Aging and low-intensity exercise change oxidative biomarkers in brain regions and radiographic measures of femur of Wistar rats

We investigated changes in oxidative biomarkers in brain regions such as brainstem, cerebellum, and cerebral cortex of 3-, 6-, 18-, 24-, and 30-month-old rats. We also assessed the effects of low-intensity exercise on these biomarkers in these regions of 6-, 18-, and 24-month-old rats that started exercise on a treadmill at 3, 15, and 21 months of age, respectively. Radiographic images of the femur were taken for all rats. A total of 25 rats (age: twelve 6-, ten 18-, ten 24-, and three 30-month-old rats) were used. Lipid hydroperoxide levels increased in cerebellum at 18 months. Total antioxidant activity exhibited lowest values in brainstem at 3 months. Superoxide dismutase activity did not exhibit significant changes during aging. Total thiol content exhibited lowest values in brain regions of 24- and 30-month-old rats. Exercise reduced total thiol content in brainstem at 6 months, but no change occurred in other regions and other ages. Femur increased its length and width and cortical thickness with advancing age. No change occurred in medullary width. Radiolucency increased and sclerosis was found in cortical and medullary bone with advancing age. Exercise reduced radiolucency and medullary sclerosis. Therefore, aging differentially changed oxidative biomarkers in different brain regions and radiographic measures of the femur. Low-intensity exercise only ameliorated some radiographic measurements of femur. Since the present study possessed limitations (small number of rats per group), a beneficial effect of regular low-intensity exercise on oxidative markers in brain cannot be ruled out.

Avaliação de propriedades funcionais e oxidação lipídica em mortadela com aplicação de maca peruana / Evaluation of functional properties and lipid oxidation in mortadella with application of maca peruana

Avaliou-se durante 90 dias o pH, a cor, a capacidade de retenção de água (CRA), a textura e a oxidação lipídica, de uma formulação de mortadela otimizada por meio de um delineamento experimental de mistura para dois componentes. Desenvolveram-se duas amostras da formulação de mortadela otimizada, com antioxidante (OA) e sem antioxidante (OS). Os valores de pH e CRA não apresentaram diferenças significativas ao final dos 90 dias entre as amostras, OA (6,02 e 94,05 g/100g) e OS (6,07 e 93,25 g/100g). Na cor houve diferenças significativas. Na textura, apenas a dureza, mastigabilidade e coesividade apresentaram diferenças significativas. E aos 90 dias as amostras com (2,10 mg de MDA/Kg) e sem antioxidante (2,59 mg de MDA/Kg) não apresentaram diferenças significativas para oxidação lipídica e podem ser considerados aceitáveis para produtos cárneos.

Efeito da adição de óleo essencial de Origanum vulgar e Ocimum gratissimum L. no perfil lipídico da gordura de palma usada em fritura de batata tipo chips / Palm oil fatty acid profile evaluation during the potato chips processing with Origanum vulgar and Ocimum gratissimum L

O objetivo deste trabalho foi avaliar o efeito antioxidante dos óleos essenciais de orégano e alfavacão sobre a estabilidade e perfil de ácidos graxos da gordura de palma utilizada no processamento industrial. Foram adicionados 100ug.g-1 de óleos essenciais em gordura de palma, que foi submetida a onze ciclos de fritura de batatas tipo chips. Amostras da gordura submetidas ao processamento foram analisadas quanto às características físico-químicas e perfil de ácidos graxos. Nas condições do estudo, não foi observado efeito dos óleos essenciais sobre a inibição na formação de compostos trans. Não houve alteração da relação de ácidos graxos poli-insaturados e ácidos graxos saturados da gordura. No entanto, a análise de peróxido indicou um efeito positivo do óleo essencial de alfavacão na redução da formação de radicais livres.

Effects of N-acetylcysteine on spinal cord oxidative stress biomarkers in rats with neuropathic pain

N-acetylcysteine (NAC) inhibits nociceptive transmission. This effect has been associated partly with its antioxidant properties. However, the effect of NAC on the levels of lipid hydroperoxides (a pro-oxidant marker), content of ascorbic acid (a key antioxidant molecule of nervous tissue) and total antioxidant capacity (TAC) is unknown. Thus, our study assessed these parameters in the lumbosacral spinal cord of rats with chronic constriction injury (CCI) of the sciatic nerve, one of the most commonly employed animal models of neuropathic pain. Thirty-six male Wistar rats weighing 200-300 g were equally divided into the following groups: Naive (rats did not undergo surgical manipulation); Sham (rats in which all surgical procedures involved in CCI were used except the ligature), and CCI (rats in which four ligatures were tied loosely around the right common sciatic nerve). All rats received intraperitoneal injections of NAC (150 mg·kg−1·day−1) or saline for 1, 3, or 7 days. Rats were killed 1, 3, and 7 days after surgery. NAC treatment prevented the CCI-induced increase in lipid hydroperoxide levels only at day 1, although the amount was higher than that found in naive rats. NAC treatment also prevented the CCI-induced increase in ascorbic acid content, which occurred at days 1, 3, and 7. No significant change was found in TAC with NAC treatment. The changes observed here may be related to the antinociceptive effect of NAC because modulation of oxidative-stress parameters seemed to help normalize the spinal cord oxidative status altered by pain.

Efeito do betacaroteno sobre o estresse oxidativo e a expressão de conexina 43 cardíaca / Effect of beta-carotene on oxidative stress and expression of cardiac connexin 43

FUNDAMENTO: Estudos de intervenção mostraram aumento da mortalidade em pacientes que receberam betacaroteno. Contudo, não são conhecidos os mecanismos envolvidos nesse fenômeno. OBJETIVO: Avaliar a influência do betacaroteno sobre o estresse oxidativo e a expressão de conexina 43 em coração de ratos. MÉTODOS: Ratos Wistar, pesando aproximadamente 100 g, foram alocados em dois grupos: Grupo Controle (n = 30), que recebeu a dieta usada de rotina em nosso laboratório, e Grupo Betacaroteno (n = 28), que recebeu betacaroteno (na forma de cristal, adicionado e misturado à dieta) na dose de 500 mg de betacaroteno/kg de dieta. Os animais receberam tratamento até que atingissem entre 200 e 250 g, quando eram sacrificados. Foram coletados sangue, fígado e coração para realização de Western blotting e imunoistoquímica para conexina 43; foram realizados estudos morfométricos, dosagens de betacaroteno por cromatografia líquida de alta eficiência bem como de glutationa reduzida, glutationa oxidada e hidroperóxidos de lipídeos por análises bioquímicas. RESULTADOS: O betacaroteno foi detectado apenas no fígado dos animais do Grupo Betacaroteno (288 ± 94,7 µg/kg). Os níveis de glutationa reduzida/glutationa oxidada foram maiores no fígado e no coração dos animais do Grupo Betacaroteno (fígado - Grupo Controle: 42,60 ± 1,62; fígado - Grupo Betacaroteno: 57,40 ± 5,90; p = 0,04; coração: - Grupo Controle: 117,40 ± 1,01; coração - Grupo Betacaroteno: 121,81 ± 1,32 nmol/mg proteína; p = 0,03). O conteúdo de conexina 43 total foi maior no Grupo Betacaroteno. CONCLUSÃO: O betacaroteno apresentou efeito benéfico, caracterizado pelo aumento da comunicação intercelular e melhora do sistema de defesa antioxidante. Nesse modelo, os mecanismos não explicam a maior mortalidade observada com a suplementação de betacaroteno em estudos clínicos. (Arq Bras Cardiol. 2013; [online].ahead print, PP.0-0).

BACKGROUND: Intervention studies have shown an increased mortality in patients who received beta-carotene. However, the mechanisms involved in this phenomenon are still unknown. OBJECTIVE: Evaluate the influence of beta-carotene on oxidative stress and the expression of connexin 43 in rat hearts. METHODS: Wistar rats, weighing approximately 100 g, were allocated in two groups: Control Group (n=30), that received the diet routinely used in our laboratory, and Beta-Carotene Group (n = 28), which received beta-carotene (in crystal form, added and mixed to the diet) at a dose of 500 mg of beta-carotene/kg of diet. The animals received the treatment until they reached 200-250g, when they were sacrificed. Samples of blood, liver and heart were collected to perform Western blotting and immunohistochemistry for connexin 43; morphometric studies, dosages of beta-carotene by high-performance liquid chromatography as well as reduced glutathione, oxidized glutathione and lipids hydroperoxides were performed by biochemical analysis. RESULTS: Beta-carotene was detected only in the liver of Beta-Carotene Group animals (288 ± 94.7 µg/kg). Levels of reduced/oxidized glutathione were higher in the liver and heart of Beta-Carotene Group animals (liver - Control Group: 42.60 ± 1.62; liver - Beta-Carotene Group: 57.40 ± 5.90; p = 0.04; heart: - Control Group: 117.40 ± 1.01; heart - Beta-Carotene Group: 121.81 ± 1.32 nmol/mg protein; p = 0.03). The content of total connexin 43 was larger in Beta-Carotene Group. CONCLUSION: Beta-carotene demonstrated a positive effect, characterized by the increase of intercellular communication and improvement of anti-oxidizing defense system. In this model, mechanism does not explain the increased mortality rate observed with the beta-carotene supplementation in clinical studies. (Arq Bras Cardiol. 2013; [online].ahead print, PP.0-0).

Chronic treatment with ethanolic extract of the leavesof Azadirachta indica ameliorates lesions of pancreatic islets in streptozotocin diabetes / Tratamiento crónico con extracto etanólico de hojas de Azadirachta indica disminuye las lesiones de los islotes pancreáticos en diabetes por estreptozotocina

Botanical drugs are complementary therapies in the management of diabetes mellitus. In this work, we studied the effects of chronic treatment of diabetic rats with A. indica (neem) on blood glucose, pancreatic islet histopathology, and oxidative status of the pancreas. Fifty-four Wistar rats (5-8 weeks old) were randomly assigned to 5 treatment groups. Hyperglycemia was induced in 34 fasted rats with a single i.p. injection of STZ (70 mg/kg bw/d). Ethanolic extract of A. indica leaves (500 mg/kg bw/d) was given orally to diabetic rats (n=12) for 50d. Glibenclamide was given (p.o) at 600 µg/ kg bw/d. In each group, blood glucose, islet histopathology, and pancreatic oxidative status, were assessed. All hyperglycemic rats in the neem-treated group had become normoglycemic at the end of week 2. By 50d, the number of viable b cells was highest in the neem-treated diabetic rats (compared with the diabetic and glibenclamide groups). Similarly, islet histology showed marked improvement in this group, in addition to improved oxidative stress. Our findings confirmed the hypoglycemic effect of neem. Besides, the improved islet morphology and oxidative status in neem-treated diabetic rats suggest the potential of this herb at improving lesions of the pancreatic islet in diabetes mellitus.

Los medicamentos a base de plantas son terapias complementarias en el manejo de la diabetes mellitus. En este trabajo se estudiaron los efectos del tratamiento crónico de ratas diabéticas con A. indica (Neem) sobre la glucosa de la sangre, la histopatología de los islotes pancreáticos, y el estado oxidativo del páncreas. Cincuenta y cuatro ratas Wistar (5-8 semanas de edad) fueron asignadas aleatoriamente a 5 grupos de tratamiento. La hiperglucemia fue inducida en 34 ratas en ayunas con una única inyección IP de STZ (70 mg/kg peso corporal/d). El extracto etanólico de hojas de A. indica (500 mg/kg de peso corporal/día) fue administrado por vía oral a ratas diabéticas (n=12) por 50d. Glibenclamida fue dada (PO) a 600 mg/kg peso corporal/d. En cada grupo, la glucosa en la sangre, la histopatología de los islotes, y el estado oxidativo de páncreas, se evaluaron. Todas las ratas de hiperglucemia en el grupo tratado con el Neem se habían convertido en normoglucémicas al final de la semana 2. Por 50d, el número de células b viables fue mayor en el Neem ratas tratadas con diabetes (en comparación con los grupos de diabéticos y glibenclamida). Del mismo modo, la histología de los islotes mostró una notable mejoría en este grupo, además de mejorar el estrés oxidativo. Nuestros resultados confirman el efecto hipoglucemiante de Neem. Además, la mejora de la morfología de los islotes y el estado de oxidación en el neem tratados con ratas diabéticas sugieren el potencial de esta hierba en la mejora de las lesiones de los islotes pancreáticos en la diabetes mellitus.

Superoxide dismutase and lipid hydroperoxides in blood and endometrial tissue of patients with benign, hyperplastic and malignant endometrium

Epidemiological and experimental data point to involvement of oxygen derived radicals in the pathogenesis of gynecological disorders, as well as in cancer development. The objective of the present study was to examine changes in activities and levels of copper/zinc superoxide dismutase (CuZnSOD) and lipid hydroperoxides (LOOH) in blood and endometrial tissue of patients diagnosed with uterine myoma, endometrial polypus, hyperplasia simplex, hyperplasia complex and adenocarcinoma endometrii. The results of our study have shown decreased SOD activities and unchanged SOD protein level in blood of all examined patients in comparison to healthy subjects. Decrease of both SOD activity and level was found in endometrium of patients with hyperplasia simplex, hyperplasia complex and adenocarcinoma in comparison to women with polypus or myoma. LOOH level was elevated in both tissues of patients with hyperplasiaor adenocarcinoma in comparison to healthy subjects or patients with benign diagnosis. Our findings suggest that the decrease in SOD activity and level, as well as the increase in LOOH level, in patients with gynecological disorders, render these patients more susceptible to oxidative damage caused by reactive oxygen species (ROS). An imbalance in ROS formation and SOD level may be important in the pathogenesis and/or perpetuation of tissue damage in gynecological patients. Since evidence suggests that SOD may be a therapy target for cancer treatment, our findings provide a basis for further research and options for clinical applications.

Resultados epidemiológicos e experimentais apontam para o envolvimento dos radicais derivados do oxigênio na patogênese das moléstias ginecológicas, assim como no desenvolvimento do câncer. O objetivo do presente estudo foi o de examinar as alterações nas atividades e níveis de Cu/Zn superóxido dismutase (CuZnSOD) e hidroperóxidos lipídicos (LOOH)no sangue e tecido endometrial de pacientes diagnosticados com mioma uterino, pólipo endometrial, hiperplasia simplex, hiperplasia complex e adenocarcinoma do endométrio. Os resultados de nosso estudo mostraram atividades de SOD diminuídas e nível de SOD proteína inalterado no sangue de todos os pacientes examinados em comparação a indivíduos saudáveis. Diminuição de ambos, atividade de SOD e nível protéico, foram encontrados no endométrio de pacientes com hiperplasia simplex, hiperplasia complex e adenocarcinoma em comparação às mulheres com pólipos e/ou mioma. O nível de LOOH estava elevado em ambos os tecidos de pacientes com hyperplasia e adenocarcinoma em comparação a indivíduos saudáveis ou pacientes com diagnóstico benigno. Nossos resultados sugerem que um decréscimo na atividade e nível protéico de SOD, assim como um incremento no nível de LOOH, em pacientes com desordens ginecológicas, tornam esses pacientes mais susceptíveis ao dano oxidativo causado pelas espécies reativas de oxigênio (ROS). Um desequilíbrio na formação de ROS e no nível de SOD pode ser importante na patogênese e/ou perpetuação do dano tecidual em pacientes ginecológicos. Desde que existe evidência de que SOD pode ser um alvo para terapia de câncer, nossos resultados fornecem uma base para futura pesquisa e opções para aplicações clínicas.

Antioxidant responses of Laeonereis acuta (Polychaeta) after exposure to hydrogen peroxide

The effects of H2O2 were evaluated in the estuarine worm Laeonereis acuta (Polychaeta, Nereididae) collected at the Patos Lagoon estuary (Southern Brazil) and maintained in the laboratory under controlled salinity (10 psu diluted seawater) and temperature (20°C). The worms were exposed to H2O2 (10 and 50 µM) for 4, 7, and 10 days and the following variables were determined: oxygen consumption, catalase (CAT) and glutathione peroxidase activity in both the supernatant and pellet fractions of whole body homogenates. The concentrations of non-protein sulfhydryl and lipid peroxides (LPO) were also measured. The oxygen consumption response was biphasic, decreasing after 4 days and increasing after 7 and 10 days of exposure to 50 µM H2O2 (P < 0.05). At the same H2O2 concentration, CAT activity was lower (P < 0.05) in the pellet fraction of worms exposed for 10 days compared to control. Non-protein sulfhydryl concentration and glutathione peroxidase activity were not affected by H2O2 exposure. After 10 days, LPO levels were higher (P < 0.05) in worms exposed to 50 µM H2O2 compared to control. The reduction in the antioxidant defense was paralleled by oxidative stress as indicated by higher LPO values (441 percent compared to control). The reduction of CAT activity in the pellet fraction may be related to protein oxidation. These results, taken together with previous findings, suggest that the worms were not able to cope with this H2O2 concentration.

Level of oxidative stress in the red blood cells of patients with liver cirrhosis.

BACKGROUND & OBJECTIVE: Liver cirrhosis is associated with gastrointestinal haemorrhage and oesophageal variceal bleeding. Altered platelet functions has been reported to be a cause of bleeding complication. We carried out this study to find out the level of oxidative stress in the red blood cells of patients with liver cirrhosis. METHODS: Fifty patients admitted with the complication of liver cirrhosis (with bleeding complications, n=30 and without bleeding complications, n=20) were included in the study. Age and sex matched normal healthy volunteers (n=45) served as controls. The levels of oxyhaemoglobin and methaemoglobin were assayed in the red blood cells. Oxidative stress markers such as lipid peroxides, lipid hydroperoxides and nitric oxide were determined along with enzymatic antioxidants. Membrane bound adenosine triphosphatases, cytosolic glucose-6-phosphate dehydrogenase and NADHmethaemoglobin reductase were also measured. The levels of cholesterol and total phospholipids were assessed in red blood cell membrane. The osmotic fragility of red blood cells was monitored using different concentrations of sodium chloride. RESULTS: The level of methaemoglobin was significantly higher (P < 0.001) in the red blood cells of liver cirrhotic patients with bleeding complication compared to that of non bleeding patients. The activity level of NADH-methaemoglobin reductase was significantly lower (P<0.001) compared to that of normal subjects. Levels of oxidative stress markers including nitric oxide were found to be higher in patients. The levels of enzymatic antioxidants were low except of glutathione peroxidase. The activity levels of adenosine triphosphatases were also found to be significantly lower (P<0.001) in patients compared to normal subjects. A significant alteration (P<0.05) was found in membrane cholesterol/phospholipid ratio of cirrhotic bleeders. Osmotic fragility of red blood cells was also altered in patients. INTERPRETATION & CONCLUSION: In cirrhotic condition red blood cells are subjected to severe oxidative stress with significant alterations in the membrane properties.

Effect of Terminalia arjuna stem bark on antioxidant status in liver and kidney of alloxan diabetic rats.

Free radicals and associated oxidative stress induced by alloxan are implicated in eliciting pathological changes in diabetes mellitus. Terminalia arjuna bark, an indigenous plant used in ayurvedic medicine in India, primarily as a cardiotonic is also used in treating diabetes, anemia, tumors and hypertension. The present study examined the effect of ethanolic extract (250 and 500 mg/kg body weight) of Terminalia arjuna stem bark in alloxan induced diabetic rats and its lipid peroxidation, enzymatic and nonenzymatic activity was investigated in the liver and kidney tissues. The extract produced significant (P<0.05) reduction in lipid peroxidation (LPO). The effect of oral T. arjuna at the dose of 500 mg/kg body weight was more than the 250 mg/kg body weight. The extract also causes a significant (P<0.05) increase in superoxide dismutase, catalase, glutathione peroxidase, glutathione-s-transferase glutathione reductase and glucose-6-phosphate dehydrogenase, reduced glutathione, vitamin A, vitamin C, vitamin E, total sulfhydryl groups (TSH) and non protein sulfhydryl groups (NPSH) in liver and kidney of alloxan induced diabetic rats, which clearly shows, the antioxidant property of T. arjuna bark. The result indicates that the extract exhibit the antioxidant activity through correction of oxidative stress and validates the traditional use of this plant in diabetic animals.

Antioxidant capacity in relationship to serum lipid peroxides levels in healthy elderly of Mexico City / Capacidad antioxidante en relación a niveles séricos de lipoperóxidos en ancianos sanos de la ciudad de México

The aging is one of the factors that cause decrease in the antioxidant capacity. Likewise, it has been proposed that subjects exposed permanently to air pollution develop deficient antioxidant capacity to oxidative stress (OxS). This study aimed to analyze the antioxidant capacity against elevated lipid peroxides in healthy elderly of Mexico City. 105 adults (44 ± 10.8 years) and 126 elderly subjects were studied (68 ± 7.1 years); residents of Mexico City (clinically healthy, non-smokers, non-vitamin supplement takers) who had lived in the city for >10 years. Plasma lipoperoxides (LPO), total antioxidant status (TAS), the activity of red blood cells superoxide dismutase (SOD), and plasma glutathione peroxidase (GPx), were studied in all subjects. LPO levels were found significantly higher (p < 0.05) in the elderly subjects in comparison with the adults; in addition, TAS and GPx were higher in adults than among the elderly people (p < 0.0001). Nevertheless, SOD was similar in both groups (p = 0.346). These findings reveal that the elderly residents of Mexico City have TAS and GPx lower than adults, and similar SD activity, probably due to the fact that these antioxidants are neutralizing the higher LPO levels of elderly people. Therefore, this mechanism could be considered as an efficient antioxidant capacity in the elderly, as response to high LPO levels, since the health status, mortality prevalence and life span life of the older people of Mexico City are similar or better than other cities of Mexican Republic.

Se ha propuesto que los sujetos expuestos permanentemente a la contaminación ambiental tienen una deficiente capacidad para contrarrestar el estrés oxidativo (EOx) y que el envejecimiento es un factor causante de dicha alteración. El objetivo de este estudio fue analizar la capacidad antioxidante contra el aumento de lipoperóxidos (LPO) en adultos mayores sanos de la ciudad de México. Se estudiaron 105 adultos residentes de la ciudad de México (44 ± 10,8 años) y 126 adultos mayores (68 ± 7,1 años) clínicamente sanos, no fumadores, sin ingesta de vitaminas antioxidantes, con residencia en esta ciudad por más 10 años. Se cuantificó a todos los sujetos los LPO plasmáticos, capacidad sérica antioxidante total (AT), actividad eritrocitaria de superóxido dismutasa (SOD) y plasmática de glutatión peroxidasa (GPx). Se encontró que los niveles de LPO fueron más altos en los adultos mayores comparados con los jóvenes (p < 0,05); asimismo, AT y GPx fueron mayores en los jóvenes (p < 0,0001). La SOD fue similar en ambos grupos (p = 0,346). Estos hallazgos revelan que los ancianos residentes de la ciudad de México tienen concentraciones más bajas de AT y GPx en comparación con los adultos y una actividad similar de la SOD, debido probablemente a que estos antioxidantes están neutralizando los niveles más altos de los LPO de los ancianos. Por lo tanto, este mecanismo podría ser considerado como una capacidad antioxidante eficiente en los ancianos como respuesta a los altos niveles de LPO, ya que el estado de salud, prevalencia de mortalidad y longevidad de los adultos mayores de la ciudad de México es similar o mejor al de los residentes de otros estados de la República Mexicana.

High density lipoprotein subclasses inhibit low density lipoprotein oxidation.

It has been reported earlier that high density lipoprotein (HDL) is a scavenger of superoxide anions, hydroxyl radicals (OH-) and behaves like superoxide dismutase. In the present investigation, we have studied the effect of HDL subclasses: HDL2 and HDL3 on non enzymatically induced oxidation of low density lipoprotein (LDL) by Fe2+ and sodium ascorbate. Both HDL2 and HDL3 showed protection against the oxidative degradation of LDL-lipids, measured as thiobarbituric acid reactive substance, lipid hydroperoxide and conjugated diene. Oxidized LDL was more electronegative, as evidenced by the increase in relative electrophoretic mobility(REM) on agarose gel. HDL3 significantly protected LDL apoprotein as assessed by reversal of REM after oxidation. HDL2 and HDL3 significantly inhibited the generation of OH- in nonenzymic systems in vitro. However, HDL2 was more active against enzymic formation of OH- as compared to HDL3. Alpha-tocopherol could protect LDL lipids and apoprotein components by Fe2+ mediated oxidation but the effects were lower than HDL subclasses. Our findings suggest that HDL subclasses, the potent scavenger of oxygen derived free radicals, play an important role to prevent the oxidative modifications in LDL.

Effect of administration of galactosamine hydrochloride on rat liver mitochondria.

The effect of galactosamine on liver mitochondrial functions was studied in vivo in rats at 12hr, 24hr and 36hr after the administration of the drug. State 3 respiration decreased significantly with both NAD+ linked and FAD linked substrates. Respiratory control ratio, an index of membrane integrity and P/O ratio which is a measure of phosphorylation efficiency decreased significantly. There was a significant decrease in the activities of NADH dehydrogenase, succinate dehydrogenase and cytochrome oxidase. A significant decrease was also seen on membrane potential, cytochrome aa3, cytochrome b, cytochrome c and on phospholipids of mitochondria. The observed mitochondrial dysfunctions were related to increased lipid peroxidation, which could cause loss of membrane integrity and a decreased rate of phosphorylation. It is proposed that increased lipid peroxidation was responsible for the inhibition on both oxidation and phosphorylation in mitochondria in galactosamine treated rats.

Modulatory effects of N-acetylcysteine and alpha tocopherol on brain glutathione and lipid peroxides in experimental diabetic and endotoxin stressed rats

Two oxidative stress markers, reduced glutathione [GSH] and lipid peroxides [LP] were determined in the whole brain of normal, alloxan-diabetic, endotoxin-stressed and combined diabetic and endotoxin stressed rats. Effects of treatment with the antioxidants; N-acetylcysdiabetic and endotoxin stressed rats. Effects of treatment with the antioxidants; N-acetylcysteine [NAC] and alpha-tocopherol [AT] on the stress makers in the experimental groups were studied. Significant depletion of brain GSH, associated with marked elevation of LP, was observed in all groups especially the combined diabetes-stress model. The oxidation markers were relatively improved towards the control values as a result of treatment with antioxidants. However. At proved to be more effective in the combined diabetes-stress mode. The results draw attention to the possible use of vitamin E preparations as adjuvant in the treatment of the diabetic conditions which are complicated with bacterial infections

Effect of aspirin on isoproterenol induced myocardial infarction--a pilot study.

Effect of aspirin (1.2 mg/100 g body wt orally for 30 days) on myocardial infarction induced by isoproterenol (200 mg/kg body wt, subcutaneously for 2 days) has been studied in rats using activities of creatine kinase, aspartate amino transaminase, alanine amino transaminase and lactate dehydrogenase and levels of lipid peroxides as standard markers. Aspirin treatment is found to counteract the effect of isoproterenol on lipid peroxide formation and associated enzyme changes in serum and heart.

Assessment of lipid peroxidation inhibitory potential of bronchoalveolar lavage fluid from rat lungs.

Studies were carried out to further localize pulmonary tissue lipid peroxidation inhibitor reported earlier to be present in whole lung homogenate in rat. A major portion of the inhibitory material could be lavaged from bronchoalveolar region using various wash media. The material was heat labile and exhibited higher degree of inhibition when recovered from the lungs of mature and aged rats.