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1.
In this study, prooxidant and antioxidant status in liver homogenates and their mitochondrial fractions were investigated in both chronic and chronic plus acute ethanol-treated rats. Increases in serum transaminase activities, as well as increases in total lipid, triglyceride, malondialdehyde (MDA) and diene conjugate (DC) levels and decreases in glutathione (GSH), vitamin E and vitamin C levels, have been observed in liver homogenates following chronic ethanol treatment (20% ethanol, v/v as drinking water for 3 months), but CuZn-superoxide dismutase (CuZnSOD), glutathione peroxidase (GSH-Px) and glutathione transferase (GST) activities remained unchanged in postmitochondrial fractions. When an acute dose of ethanol (5 g/kg, i.p.) was given rats which had received ethanol chronically, serum transaminase activities and hepatic lipid and MDA and DC levels increased further, but GSH levels and antioxidant enzymes decreased more compared to the chronic ethanol-treated rats. There were no significant differences in the levels of MDA, DC and protein carbonyl and the activities of GSH-Px and GST in the hepatic mitochondrial fraction of rats following both chronic and chronic plus acute treatments. Mn-superoxide dismutase (MnSOD) activities increased in both groups, but mitochondrial GSH levels decreased only after chronic plus acute treatment. Therefore, we suggest that the increase in MnSOD activity may play an important role in the regulation of mitochondrial susceptibility against ethanol-induced oxidative stress.  相似文献   

2.
Thioacetamide (TAA) administration (0.3 g/l of tap water for a period of 3 months) to rats resulted in hepatic cirrhosis as assessed by biochemical and histopathological findings. This treatment caused an increase in the levels of malondialdehyde (MDA) and diene conjugates (DCs) and a decrease in the levels of glutathione (GSH), vitamin E, vitamin C and the activities of glutathione peroxidase (GSH-Px) in the liver of rats. Superoxide dismutase (SOD) activities were unchanged. Taurine (2% w/w, added to the chow diet) was administered together with TAA (0.3 g/l of drinking water) for 3 months. Taurine was found to decrease TAA-induced hepatic lipid peroxidation and to increase TAA-depleted vitamin E levels and GSH-Px activities. Histopathological findings also suggested that taurine has an inhibitive effect on TAA-induced hepatic cirrhosis. These results indicate that taurine treatment has a protective effect against TAA-induced liver cirrhosis by decreasing oxidative stress.  相似文献   

3.
The protective effect of taurine against thioacetamide hepatotoxicity of rats   总被引:10,自引:0,他引:10  
Thioacetamide (TAA) administration (three consecutive intraperitoneal injections of 400 mg/kg at 24-h interval) to rats resulted in hepatic injury as assessed by the measurement of serum transaminase activities and histopathological findings. This treatment caused an increase in the levels of malondialdehyde (MDA), diene conjugates (DCs) and glutathione (GSH) and the activity of superoxide dismutase SOD ), and a decrease in the levels of vitamins E and C and the activity of glutathione peroxidase (GSH-Px) in the liver of rats. Taurine administration (400 mg/kg, i.p., every 12 h and started 24 h prior to the first TAA injection) was found to decrease serum transaminase activities and hepatic lipid peroxidation without any significant change in hepatic antioxidant system. Histopathological findings also suggested that taurine has ameliorated effect on TAA-induced hepatic necrosis. These results indicate that taurine treatment, together with TAA administration, diminished the severity of the liver injury by decreasing oxidative stress due to its possible scavenger effect.  相似文献   

4.
Rats were fed with diets containing differing amounts of α-tocopherol for 21 days. For the latter 14 days of this period, one half of the rats also received ethanol (7% v/v) in the drinking water. Treatments did not alter the rate of weight gain between groups. Hepatic glutathione levels were depressed by ethanol treatment in rats receiving diets deficient in α-tocopherol or containing normal levels of the vitamin (50 ppm). However, this depression was not found in rats maintained on a high α-tocopherol diet (1000 ppm). The high α-tocopherol diet also prevented the ethanol-induced inhibition of proteolytic activity within the liver. A dose-dependent reduction of rates of hepatic generation of reactive oxygen species was effected by this vitamin. Within the central nervous system, the only region showing an ethanol-induced lowering of glutathione levels, was the midbrain of rats receiving the α-tocopherol deficient diet.  相似文献   

5.
To investigate whether diabetes-induced alterations of CYP2E1 and oxidative stress can be modulated by dietary taurine supplementation, male Wistar rats were divided into non-diabetic, diabetic, and diabetic taurine-supplemented groups (administered at 2% in the drinking water). Increased levels of CYP2E1-catalyzed p-nitrophenol hydroxylation were found in liver and kidney microsomes of rats with STZ-induced diabetes compared to those of non-diabetic control rats. Immunoblot and RT-PCR analyses of CYP2E1 protein and mRNA levels in the liver and kidneys showed the same trend as with enzyme activities. Taurine supplementation significantly decreased the enzyme activity and expression (protein and mRNA) of CYP2E1 in diabetic rat kidneys. Plasma β-hydroxybutyrate concentration was significantly reduced in taurine-treated diabetic rats. The induction of heme oxygenase-1 mRNA was suppressed by taurine treatment in diabetic rat kidneys. An increase in reduced glutathione (GSH) and a higher ratio of reduced to oxidized glutathione (GSH/GSSG) together with lower values of thiobarbituric acid-reactive substances (TBARS) were observed in the kidneys of taurine-treated diabetic rats. However, taurine supplementation caused only a slight or insignificant effect on these alternations in the liver of diabetic rats. Our results show dietary taurine may reduce CYP2E1 expression and activity, and oxidative stress in kidneys of diabetic rats.  相似文献   

6.
Hagar HH 《Toxicology letters》2004,151(2):335-343
Cyclosporine A (CsA) is the immunosuppressor which is most frequently used in transplant surgery and in the treatment of autoimmune diseases. Oxidative stress has been implicated as one of the possible mechanisms of CsA-induced hepatotoxicity. The present investigation examined the ability of taurine as an antioxidant to protect against CsA-induced oxidative stress and hepatotoxicity. CsA hepatotoxicity was induced by subcutaneous injection of CsA at a dose of 20mg/kg body weight daily for 21 days. Hepatotoxicity was assessed by reduced serum total protein level and increased serum levels of gamma glutamyl transferase (GGT), alanine aminotransferase (ALT), and aspartate aminotransaminase (AST). CsA treatment increased lipid peroxidation measured as thiobarbituric acid reactive substances (TBARS) concentration and decreased reduced glutathione (GSH) content and activities of catalase and glutathione peroxidase (GSH-Px) in the rat liver. Taurine administration (1% in the drinking water) for 3 days before and concurrently during CsA injections improved liver functions, as indicated by decline of serum transaminases and GGT levels and elevation of serum total protein. Moreover, taurine significantly reduced hepatic TBARS and increased GSH content and catalase and GSH-Px activities in the hepatic tissue. These results indicate that taurine has a protective action against CsA hepatotoxicity and suggest that taurine may find clinical application against a variety of toxins where cellular damage is a consequence of reactive oxygen species.  相似文献   

7.
Bindhumol V  Chitra KC  Mathur PP 《Toxicology》2003,188(2-3):117-124
Bisphenol A, an environmental contaminant, widely used as a monomer in polycarbonate plastics, has been shown to cause abnormalities in liver of rats and mice. The nature and mechanism of action of bisphenol A on liver is not clear. The aim of the present study was to investigate if bisphenol A induces oxidative stress in the liver of rats and if co-administration of vitamin C, an antioxidant, can prevent oxidative stress. Bisphenol A (0.2, 2.0 and 20 micro g/kg body weight per day) and bisphenol A+vitamin C (0.2, 2.0, 20 micro g+40 mg/kg body weight per day) was orally administered to rats for 30 days. After 24 h of the last treatment, rats were killed using overdose of anesthetic ether. Body weights of the animals and the weights of liver showed no significant changes. The activities of antioxidant enzymes, superoxide dismutase, catalase, glutathione reductase and glutathione peroxidase were decreased in mitochondrial and microsome-rich fractions of liver. The levels of hydrogen peroxide and lipid peroxidation increased in the treated rats when compared with the corresponding group of control animals. Activity of alanine transaminase, a marker enzyme of hepatic injury remained unchanged in the treated rats as compared with the corresponding control rats. Co-administration of bisphenol A and vitamin C showed no changes in the activities of superoxide dismutase, catalase, glutathione reductase and glutathione peroxidase and in the levels of hydrogen peroxide and lipid peroxidation as compared with the corresponding control groups. The results indicated that bisphenol A induces oxidative stress in the liver of rats by decreasing the antioxidant enzymes. Co-administration of vitamin C reversed the effects of bisphenol A-induced oxidative stress in the liver of rats.  相似文献   

8.
Lindane administration to rats (60 mg/kg b.w.) led to an enhancement in the oxidative stress status of the liver at 4 h after treatment, characterized by increases in hepatic thiobarbituric acid reactants (TBARS) formation and chemiluminescence, reduced glutathione (GSH) depletion, and diminution in the biliary content and release of GSH. These changes were observed in the absence of changes in either microsomal functions (cytochrome P450 content, NADPH-dependent superoxide radical production, and NADPH-cytochrome P450 reductase or NADPH oxidase activities) or in oxidative stress-related enzymatic activities (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glucose-6-phosphate dehydrogenase, and glutathione-S-transferases), over control values. Phenobarbital (PB) administration (0.1% in drinking water; 15 days) elicited an enhancement in liver microsomal functions, lipid peroxidation, and GSH content, without changes in oxidative stress-related enzymatic activities, except for the elevation in those of glutathione reductase and glutathione-S-transferase, compared to control rats. Lindane given to PB-pretreated rats did not alter liver microsomal functions, lipid peroxidation, glutathione status, or oxidative stress-related enzymatic activities, as compared to PB-pretreated animals. In addition, lindane induced periportal necrosis with hemorrhagic foci in untreated rats, but not in PB-pretreated animals. It is concluded that the early oxidative stress response of the liver to lindane and hepatic injury are suppressed by PB pretreatment via induction of microsomal enzymes in all zones of the hepatic acinus. reserved.  相似文献   

9.
We studied the effect of administering glycine on tissue lipid peroxidation and enzymic and non-enzymic antioxidants in experimental hepatotoxic Wistar rats. Hepatotoxicity was induced by administering ethanol for 30 days by intragastric intubation. Glycine administered at a dose of 0.6 g kg(-1) body weight for 30 days significantly inhibited the severe oxidative stress as evidenced by the decreased levels of liver and brain thiobarbituric acid reactive substances (TBARS) and hydroperoxides compared to control. The activities of enzymic and non-enzymic antioxidants such as reduced glutathione (GSH), glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT) in the liver and brain were significantly elevated on glycine supplementation as compared to the untreated alcohol fed rats. The levels of serum vitamin E and vitamin C were also increased to near normal levels on glycine treatment. Microscopic examination of alcohol treated rat liver showed inflammatory cell infiltrates and fatty changes, which were alleviated on treatment with glycine. Alcohol treated rat brain demonstrated oedma, which was significantly lowered on treatment with glycine. Thus our study shows that administering glycine to alcohol supplemented rats, markedly reduced the oxidative stress and elevated the enzymic and non-enzymic antioxidants in the liver and brain, which a was associated with a reversal of hepatic steatosis and cerebral oedma.  相似文献   

10.
In rats given ethanol 20% (v/v) in drinking water the hepatic antioxidant enzymes, superoxide dismutase (SOD), catalase and glutathione peroxidase were assayed at the end of 4 and 10 months of ethanol consumption. Simultaneously hepatic lipid peroxidation was monitored. At 4 months SOD and catalase were unaffected, while glutathione peroxidase was decreased by 48%. By the end of 10 months SOD had declined by 16% and glutathione peroxidase activity increased by 49%, while catalase again remained stable. However, hepatic lipid peroxidation was not significantly affected throughout the study. The controversy in the literature over the conflicting results of hepatic lipid peroxidation in chronically ethanol-fed rats is discussed in the light of mode, dose, duration of ethanol consumption, nutritional status of the rat, and primacy of glutathione peroxidase.  相似文献   

11.
Persons afflicted with protein malnutrition are generally deficient in a variety of essential micronutrients like zinc, copper, iron, and selenium, which in turn affects number of metabolic processes in the body. To evaluate the protective effects of zinc on the enzymes involved in oxidative stress induced in liver of protein-deficient rats, the current study was designed. Zinc sulfate at a dose level of 227mg/L zinc in drinking water was administered to female Sprague–Dawley normal control as well as protein-deficient rats for a total duration of 8 weeks. The effects of zinc treatment in conditions of protein deficiency were studied on rat liver antioxidant enzymes, which included catalase, glutathione peroxidase (GPx), glutathione reductase (GR), superoxide dismutase (SOD), glutathione reduced (GSH), and glutathione-S-transferase (GST). Protein deficiency in normal rats resulted in a significant increase in hepatic activities of catalase, glutathione peroxidase, glutathione reductase, and glutathione-S-transferase and the levels of lipid peroxidation. A significant inhibition in the levels of reduced glutathione and the enzyme activity of superoxide dismutase has been observed after protein deficiency in normal rats. Interestingly, Zn treatment to protein-deficient animals lowered already raised activity catalase, glutathione peroxidase, and glutathione-S-transferase and levels of lipid peroxidation to significant levels when compared to protein-deficient animals. Also, Zn treatment to the protein-deficient animals resulted in a significant elevation in the levels of GSH and SOD activity as compared to their respective controls, thereby indicating its effectiveness in regulating their levels in adverse conditions. It has also been observed that concentrations of zinc, copper, iron, and selenium were found to be decreased significantly in protein-deficient animals. However, the levels of these elements came back to within normal limits when zinc was administrated to protein-deficient rats. This study concludes that zinc has thepotential to regulate the activities of oxidative stress enzymes as well as essential hepatic elements.  相似文献   

12.
Persons afflicted with protein malnutrition are generally deficient in a variety of essential micronutrients like zinc, copper, iron, and selenium, which in turn affects number of metabolic processes in the body. To evaluate the protective effects of zinc on the enzymes involved in oxidative stress induced in liver of protein-deficient rats, the current study was designed. Zinc sulfate at a dose level of 227 mg/L zinc in drinking water was administered to female Sprague-Dawley normal control as well as protein-deficient rats for a total duration of 8 weeks. The effects of zinc treatment in conditions of protein deficiency were studied on rat liver antioxidant enzymes, which included catalase, glutathione peroxidase (GPx), glutathione reductase (GR), superoxide dismutase (SOD), glutathione reduced (GSH), and glutathione-S-transferase (GST). Protein deficiency in normal rats resulted in a significant increase in hepatic activities of catalase, glutathione peroxidase, glutathione reductase, and glutathione-S-transferase and the levels of lipid peroxidation. A significant inhibition in the levels of reduced glutathione and the enzyme activity of superoxide dismutase has been observed after protein deficiency in normal rats. Interestingly, Zn treatment to protein-deficient animals lowered already raised activity catalase, glutathione peroxidase, and glutathione-S-transferase and levels of lipid peroxidation to significant levels when compared to protein-deficient animals. Also, Zn treatment to the protein-deficient animals resulted in a significant elevation in the levels of GSH and SOD activity as compared to their respective controls, thereby indicating its effectiveness in regulating their levels in adverse conditions. It has also been observed that concentrations of zinc, copper, iron, and selenium were found to be decreased significantly in protein-deficient animals. However, the levels of these elements came back to within normal limits when zinc was administrated to protein-deficient rats. This study concludes that zinc has the potential to regulate the activities of oxidative stress enzymes as well as essential hepatic elements.  相似文献   

13.
The study examines the effects of taurine on the metabolism and detoxification of ethanol in liver fibrosis induced by simultaneous administration of iron carbonyl (0.5%, w/w) and ethanol (6g/(kgday)). Ethanol and iron administration caused liver damage and fibrosis as evidenced by liver histology and biochemical profile in plasma. Over accumulation of iron and a loss in taurine in hepatic tissue was observed in fibrotic animals. The activities of alcohol dehydrogenase and aldehyde dehydrogenase were significantly reduced in these rats compared to control. Adaptive induction of activities of Cytochrome P4502E1 (CYP2E1) and aniline hydroxylase accompanied by the reduction in glutathione-S-transferase, DT-diaphorase and glyoxalases I and II was observed. Taurine administration (2% in drinking water) ameliorated the effects of ethanol and iron. Hepatic damage and fibrosis were reduced in taurine-supplemented rats. Thus taurine has the potential for the treatment of alcoholic liver fibrosis.  相似文献   

14.
The effects of betaine or taurine on hepatotoxicity induced by lipopolysaccharide (LPS) were examined in adult male SD rats. Rats were provided with drinking water containing either 1% betaine or taurine for 2 weeks prior to challenge with LPS (5 mg/kg, iv). Supplementation with betaine or taurine protected the animals from induction of LPS hepatotoxicity as measured by changes in aspartate aminotransferase (AST), alanine aminotransferase (ALT) activities and total bilirubin levels in serum, and hepatic glutathione contents. LPS challenge increased serum TNF-alpha and nitrate/nitrite in rats, which were reduced by betaine or taurine intake. Taurine depletion induced by supply of drinking water containing 3% beta-alanine for 7 days did not enhance the LPS-induced hepatic damage or the decrease in hepatic glutathione level. The results indicate that intake of betaine or taurine attenuates the LPS-induced hepatotoxicity resulting from activation of Kupffer cells.  相似文献   

15.
We investigated the effect of daily oral administration to young rats of lead (10 mg/kg) and ethanol (10%, v/v, in drinking water), either alone or in combination, for 8 weeks on the uptake of lead in tissues, brain biogenic amines, hepatic alcohol dehydrogenase and cytosolic and mitochondrial aldehyde dehydrogenase and some selected lead-sensitive variables. Lead given in combination with ethanol produced more pronounced inhibition in the activities of hepatic glutamic oxalacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) as compared to lead alone treatment. Simultaneous exposure to lead and ethanol produced a greater depression of dopamine (DA) and 5-hydroxytryptamine (5-HT) levels in the whole brain of rats, compared to rats treated with lead alone. The concentrations of lead in blood, liver and brain were significantly higher in rats exposed simultaneously to lead and ethanol. Though ethanol treatment alone inhibited the activities of hepatic alcohol dehydrogenase and cytosolic and mitochondrial aldehyde dehydrogenase, no effect of lead treatment alone on these variables was observed. The results suggested that animals exposed to ethanol and lead are more vulnerable to the neurologic and hepatotoxic effects and the systemic toxicity of lead.  相似文献   

16.
The possible oxidative stress inducing effect of a fluoroquinolone (FQ) antibiotic, ciprofloxacin (CPFX), was investigated in rats measuring glutathione redox status. For this purpose, the drug was administered to rats as two different single doses (100 and 150 mg/kg, ip) or a repeated dose (500 mg/kg/d, ig, for 5d). Then, total and oxidized glutathione levels were determined in hepatic and cerebral tissues of the rats by an enzymatic cycling assay, and the glutathione redox status was calculated. The possible protective effects of vitamin E or allopurinol against CPFX-induced alterations on glutathione system have also been examined. Following both routes of administration of CPFX, the total glutathione content of the liver, but not of brain decreased significantly. The oxidized glutathione (GSSG) in the brain increased after single or repeated dose treatments, but only with repeated doses of CPFX in the liver. CPFX induced dose-dependent alterations in the glutathione redox status in both tissues. With single doses the effect was more pronounced in cerebral tissue, and with repeated ig doses it was significant in both tissues. Pretreatment of rats with vitamin E or allopurinol before the administration of CPFX provided marked protection against glutathione redox status alterations in both tissues. Our results, thus, indicate that CPFX treatment introduces an oxidative stress in cerebral and hepatic tissues of rat.  相似文献   

17.
The possible oxidative stress inducing effect of a fluoroquinolone (FQ) antibiotic, ciprofloxacin (CPFX), was investigated in rats measuring glutathione redox status. For this purpose, the drug was administered to rats as two different single doses (100 and 150 mg/kg, ip) or a repeated dose (500 mg/kg/d, ig, for 5d). Then, total and oxidized glutathione levels were determined in hepatic and cerebral tissues of the rats by an enzymatic cycling assay, and the glutathione redox status was calculated. The possible protective effects of vitamin E or allopurinol against CPFX‐induced alterations on glutathione system have also been examined. Following both routes of administration of CPFX, the total glutathione content of the liver, but not of brain decreased significantly. The oxidized glutathione (GSSG) in the brain increased after single or repeated dose treatments, but only with repeated doses of CPFX in the liver. CPFX induced dose‐dependent alterations in the glutathione redox status in both tissues. With single doses the effect was more pronounced in cerebral tissue, and with repeated ig doses it was significant in both tissues. Pretreatment of rats with vitamin E or allopurinol before the administration of CPFX provided marked protection against glutathione redox status alterations in both tissues. Our results, thus, indicate that CPFX treatment introduces an oxidative stress in cerebral and hepatic tissues of rat.  相似文献   

18.
Taurine (TAU) has protective effects on experimental liver fibrosis. The present study investigates whether benefits of TAU are mediated through attenuation of oxidative and nitrosative stresses. Liver fibrosis was induced in male Wistar rats by simultaneous administration of iron (0.5%, w/w) and ethanol (6g/kg/day) for 60 days consecutively. Significant increases in thiobarbituric acid reactive substances (TBARS), lipid hydroperoxides, protein carbonyl content and loss of non-protein, protein and total thiols were observed in the liver of iron plus alcohol-fed rats. Nitrosative stress was marked by increased levels of S-nitrosothiols and decreased nitrite content. Accumulation of nitrated and oxidatively modified proteins in liver was further evidenced by immunohistochemical localization with specific antibodies for 4-hydroxynonenol (4-HNE), 3-nitrotyrosine (3-NT) and dinitrophenol (DNP). Decrease in mitochondrial ion-transport enzymes and disturbances in calcium and iron levels were also observed in these rats. TAU administration (2% (w/v) in drinking water) significantly reduced the levels of lipid hydroperoxides, TBARS, protein carbonyl with concomitant elevation in thiol levels. The presence of 4-HNE, 3-NT and DNP-protein adducts was minimal. TAU also improved mitochondrial enzyme activities and regulated iron and calcium levels. These results show that the restorative effect of taurine in fibrosis involves amelioration of protein and lipid damage by decreasing oxidative and nitrosative stresses.  相似文献   

19.
Rat liver and brain lipid peroxide and glutathione levels were determined after chronic ethanol treatment. Although hepatic lipid peroxidation was significantly stimulated, we have failed to observe any change in brain lipid peroxide and glutathione levels of rats chronically treated with ethanol.  相似文献   

20.
Taurine prevents acrylonitrile-induced oxidative stress in rat brain   总被引:1,自引:0,他引:1  
Acrylonitrile (ACN) is a volatile, toxic liquid used as a monomer in the manufacture of synthetic rubber, styrene plastics, acrylic fiber and adhesives. ACN is a potent neurotoxin and a carcinogen, which produces tumors in rats, particularly gliomas of the brain. A role for free radical-mediated lipid peroxidation in the toxicity of ACN has been suggested. We examined the ability of taurine, an antioxidant amino acid, to attenuate ACN-induced alterations in lipid peroxidation, cellular DNA fragmentation, GSH, vitamin C and vitamin E levels in blood and brain of rats. Rats were administered with ACN at a concentration of 100 ppm in drinking water and sacrificed after 14 and 28 days. The level of lipid peroxidation and the enzymatic and non-enzymatic antioxidants were assayed. The obtained data were compared with those obtained from ACN rats co-treated with taurine for 14 and 28 days. It was observed that taurine treatment counteracted the oxidative stress induced by ACN by reducing the levels of peroxidation, and enhancing the activities of enzymatic and non-enzymatic antioxidants.  相似文献   

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