8-hydroxy-2--deoxyguanosine and Chemical-and-Drug-Induced-Liver-Injury

The objective of this study was to assess the risk of genotoxicity of d-phenothrin by measuring the oxidative stress it causes in rat liver and kidney. The level of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG)/10(6) 2'-deoxyguanosine (dG) was measured by using high performance liquid chromatography (HPLC) with a diode array (DAD) and an electrochemical detector (ECD). Sixty male Wistar albino rats were randomly divided into five experimental groups and one control group of 10 rats/group. d-phenothrin was administered intraperitoneally (IP) to the five experimental groups at 25 mg/kg (Group I), 50 mg/kg (Group II), 66.7 mg/kg (Group III), 100 mg/kg (Group IV), and 200 mg/kg (Group V) for 14 consecutive days, and the control group received only the vehicle, dimethyl sulfoxide (DMSO). DNA from samples frozen in liquid nitrogen was isolated with a DNA isolation kit. Following digestion with nuclease P1 and alkaline phosphatase (ALP), hydrolyzed DNA was subjected to HPLC. The dG and 8-oxodG levels were analyzed with a DAD and ECD, respectively. In the experimental groups, the mean 8-oxodG/10(6) dG levels were 48.15 ± 7.43, 68.92 ± 20.66, 82.07 ± 14.15, 85.08 ± 28.50, and 89.14 ± 21.73 in livers and 39.06 ± 7.63, 59.69 ± 14.22, 61.13 ± 17.46, 65.13 ± 23.40, and 72.66 ± 19.04 in kidneys of Groups I, II, III, IV, and V, respectively. The mean 8-oxodG/10(6) dG levels in the control groups were 44.96 ± 12.66 for the liver and 39.07 ± 4.80 for the kidney. A statistically significant (p < 0.05), dose-dependent increase in oxidative DNA damage was observed in both organs of animals exposed to d-phenothrin when compared to controls. Furthermore, the liver showed a significantly higher level of oxidative DNA damage than the kidney (p < 0.01). In conclusion, d-phenothrin administered to rats intraperitoneally for 14 consecutive days generated free radical species in a dose-dependent manner and caused oxidative DNA damage in the liver and kidney.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Calibration; Chemical and Drug Induced Liver Injury; Chromatography, High Pressure Liquid; Deoxyguanosine; DNA Damage; Electrochemistry; Insecticides; Kidney Diseases; Male; Oxidative Stress; Pyrethrins; Rats; Rats, Wistar; Reproducibility of Results

Protective effect of resveratrol on sodium fluoride-induced oxidative stress, hepatotoxicity and neurotoxicity were studied in rats. A total of 28 Wistar albino male rats were used. Four study groups were randomly formed with seven animals in each. The groups were treated for 21days with distilled water (control group), with water containing 100ppm fluoride (fluoride group), with resveratrol (12.5mg/kg i.p., resveratrol group), or with 100ppm fluoride+12.5mg/kg resveratrol i.p. (fluoride+resveratrol group). At the end of the trial, blood samples were collected by cardiac puncture and tissue samples were taken simultaneously. The total antioxidant and oxidant status in plasma and tissues as well as plasma 8-hydroxydeoxyguanosine levels were measured. Histopathological analyses of rat liver and brain tissues were performed in all groups to identify any changes. In the fluoride group, the total oxidant levels increased in plasma, liver and brain and total antioxidant levels decreased, as did the plasma 8-hydroxy-deoxyguanosine levels. These changes were prevented by co-administration of resveratrol. In addition, fluoride-associated severe histopathological changes in brain and liver tissues were not observed in the fluoride+resveratrol group. Consequently, these data suggested that resveratrol had beneficial effects in alleviating fluoride-induced oxidative stress.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Antioxidants; Brain; Chemical and Drug Induced Liver Injury; Deoxyguanosine; Heart; Liver; Male; Neurotoxicity Syndromes; Oxidative Stress; Rats; Rats, Wistar; Resveratrol; Sodium Fluoride; Stilbenes

In order to investigate a medium-term animal model using reporter gene transgenic rodents in which general toxicity, genotoxicity and carcinogenicity are evaluated, F344 gpt delta rats were given a diet containing 0.1% and 0.5% (a carcinogenic dose) safrole for 13 weeks. Serum biochemistry and histopathological examinations revealed overt hepatotoxicity of safrole, in line with previous reports. In the current study, safrole treatment possibly resulted in renal toxicity in male rats. In the in vivo mutation assays, an increase or a tendency to increase of the gpt mutant frequencies (MFs) was observed in both sexes at the carcinogenic dose. The number and area of foci of glutathione S-transferase placental form (GST-P) positive hepatocytes, ratio of proliferating cell nuclear antigen (PCNA)-positive hepatocytes and 8-hydroxydeoxyguanosine (8-OHdG) levels in liver DNA were significantly increased in both sexes of the 0.5% group. The overall data suggested that the present model might be a promising candidate for investigating comprehensive toxicities of the agents. In addition, data demonstrating the base modification and cell proliferation due to exposure to safrole could contribute to understanding safrole-induced hepatocarcinogenesis, which imply expanding in application of this model.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Cell Proliferation; Chemical and Drug Induced Liver Injury; Deoxyguanosine; Disease Models, Animal; Dose-Response Relationship, Drug; Escherichia coli Proteins; Female; Glutathione Transferase; Hepatocytes; Male; Mutagenicity Tests; Pentosyltransferases; Proliferating Cell Nuclear Antigen; Rats; Rats, Inbred F344; Rats, Transgenic; Safrole; Sex Factors

Periodontitis increases the serum lipopolysaccharide level, contributing to liver injury. Toothbrushing improves periodontitis and may also affect serum lipopolysaccharide concentration and periodontitis-induced liver injury. The purpose of the present study was to examine whether the improvement in periodontal inflammation by toothbrushing clinically affects the serum lipopolysaccharide level and hepatic pathological changes in rat periodontitis.. Thirty male Wistar rats were divided into 5 groups, 2 groups receiving topical application of pyrogen-free water to the gingival sulcus for 4 or 8 weeks. The next 2 groups received topical application of lipopolysaccharide and proteases for 4 or 8 weeks. The last group received topical application of lipopolysaccharide and proteases for 8 weeks, and the palatal gingiva was brushed with a powered toothbrush once a day for 4 weeks prior to the end of the experimental period.. Topical application of lipopolysaccharide and proteases induced not only periodontal inflammation but also an elevation in the serum lipopolysaccharide concentration, with increasing hepatic inflammation, steatosis and 8-hydroxydeoxyguanosine levels in a time-dependent manner. The rats that received gingival stimulation showed decreased polymorphonuclear leukocyte infiltration and collagen loss levels in the periodontal lesions. Furthermore, this group also showed a decrease in serum lipopolysaccharide concentration and hepatic inflammation, steatosis and 8-hydroxydeoxyguanosine levels, compared with the group receiving no treatment.. Toothbrushing promoted healing of periodontal lesions, decreased serum lipopolysaccharide concentration and suppressed liver injury in a rat periodontitis model.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Alveolar Bone Loss; Animals; Chemical and Drug Induced Liver Injury; Collagen; Connective Tissue; Deoxyguanosine; DNA, Mitochondrial; Epithelial Attachment; Escherichia coli; Fatty Liver; Gingiva; Leukocyte Count; Lipopolysaccharides; Liver Diseases; Male; Neutrophil Infiltration; Neutrophils; Peptide Hydrolases; Periodontal Attachment Loss; Periodontitis; Random Allocation; Rats; Rats, Wistar; Reactive Oxygen Species; Streptomyces griseus; Toothbrushing; Tumor Necrosis Factor-alpha

We have shown that direct reaction of catechol with nitric oxide (NO) results in generation of reactive oxygen and nitrogen species (RNS) through semiquinone radical formation, leading to oxidative DNA damage in rat forestomach. In the present study, we investigated whether dietary catechol systemically exerts the same effects under NO-rich circumstances, when given before and during induction of inflammatory lesions. Male ICR mice were treated with or without 0.8% catechol in the diet for 2 weeks followed by acetaminophen (APAP) administration at a dose of 300mg/kg by single i.p. injection. Along with several indicators of APAP-induced hepatitis, 8-hydroxydeoxyguanosine (8-OHdG) levels and immunohistochemistry for 3-nitrotyrosine (NO(2)Tyr) in the livers were examined at 1.5, 4 and 24h after APAP injection. 8-OHdG was significantly increased at 24h in the co-treatment group, but not with either catechol or APAP alone. Elevation of serum ALT and AST activities, decrease of reduced glutathione levels and histopathological liver changes were observed to the same extents in both APAP-treated groups. In view of the finding of positive hepatocytes for NO(2)Tyr prior to generation of 8-OHdG, the process of oxidative DNA damage might involve RNS formation. Precise quantitative analysis of NO(2)Tyr by means of liquid chromatography with tandem mass spectrometry (LC-MS/MS) in an additional study with the same experimental protocol confirmed increase of RNS due to the reaction of catechol with NO produced after APAP-induced hepatitis. The overall data imply that antioxidants with a catechol structure can cause oxidative DNA damage under inflammatory conditions.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Acetaminophen; Alanine Transaminase; Animals; Catechols; Chemical and Drug Induced Liver Injury; Deoxyguanosine; Diet; DNA Damage; Glutathione; Immunohistochemistry; Inflammation; Liver; Male; Mice; Mice, Inbred ICR; Nitric Oxide; Oxidation-Reduction; Time Factors; Transaminases; Tyrosine

Isoniazid is a widely used drug for the treatment of tuberculosis, but hepatotoxicity is a major concern during treatment. Thiopronin contains an SH-group and is generally considered an antioxidant. The aim of the present study was to investigate the effects of thiopronin during liver injury and DNA damage induced by isoniazid. Rats were injected daily with isoniazid (100 mg/kg, i.p.) for 21 days with or without thiopronin co-administration (60 mg/kg, i.p.) from day 11 to day 21. The influence of thiopronin on isoniazid-induced DNA oxidative damage was analyzed in precision-cut rat liver slices by HPLC-MS/MS. Thiopronin prevented isoniazid-induced hepatotoxicity, indicated by both diagnostic indicators of liver damage (alanine aminotransferase and aspartate aminotransferase) and histopathological analysis. In vivo, thiopronin significantly inhibited isoniazid-induced CYP2E1 activity as assessed by both chlorzoxazone hydroxylase and aniline hydroxylase (p<0.001). Thiopronin concentration-dependently inhibited CYP2E1-dependent aniline hydroxylation, and the Dixon plots suggest that thiopronin is a competitive inhibitor of CYP2E1. Thiopronin markedly attenuated isoniazid-induced inhibition of the detoxification system through cytosolic glutathione S-transferases (GSTs), including mu GST and alpha GST. In precision-cut liver slices, the free radical scavenging activity of thiopronin reduced the generation of DNA adducts induced by isoniazid (p<0.05). Altogether, these results suggest that thiopronin exerts its hepatoprotective activity against isoniazid-induced hepatotoxicity by inhibiting the production of free radicals in addition to its role as a scavenger. Thiopronin may reduce free radical generation via inhibition of hepatic CYP2E1 and increase the removal of free radicals directly or through the induction of cytosolic GSTs.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Alanine Transaminase; Aniline Compounds; Animals; Aspartate Aminotransferases; Chemical and Drug Induced Liver Injury; Chlorzoxazone; Cytochrome P-450 CYP2E1; Cytochrome P-450 CYP2E1 Inhibitors; Cytoprotection; Deoxyguanosine; Disease Models, Animal; DNA Adducts; Dose-Response Relationship, Drug; Enzyme Inhibitors; Free Radical Scavengers; Glutathione Transferase; Hydroxylation; Isoniazid; Kinetics; Liver; Liver Diseases; Male; Oxidative Stress; Rats; Rats, Wistar; Tiopronin

An amphiphilic alpha-phenyl-N-(tert-butyl) nitrone (PBN) derivative, N-{[4-(lactobionamido)methyl]benzylidene}-1,1-dimethyl-2-(octylsulfanyl)ethylamine N-oxide (LPBNSH), newly synthesized from its original form PBN in hopes of clinical use, was intraperitoneally administered to Long-Evans Cinnamon (LEC) rats every 2 days at the concentrations of 0.1, 0.5, 1.0, and 2.0 mg/kg. We found that LPBNSH protected against copper-induced hepatitis with jaundice in LEC rats at concentrations of 0.1 and 0.5 mg/kg, which were extremely low compared with that of PBN. It also effectively prevented the loss of body weight, reduced the death rate, and suppressed the increase in serum aspartate aminotransferase and alanine aminotransferase values arising from fulminant hepatitis with jaundice at the same concentrations. Similar results were observed when PBN was administered at the concentration of 150 mg/kg. Immunohistochemical analysis of 8-hydroxy-2'-deoxyguanosine and measurement of thiobarbituric acid-reactive substances in the liver showed that LPBNSH largely suppressed the formation of these oxidative products at same concentrations. No difference in the abnormal accumulation of copper in the liver between the LPBNSH administered and control groups was observed. From these results, it was concluded that LPBNSH exhibited liver-protective effects against fulminant hepatitis with jaundice at ca. 1/1000, 500 the molar concentration of PBN and, therefore, was clinically promising.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Antioxidants; Chemical and Drug Induced Liver Injury; Copper; Cyclic N-Oxides; Deoxyguanosine; Disaccharides; Imines; Immunohistochemistry; Liver; Liver Failure, Acute; Male; Rats; Rats, Inbred LEC; Thiobarbituric Acid Reactive Substances

Excessive alcohol consumption is associated with increased risks of many diseases including cancer. We evaluated oxidative DNA damage in Aldh2 +/+ and Aldh2 -/- mice after they had been subjected to acute ethanol exposure. Olive tail moment, which was measured using a comet assay, was not increased by ethanol treatment in both Aldh2 +/+ and Aldh2 -/- mice. However, after controlling for the effect of ethanol exposure, the Aldh2 genotype was a significant determinant for Olive tail moments. Although the ethanol treatment significantly increased the hepatic 8-OHdG generation in only Aldh2 +/+ mice, the level of 8-OHdG was the highest in Aldh2 -/- ethanol treated mice. The increase in the level of 8-OHdG was associated with hepatic expression of cytochrome P450 2E1 (CYP2E1). The levels of Olive tail moment and the hepatic 8-OHdG in the Aldh2 -/- control group were significantly higher than those of the Aldh2 +/+ control group. The level of CYP2E1 in liver tissue showed a similar pattern to those of the oxidative DNA damage markers. This study shows that acute ethanol consumption increases oxidative DNA damage and that expression of CYP2E1 protein may play a pivotal role in the induction of oxidative DNA damage. The finding that oxidative DNA damage was more intense in Aldh2 -/- mice than in Aldh2 +/+ mice suggests that ALDH2-deficient individuals may be more susceptible than wild-type ALDH2 individuals to ethanol-mediated liver disease, including cancer.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aldehyde Dehydrogenase; Aldehyde Dehydrogenase, Mitochondrial; Analysis of Variance; Animals; Blotting, Western; Chemical and Drug Induced Liver Injury; Comet Assay; Cytochrome P-450 CYP2E1; Deoxyguanosine; Disease Models, Animal; DNA Damage; Ethanol; Genetic Predisposition to Disease; Liver; Liver Diseases; Male; Mice; Mice, Knockout; Microsomes, Liver; Oxidative Stress; Polymorphism, Genetic

Ixeris chinesis (Thunb.) Ankai has been used as a Chinese folk medicine, but only scanty information is available on the physiological and biochemical functions of the compounds extracted from I. chinesis. In the present study the effects of apigenin-7-glucoside (APIG) isolated from I. chinesis against liver injury caused by carbon tetrachloride (CCl4) were investigated.. The contents of malondialdehyde (MDA), glutamic pyruvic transaminase (GPT), glutamic oxaloacetic transaminase (GOT), and reduced glutathione (GSH) were evaluated by spectrophotography. The content of 8-Hydroxydeoxyguanosine (8-OHdG) was measured with high-performance liquid chromatography (HPLC) equipped with electrochemical and UV detection methods. The antioxidant activity of APIG was evaluated using chemiluminescence single photon counting technology.. CCl4 significantly increased the enzyme activities of GPT and GOT in blood serum, as well as the level of MDA and 8-OHdG in liver tissue, and decreased the levels of GSH. Pretreatment with APIG was able not only to suppress the elevation of GPT, GOT, MDA and 8-OHdG, and inhibit the reduction of GSH in a dose-dependent manner in vivo, but also to reduce the damage of hepatocytes in vitro. On the other hand, we also found that APIG had strong antioxidant activity against reactive oxygen species (ROS) in vitro in a concentration-dependent manner.. The hepatoprotective activity of APIG is possibly due to its antioxidant properties, acting as scavengers of ROS. These results obtained in vivo and in vitro suggest that APIG has protective effects against hepatic oxidative injury induced by chemicals. Further studies on the pharmaceutical functions and immunological responses of APIG may help its clinical application.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Alanine Transaminase; Animals; Antioxidants; Apigenin; Aspartate Aminotransferases; Asteraceae; Carbon Tetrachloride; Chemical and Drug Induced Liver Injury; Deoxyguanosine; DNA Damage; Drugs, Chinese Herbal; Glutathione; Hepatocytes; Lipid Peroxidation; Liver; Male; Malondialdehyde; Protective Agents; Rats; Rats, Wistar; Reactive Oxygen Species

Long-Evans Cinnamon (LEC) rats are characterized by an abnormal hepatic deposition of copper (Cu) due to a lack of the Cu-transporter P-type adenosine triphosphatase: accordingly, the strain is a good animal model of Wilson's disease. The effect of oral zinc (Zn) acetate treatment on the development of acute hepatitis and the biochemical parameters of Cu-induced liver damage was studied in 5-week-old LEC rats (n=52).. Rats receiving 50 or 80 mg/ml/day Zn acetate by gavage and control rats receiving a daily dose of glucose solution 0.02 g/ml by gastric intubation were killed at 1, 2 or 8 weeks after the start of treatment.. Treatment with Zn acetate resulted in the prevention of acute hepatitis: 10 of the 13 untreated rats developed signs and symptoms compatible with acute hepatitis between the 6th and 7th week of treatment. Tissue metallothionein (MT) significantly increased in the treated rats and positively correlated with Zn concentrations within the liver. Control rats had a significantly higher iron concentration in the liver and kidneys compared with supplemented rats, after both short- and long-term experiments. 8-hydroxy-2'-deoxyguanosine amounts were significantly lower in untreated rats.. Zn acetate prevents acute hepatitis, by increasing tissue MT concentrations, reducing Cu absorption and interfering with Fe metabolism.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Administration, Oral; Animals; Chemical and Drug Induced Liver Injury; Deoxyguanosine; Disease Models, Animal; Dose-Response Relationship, Drug; Hepatitis, Animal; Iron; Kidney; Liver; Male; Metallothionein; Protective Agents; Rats; Rats, Inbred LEC; Zinc; Zinc Acetate

This study investigates the oxidative damage of biomolecules in livers of mice treated with morphine intraperitoneally. The oxidative damage of DNA as measured by single cell electrophoresis and high-performance liquid chromatography equipped with electrochemical and UV detection, the protein carbonyl content was measured by 2,4-dinitrophenylhydrazine method, and the malondialdehyde content was measured by the HPLC method. The activities of antioxidative enzymes, superoxide dismutase, catalase and glutathione peroxidase, and the activity of alanine aminotransferase were assayed by spectrophotometer method. Glutathione and oxidized glutathione were detected by fluorescence spectrophotometer method. All the indexes of oxidative damage, such as 8-OHdG, protein carbonyl group and malondialdehyde content, and the activity of alanine aminotransferase (n=27) increased significantly compared to those of control (n=27) (P<0.01) in livers of morphine-administered alone mice, while the indexes related with the in vivo antioxidative capacity, such as the ratio of glutathione and oxidized glutathione, activities of superoxide dismutase, catalase and glutathione peroxidase significantly decreased (P<0.01). When mice were treated with morphine combined with exogenous antioxidants, glutathione and ascorbic acid, all the indexes of oxidative damage and the activity of alanine aminotransferase showed no changes as compared to those of control (P>0.05), i.e., both glutathione and ascorbic acid completely abolished the damage of morphine on the hepatocyte. These results implied that morphine caused a seriously oxidative stress in mice livers and hence caused hepatotoxicity, while exogenous antioxidants were able to prevent the oxidative damage of biomolecules and hepatotoxicity caused by morphine. Thus, blocking oxidative damage may be a useful strategy for the development of a new therapy for opiate abuse.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Alanine Transaminase; Animals; Antioxidants; Ascorbic Acid; Catalase; Chemical and Drug Induced Liver Injury; China; Chromatography, High Pressure Liquid; Deoxyguanosine; DNA Damage; Drug Administration Schedule; Drug Therapy, Combination; Electrophoresis; Glutathione; Glutathione Peroxidase; Injections, Intraperitoneal; Liver; Malondialdehyde; Mice; Morphine; Organic Chemicals; Oxidation-Reduction; Oxidative Stress; Phenylhydrazines; Proteins; Superoxide Dismutase

The protective activity of melanin derived from tea (MDFT) was studied using hydrazine as a DNA-reactive chemical agent. Intra-peritoneal administration of MDFT at the doses of 5 or 20 mg/kg dose-dependently prevented liver toxicity induced by hydrazine in rats. It normalized rises in serum alanine transferase activity and a decrease in the glutathione level in the liver. It also reduced the hepatic malondialdehyde concentration. Monitoring the intensity of chemiluminescence showed that MDFT could prevent the production of free radicals that are generated owing to metabolic transformation of hydrazine. It also prevented the formation 8-hydroxy-deoxyguanosine (8-OH-dG) DNA adducts. The results obtained in vivo and in vitro suggest that MDFT confers marked protection of the liver against hydrazine-induced oxidative toxicity.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Alanine Transaminase; Animals; Antioxidants; Chemical and Drug Induced Liver Injury; Deoxyguanosine; DNA Adducts; DNA Damage; Dose-Response Relationship, Drug; Free Radicals; Glutathione; Hydrazines; Injections, Intraperitoneal; Liver; Male; Malondialdehyde; Melanins; Plant Extracts; Rats; Rats, Wistar; Tea

In the present study we demonstrated the protective effects of the spin-trapping agent alpha-phenyl-tert-butyl nitrone (PBN) against fulminant hepatitis with jaundice in LEC rats. In LEC rats an excess amount of copper is accumulated in the liver and causes hepatitis with severe jaundice. PBN was subcutaneously administered every 2 d at the concentration of 128 mg/kg, beginning with 13-week-old rats and continuing for 17 weeks. PBN prevented the loss of body weight, reduced death rate, and suppressed the increase in GTP and GOT values reflecting hepatic cell destruction. Ocular inspection also confirmed the suppressive effects of PBN on jaundice. In parallel with these phenomena, the amounts of thiobarbituric acid-reactive substances (TBARS) in livers of PBN-administered rats were found to be lower than those of non-PBN-administered rats. Little histological changes were observed in PBN-administered rats in comparison with non-PBN-administered rats. The protective effect of PBN on the formation of oxidative damage in liver DNA was observed but not so remarkable as that on lipid peroxidation. From these results, it was concluded that PBN had the liver-protective effects against fulminant hepatitis with jaundice. This suggested that free radicals play an important role in abnormally accumulated copper-induced liver injury and that PBN potentially has therapeutic value for the treatment of hepatitis.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aging; Alanine Transaminase; Animals; Aspartate Aminotransferases; Chemical and Drug Induced Liver Injury; Copper; Cyclic N-Oxides; Deoxyguanosine; DNA; Jaundice; Lipid Peroxidation; Liver; Nitrogen Oxides; Rats; Rats, Mutant Strains; Spin Labels; Thiobarbituric Acid Reactive Substances; Weight Loss