaved caspase-3 and reduced the counts of TUNEL positive cells. These results indicate that mitochondrial ROS is involved in the development of LPS-induced acute liver injury and the mitochondria-targeting antioxidant MitoQ might have potential value for the treatment of inflammation-based acute liver injury.

Topics: Animals; Antioxidants; Chemical and Drug Induced Liver Injury; Galactosamine; Lipopolysaccharides; Male; Mice; Mice, Inbred BALB C; Mitochondria, Liver; Organophosphorus Compounds; Ubiquinone

Coenzyme Q10 (CoQ10) which acts as an electron transporter in the mitochondrial respiratory chain has many beneficial effects on liver diseases. In our previous research, CoQ10 has been found to attenuate acetaminophen (APAP)-induced acute liver injury (ALI). However, whether CoQ10 administration is still effective at the late stage of APAP overdose is still unknown. In this study, we aimed to test CoQ10 efficacy at the late stage of APAP overdose. C57BL/6J mice were intraperitoneally treated with APAP to induce liver injury. CoQ10 (5 mg/kg) was given to mice at 16 h after APAP treatment. The results showed that while CoQ10 treatment at 16 h post-APAP overdose had no effects on the expression of ROS generated genes or scavenged genes, it still significantly decreased necrosis of hepatocytes following APAP-induced ALI. Moreover, CoQ10 increased MerTK+ macrophages accumulation in the APAP-overdose liver and inhibition of MerTK signaling partly abrogated the protective role of CoQ10 treatment on the hepatic necrosis. CoQ10 treatment also significantly enhanced hepatocytes proliferation as shown in the increased 5-bromodeoxyuridine incorporation in the APAP-intoxicated mice liver section. In addition, CoQ10 treatment increased hepatic Proliferating Cell Nuclear Antigen (PCNA) and Cyclin D1 expression and promoted activation of the β-catenin signaling in APAP-overdose mice. To conclude, these data provide evidence that CoQ10 treatment is still effective at the late stage of APAP-induced ALI and promotes resolution of necrosis and liver regeneration following ALI.

Topics: Acetaminophen; Animals; Chemical and Drug Induced Liver Injury; Chemical and Drug Induced Liver Injury, Chronic; Hepatocytes; Liver; Liver Regeneration; Mice; Mice, Inbred C57BL; Necrosis; Ubiquinone

Coenzyme Q10 (CoQ10), which is a key cofactor of the electron transport chain in the mitochondria has shown many beneficial effects on liver diseases. However, the mechanisms of CoQ10 protective role on the acetaminophen (APAP)-induced liver injury are elusive and unclear. In this study, we further investigated the CoQ10 therapeutic effects on APAP-overdose liver injury. C57BL/6 J mice were intraperitoneally treated with APAP to induce liver injury. CoQ10 (5 mg/kg) was given to mice at 1.5 h after APAP treatment. The results showed that hepatic CoQ10 levels were decreased during the APAP-induced hepatotoxicity and preceded serum ALT elevation. Treatment of CoQ10 significantly improved the liver injury induced by APAP. Moreover, CoQ10 treatment decreased the ROS levels and promoted the antioxidative related gene expression in APAP overdose mice. Importantly, results showed that even though CoQ10 had no effects on the mtDNA copy number and the expression of genes related to mitochondrial biogenesis, it significantly improved the mitochondrial complex I and V activities and promoted the mitophagy in APAP-overdose mice. To further authenticate mitophagy role in CoQ10-mediated improved liver injury in vivo, we administrated APAP-overdose mice with chloroquine 1 h prior to APAP treatment and found that chloroquine treatment functionally abrogated the CoQ10 protective role on APAP overdose mice. To conclude, this study provides evidence that CoQ10 activates mitophagy to protect against APAP-induced liver injury. Therefore, CoQ10 may represent a novel therapeutic option for the prevention and treatment of drug-induced liver injury.

Topics: Acetaminophen; Analgesics, Non-Narcotic; Animals; Chemical and Drug Induced Liver Injury; Male; Mice; Mice, Inbred C57BL; Mitophagy; Ubiquinone; Vitamins

Despite the extensive use of cisplatin (CP) as a chemotherapeutic agent, its clinical use is often restricted by undesirable side effects, such as toxicity to normal tissues. The aim of this study was to probe the effect of a combinatorial treatment of low multiple doses of antioxidants on CP-induced toxicity and the mitochondrial apoptotic pathway in hepatocytes. Animals received a single toxic dose of CP (7.5 mg/kg body weight) with or without combined multiple doses of epigallocatechin gallate (EGCG) and coenzyme Q10 (CoQ10) (15 and 5 mg/kg body weight, respectively). CP-treated animals showed altered biochemical parameters, denoting hepatotoxicity, which was markedly improved by the multidose treatment with EGCG + CoQ10. The increased levels of oxidants found in the cytosolic and mitochondrial fractions isolated from the liver of CP-administered rats were significantly attenuated by the combinatorial doses of antioxidants. EGCG + CoQ10 ameliorated the CP-induced compromised antioxidant defenses, oxidative modification of macromolecules, decreased activities of respiratory chain enzymes, altered membrane depolarization, and swelling of liver mitochondria. Furthermore, EGCG + CoQ10 treatment inhibited CP-induced apoptosis by suppressing the activation and mitochondrial accumulation of proapoptotic proteins and preventing the inhibition of antiapoptotic protein expression, cytochrome c efflux, caspase-3 activation, and DNA fragmentation. Histological findings further confirmed the protective effects of EGCG + CoQ10 against CP-induced cellular injury. Our findings revealed that the combination of EGCG and CoQ10, owing to their individual antioxidant properties, can be an effective remedy, which by maintaining redox hemostasis attenuate the mitochondrial stress-mediated molecular and cellular processes involved in CP-induced liver toxicity and cell death.

Topics: Animals; Apoptosis; Catechin; Chemical and Drug Induced Liver Injury; Cisplatin; Hepatocytes; Liver; Male; Mitochondria, Liver; Oxidative Stress; Rats; Rats, Wistar; Ubiquinone

The normal functioning of Kelch-like ECH-associated protein-1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) complex is necessary for the cellular protection against oxidative stress. We investigated the effect of chlorogenic acid (CGA), quercetin (Qt), coenzyme Q10 (Q10) and silymarin on the expression of Keap1/Nrf2 complex and its downstream target; heme oxygenase-1 (HO-1) as well as inflammation and apoptosis in an acute liver toxicity model induced by thioacetamide (TAA).. Wistar rats were divided into 13 groups: Control, silymarin, CGA, Qt, Q10, TAA (single dose 50 mg/kg, i.p.), TAA + silymarin (400 mg/kg, p.o.), TAA + CGA (100 & 200 mg/kg, p.o.), TAA + Qt (200 &300 mg/kg, p.o.) and TAA+ Q10 (30&50 mg/kg, p.o.) and treated for 8 days.. The results showed improved liver functions and hepatic tissue integrity in all tested doses of TAA + silymarin, TAA + CGA, TAA + Qt and TAA + Q10 groups compared to the TAA group. Furthermore, these groups showed significantly lower ROS, malondialdehyde and nitric oxide levels but higher glutathione content and superoxide dismutase activity compared to the TAA group, p < 0.05. In these groups, Keap1 expression was significantly decreased while Nrf2 expression and HO-1 activity were increased. In addition, the number of apoptotic cells and the expression level of TNF-α in the liver tissues were significantly decreased compared to the TAA group.. CGA, Qt, Q10 and silymarin protect against TAA-induced acute liver toxicity via antioxidant, anti-inflammatory, anti-apoptotic activities and regulating Keap1-Nrf2/HO-1 expression.

Topics: Animals; Chemical and Drug Induced Liver Injury; Chlorogenic Acid; Heme Oxygenase (Decyclizing); Heme Oxygenase-1; Kelch-Like ECH-Associated Protein 1; Liver; Male; NF-E2-Related Factor 2; Quercetin; Rats; Rats, Wistar; Signal Transduction; Silymarin; Thioacetamide; Ubiquinone

Development of biocompatible antioxidant nanoparticles for xenobiotic-induced liver disease treatment by oral or parenteral administration is of great interest in medicine. In the current study, we demonstrate the protective effects of coenzyme Q10 nanoparticles (CoQ10-NPs) on hepatotoxicity induced by dichlorvos (DDVP) as an organophosphate. Although CoQ10 is an efficient antioxidant, its poor bioavailability has limited the applications of this useful agent. First, CoQ10-NPs were prepared then characterized using dynamic light scattering (DLS) and transmission electron microscopy (TEM). In DDVP-treated and non-treated hepatocytes in the presence of CoQ10-NPs, cell viability, the level of reactive oxygen species (ROS), lipid peroxidation (LPO), mitochondrial membrane potential (MMP), lysosome membrane integrity, and cellular glutathione (GSH) content were measured. The prepared CoQ10-NPs were mono-dispersed and had narrow size distribution with average diameter of 54 nm. In the in vivo study, we evaluated the enzymes, which are involved in the antioxidant system for maintenance of normal liver function. In comparison to nonparticulate CoQ10, the CoQ10-NPs efficiently decreased the ROS formation, lipid peroxidation and cell death. Also, particulate form of CoQ10 improved MMP, GSH level and lysosome membrane integrity. In the in vivo, study, we revealed that CoQ10-NPs were better hepatoprotective than its nonparticulate form (P < .05). Altogether, we propose that the CoQ10-NPs have potential capability to be used as a therapeutic and prophylactic agent for poisoning that is induced by organophosphate agents, especially in the case of DDVP. Furthermore, these positive remarks make this nanoparticle amenable for the treatment of xenobiotic-induced liver diseases.

Topics: Animals; Antioxidants; Cell Survival; Cells, Cultured; Chemical and Drug Induced Liver Injury; Dichlorvos; Glutathione; Hepatocytes; Lipid Peroxidation; Lysosomes; Male; Membrane Potential, Mitochondrial; Mitochondria; Nanoparticles; Protective Agents; Rats; Rats, Wistar; Reactive Oxygen Species; Ubiquinone

The hepatotoxic effects of the antipsychotic agent, risperidone (RIS) were investigated for better understanding the pathogenesis of RIS in liver toxicity in vivo and in in vitro. Isolated rat hepatocytes were obtained by collagenase perfusion technique and were then incubated with RIS, different antioxidants in particular coenzyme Q10 (CoQ10), N-acetyl cysteine (NAC). Our results showed that RIS could induce cytotoxicity via rising reactive oxygen species (ROS), mitochondrial potential collapse, lysosomal membrane leakiness, GSH depletion and lipid peroxidation. All of these effects were significantly (p < 0.05) inhibited by ROS scavengers, antioxidants, endocytosis inhibitors and adenosine triphosphate (ATP) generators. Similar outcomes were obtained from the in vivo experiments. Liver function enzyme test and histopathological evaluation confirmed RIS-(6 mg/kg) induced damage. Based on these results, it is suggested that RIS-induced liver toxicity is associated with mitochondrial/lysosomal cross-talk following the initiation of oxidative stress. Thus, the use of CoQ10 and/or NAC seems to be a safe therapeutic option in this context.

Topics: Acetylcysteine; Animals; Antioxidants; Cell Survival; Cells, Cultured; Chemical and Drug Induced Liver Injury; Hepatocytes; Lipid Peroxidation; Liver; Male; Membrane Potential, Mitochondrial; Oxidative Stress; Rats; Rats, Sprague-Dawley; Risperidone; Ubiquinone

The present study investigated the in vitro and in vivo effects of individual and combined doses of idebenone, carnosine and vitamin E on ameliorating some of the biochemical indices of nano-sized titanium dioxide (n-TiO2) in mice liver.. The in vitro cytotoxic effect of nano-sized anatase TiO2 (21 nm) on hepatic cell lines (HepG 2) was investigated. Additionally, n-TiO2 was orally administered (150 mg/kg/day) for 2 weeks, followed by a daily intragastric gavage of the aforementioned antioxidants for 1 month.. n-TiO2 induced significant cytotoxicity in hepatic cell lines and elevated the levels of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), hepatic total antioxidant capacity (TAC) and nitrite/nitrate (NOx) levels. Meanwhile, glutathione-S-transferase (GST) activity was significantly reduced. Moreover, RT-PCR and western blot analysis showed that n-TiO2 significantly altered the mRNA and protein expressions of transforming growth factor-beta (TGF-β1) and Smad-2, as well as vascular endothelium growth factor (VEGF). Histopathological examination of hepatic tissue reinforced these results.. Idebenone, carnosine and vitamin E ameliorated the deviated parameters with the combination regimen demonstrating the most pronounced effect. Oxidative stress, liver fibrosis and angiogenesis may be implicated in n-TiO2-induced liver toxicity.

Topics: Alanine Transaminase; Angiogenesis Inhibitors; Animals; Antioxidants; Aspartate Aminotransferases; Carnosine; Cell Line, Tumor; Chemical and Drug Induced Liver Injury; Glutathione Transferase; Hep G2 Cells; Humans; Liver Cirrhosis; Male; Mice; Nitrates; Nitrites; Smad2 Protein; Titanium; Transforming Growth Factor beta; Ubiquinone; Vascular Endothelial Growth Factor A; Vitamin E

Isoniazid (INH) and rifampicin (RIF), the most common anti-tubercular therapy, causes hepatotoxicity through a multi-step mechanism in certain individuals. The present study was an attempt to evaluate the hepatoprotective effect of coenzyme Q10 against INH + RIF-induced hepatotoxicity in Wistar albino rats.. Hepatotoxicity was induced by the oral administration of INH + RIF (50 mg/kg b.w. each/day) in normal saline water for 28 days. The hepatoprotective effect of coenzyme Q10 (10 mg/kg b.w./day) was compared with that of the standard drug silymarin (25 mg/kg b.w./day). Animals were sacrificed at the end of the study period, and blood and liver were collected for biochemical, immunological and histological analyses.. Evaluation of biochemical parameters showed that coenzyme Q10 treatment caused significant (P < 0.05) reduction in the elevated levels of serum liver function markers and restored normal levels of total protein, albumin and lipids in INH + RIF-treated rats. Also, it was observed that coenzyme Q10 was able to restore normal levels of enzymic antioxidants, reduced glutathione and lipid peroxidation in the INH + RIF-treated rats. Coenzyme Q10 was found to effectively reduce the extent of liver damage caused due to INH + RIF. In addition, the levels of IL-10 and IL-6 were significantly elevated in the INH + RIF-induced rats treated with CoQ10.. Our study indicates the protective role of coenzyme Q10 in attenuating the hepatotoxic effects of INH + RIF in a rat model and that it could be used as a food supplement during anti-tubercular therapy.

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Antitubercular Agents; Chemical and Drug Induced Liver Injury; Dietary Supplements; Female; Interleukin-10; Isoniazid; Liver; Rats; Rats, Wistar; Rifampin; Silymarin; Ubiquinone; Vitamins

The present study aimed to develop a nano-crystalline solid dispersion (CSD) of coenzyme Q10 (CoQ10) using a newly developed cold wet-milling (CWM) system to enhance the dissolution and biopharmaceutical properties of CoQ10. CSD formulations of CoQ10 were prepared by the CWM system, and their physicochemical properties were characterized in terms of morphology, crystallinity, particle size distribution, dissolution, and photostability. Application of the CWM system to CoQ10 led to successful development of a CSD formulation (CoQ10/CWM) with a mean CoQ10 diameter of ca. 129 nm, although a conventional wet-milling system failed due to evident formation of large particles. In comparison with crystalline CoQ10, marked improvement in the aqueous dissolution was seen for the CoQ10/CWM, with no significant decrease of photostability. Oral bioavailability and hepatoprotective effects of orally dosed CoQ10 samples were also evaluated in rats. After oral administration of CoQ10/CWM (100 mg CoQ10/kg) in rats, there appeared to be a similar Tmax value and 13-fold increase of bioavailability compared with crystalline CoQ10. In a rat model of acute liver injury, pretreatment with CoQ10/CWM (100 mg CoQ10/kg, twice) led to marked attenuation of hepatic damage as evidenced by decreased ALT and AST, surrogate biomarkers for hepatic injury, whereas crystalline CoQ10 was less effective. The CSD approach with the new CWM system might be a promising dosage option for improving the nutraceutical values of CoQ10.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Carbon Tetrachloride; Chemical and Drug Induced Liver Injury; Crystallization; Drug Compounding; Drug Stability; Light; Male; Nanoparticles; Protective Agents; Rats; Rats, Sprague-Dawley; Ubiquinone

The potential protective effect of coenzyme Q10 against acute liver injury induced by a single dose of acetaminophen (700 mg/kg, p.o.) was investigated in rats. Coenzyme Q10 treatment was given as two i.p. injections, 10 mg/kg each, at 1 and 12 h following acetaminophen administration. Coenzyme Q10 significantly reduced the levels of serum aminotransferases, suppressed lipid peroxidation, prevented the decreases of reduced glutathione and catalase activity, decreased the elevations of tumor necrosis factor-α and nitric oxide as well as attenuating the reductions of selenium and zinc ions in liver tissue resulting from acetaminophen administration. Histopathological liver tissue damage mediated by acetaminophen was ameliorated by coenzyme Q10. Immunohistochemical analysis revealed that coenzyme Q10 significantly decreased the acetaminophen-induced overexpression of inducible nitric oxide synthase, nuclear factor-κB, caspase-3 and p53 in liver tissue. It was concluded that coenzyme Q10 protects rat liver against acute acetaminophen hepatotoxicity, most probably through its antioxidant, anti-inflammatory and antiapoptotic effects.

Topics: Acetaminophen; Animals; Anti-Inflammatory Agents; Antioxidants; Apoptosis; Biomarkers; Caspase 3; Catalase; Chemical and Drug Induced Liver Injury; Cytoprotection; Disease Models, Animal; Drug Administration Schedule; Glutathione; Immunohistochemistry; Injections, Intraperitoneal; Lipid Peroxidation; Liver; Male; Malondialdehyde; NF-kappa B; Nitric Oxide; Nitric Oxide Synthase Type II; Oxidative Stress; Rats; Rats, Sprague-Dawley; Selenium; Time Factors; Tumor Necrosis Factor-alpha; Tumor Suppressor Protein p53; Ubiquinone; Zinc

Alcohol consumption has been implicated to cause severe hepatic steatosis which is mediated by alcohol dehydrogenase (ADH) activity and CYP(450) 2E1 expression. In this context, the effect of ethanol was studied for its influence on lipogenesis in HepG2 cell which is deficient of ADH and does not express CYP(450) 2E1. The results showed that ethanol at 100mM concentration caused 40% cytotoxicity at 72h as determined by MTT assay. The incorporation of labeled [2-(14)C] acetate into triacylglycerol and phospholipid was increased by 40% and 26% respectively upon 24h incubation, whereas incorporation of labeled [2-(14)C] acetate into cholesterol was not significantly increased. Further, ethanol inhibited HMG-CoA reductase which is a rate-limiting enzyme in the cholesterol biosynthesis. It was observed that, HMG-CoA reductase inhibition was brought about by ethanol as a consequence of decreased cell viability, since incubation of HepG2 cells with mevalonate could not increase the cholesterol content and increase the cell viability. Addition of ethanol significantly increased TNF-alpha secretion and depleted mitochondrial coenzyme-Q(10) which is detrimental for cell viability. But vitamin E (10mM) could partially restore coenzyme-Q(10) and glutathione content with decreased TNF-alpha secretion in ethanol treated cells. Further, lipid peroxidation, glutathione peroxidase and superoxide dismutase enzyme activities remained unaffected. Ethanol decreased glutathione content while, GSH/GSSG ratio was significantly higher compared to other groups showing cellular pro-oxidant and antioxidant balance remained intact. Alanine amino transferase activity was increased by 4.85 folds in cells treated with ethanol confirming hepatocyte damage. Hence, it is inferred that ethanol induced cytotoxicity in HepG2 cells due to coenzyme-Q(10) depletion and increased TNF-alpha secretion.

Topics: Alanine Transaminase; Alcohol Dehydrogenase; Alcohol Drinking; Cell Survival; Chemical and Drug Induced Liver Injury; Cholesterol; Cytochrome P-450 CYP2E1; Ethanol; Glutathione; Hep G2 Cells; Hepatocytes; Humans; Hydroxymethylglutaryl CoA Reductases; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Lipogenesis; Mitochondria, Liver; Tumor Necrosis Factor-alpha; Ubiquinone; Vitamin E

The present study aims to clarify the protective effect of supplementation with some antioxidants, such as idebenone (200 mg/kg, ip), melatonin (10 mg/kg, ip) and arginine (200 mg/kg, ip) and their combination, on liver function (T. protein, albumin, alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase), energetic parameters (adenosine triphosphate, adenosine diphosphate, adenosine monophosphate, inorganic phosphate, total adenylate, adenylate energy charge and potential phosphate). The effect on glycolytic and glycogenolytic enzymes (glucose, glycogen, glycogen phosphorylase, pyruvate kinase and phosphofructokinase against hypoxia) was also studied. The drugs were administered 24 and 1 h prior sodium nitrite intoxication. All biochemical parameters were estimated 1 h after sodium nitrite injection. Injection of sodium nitrite (75 mg/kg, sc) produced a significant disturbance in all biochemical parameters of liver function, energetic parameters and glycolytic and glycogenolytic enzymes. Hepatic damage was confirmed by histopathological examination of the liver as compared to controls. The marked changes in hepatic cells induced by sodium nitrite were completely abolished by pretreatment with the drug combination, suggesting potential protection against sodium nitrite-induced hypoxia. It could be concluded that a combination of both idebenone and melatonin or idebenone and arginine provides potential protection against sodium nitrite-induced hypoxia by improving biochemical parameters and preserving liver histology.

Topics: Animals; Antioxidants; Arginine; Chemical and Drug Induced Liver Injury; Cytoprotection; Dietary Supplements; Disease Models, Animal; Drug Therapy, Combination; Energy Metabolism; Hypoxia; Liver; Male; Melatonin; Oxidative Stress; Rats; Reactive Oxygen Species; Sodium Nitrite; Time Factors; Ubiquinone

In recent years, the medicinal mushroom Antrodia cinnamomea, known as "niu-chang chih" has received much attention with regard to its possible health benefits; especially its hepatoprotective effects against various drugs, toxins, and alcohol induced liver diseases. However, the molecular mechanism underlying this protective effect of Antrodia cinnamomea and its active compound antroquinonol was poorly understood. In the present study we evaluated to understand the hepatoprotective efficacy of antroquinonol and ethanolic extracts of mycelia of Antrodia cinnamomea (EMAC) in vitro and in vivo.. The protective mechanism of antroquinonol and EMAC against ethanol-induced oxidative stress was investigated in cultured human hepatoma HepG2 cells and ICR mice model, respectively. HepG2 cells were pretreated with antroquinonol (1-20μM) and oxidative stress was induced by ethanol (100mM). Meanwhile, male ICR mice were pretreated with EMAC for 10 days and hepatotoxicity was generated by the addition of ethanol (5g/kg). Hepatic enzymes, cytokines and chemokines were determined using commercially available assay kits. Western blotting and real-time PCR were subjected to analyze HO-1 and Nr-2 expression. EMSA was performed to monitor Nrf-2 ARE binding activity. Possible changes in hepatic lesion were observed using histopathological analysis.. Antroquinonol pretreatment significantly inhibited ethanol-induced AST, ALT, ROS, NO, MDA production and GSH depletion in HepG2 cells. Western blot and RT-PCR analysis showed that antroquinonol enhanced Nrf-2 activation and its downstream antioxidant gene HO-1 via MAPK pathway. This mechanism was then confirmed in vivo in an acute ethanol intoxicated mouse model: serum ALT and AST production, hepatocellular lipid peroxidation and GSH depletion was prevented by EMAC in a dose-dependent manner. EMAC significantly enhanced HO-1 and Nrf-2 activation via MAPKs consistent with in vitro studies. Ethanol-induced hepatic swelling and hydropic degeneration of hepatocytes was significantly inhibited by EMAC in a dose-dependent manner.. These results provide a scientific basis for the hepatoprotective effects of Antrodia cinnamomea. Data also imply that antroquinonol, a potent bioactive compound may be responsible for the hepatoprotective activity of Antrodia cinnamomea. Moreover, the present study highly supported our traditional knowledge that Antrodia cinnamomea as a potential candidate for the treatment of alcoholic liver diseases.

Topics: Animals; Antioxidants; Antrodia; Biological Products; Chemical and Drug Induced Liver Injury; Disease Models, Animal; Dose-Response Relationship, Drug; Ethanol; Glutathione; Heme Oxygenase-1; Hep G2 Cells; Hepatocytes; Humans; Lipid Peroxidation; Male; Malondialdehyde; Mice; Mice, Inbred ICR; Mitogen-Activated Protein Kinases; Mycelium; NF-E2-Related Factor 2; Nitric Oxide; Oxidative Stress; Phytotherapy; Reactive Oxygen Species; Transaminases; Ubiquinone

Studies were carried out to examine the anti-oxidative effect(s) of oral coenzyme Q10 supplementation (10 mg/kg b.w./day) in rats treated per os with either sodium nitrite (10 mg/kg b.w./day) or saline (control) for 14 days. Results showed that sodium nitrite increases thiobarbituric-acid reactive substances (TBARS in rat small intestinal mucosa and liver, and the agent did not have any effect(s) on the total anti-oxidant status (TAS) and lipid peroxidation of rat blood. Pretreatment of nitrite-poisoned rats with coenzyme Q10 mitigated TBARS and increased TAS in animal blood. Coenzyme Q10 has been found to be a promising anti-oxidant agent in sodium nitrite-induced lipid peroxidation.

Topics: Animals; Antioxidants; Carcinogens; Chemical and Drug Induced Liver Injury; Coenzymes; Intestine, Small; Lipid Peroxidation; Liver; Liver Diseases; Male; Nitrates; Oxidation-Reduction; Pilot Projects; Rats; Rats, Wistar; Thiobarbituric Acid Reactive Substances; Ubiquinone

Oxidant stress induced by hydrophobic bile acids has been implicated in the pathogenesis of liver injury in cholestatic liver disorders. We evaluated the effect of idebenone, a coenzyme Q analogue, on taurochenodeoxycholic acid (TCDC)-induced cell injury and oxidant stress in isolated rat hepatocytes and on glycochenodeoxycholic acid (GCDC)-induced generation of hydroperoxides in fresh hepatic mitochondria. Isolated rat hepatocytes in suspension under 9% oxygen atmosphere were preincubated with 0, 50, and 100 micromol/l idebenone for 30 min and then exposed to 1000 micromol/l TCDC for 4 h. LDH release (cell injury) and thiobarbituric acid reactive substances (measure of lipid peroxidation) increased after TCDC exposure but were markedly suppressed by idebenone pretreatment. In a second set of experiments, the addition of 100 micromol/l idebenone up to 3 h after hepatocytes were exposed to 1000 micromol/l TCDC resulted in abrogation of subsequent cell injury and markedly reduced oxidant damage to hepatocytes. Chenodeoxycholic acid concentrations increased to 5.15 nmol/10(6) cells after 2 h and to 7.05 after 4 h of incubation of hepatocytes with 1000 micromol/l TCDC, and did not differ in the presence of idebenone. In freshly isolated rat hepatic mitochondria, when respiration was stimulated by succinate, 10 micromol/l idebenone abrogated the generation of hydroperoxides during a 90-minute exposure to 400 micromol/l GCDC. These data demonstrate that idebenone functions as a potent protective hepatocyte antioxidant during hydrophobic bile acid toxicity, perhaps by reducing generation of oxygen free radicals in mitochondria.

Topics: Animals; Antioxidants; Benzoquinones; Bile Acids and Salts; Chemical and Drug Induced Liver Injury; Glycochenodeoxycholic Acid; L-Lactate Dehydrogenase; Lipid Peroxidation; Liver; Male; Mitochondria, Liver; Oxidative Stress; Rats; Rats, Sprague-Dawley; Succinic Acid; Taurochenodeoxycholic Acid; Thiobarbituric Acid Reactive Substances; Ubiquinone

S-Allylmercaptocysteine (SAMC), one of the water-soluble organosulfur compounds in ethanol extracts of garlic (Allium sativum L.), has been shown to protect mice against acetaminophen (APAP)-induced liver injury. In this study, we examined the mechanisms underlying this hepatoprotection. SAMC (100 mg/kg, p.o.) given 2 and 24 hr before APAP administration (500 mg/kg, p.o.) suppressed the plasma alanine aminotransferase activity increases 3 to 12 hr after APAP administration significantly. The hepatic reduced glutathione levels of vehicle-pretreated mice decreased 1 to 6 hr after APAP administration, but SAMC pretreatment suppressed the reductions 1 to 6 hr after APAP administration significantly. These inhibitory effects of SAMC were dose-dependent (50-200 mg/kg) 6 hr after APAP administration. As SAMC pretreatment (50-200 mg/kg) suppressed hepatic cytochrome P450 2E1-dependent N-nitrosodimethylamine demethylase activity significantly in a dose-dependent manner, we suggest that one of its protective mechanisms is inhibition of cytochrome P450 2E1 activity. SAMC pretreatment also suppressed the increase in hepatic lipid peroxidation and the decrease in hepatic reduced coenzyme Q9 (CoQ9H2) levels 6 hr after APAP administration. The hepatic CoQ9H2 content of the SAMC pretreatment group was maintained at the normal level. Therefore, we suggest that another hepatoprotective mechanism of SAMC may be attributable to its antioxidant activity.

Topics: Acetaminophen; Alanine Transaminase; Animals; Chemical and Drug Induced Liver Injury; Coenzymes; Cysteine; Cytochrome P-450 CYP2E1; Glucuronosyltransferase; Glutathione; Lipid Peroxidation; Liver; Liver Diseases; Male; Mice; Proteins; Sulfhydryl Compounds; Sulfotransferases; Ubiquinone; Vitamin E

To confirm whether or not cytosolic NADPH-UQ reductase is involved in the recycling of cellular ubiquinol (UQH2) consumed during lipid peroxidation, the effect of a UQ-10 supplement on the NADPH-UQ reductase and cellular defense against oxidative damage in rat livers was investigated. Supplements of UQ-10 for 14 days enhanced the levels of UQH2-10 and NADPH-UQ reductase in rat livers without any appreciable changes in other antioxidant contents and related enzyme activities. However, the injection of carbon tetrachloride (CCl4) into the rats induced lipid peroxidation and decreased the cellular UQH2-10 contents (and increased equivalent amounts of UQ-10), as well as decreasing the ascorbic acid, reduced glutathione (GSH) and alpha-tocopherol contents of the rat livers. Administration of the UQ-10 supplement prior to the CCl4 treatment spared alpha-tocopherol (but not GSH or ascorbic acid), inhibited lipid peroxidation, and thus improved CCl4-induced hepatitis. These findings support the notion that NADPH-UQ reductase in cytosol is the enzyme responsible for the regeneration of UQH2 from UQ formed by lipid peroxidation in cells.

Topics: Animals; Carbon Tetrachloride; Chemical and Drug Induced Liver Injury; Cytosol; Liver; Male; Microsomes, Liver; Mitochondria, Liver; NAD(P)H Dehydrogenase (Quinone); Oxidation-Reduction; Rats; Rats, Wistar; Specific Pathogen-Free Organisms; Ubiquinone

This investigation was conducted to ascertain whether administration of L-carnitine and coenzyme Q10 could protect from the experimentally-induced hepatic lipid infiltration and glutathione content decrease in rats exposed to hyperbaric oxygen and prolonged alcohol administration. The results indicate that administration of L-carnitine and coenzyme Q10 in association reduces damage induced by chronic alcohol poisoning and hyperbaric oxygen. This protective action is more marked when L-carnitine and coenzyme Q10 are administered together. The combined complementary biochemical activity of these two compounds is discussed.

Topics: Animals; Carnitine; Chemical and Drug Induced Liver Injury; Drug Synergism; Ethanol; Glutathione; Hyperbaric Oxygenation; Lipid Peroxides; Liver; Male; Rats; Rats, Wistar; Triglycerides; Ubiquinone

It has been shown that prophylactic administration of ubiquinone protects rats liver from the toxic damage by D-galactosamine both on ultrastructural and on cell levels. Ubiquinone administration prevents necrosis in hepatocytes and preserves their ability for compensatory reactions expressed in activation of protein-synthesis regulating structures in the cell. Ubiquinone decreases hyperfermentemia and hyperbilirubinemia as well as prevents the decrease in liver protein content caused by galactosamine. Ubiquinone exerts an antioxidant effect, blocking the induction of lipid peroxidation both in intact and hepatic rats.

Topics: Animals; Chemical and Drug Induced Liver Injury; Disease Models, Animal; Drug Evaluation, Preclinical; Galactosamine; Liver; Male; Microscopy, Electron; Rats; Ubiquinone

It has been suggested that lipid peroxidation is an important factor in the pathogenesis of carbon tetrachloride (CCl4) hepatotoxicity. In the present study, experimental liver injury induced by CCl4 could be inhibited by Coenzyme Q10 (CoQ10) and in spite of exposure to CCl4 the liver tissue levels of thiobarbituric acid (TBA) reacting substances were not increased in rats pretreated with CoQ10. In the in vitro experiment as well, the apparent liver tissue levels of TBA were decreased after addition of CoQ10. These facts provided evidences that CoQ10 possessed a direct antioxidative effect and protected against CCl4 hepatotoxicity by this antioxidative effect.

Topics: Animals; Antioxidants; Carbon Tetrachloride; Carbon Tetrachloride Poisoning; Chemical and Drug Induced Liver Injury; Female; Liver; Rabbits; Thiobarbiturates; Ubiquinone