Erythrocyte antioxidant activity, serum ceruloplasmin, and trace element levels in subjects with alcoholic liver disease.

Erythrocyte antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase) and reduced glutathione, serum ceruloplasmin, and serum trace elements (copper, zinc, iron, and selenium) related to antioxidant enzymes were assayed in subjects with alcoholic liver disease of different degrees of severity. The erythrocytes of subjects with moderate and severe alcoholic liver cirrhosis had an unbalanced antioxidant system (normal superoxide dismutase, low catalase and glutathione peroxidase activities, and low glutathione content). Serum ceruloplasmin levels were in the normal range. Levels of the serum trace elements zinc and selenium were significantly low in subjects with moderate and severe cirrhosis, whose red cell half-life was also significantly short, as measured by radioactive chromium. These data suggest that the erythrocytes of subjects with moderate and severe alcoholic liver cirrhosis are less protected against oxidant stress. The particular erythrocyte antioxidant system and serum trace element pattern may play a role in the genesis of hemolytic disorders and of alcoholic hepatic damage.     

Effect of age on the expression of antioxidant enzymes in male Fischer F344 rats

Age-related changes in the activities of superoxide dismutase, catalase, and glutathione peroxidase were determined in brain, heart, hepatocytes, intestinal mucosa, and kidney from male Fischer F344 rats. Superoxide dismutase activity decreased significantly with age in all five tissues studied. The activity of catalase decreased with age in brain, hepatocytes, and kidney while glutathione peroxidase activity decreased significantly with age only in intestinal mucosa and kidney. The relative levels of superoxide dismutase, catalase, and glutathione peroxidase mRNA were measured in brain, hepatocytes, and kidney. An age-related decrease in SOD and catalase mRNA was observed for brain, hepatocytes, and kidney. GPX mRNA levels decreased with age in hepatocytes and kidney but did not change with age in brain. In general, the age-related changes in the activities of SOD, catalase, and GPX were paralleled by a similar change in the relative level of the mRNAs coding for these enzymes.     

Alternations in free radical erythrocyte-defense mechanisms in streptozotocin induced diabetic rats - effect of antioxidant treatment.

The activities of superoxide dismutase, glutathione peroxidase and the contents of glutathione, malondialdehyde were examined in erythrocytes of streptozotocin induced diabetic rats. The above mentioned antioxidant systems of erythrocyte were determined after treatment of diabetic rats with superoxide dismutase, trolox, catalase and allopurinol. In erythrocytes of streptozotocin induced diabetic rats the activities of superoxide dismutase, glutathione peroxidase as well as the levels of reduced glutathione were lower whereas the contents of oxidized glutathione and malondialdehyde were higher than in controls. Superoxide dismutase and trolox treatment of diabetic rats resulted in an increase of erythrocyte glutathione peroxidase activities and in reduced glutathione levels. However the levels of oxidized glutathione decreased after treatment of diabetic rats with superoxide dismutase and trolox. Catalase and allopurinol administration did not have any influence on the activities of the investigated enzymes nor on the levels of glutathione in diabetic rats. The antioxidants under study did not cause any changes in the increased level of malondialdehyde in erythrocytes.     

Age-related changes in Cu,Zn superoxide dismutase, Se-dependent and -independent glutathione peroxidase and catalase activities in specific areas of rat brain.

Oxidative injury of tissues involves both accumulation of damage due to persistent oxidative stress and loss of the proper balance of antioxidative enzymes. These events may produce a faster rate of tissue senescence. In this regard, we have assayed the antioxidative enzyme activities (Cu,Zn superoxide dismutase, glutathione peroxidase and catalase), in various areas of rat brain (prefrontal cortex, parietal cortex, hippocampus, hypothalamus, caudate nucleus, mesencephalon and lower brain stem) for the age groups of 3, 6, 12, 24 months. The results obtained show that the levels of antioxidant enzyme activities differed considerably in the various brain parts studied. Furthermore, changes in the specific activities of superoxide dismutase, catalase, and glutathione peroxidase did not follow the same pattern as a function of aging. In particular, in prefrontal cortex and caudate nucleus, superoxide dismutase and glutathione peroxidase activities did not change, while catalase activity decreased. In parietal cortex and mesencephalon, superoxide dismutase and glutathione peroxidase activities increased, but the catalase activity decreased in parietal cortex and did not change in mesencephalon. In lower brain stem, the activities of glutathione peroxidase and catalase decreased in 3-12-month-old rats. The activity of glutathione peroxidase was increased in the hippocampus and was decreased in hypothalamus during aging. In this area the catalase activity was also significantly diminished.     

Preliminary study on the protective effect of vitamin C on monosodium glutamate-induced hepatotoxicity in rats

Monosodium glutamate (MSG) is a food additive with a wide range of biological effects but its high dose and prolonged use can cause a toxic effect on the liver. Therefore, the present study was aimed at investigating the role of vitamin C in MSG-induced hepatotoxicity in rats. MSG was administered to rats (by gavage) at a dose of 6 mg/g body weight for 10 days to induce hepatotoxicity, and vitamin C at a dose of 500 mg/kg body weight was coadministered to evaluate its ameliorating effect by measuring alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities in serum; superoxide dismutase (SOD) and catalase activities in liver fraction; lipid peroxidation; and liver weight. It was found that MSG significantly (P?<?0.05) induced lipid peroxidation (LPO), increased liver weight, and increased activity of SOD and catalase in the liver of animals. The activity of ALT and AST was also increased in the serum on MSG administration. Vitamin C (500 mg/kg) coadministered with MSG significantly reduced LPO and liver weight and decreased the hepatic activity of catalase, but the activity of SOD was not reduced significantly. Also, a significant reduction in ALT and AST activity was observed. MSG induced oxidative stress and hepatic toxicity in the experimental animals at a dose of 6 mg/g body weight. Vitamin C significantly reduced the oxidative stress and hepatic toxicity induced by MSG, thereby providing a protective effect against the MSG-induced hepatotoxicity. The protective effect is associated with decreased LPO and liver weight and decreased activities of catalase, ALT, and AST.     

Heme oxygenase activity and some indices of antioxidant protection in rat liver and kidney in glycerol model of rhabdomyolysis

Activity of heme oxygenase, superoxide dismutase, and catalase, the content of reduced glutathione and total heme in the liver and kidneys, and serum absorption spectrum in the Soret band were studied in rats with glycerol-induced rhabdomyolysis. Glycerol increased the content of heme-containing metabolites in the serum and the total heme content in the liver and kidneys, and decreased the content of reduced glutathione and catalase activity in the examined organs. Superoxide dismutase activity increased in the liver and decreased in the kidneys. Heme oxygenase activity increased in the liver and kidneys 2 and 6 h postinjection, respectively. The effects of heme delivered to the liver and kidneys from the vascular bed on the antioxidant defense and heme oxygenase activity were studied.     

Investigation of oxidative stress involvement in hippocampus in epilepsy model induced by pilocarpine

The relationship between free radical and scavenger enzymes has been found in the epileptic phenomena and reactive oxygen species have been implicated in seizure-induced neurodegeneration. Using the epilepsy model obtained by systemic administration of pilocarpine in rats, we investigated the lipid peroxidation, nitrite content, superoxide dismutase (SOD) and catalase activities in the hippocampus of rats during chronic period. The enzyme activities as well as the lipid peroxidation and nitrite concentrations were measured using spectrophotometric methods and the results compared to values obtained from saline-treated animals. The superoxide dismutase and catalase activities increased during the chronic phase. In addition, lipid peroxidation and nitrite levels increased in same period in the hippocampus of animals observed during spontaneous recurrent seizures. Previous studies showed that animals presenting seizures and submitted to 24 h of status epilepticus showed normal levels of superoxide dismutase and increased in catalase activities as well as an increase in hippocampal lipid peroxidation and nitrite concentrations. These results show a direct evidence of lipid peroxidation and nitrite during seizure activity that could be responsible for neuronal damage in the hippocampus of rats, during the establishment of pilocarpine model of epilepsy.     

Evaluation of the Antioxidant Effects of Ziziphus Mauritiana Lam. Leaf Extracts Against Chronic Ethanol-Induced Hepatotoxicity in Rat Liver

Chronic alcohol ingestion is known to increase the generation of reactive oxygen species (ROS), thereby leading to liver damage. Antioxidant enzymes act individually or in combination to reduce or counter the effect of these ROS. Chronic administration of alcohol at (40% v/v, 1ml/100g), for 6 weeks showed a significant (p<0.05) elevated levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and total bilirubin (TB). There was also a significant (p<0.05) decreased levels of catalase, glutathione peroxidase, glutathione reductase and superoxide dismutase compared to control rats. Pre-treatment of rats with 200, 400 mg/kg body weight of aqueous leaf extract of Ziziphus mauritiana or 100 mg/kg silymarin resulted in a significant (p<0.05) decreased levels of ALT, AST, ALP, and TB with levels of catalase, glutathione peroxidase, glutathione reductase and superoxide dismutase showing a significant (p<0.05) increase compared to group administered alcohol only. Histopathology of rat liver administered with alcohol only resulted in severe necrosis, mononuclear cell aggregation and fatty degeneration in the central and mid zonal areas which was a characteristic of a damaged liver. Pre-treatment with the aqueous extract of Ziziphus mauritiana or silymarin reduced the morphological changes that are associated with chronic alcohol administration. The presence of tannins, saponins and phenolic compounds observed in the plant extract could be responsible for the observed effects of decreasing the levels of injured tissue marker and lipid peroxidation.     

Antioxidant enzyme activity and malondialdehyde levels can be modulated by Piper betle,tocotrienol rich fraction and Chlorella vulgaris in aging C57BL/6 mice

OBJECTIVE:

The aim of this study was to determine the erythrocyte antioxidant enzyme activity and the superoxide dismutase, catalase, glutathione peroxidase, and plasma malondialdehyde levels in aging mice and to evaluate how these measures are modulated by potential antioxidants, including the tocotrienol-rich fraction, Piper betle, and Chlorella vulgaris.

METHOD:

One hundred and twenty male C57BL/6 inbred mice were divided into three age groups: young (6 months old), middle-aged (12 months old), and old (18 months old). Each age group consisted of two control groups (distilled water and olive oil) and three treatment groups: Piper betle (50 mg/kg body weight), tocotrienol-rich fraction (30 mg/kg), and Chlorella vulgaris (50 mg/kg). The duration of treatment for all three age groups was two months. Blood was withdrawn from the orbital sinus to determine the antioxidant enzyme activity and the malondialdehyde level.

RESULTS:

Piper betle increased the activities of catalase, glutathione peroxidase, and superoxide dismutase in the young, middle, and old age groups, respectively, when compared to control. The tocotrienol-rich fraction decreased the superoxide dismutase activity in the middle and the old age groups but had no effect on catalase or glutathione peroxidase activity for all age groups. Chlorella vulgaris had no effect on superoxide dismutase activity for all age groups but increased glutathione peroxidase and decreased catalase activity in the middle and the young age groups, respectively. Chlorella vulgaris reduced lipid peroxidation (malondialdehyde levels) in all age groups, but no significant changes were observed with the tocotrienol-rich fraction and the Piper betle treatments.

CONCLUSION:

We found equivocal age-related changes in erythrocyte antioxidant enzyme activity when mice were treated with Piper betle, the tocotrienol-rich fraction, and Chlorella vulgaris. However, Piper betle treatment showed increased antioxidant enzymes activity during aging.     

The effect of betaine treatment on triglyceride levels and oxidative stress in the liver of ethanol-treated guinea pigs

We investigated the effect of betaine supplementation on ethanol induced steatosis and alterations in prooxidant and antioxidant status in the liver of guinea pigs. Animals were fed with normal chow or betaine containing chow (2% w/w) for 30 days. Ethanol (3 g/kg, i.p.) was given for the last 10 days. We found that ethanol treatment caused significant increases in plasma transaminase activities, hepatic triglyceride and lipid peroxide levels. Significant decreases in glutathione (GSH), -tocopherol and total ascorbic acid (AA) levels were also observed, but hepatic superoxide dismutase, glutathione peroxidase and glutathione transferase activities remained unchanged as compared with those in controls. Betaine treatment together with ethanol in guinea pigs is found to decrease hepatic triglyceride, lipid peroxide levels and serum transaminase activities and to increase GSH levels. No changes in a-tocopherol and total AA levels and antioxidant enzyme activities were observed with betaine treatment in alcohol treated guinea pigs. In addition, histopathological assessment of guinea pigs showed that betaine reduced the alcoholic fat accumulation in the liver. Based on these data, betaine treatment has a restoring effect on the alterations in triglyceride, lipid peroxide and GSH levels following ethanol ingestion.     

Mechanism of liver injury following ischemia.

To clarify whether ischemic liver injury is due to ischemia itself or reperfusion, histopathological and functional changes in the liver were examined before and after liver ischemia in rats with porto-systemic collateral channels. Effects of oxygen-derived free radical scavengers or an inhibitor of platelet aggregation on development of ischemic liver injury were also examined. Liver ischemia was produced by ligation of the portal vein and hepatic artery at liver hilum for 1 hr. The primary lesion of ischemic liver injury was cloudy swelling of liver cells in the periportal and midzonal regions; it developed during ischemia. The cloudy swelling of liver cells induced uneven distribution of sinusoidal blood flow after reperfusion, and consequently individual liver cell necrosis and focal hepatocellular necrosis in the midzonal regions developed later. Elevation of cytoplasmic enzyme activities in the serum after reperfusion was due to leakage across the damaged plasma membrane of liver cells. The treatment with superoxide dismutase, catalase, or heparin had not altered the liver injury that was attributed to ischemia, biochemically and histologically. These results suggest that ischemic liver injury is due to liver cell damage developed during ischemia, and that the ischemic liver injury is not alleviated or prevented by superoxide dismutase, catalase, or heparin.     

Changes in oxygen-metabolizing enzymes and lipid peroxidation in human erythrocytes as a function of age of donor

We have studied the activities of enzymes, which afford protection against superoxide radical anion and hydrogen peroxide and estimated the content of malondialdehyde. Superoxide dismutase activity decreased slightly with advanced age of donors. The activities of catalase and peroxidases were higher in the erythrocytes of the middle age group and the old age group than in the young individuals. Thiobarbituric acid-reactive product was also significantly elevated in the aged donors. These results support the hypothesis that observed differences in the activities of enzymes and the level of malondialdehyde may contribute to the changes associated with aging, produced by the free radical reactions.     

Expression of superoxide dismutase and catalase in rat brain as a function of age

Active oxygen species have been proposed to be involved in the aging process of the brain, therefore alterations of the levels of enzymes involved in the defence system against free radicals and other active species could substantially influence the aging process. In this study the enzyme activities of superoxide dismutase (Cu/Zn) and catalase as well as the relative levels of their mRNA were measured in the brain of Fischer F344 rats of various ages (5-37 months old). A gradual decrease in the activity of these enzymes (21-27%) was observed with increasing age. The alterations were paralleled by a decrease (39-40%) in the relative levels of these mRNA species. Thus the decrease in the activity of superoxide dismutase and catalase appears to be due to an age-dependent change in the expression of these genes.     

Effect of N-[Imino(4-morpholyl)methyl]guanidine on the Oxidative Status in Rats with Toxic Hepatitis

The hepatoprotective and antioxidant properties of a synthetic biguanide N-[imino(4-morpholyl) methyl]guanidine (IMMG) were prognosticated by the method of computer prediction. Administration of IMMG was accompanied by a decrease in serum transaminase activity in rats with toxic hepatitis, which reflects inhibition of hepatocyte cytolysis. IMMG treatment was followed by a decrease in biochemiluminescence parameters reflecting the intensity of free radical oxidation. We revealed an increase in activity of aconitase, which was reduced during toxic hepatitis. The content of citrate in the liver and serum was returned to normal under these conditions. IMMG also increased activities of superoxide dismutase and catalase and total antioxidant activity in rat liver. Our results suggest that the hepatoprotective effect of IMMG is associated with its antioxidant activity.     

Ageing alters aortic antioxidant enzyme activities in Fischer-344 rats.

Oxidative stress imposed by reactive oxygen species is now believed to contribute to hypertension, atherosclerosis and ageing of the vasculature all involving a loss of relaxation. The antioxidant enzymes glutathione peroxidase, superoxide dismutase and catalase play a crucial role in defending against the ravages of oxidative stress. Our purpose was to characterize age-related changes in glutathione peroxidase, superoxide dismutase and catalase in the rat aorta. Aortas were extracted from seven young (4 months), seven middle aged (18 months) and seven old (24 months) animals. Analysis of variance was used with Fisher-LSD post hoc to determine mean differences among glutathione peroxidase, superoxide dismutase and catalase. Aortic glutathione peroxidase activities rose steadily with age expressed in micromol mg protein-1 min-1 +/- SEM (young: 141 +/- 22; middle aged: 198 +/- 18; old: 229 +/- 26) reaching significance between young and old. Superoxide dismutase activities significantly decreased in middle aged when compared with young (young: 22 +/- 2 vs. middle aged: 15 +/- 2 U mg protein-1) before trending upward again in old age (19 +/- 2). Catalase activities dropped significantly between young and old when expressed in mU mg protein-1 (young: 230 +/- 30; middle aged: 173 +/- 18; old: 144 +/- 23). Ratios for the various enzymes indicate a shrinking contribution of catalase with ageing, with an enhanced role for glutathione peroxidase in the antioxidant defence. These data in aortas of ageing rats show a complex alteration of the antioxidant profile.     

Immunogold analysis of antioxidant enzymes in human renal cell carcinoma

Analysis of activities of the antioxidant enzyme manganese superoxide dismutase in human renal cell carcinomas often showed greatly altered enzyme levels (either elevated or depressed) compared to the cell of origin, the kidney proximal tubule. In order to better understand the variability observed, immunogold studies were performed on human renal cell carcinomas using a polyclonal antibody to human kidney manganese superoxide dismutase. For comparison, studies were also performed using antibodies to other antioxidant enzymes. For histologic studies, renal cell carcinomas were subclassified on the basis of light microscopy and ultrastructural analysis into clear cell, granular cell, or mixed clear and granular cell variants. In all three types of tumor, immunogold studies showed little staining using antibodies to copper, zinc superoxide dismutase or glutathione-dependent enzymes. However, intensity of labeling for manganese superoxide dismutase and catalase depended on the cell type(s) in the tumor. Clear cell variants demonstrated trace staining for manganese superoxide dismutase and catalase, while granular cell variants exhibited heavy staining for both of these enzymes. Mixed types of tumors showed clear cells with trace staining for all antioxidant enzymes examined, while granular cells again showed intense labeling for manganese superoxide dismutase and catalse. Using normal kidney proximal tubule as a comparison, immunogold ultrastructural analysis using antibody to manganese superoxide dismutase demonstrated infrequent small lightly labeled mitochondria in clear cell variants, while granular cell variants exhibited numerous medium-sized heavily labeled mitochondria. These data suggest that: 1) the variability in activity values for manganese superoxide dismutase may be due to heterogeneity of cell types in these tumors and 2) manganese superoxide dismutase immunoreactive protein was elevated in granular cells both because of an increase in number of mitochondria and because the labeling density in mitochondria was increased compared to mitochondria in clear cell types or in normal proximal tubular cells.     

Activity of antioxidant enzymes and lipid peroxidation in intact and mutagen-treated NZW mice

Catalase and superoxide dismutase activities in the liver of NZW mice are 29.3 μmol H₂O₂/min×mg protein and 10.6 U/mg protein, respectively. The rate of accumulation of lipid peroxidation (LPO) products is low within the first 60 min of incubation of liver homogenates with ascorbate and then rapidly increases. A similar process is observed with Fe+ascorbate system, where LPO rate is markedly higher and lag-period lasts 10 min. Under the action of cyclophosphane the activity of catalase increases by 32%, while that of superoxide dismutase decreases by 46%, which is accompanied by a decline in the sensitivity of liver tissue to LPO induction. When LPO is inducedin vitro by ascorbate, lag-period decreases 2-fold, while the rate of accumulation of LPO products increases by 38% and their maximum level by 35% compared with the control. Similar processes develop in the Fe+ascorbate system. Dioxydine induces no significant changes in the activities of catalase and superoxide dismutase as well as in LPO product accumulation in the ascorbate and Fe+ascorbate systems. Translated fromByulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 123, No. 4, pp. 381–384, April, 1997     

Protective effect of curcumin on cypermethrin-induced oxidative stress in Wistar rats

The aim of present study was to investigate the protective effect of curcumin on cypermethrin-induced changes in blood biochemical markers and tissue antioxidant enzyme in rats. Rats were divided into six groups of six each: group I used as control and II and III groups were used as vehicle control. While, groups IV, V and VI were orally treated with curcumin (100 mg/kg body weight), cypermethrin (25 mg/kg body weight) and cypermethrin plus curcumin, respectively for 28 days. Serum biochemical markers were measured in the serum, and the levels of lipid peroxidation and antioxidant enzyme activity were determined in the liver, kidney and brain. Cypermethrin administration caused elevated level of blood biochemical markers in serum and lipid peroxidation in liver, kidney and brain. While the activities of non-enzymatic and enzymatic antioxidants levels were decreased except superoxide dismutase in liver, kidney and brain tissues. The presence of curcumin with cypermethrin significantly decreased the blood biochemical markers and lipid peroxidation but significantly increased the reduced glutathione, catalase and glutathione peroxidase level and preserved the normal histological architecture of the liver, kidney and brain. Our results indicate that curcumin can be potent protective agent against cypermethrin-induced biochemical alterations and oxidative damage in rats.     

Cadmium-induced hepatotoxicity in rats and the protective effect of naringenin

This experiment pertains to the protective role of naringenin against cadmium (Cd)-induced oxidative stress in the liver of rats. Cadmium is a major environmental pollutant and is known for its wide toxic manifestations. Naringenin is a naturally occurring citrus flavonone which has been reported to have a wide range of pharmacological properties. In the present investigation cadmium (5 mg/kg) was administered orally for 4 weeks to induce hepatotoxicity. Liver damage induced by cadmium was clearly shown by the increased activities of serum hepatic marker enzymes namely aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), gamma glutamyl transferase (GGT) and serum total bilirubin (TB) along with the increased level of lipid peroxidation indices (thiobarbituric acid reactive substances (TBARS) and lipid hydroperoxides) and protein carbonyl contents in liver. The toxic effect of cadmium was also indicated by significantly decreased levels of enzymatic antioxidants (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione S-transferase (GST)) and non-enzymatic antioxidants (reduced glutathione (GSH), vitamin C and vitamin E). Administration of naringenin at a dose of (50 mg/kg) significantly reversed the activities of serum hepatic marker enzymes to their near-normal levels when compared to Cd-treated rats. In addition, naringenin significantly reduced lipid peroxidation and restored the levels of antioxidant defense in the liver. The histopathological studies in the liver of rats also showed that naringenin (50 mg/kg) markedly reduced the toxicity of cadmium and preserved the normal histological architecture of the tissue. The present study suggested that naringenin may be beneficial in ameliorating the cadmium-induced oxidative damage in the liver of rats.     

Antioxidant parameters and ageing in some animal species

Connection between ageing and some tissue antioxidant parameters have been studied in four experiments on different animal species. Prenatal studies on the developing chick embryos showed discrepancies between the lipid-rich liver and brain antioxidant defence. In the liver, high levels of reduced glutathione (GSH), vitamins A and E and high activities of the antioxidant enzymes glutathione peroxidase (GPX) and superoxide dismutase (SOD) were found whereas brain expressed a high vitamin C concentration. In newborn healthy calves during the first two days of life, atmospheric oxygen tension did not cause either increased lipid peroxidation as reflected in a high malondialdehyde (MDA) level or any changes in GSII, GPX, SOD and catalase (CAT) activities in red blood cells (RBC). Plasma vitamin E and carotene concentrations also did not change. In growing healthy calves during two months after birth increasing MDA, decreasing GSH, GPX and CAT are leading features, whereas plasma vitamin E and carotene concentrations significantly increased. In young (1-year-old) and old (9-year-old) dogs RBC results showed significant differences with the highest MDA and lowest GSH levels in the old males. Activity of GPX and SOD was higher in old dogs than in the young ones, especially in the females.