Protein-energy malnutrition and oxidative injury in growing rats

1. Weaning rats were fed ad libitum isocaloric diets containing 5% and 20% casein based proteins. 5% protein diet was protein deficient diet. Pair fed rats with the 5% protein group were maintained simultaneously on 20% protein diet but the amount restricted to the amount taken up by PEM group. 2. Glutathione, antioxidative enzymes, lipid peroxidation and histopathological studies in liver and only glutathione and antioxidative enzymes in blood were carried out. 3. Rats fed the 5% protein diet developed a severe protein energy malnutrition (PEM) whereas those on pair-fed diet developed mild to moderate PEM. 4. Glutathione related thiols superoxide dismutase, glutathione peroxidase, catalase and glutathione-Stransferase with (1 Chloro 2,4-dinitro benzene (CDNB) substrate) were decreased in liver with concomitant increase of lipid peroxidation in severe PEM. In blood glutathione, glutathione peroxidase and catalase were decreased while superoxide dismutase was increased in severe PEM group. 5. Mild to moderate PEM (pair-fed group) also resulted in similar changes in liver except glutathione peroxidase, lipid peroxidation in liver and superoxide dismutase in blood. 6. Hepatic injury was detectable only in the severe PEM group. 7. Oxidative-stress and hepatic injury occurred in severe PEM and to a lesser degree in mild to moderate PEM.     

Abnormal hepatic mitochondrial respiration and cytochrome C oxidase activity in rats with long-term copper overload

BACKGROUND: Dietary copper overload in the rat is associated with morphological abnormalities and lipid peroxidation of hepatic mitochondria. This study was designed to determine if copper hepatotoxicity was associated with functional alterations in mitochondrial respiration in conjunction with lipid peroxidation. METHODS: Weanling male rats were pair-fed for 8 weeks on diets containing normal or high levels of copper in combination with sufficient vitamin E. Serum and liver samples were obtained, and hepatic mitochondria were isolated by differential centrifugation. RESULTS: Oxidant injury (decreased levels of hepatic glutathione and alpha tocopherol and increased levels of mitochondrial thiobarbituric acid-reacting substances) was present in the copper-overloaded rats. Serum aminotransferase levels correlated with concentrations of mitochondrial copper and thiobarbituric acid-reacting substances. Copper overload caused a decrease in state 3 respiration and the respiratory control ratio in hepatic mitochondria when several electron donors were used. Analysis of the oxidoreductase activities of the four mitochondrial electron transport protein complexes showed that complex IV (cytochrome C oxidase) activity was reduced by 60% in copper overload. CONCLUSIONS: Functional abnormalities of mitochondria accompany lipid peroxidation and the morphological alterations caused by copper overload, supporting the hypothesis that the mitochondrion is one of the major intracellular targets in copper hepatotoxicity.     

Antiandrogen treatment of aggressivity in men suffering from dementia

The effect of Shengmaisan (SMS) on 62 acute viral myocarditis patients and its peroxidation damage was studied. The results revealed that the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in blood were decreased and the content of malondialdehyde (MDA) in plasma was increased in acute viral myocarditis patients in comparison with the healthy controls (P < 0.001). 62 acute viral myocarditis patients were divided into two groups: SMS group and placebo group. After treatment, both SOD and GSH-Px activities were increased and the level of MDA decreased (P < 0.001) in SMS group, while those in placebo group were not changed (P < 0.05). The results suggested that the myocardial damage of viral myocarditis is closely related with lipid peroxidation SMS acts as an effective free radical scavenger and anti-lipid peroxidation drug. SMS could prevent the damage of myocardia and might be taken as one of the effective therapeutic methods in treatment of acute viral myocarditis.     

Pharmacokinetics and metabolism of the new thromboxane A2 receptor antagonist ramatroban in animals. 2nd communication: distribution to organs and tissues in male, female and pregnant rats, and characteristics of protein binding in plasma

Developmental profiles of antioxidant enzymes and lipid peroxidation were investigated in rat cerebral hemisphere from birth to 600 days of age. Lipid peroxidation level decreased in the crude homogenate from birth until 15 days and, thereafter increased gradually up to 600 days. However, susceptibility of sub-cellular fractions to lipid peroxidation displayed an increasing trend with increasing age. Superoxide dismutase activity decreased gradually with age, whereas activities of catalase, glutathione peroxidase and glutathione reductase exhibited an elevation up to 90 days followed by either a stagnancy or diminution in the later life. No linearity was observed in the contents of glutathione, ascorbic acid and H2O2 in the tissue. The results suggest that free radicals could be the causative agents of the aging process in which antioxidant enzymes have a definite regulatory contribution.     

Receptor mediated effects of adenosine and caffeine

The inhibition of glutathione (GSH) synthesis by L-buthionine-SR-sulfoximine (BSO) causes aggravation of hepatotoxicity of paraquat (PQ), an oxidative-stress inducing substance, in mice. On the other hand, synthesis of metallothionein (MT), a cysteine-rich protein having radical scavenging activity, is induced by PQ, and the induction by PQ is significantly enhanced by pretreatment of mice with BSO. The purpose of present study is to examine whether generation of reactive oxygens is involved in the induction of MT synthesis by PQ under inhibition of GSH synthesis. Administration of PQ to BSO-pretreated mice increased hepatic lipid peroxidation and frequency of DNA single strand breakage followed by manifestation of the liver injury and induction of MT synthesis. Both vitamin E and deferoxamine prevented MT induction as well as lipid peroxidation in the liver of mice caused by administration of BSO and PQ. In cultured colon 26 cells, both cytotoxicity and the increase in MT mRNA level caused by PQ were significantly enhanced by pretreatment with BSO. Facilitation of PQ-induced reactive oxygen generation was also observed by BSO treatment. These results suggest that reactive oxygens generated by PQ under inhibition of GSH synthesis may stimulate MT synthesis. GSH depletion markedly increased reactive oxygen generation induced by PQ, probably due to the reduced cellular capability to remove the radical species produced.     

Influence of pretreatment with carbon tetrachloride on paracetamol-induced hepatotoxicity

The influence of preventive treatment with a low dose of carbon tetrachloride on paracetamol-induced hepatotoxicity was evaluated in the rat. The haloalkane was given intraperitoneally (200 microliter/kg) 48 hours prior to paracetamol (PRCT; 2000 mg/kg, os). In parallel groups of rats were treated with CCl4 or PRCT alone. Twelve hours after paracetamol all the animals were killed. Liver damage was determined by evaluating total lipid and triglyceride accumulation in hepatic tissue and the serum activity of alanine-amino transferase (S.GPT). In addition, both the hepatic concentration of reduced glutathione (GSH) and the production "in vitro" of TBA-reacting compounds by liver homogenate were assayed. The results obtained indicate CCl4 "per se" induces a significant triglyceride accumulation but does not influence either the hepatic GSH level or the leakage of GPT into the blood stream. In addition, the haloalkane does not stimulate the production of TBA-reacting substances by hepatic tissue. Paracetamol, alone, produces a slight increase of hepatic triglycerides while induces a significant (+ 108%) enhancement of S.GPT activity. The drug is also able to stimulate the lipid peroxidation "in vitro", whereas provokes a marked decrease of GSH in liver tissue. Combined treatment with the two poisons results in a minor alteration of hepatocyte function as shown by the lack of GPT in serum and by the reduced fall of hepatic GSH as well as by a decreased production of TBA-reacting compounds. In our opinion, CCl4 partially protects against paracetamol-induced liver injury by interacting with enzymes which are responsible for the biotransformation of PRCT to a reactive arylating species that bind to cell molecules.     

Quantitation of T2 lesion load in multiple sclerosis with magnetic resonance imaging: a pilot study of a probabilistic neural network approach

We studied the effect of prostaglandin F2 alpha on parameters related to microsomal metabolism (free radical production and lipid peroxidation, glutathione content and activity of microsomal oxidases) after an induction by ethanol or acetone combined with starvation. Long-term ethanol administration led to a significant increase in lipid peroxide formation and NADPH-dependent chemiluminescence amplified by luminol and lucigenin. At the same time hydrogen peroxide production and NADPH-stimulated lipid peroxidation were enhanced although the effect did not reach the level of statistical significance. The concentration of reduced glutathione (GSH) in the liver was decreased 2-fold, whereas oxidized glutathione (GSSG) content remained unaltered. Ethanol intoxication resulted in an increase in 7-ethoxycoumarin-O-deethylase (ECOD), 7-benzyloxycoumarin-O-deethylase (BCOD) and 7-ethoxy-resorufin-O-deethylase (EROD) activities, whereas 7-pentoxyresorufin-O-deethylase (PROD) and ethylmorphin-N-demethylase (EMND) activities were unaltered. The combination of acetone treatment with starvation resulted in a significant increase in lipid and hydrogen peroxide formation, NADPH-dependent lipid peroxidation and chemiluminescence. GSH and GSSG concentration in the liver dramatically decreased 5- and 3-fold, respectively. The acetone treatment led to significant increase in EROD, ECOD, BCOD, PROD and EMND activities. The treatment of ethanol-intoxicated rats with prostaglandin F2 alpha (PGF2 alpha) exerted more pronounced prooxidant effect on liver than action of alcohol itself. At the same time, PGF2 alpha improved most of parameters changed by acetone treatment combined with starvation, decreasing lipid peroxide and radical formation and enhancing GSH and GSSG contents.     

Low doses of eicosapentaenoic acid, docosahexaenoic acid, and hypolipidemic eicosapentaenoic acid derivatives have no effect on lipid peroxidation in plasma

It was of interest to investigate the influence of both high doses of eicosapentaenoic acid (EPA) and low doses of 2- or 3-methylated EPA on the antioxidant status, as they all cause hypolipidemia, but the dose required is quite different. We fed low doses (250 mg/d/kg body wt) of different EPA derivatives or high doses (1500 mg/d/kg body wt) of EPA and DHA to rats for 5 and 7 d, respectively. The most potent hypolipidemic EPA derivative, 2,2-dimethyl-EPA, did not change the malondialdehyde content in liver or plasma. Plasma vitamin E decreased only after supplementation of those EPA derivatives that caused the greatest increase in the fatty acyl-CoA oxidase activity. Fatty acyl-CoA oxidase activity increased after administration of both EPA and DHA at high doses. High doses of EPA and DHA decreased plasma vitamin E content, whereas only DHA elevated lipid peroxidation. In liver, however, both EPA and DHA increased lipid peroxidation, but the hepatic level of vitamin E was unchanged. The glutathione-requiring enzymes and the glutathione level were unaffected, and no significant changes in the activities of xanthine oxidase and superoxide dismutase were observed in either low- or high-dose experiments. In conclusion, increased peroxisomal beta-oxidation in combination with high amounts of polyunsaturated fatty acids caused elevated lipid peroxidation. At low doses of polyunsaturated fatty acids, lipid peroxidation was unchanged, in spite of increased peroxisomal beta-oxidation, indicating that polyunsaturation is the most important factor for lipid peroxidation.     

Adriamycin-induced oxidative stress in rat central nervous system

Adriamycin elicited a stimulation of rat central nervous system lipid peroxidation, both in vivo and in vitro, as evidenced by the increase in the content of thiobarbituric acid reactants, which was found to be NADPH-dependent. The antioxidant enzymes superoxide dismutase, catalase and glutathione peroxidase were seen to decrease on exposure to adriamycin (1 mg/kg for a period of 7 days), together with a significant decrement in the GSH/GSSG ratio, thus contributing to the oxidative insult to the tissue. The in vitro addition of GSH or vitamin E to brain homogenates offered protection against adriamycin-induced lipid peroxidation, suggesting that supplementation with these antioxidants could improve the therapeutic value of the drug.     

A severe case of Moebius syndrome with calcification on the fourth ventricular floor

Disturbance of metabolism of trace elements and antioxidants are investigated in epileptic patients with long-term therapy of anticonvulsants. One hundred and fifteen subjects including healthy controls, untreated epileptic patients, and phenytoin (PHT)- or carbamazepine (CBZ)-treated epileptic patients were recruited in this study. Serum malondialdehyde was measured as an index of extracellular lipid peroxidation. The levels of serum copper (S-Cu), serum zinc, copper/zinc superoxide dismutase (CuZn-SOD), and reduced glutathione in the serum were monitored simultaneously. The results showed that malondialdehyde, S-Cu, and CuZn-SOD levels in the serum all were significantly increased, but the glutathione level was significantly decreased, in all the epileptic patients with PHT monotherapy compared with those of the controls. However, no significant differences of these parameters in the epileptic patients with CBZ monotherapy were found except for a mild elevation of the activity of serum CuZn-SOD. We conclude that compared with PHT monotherapy, the CBZ monotherapy induced less disturbance in trace element metabolism, antioxidants, and lipid peroxidation in the serum of epileptic patients.     

Lipid peroxidation and antioxidant status in the liver, erythrocytes, and serum of rats after methanol intoxication

Lipid peroxidation products measured as a malondialdehyde and activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutathione reductase (GSSG-R), and concentrations of ascorbic acid, alpha-tocopherol, and glutathione (GSH) were measured in the liver, erythrocytes, and serum of rats 6, 14, and 24 h and 2, 5, and 7 d after treatment with 3 g methanol/kg. GSH-Px and GSSG-R activities, GSH level, and ascorbate concentration in the liver, erythrocytes, and blood serum were significantly decreased. In addition, SOD and alpha-tocopherol in erythrocytes were diminished, while malondialdehyde (MDA) in liver, erythrocytes, and serum were elevated. Further, erythrocyte counts, hemoglobin levels, hematocrit, and mean corpuscular volume (MCV) were reduced. These results indicate that methanol intoxication in rats leads to an increase in the lipid peroxidation and impairment in the antioxidant mechanisms in liver, erythrocytes, and blood serum.     

Effect of sustained nocturnal transbuccal melatonin administration on sleep and temperature in elderly insomniacs

This study was mainly aimed to investigate the efficacy of trypsin:chymotrypsin to elicit anti-oxidant properties. In our earlier studies it was observed that the enzyme preparation exhibited an anti-inflammatory action as there was a remarkable reduction in oedema formation and tissue destruction. This led to further study on the amount of lipid peroxidation products formed and the levels of enzymatic and non-enzymatic anti-oxidants and relative trace element contents of copper, selenium, iron and zinc during administration of the enzyme preparation. Decreased formation of lipid peroxidation products was observed in treated group in comparison with the untreated group. Higher levels of enzymatic anti-oxidants mainly super oxide dismutase, catalase, glutathione peroxidase and glutathione-s-transferase and non-enzymatic antioxidant namely ceruloplasmin persisted for a longer period of time in the treated group than in the untreated group. No statistical significance was observed in non-enzymatic antioxidants viz. ascorbic acid and tocopherol levels in both the groups. Increased serum copper and selenium levels in the treated group could be related to higher levels of the ceruloplasmin and glutathione peroxidase observed in the treated group. The above studies support the finding that treatment with the enzyme preparation reduced tissue destruction leading to decreased formation of free radicals and subsequent effective scavenging of free radicals by the higher levels of enzymatic and non-enzymatic anti-oxidants.     

Cellular thiols as a determinant of responsiveness to menadione in cardiomyocytes

The role of intracellular thiols in menadione-mediated toxicity was studied in neonatal rat cardiomyocytes. The sensitivity of cardiomyocytes to menadione was greater than that of skeletal muscle cells and 3T3 fibroblasts. Before cell degeneration, menadione induced marked depletion of intracellular thiols and an increase of oxidized glutathione. The sensitivity of these cells to menadione correlated with the level of depletion of intracellular thiols. After incubation of cardiomyocytes with menadione, glutathione reductase activity was inhibited and lipid peroxidation was increased. Both dicumarol (an inhibitor of DT-diaphorase) and diethyldithiocarbamate (an inhibitor of superoxide dismutase) enhanced the capacity of menadione to induce cellular damage and to cause depletion of intracellular glutathione. Decreasing intracellular glutathione by pretreatment of cells with N-ethylmaleimide or buthionine sulphoximine also increased menadione-induced cell degeneration. Preincubation with cysteine or dithiothreitol suppressed the capacity of menadione to damage the cells. Menadione-induced lipid peroxidation was also suppressed by the same treatment. These results show that the oxidative stress induced by menadione in cardiomyocytes results in the depletion of glutathione and protein thiols. Both DT-diaphorase and superoxide dismutase can protect cells from the toxicity of menadione. Cellular thiols are determinants of the responsiveness to menadione.     

Effect of cis-unsaturated fatty acids on cellular oxidant stress in macrophage tumor (AK-5) cells in vitro

Cis-unsaturated fatty acids (c-UFAs) induced decreased survival of macrophage tumor (AK-5) cells in vitro. The cytotoxic action of c-UfAs was associated with an increase in free radical generation and lipid peroxidation process. In addition, exposure of AK-5 cells to various c-UFAs for a short period (1 h) decreased the cellular concentrations of anti-oxidants: superoxide dismutase (SOD), catalase, glutathione peroxidase, glutathione reductase, glutathione and vitamin E. However, prolonged (24 h) exposure of AK-5 cells to c-UFAs enhanced the levels of SOD with little or no change in the concentrations of catalase, glutathione peroxidase and glutathione reductase. These results indicate that c-UFAs can enhance free radical generation and lower the concentrations of various anti-oxidants in the tumor cells which may explain the cytotoxic action of c-UFAs.     

Chest physiotherapy and post-extubation atelectasis in infants

The present study describe the role of copper zinc superoxide dismutase (CuZnSOD) in the short-term treatment of experimental colitis induced with 8% acetic acid. The colonic mucosa damage index in the group of 10 rats treated intravenously with 30,000 U/kg CuZnSOD was significantly decreased when compared with the control group (10 rats) treated with normal saline (0.4 +/- 0.6 vs 1.5 +/- 0.5 p < 0.01). Assay of SOD in the control group was 0.3 +/- 0.08 and in the SOD treated group, SOD was significantly increased to 0.8 +/- 0.1, glutathione peroxidase was 44.8 +/- 6.3 in the control and 56.4 +/- 9.1 in the treated group (difference not significant). Both myeloperoxidase activity (14.0 +/- 2.5 vs 22.7 +/- 2.5) and lipid peroxidation products (13.8 +/- 2.9 vs 52.9 +/- 9.6) were significantly lower in the colonic mucosa of the SOD treated group in comparison with the control. These results indicate that the anti-inflammatory effects of CuZnSOD were mainly the removal of oxygen free radicals and indirectly the prevention of lipid peroxidation. This study suggests that CuZnSOD may be beneficial in the treatment of patients with ulcerative colitis. However, our experimental data suggest that this treatment will not have strong effects on the control of severe ulcerative colitis.     

Effect of arsenic (V) on the antioxidant defense system: in vitro oxidation of rat plasma lipoprotein

Adult male rats were treated orally with sodium arsenate (10 mg As/kd/day) for 2 days, and in increase in hepatic glutathione level was seen. Ascorbic acid content increased in both liver and plasma of intoxicated animals. Hepatic activities of superoxide dismutase and glutathione peroxidase did not change with the treatment and there was no increase in the level of lipid peroxidation measured as thiobarbituric acid-reacting substances (TBARS). Arsenic decreased the plasma level of uric acid and increased the plasma triglycerides content without modifying vitamin E levels. Both total lipoproteins and very low density lipoprotein plus low density lipoprotein (VLDL + LDL) fractions demonstrated greater propensity for in vitro oxidation than the corresponding untreated rats. The last finding might be a useful parameter for determining the degree of oxidative stress in the initial steps of intoxication with arsenic.     

Thymic epithelial cells as a diagnostic pitfall in the fine-needle aspiration diagnosis of primary mediastinal lymphoma

This paper reports data on the effect of a new antioxidant, U-83836E, on the lipid peroxidation and antioxidant status of liver, red blood cells (RBCs) and blood serum of rats intoxicated with methanol (3.0 g/kg body weight). Methanol administration slightly increased the levels of peroxidation products in the liver, and markedly increased them in RBCs and serum. In contrast, glutathione-peroxidase, glutathione-reductase activity, reduced glutathione concentration and total antioxidant status were decreased. The use of U-83836E, containing a trolox ring, appeared to be beneficial in reducing lipid peroxidation products and in partially in preventing the decrease in glutathione and antioxidant enzymes induced by methanol in liver and serum. These results show that antioxidant U-83836E may partially prevent methanol toxicity.     

Intensive short course chemotherapy in the management of tuberculous meningitis

SETTING: Short course chemotherapy for tuberculous meningitis (TBM) is advocated by several groups, but relatively few children have been so treated and followed up. METHODS: A prospective, observational study of isoniazid (INH), rifampicin (RMP) and ethionamide (ETH) in a dosage of 20 mg/kg, and pyrazinamide (PZA) 40 mg/kg, all given once daily in hospital for 6 months. Surviving children were followed up for a year after discharge. RESULTS: Ninety five children, 39 (41%) at stage III, 52 (55%) at stage II and 4 (4%) at stage I TBM were studied. Ten (26%) at stage III and 3 (6%) at stage II died before completion of therapy. Five surviving children (6%) moved on discharge and were untraceable; seven children (9%) were lost during follow up and three were inadvertently restarted on antituberculosis therapy. Two children with severe stage III disease died after discharge. One child experienced a probable disease recrudescence 1 month after discharge. Eighteen children (20%) developed a mildly elevated serum bilirubin concentration during the first month of treatment. In five of these children INH, RMP, ETH and PZA were stopped and streptomycin (SM) and ethambutol substituted. In all cases the original treatment was restarted without incident. One child developed overt jaundice after 5 months of treatment due to hepatitis A infection. CONCLUSIONS: Our experience suggests that young children with TBM can be safely treated for 6 months with high doses of antituberculosis agents without overt hepatotoxicity and with a low risk of relapse.     

Eosinophil infiltration in nonallergic chronic hyperplastic sinusitis with nasal polyposis (CHS/NP) is associated with endothelial VCAM-1 upregulation and expression of TNF-alpha

New Zealand White rabbits (6 males and 6 females) were fed a diet of high lipid peroxide content (peroxide value: 249.05 meq/kg fat) for 21 days. Twelve rabbits served as controls (peroxide value: 40.3 meq/kg fat). The lipid peroxide loading did not cause clinical signs. The rate of lipid peroxidation, as measured on the basis of thiobarbituric acid reactive substances (TBARS), was significantly (P < 0.05) higher in all of the investigated tissues, in the following order: liver > red blood cells (RBC) > blood plasma. Reduced and oxidised glutathione content was higher in the blood plasma (P < 0.01) and liver (P < 0.001) of rabbits exposed to the peroxide load. Lipid peroxide loading decreased the activity of glutathione peroxidase in the blood plasma, RBC haemolysate and liver and that of glutathione reductase in the liver. The amount of cytochrome P450 (both CO- and metyrapone-reduced) and the activity of cytochrome c (P450) oxidoreductase in the microsomal fraction of the liver homogenate were also lower in the group exposed to lipid peroxide load. Subchronic alimentary lipid peroxide loading in the presence of sufficiently high levels of antioxidants in the complete feed was found to increase the rate of lipid peroxidation and markedly lower the activities of both the glutathione and xenobiotic transforming enzyme systems without causing any clinical signs of toxicity.     

Lipid peroxidation in mitochondrial inner membranes. I. An integrative kinetic model

An integrative mathematical model was developed to obtain an overall picture of lipid hydroperoxide metabolism in the mitochondrial inner membrane and surrounding matrix environment. The model explicitly considers an aqueous and a membrane phase, integrates a wide set of experimental data, and unsupported assumptions were minimized. The following biochemical processes were considered: the classic reactional scheme of lipid peroxidation; antioxidant and pro-oxidant effects of vitamin E; pro-oxidant effects of iron; action of phospholipase A2, glutathione-dependent peroxidases, glutathione reductase and superoxide dismutase; production of superoxide radicals by the mitochondrial respiratory chain; oxidative damage to proteins and DNA. Steady-state fluxes and concentrations as well as half-lives and mean displacements for the main metabolites were calculated. A picture of lipid hydroperoxide physiological metabolism in mitochondria in vivo showing the main pathways is presented. The main results are: (a) perhydroxyl radical is the main initiation agent of lipid peroxidation (with a flux of 10(-7)MS-1); (b) vitamin E efficiently inhibits lipid peroxidation keeping the amplification (kinetic chain length) of lipid peroxidation at low values (approximately equal to 10); (c) only a very minor fraction of lipid hydroperoxides escapes reduction via glutathione-dependent peroxidases; (d) oxidized glutathione is produced mainly from the reduction of hydrogen peroxide and not from the reduction of lipid hydroperoxides.