Lipid peroxidation, hemolysis and antioxidant enzymes of erythrocytes in stroke

Erythrocyte membrane lipid peroxidation and consequent percentage hemolysis and related antioxidant enzymes viz., superoxide dismutase, glutathione peroxidase, glutathione reductase and catalase were determined in 16 cases of hemorrhagic stroke and 30 cases of thrombotic stroke. The results obtained were compared with 50 age and sex matched controls. 12 thrombotic stroke patients who showed symptomatic recovery after medication were considered for follow up. Lipid peroxidation and percentage hemolysis in patients with thrombotic stroke and hemorrhagic stroke was significantly elevated when compared to controls. Glutathione reductase and superoxide dismutase levels were found to be significantly reduced in thrombotic stroke and hemorrhagic stroke respectively, when compared to healthy subjects. There was no significant difference in the other parameters when compared to controls. In post treatment thrombotic stoke, catalase and glutathione reductase levels increased significantly and oxidative hemolysis decreased compared to their pretreatment values. Thus, our results indicate considerable oxidative stress in stroke.     

Oxidative stress and changes in antioxidative defense system in erythrocytes of preeclampsia in women

The present study was designed to investigate whether oxidative stress occurred to erythrocytes in preeclampsia and was related to disease. Indicative markers of oxidative stress and changes in antioxidant defense system were assayed in the erythrocytes of 22 healthy pregnant and 20 women with preeclampsia. Results of our work indicated high concentration of hydrogen peroxide, nitrite, peroxynitrite and lipid peroxides in preeclampsia compared to healthy pregnant women. Concentration of superoxide anion was lower in preeclamptic women. There were no differences in concentrations of vitamin E, reduced glutathione and oxidized glutathione. Activity of glutathione-S-transferase (GST) was higher while activities of superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GR) were lower in preeclamptic women. There were no differences in glutathione peroxidase (GSH-Px) activity between the two investigated groups. These results suggest that preeclampsia was characterized by oxidative stress and alteration of antioxidative defense system by disbalance in oxidative/antioxidative status of erythrocytes.     

In vitro effects of CB1 receptor ligands on lipid peroxidation and antioxidant defense systems in the rat brain

The in vitro effects of arachidonyl-2-chloroethylamide (ACEA; a selective CB(1)-receptor agonist) and N-piperidin-l-yl)-5-(4-chlorophenyl)-1-(2,4-cochlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (SR141716A; a selective CB(1)-receptor antagonist) on lipid peroxidation (spontaneous and Fe (2+)-induced), total glutathione (GSH)-level and activity of antioxidant enzymes (superoxide dismutase, glutathione peroxidase and glutathione reductase) in the rat brain were studied. The effects of these CB(1)-induced), total glutathione (GSH)-level and activity of antioxidant enzymes (superoxide dismutase, glutathione peroxidase and glutathione reductase) in the rat brain were studied. The effects of these CB(1)-ligands in Fenton system (generating *OH radicals) were also examined. The cannabinoids did not change the total GSH-level and were without effects on the activity of antioxidant enzymes in the rat brain. These results proved a lack of in vitro pro-oxidant activity of the CB(1)-receptor ligands, as well as a lack of direct effects on GSH and enzyme molecules. ACEAand SR141716A were without effect on spontaneous lipid peroxidation, but decreased the Fe(2+)-induced brain lipid peroxidation and OH-provoked deoxyribose degradation in Fenton system. It can be suggested that the tested cannabinoids possess a metal-chelating activity, which might contribute to an antioxidant activity. The data, obtained in this study offer a background for investigation of the in vivo effects of these CB(1)-receptor ligands on antioxidant defense systems in the brain of healthy animals and animals, previously subjected to oxidative stress.     

Antioxidant status and lipid peroxidation in colorectal cancer

Colon carcinogenesis is a multistep process where oxygen radicals were found to enhance carcinogenesis at all stages: initiation, promotion, and progression. Since insufficient capacity of protective antioxidant system can result in cancer, the aim of this study was to examine the activity of antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase) and the levels of reduced glutathione, vitamin C, and vitamin E. The lipid peroxidation products were also determined by measuring malondialdehyde and 4-hydroxynonenal levels in colorectal cancer tissue collected from 55 patients. In these cases the activity of superoxide dismutase, glutathione peroxidase, and glutathione reductase was significantly increased while the activity of catalase was significantly decreased in cancer tissue. However, the level of nonenzymatic antioxidant parameters (glutathione, vitamin C, and vitamin E) was significantly decreased in cancer tissue. Further lipid peroxidation was enhanced during cancer development, manifested by a significant increase in malondialdehyde and 4-hydroxynonenal levels. The obtained results indicate significant changes in antioxidant capacity of colorectal cancer tissues, which lead to enhanced action of oxygen radicals, resulting in lipid peroxidation.     

Oxidative stress in rats after 60 days of hypergalactosemia or hyperglycemia

Two of the models used in current diabetes research include the hypergalactosemic rat and the hyperglucosemic, streptozotocin-induced diabetic rat. Few studies, however, have examined the concurrence of these two models regarding the effects of elevated hexoses on biomarkers of oxidative stress. This study compared the activities of superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase and the concentrations of glutathione, glutathione disulfide, and thiobarbituric acid reactants (as a measure of lipid peroxidation) in liver, kidney, and heart of Sprague-Dawley rats after 60 days of either a 50% galactose diet or insulin deficiency caused by streptozotocin injection. Most rats from both models developed bilateral cataracts. Blood glucose and glycosylated hemoglobin A(1c) concentrations were elevated in streptozotocin diabetic rats. Streptozotocin diabetic rats exhibited elevated activities of renal superoxide dismutase, cardiac catalase, and renal and cardiac glutathione peroxidase, as well as elevated hepatic lipid peroxidation. Insulin treatment of streptozotocin-induced diabetic rats normalized altered markers. In galactosemic rats, hepatic lipid peroxidation was increased whereas glutathione reductase activity was diminished. Glutathione levels in liver were decreased in diabetic rats but elevated in the galactosemic rats, whereas hepatic glutathione disulfide concentrations were decreased much more in diabetes than in galactosemia. Insulin treatment reversed/prevented all changes caused by streptozotocin-induced diabetes. Lack of concomitance in these data indicate that the 60-day galactose-fed rat is not experiencing the same oxidative stress as the streptozotocin diabetic rat, and that investigators must be cautious drawing conclusions regarding the concurrence of the effects of the two animal models on oxidative stress biomarkers.     

Brain Lipid Peroxidation and Antioxidant Status After Acute Methacrylonitrile Intoxication

The status of brain antioxidant enzymes and glutathione in methacrylonitrile (MeAN)-intoxicated Wistar rats was correlated with the levels of lipid peroxidation products. Optimum changes were observed 30 min and 60 min after oral administration of MeAN at dosages of 50 mg/kg body weight per day (0.25 LD₅₀) and 100 mg/kg body weight per day (0.5 LD₅₀). An increase in lipid peroxidation products, decrease in the activity of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR), glutathione S-transferase (GST), and decrease in reduced glutathione (GSH) were observed. These studies suggest that the membrane lipid peroxidation observed in MeAN intoxication is related, in part, to a compromised antioxidant defense system.     

Effect of quamatel on neutrophil properties, parameters of lipid peroxidation and the antioxidant defense system in blood of patients with duodenal ulcer and pancreatitis

The properties of neutrophils, the parameters of lipid peroxidation, and the characteristics of antioxidant protection (superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase activity) were studied in the blood of patients with duodenal ulcer and pancreatitis in the course of quamatel administration. The pattern of changes induced by quamatel shows evidence of the antioxidant activity of the drug.     

Modulation of fenthion-induced oxidative effects by BSO in the liver of Cyprinus carpio L

The objective of the present study was to evaluate the oxidative stress potential of low-level organophosphate fenthion exposure with the modulatory effect of buthionine sulfoximine in the liver of Cyprinus carpio L. The fish were exposed to 20% of 96-hour LC(50) of fenthion for 24 and 96 hours. Total and oxidized glutathione, thiobarbituric acid reactive substances, protein levels, glutathione peroxidase, glutathione reductase, glutathione-S-transferase, superoxide dismutase, and catalase-specific enzyme activities were measured spectrophotometrically. There was a 15-day depuration period to evaluate the changes in the studied parameters. Fenthion caused a time-dependent depletion of the total and reduced glutathione levels. The oxidized/reduced glutathione ratio and catalase specific enzyme activity were reduced while the glutathione-S-transferase activity was elevated. Intraperitonal buthionine sulfoximine application disclosed the inhibitory effect of fenthion on superoxide dismutase and glutathione peroxidase activities, whereas glutathione-S-transferase activity was increased. There was no change in lipid peroxidation levels during the experiments. No amelioration was observed in the affected parameters except the glutathione-S-transferase activity in the 15-day depuration period. In conclusion, glutathione-S-transferase and catalase enzyme activities and total and reduced glutathione levels were better estimators to monitor the effects of fenthion in low concentration in the liver of C. carpio. The depuration period was not adequate to recover the antioxidant capacity.     

Nicotine induced pro-oxidant and antioxidant imbalance in rat lymphocytes: in vivo dose and time dependent approaches

The immune cells use reactive oxygen species (ROS) for carrying out their normal functions while an excess amount of ROS can attack cellular components that lead to cell damage. The present study was undertaken to determine the dose as well as time dependent effects of nicotine administration on the superoxide anion generation, lipid peroxidation and antioxidant defense systems in lymphocytes. Male Wistar rats were treated with vehicle (normal saline) and nicotine [3-(1-methyl-2-pyrrolidinyl) pyridine, C₁₀H₁₄N₂] (in physiological saline, pH was adjusted at 7.4 prior to injection) as indicated in a dose and duration fashion and the superoxide anion generation, lipid peroxidation, and antioxidant enzymes status were monitored. Superoxide anion generation, lipid peroxidation and oxidized glutathione levels were increased significantly (P < 0.05), and reduced glutathione level, activity of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione-s-transferase were decreased significantly (P < 0.05) with the increasing dose and duration of nicotine treatment. The highest changes in lymphocytes were observed at the dose of 1.0?mg/kg/day for 7 days. It may be concluded that nicotine is able to enhance the production of ROS that produced oxidative stress in lymphocytes in a dose and time dependent manner.     

In vivo effects of amtolmetin guacyl on lipid peroxidation and antioxidant defence systems. Comparison with non-selective and COX-2 selective NSAIDs

1. The in vivo effects of the non-steroid anti-inflammatory drug (NSAID) amtolmetin guacyl, a pro-drug of the NSAID tolmetin, on lipid peroxidation, glutathione levels and activity of antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase) in rat gastric mucosa, colon mucosa and liver, were compared with the effects of non-selective (indomethacin, diclofenac) and COX-2 selective (celecoxib) NSAIDs. 2. Indomethacin treatment led to an increase in lipid peroxidation, glutathione peroxidase and glucose-6-phosphate dehydrogenase activities and to a decrease in catalase activity and glutathione levels in gastric mucosa. In contrast, amtolmetin guacyl treatment was without effects in gastric and colon mucosa, or liver from control animals. Like amtolmetin guacyl, celecoxib had no effect on the lipid peroxidation, or on enzyme and non-enzyme antioxidant defence systems in gastric mucosa. 3. It is suggested that the lack of pro-oxidant effects in vivo associated with amtolmetin guacyl treatment contribute improved gastric tolerability.     

Protection of arsenic-induced hepatic disorder by arjunolic acid

Arsenic is one of the ubiquitous environmental pollutants, which affects nearly all organ systems. The present study has been carried out to investigate the hepatoprotective role of arjunolic acid, a triterpenoid saponin, against arsenic-induced oxidative damages in murine livers. Administration of sodium arsenite at a dose of 10 mg/kg body weight for 2 days significantly reduced the activities of antioxidant enzymes, superoxide dismutase, catalase, glutathione S-transferase, glutathione reductase and glutathione peroxidase as well as depleted the level of reduced glutathione and total thiols. In addition, sodium arsenite also increased the activities of serum marker enzymes, alanine transaminase and alkaline phosphatase, enhanced DNA fragmentation, protein carbonyl content, lipid peroxidation end-products and the level of oxidized glutathione. Studies with arjunolic acid show that in vitro it possesses free radical-scavenging and in vivo antioxidant activities. Treatment with arjunolic acid at a dose of 20 mg/kg body weight for 4 days prior to arsenic administration prevents the alterations of the activities of all antioxidant indices and levels of the other parameters studied. Histological studies revealed less centrilobular necrosis in the liver treated with arjunolic acid prior to arsenic intoxication compared to the liver treated with the toxin alone. Effects of a known antioxidant, vitamin C, have been included in the study as a positive control. In conclusion, the results suggest that arjunolic acid possesses the ability to attenuate arsenic-induced oxidative stress in murine liver probably via its antioxidant activity.     

The potential effect of berberine in mercury-induced hepatorenal toxicity in albino rats

Mercury (Hg) is the third most dangerous heavy metal after arsenic and lead. Mercury’s toxicity brings serious risks to health through negative pathological and biochemical effects. The study was designed to investigate the possible protective role of berberine (BN) in mercuric chloride (HgCl₂) induced oxidative stress in hepatic and renal tissues. Adult male albino Wistar rats were exposed to mercuric chloride (HgCl₂; 0.4 mg/kg bwt) for 7 days. Treatment with HgCl₂ induced oxidative stress by increasing lipid peroxidation and nitric oxide production along with a concomitant decrease in glutathione and various antioxidant enzymes, namely superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase. HgCl₂ intoxication increased the activities of liver enzymes and the bilirubin level, in addition to the levels of urea and creatinine in serum. BN (100 mg/kg bwt) treatment inhibited lipid peroxidation and nitric oxide production, whereas it increased glutathione content. Activities of antioxidants enzymes, superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase, were also restored concomitantly when compared to control after BN administration. BN also inhibited the apoptotic effect of HgCl₂ by increasing the expression of Bcl-2 protein in liver and kidney. Histopathological examination of the liver and kidney tissues proved the protective effect of BN against HgCl₂ toxicity. These results demonstrated that BN augments antioxidant defense against HgCl₂-induced toxicity and provides evidence that it has therapeutic potential as hepato- and reno-protective agent.     

Protective Effects of Zinc on Oxidative Stress Enzymes in Liver of Protein-Deficient Rats

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.     

Effects of amifostine on liver oxidative stress caused by cyclophosphamide administration to rats

Cyclophosphamide is an inactive cytostatic, which is metabolised into active metabolites mainly in the liver. During bioactivation, reactive oxygen species (ROS) are also formed, which can modify the components of both healthy and neoplastic cells leading to decreased antioxidative capacity. Amifostine is a drug that can inactivate ROS. The aim of the present study was to evaluate the influence of amifostine on the antioxidative system of the liver of rats exposed to cyclophosphamide. Intraperitoneal administration of cyclophosphamide was found to decrease the activity of liver antioxidative enzymes, i.e. superoxide dismutase, glutathione peroxidase and glutathione reductase, and to increase catalase activity. Amifostine slightly influenced antioxidative enzyme activity, causing a significant increase only in superoxide dismutase activity. Co-administration of cyclophosphamide and amifostine nearly prevented changes in activities of superoxide dismutase, glutathione reductase and catalase, as well as to a high degree of glutathione peroxidase. Cyclophosphamide also evoked a decrease in the level of non-enzymatic antioxidants, such as reduced glutathione and vitamins C, E and A, as well as total antioxidant status. Administration of amifostine alone caused a significant increase in non-enzymatic antioxidant level that resulted in an increase in total antioxidant status. Administration of amifostine together with cyclophosphamide to a large extent prevented changes in the evaluated non-enzymatic antioxidative parameters, decreasing values of their concentration to the values of control group. Changes of liver antioxidative abilities during detoxification of cyclophosphamide were accompanied by intensified lipid peroxidation, manifested by an increase in concentration of products such as malondialdehyde and 4-hydroxynonenal. Amifostine caused the inhibition of lipid peroxidation in the liver of both control and cyclophosphamide-treated rats. In conclusion, our results suggest that amifostine significantly protects liver antioxidant properties from changes caused by cyclophosphamide treatment and in consequence prevents oxidative stress and phospholipid peroxidative damage.     

Dose-dependent study of the effects of acute lindane administration on rat liver superoxide anion production, antioxidant enzyme activities and lipid peroxidation

The administration of single i.p. doses of lindane (20, 40, 60 and 80 mg/kg) to rats produced a progressive increase in the liver microsomal content of cytochrome P-450 and in the rate of superoxide anion generation, as measured by adrenochrome formation. A dose-dependent increase in lipid peroxidation of liver homogenates, assessed by measuring thiobarbituric acid reactants, was also found. Lindane treatment did not alter the activity of liver glucose-6-phosphate dehydrogenase, glutathione reductase or glutathione peroxidase, while that of superoxide dismutase and catalase was significantly reduced. These changes were accompanied by a progressive liver steatosis. The collected metabolic data were interpreted in terms of a causal relationship between an increase in superoxide radical generation, secondary to cytochrome P-450 induction and a resulting increase in lipid peroxidation. The decrease in superoxide dismutase and catalase activities is likely to contribute to the increased levels of lipid peroxidation in view of their antioxidant properties.     

Protective effects of zinc on oxidative stress enzymes in liver of protein-deficient rats

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.     

Modulation of Fenthion-Induced Oxidative Effects by BSO in the Liver of Cyprinus carpio L

The objective of the present study was to evaluate the oxidative stress potential of low-level organophosphate fenthion exposure with the modulatory effect of buthionine sulfoximine in the liver of Cyprinus carpio L. The fish were exposed to 20% of 96-hour LC₅₀ of fenthion for 24 and 96 hours. Total and oxidized glutathione, thiobarbituric acid reactive substances, protein levels, glutathione peroxidase, glutathione reductase, glutathione-S-transferase, superoxide dismutase, and catalase-specific enzyme activities were measured spectrophotometrically. There was a 15-day depuration period to evaluate the changes in the studied parameters. Fenthion caused a time-dependent depletion of the total and reduced glutathione levels. The oxidized/reduced glutathione ratio and catalase specific enzyme activity were reduced while the glutathione-S-transferase activity was elevated. Intraperitonal buthionine sulfoximine application disclosed the inhibitory effect of fenthion on superoxide dismutase and glutathione peroxidase activities, whereas glutathione-S-transferase activity was increased. There was no change in lipid peroxidation levels during the experiments. No amelioration was observed in the affected parameters except the glutathione-S-transferase activity in the 15-day depuration period. In conclusion, glutathione-S-transferase and catalase enzyme activities and total and reduced glutathione levels were better estimators to monitor the effects of fenthion in low concentration in the liver of C. carpio. The depuration period was not adequate to recover the antioxidant capacity.     

Effect of cisplatin and cobalt chloride on antioxidant enzymes in the livers of Lewis lung carcinoma-bearing mice: protective role of heme oxygenase

Changes in the activities of antioxidant enzymes superoxide dismutase, catalase (CAT), glutathione peroxidase and heme oxygenase (HO) and changes in lipid peroxidation and reduced glutathione (GSH) levels were measured in the livers of control and Lewis lung carcinoma (LLC)-bearing mice 24 h after a single injection of cisplatin or CoCl(2). Treatment with cisplatin induced the same degree of lipid peroxidation and GSH depletion as did CoCl(2) but the antioxidant enzymes were differently involved in cisplatin- and cobalt-induced oxidative stress responses. In cobalt-treated mice the activities of these enzymes were either inhibited or not changed significantly and only the HO activity was increased (5-fold) as a main protective enzyme. In cisplatin-treated animals the antioxidant enzymes were activated but the enhancement of HO and CAT was greater in LLC-inoculated mice. It is suggested that these two enzymes represent the protective response against cisplatin toxicity in the livers of tumor-bearing animals.     

Effect of pentacyclic triterpenes on oxalate-induced changes in rat erythrocytes.

Investigations were carried out to evaluate the effect of two, structurally related, triterpenes-betulin and lupeol-on the membrane peroxidation and antioxidant systems in red blood cells, during pyridoxine-deficient condition in rats. Increased lipid peroxidation levels in the absence and presence of ferrous sulphate, an inducer of lipid peroxidation, indicated peroxidative damage to the red-cell membrane. Na(+), K(+)-ATPase activity was decreased while that of other ion-specific ATPases were increased in the red cells of pyridoxine-deficient rats. Antioxidants, such as reduced glutathione, glutathione peroxidase, catalase, glutathione reductase and glutathione S-transferase were decreased, while superoxide dismutase alone was increased in the pyridoxine-deficient rat red blood cells. The red-cell osmotic fragility was found to be reduced. Treatment with the triterpenes proved effective in restoring the normal condition.     

Oxidative damage of biomolecules in mouse liver induced by morphine and protected by antioxidants

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.