Marcadores de estrés oxidativo en pacientes con esclerosis múltiple durante un brote y su remisión / Oxidative stress markers in patients with multiple sclerosis during an outbreak and its remission / Marcadores de estresse oxidativo em pacientes com esclerose múltipla durante um surto e sua remissão

La esclerosis múltiple remitente-recurrente (EM-RR) es una enfermedad desmielinizante del sistema nervioso central. A fin de entender la asociación del estrés oxidativo a nivel periférico con la recaída de la enfermedad se determinaron los niveles de marcadores de estrés oxidativo en plasma de pacientes en la recaída o brote y una semana después de la misma. Se analizaron muestras de 60 personas (20 pacientes con recaída, 20 pacientes sin recaída y 20 controles sanos). Se cuantificaron mediante métodos espectrofotométricos las actividades enzimáticas de óxido nítrico sintasa (ONS), glutatión peroxidasa (GPx), los niveles de lipoperóxidos y nitritos-nitratos y la fluidez de membrana. En el brote de la enfermedad aumentan significativamente los niveles de las actividades enzimáticas de ONS y GPx y los niveles de nitritos-nitratos y lipoperóxidos (p<0,01 en todos los casos), al ser comparados con los de individuos sanos. Dichos parámetros disminuyeron significativamente una semana después de iniciado el brote. Además, los parámetros evaluados se mantuvieron elevados en pacientes que no experimentaron un brote de la enfermedad cuando se los comparó con individuos sanos. La fluidez de membrana en los pacientes con y sin brote fue similar a la de los controles. En conclusión, el estrés oxidativo es un componente importante en los pacientes con esclerosis múltiple.

Recurrent-remitting multiple sclerosis (RR-MS) is a demyelinating disease of the central nervous system. In order to understand the association of oxidative stress at the peripheral level with the relapse of the disease, the levels of oxidative stress markers in plasma of patients in the relapse or outbreak and one week after relapse were determined. Samples of 60 subjects were analyzed (20 patients in relapse, 20 patients without relapse, and 20 healthy controls). The enzymatic activities of nitric oxide synthase (NOS), glutathione peroxidase (GPx), lipoperoxides and nitrite-nitrate levels and membrane fluidity were quantified by spectrophotometric methods. In relapse, the levels of enzymatic activities of NOS and GPx, and the levels of lipoperoxides and nitrites-nitrates were significantly increased (p<0.01, in all cases), compared with healthy individuals. These parameters decreased significantly 1 week after the start of the outbreak. In addition, the parameters evaluated remained high in patients who did not experience an outbreak of the disease compared to healthy subjects. The membrane fluidity in the patients with and without outbreak was similar to that of the controls. In conclusion, oxidative stress is an important component in patients with multiple sclerosis.

A esclerose múltipla recorrente-remitente (EM-RR) é uma doença desmielinizante do sistema nervoso central. Para compreender a associação do estresse oxidativo a nível periférico com a recaída da doença foram determinados os níveis de marcadores de estresse oxidativo em plasma de doentes na recaída ou surto e uma semana após a recaída. Foram analisadas a amostras de 60 pessoas (20 pacientes com recaída, 20 pacientes sem recaída e 20 controles saudáveis). As atividades enzimáticas de óxido nítrico sintase (ONS), glutationa peroxidase (GPX), os níveis de lipoperóxidos e nitritos-nitratos e a fluidez de membrana foram quantificadas por métodos espectrofotométricos. No surto da doença aumentam em forma significativa os níveis da atividade enzimática de ONS e GPX, e os níveis de nitritos-nitratos e lipoperóxidos (p<0,01 em todos os casos), em comparação com os indivíduos saudáveis. Esses parâmetros diminuíram significativamente uma semana após o início do surto. Além disso, os parâmetros avaliados permaneceram elevados em pacientes que não experimentaram um surto da doença quando comparados com indivíduos saudáveis. A fluência de membrana nos pacientes com e sem surto foi semelhante à dos controles. Em conclusão, o estresse oxidativo é um componente importante nos pacientes com esclerose múltipla.

Aumento de estresse oxidativo no sangue de pacientes com ostomia / Increased oxidative stress in the blood of ostomy patients

ABSTRACT BACKGROUND: Ostomy is a surgical procedure that creates a stoma that aims to construct a new path for the output of feces or urine. The relationship of oxidative stress (OxS) markers in patients with ostomy is still poorly described. OBJECTIVE: The present study was aimed at investigating the changes in oxidative stress parameters in peripheral blood collected from ostomy patients when compared with a healthy control group. METHODS: It was evaluated 29 ostomy patients and 30 healthy control patients. The oxidative stress parameters evaluated were: lipid peroxidation [lipid hydroperoxide (LPO), 8-isoprostane (8-ISO) and 4-hydroxynonenal (4-HNE)], protein oxidation and nitration [carbonyl and 3-nitrotyrosine (3-NT)] and DNA oxidation [8-hydroxy-2'-deoxyguanosine (8-OHDG)] in serum from ostomy patients compared to health controls. RESULTS: The data showed an increase of LPO, 8-ISO, 4-HNE, 3-NT and 8-OHDG in serum collected from ostomy patients when compared to healthy controls. CONCLUSION: The findings support the hypothesis that ostomy triggers the oxidative stress observed in the blood collected from these patients.

RESUMO CONTEXTO: Ostomia é um procedimento cirúrgico que cria um estoma com objetivo de construir um novo caminho para a saída das fezes ou urina. A relação dos marcadores de estresse oxidativo em pacientes ostomizados ainda é pouco descrita. OBJETIVO: O presente estudo tem como objetivo investigar as alterações dos parâmetros de estresse oxidativo em sangue de pacientes ostomizados comparados a controles saudáveis. MÉTODOS: Foram avaliados 29 pacientes ostomizados e 30 controles saudáveis. Os parâmetros de estresse oxidativo avaliados foram: peroxidação lipídica [hidroperóxido de lipídio (LPO), 8-isoprostano (8-ISO) e 4-hidroxinonenal (4-HNE)], oxidação e nitração de proteínas [carbonila e 3-nitrotirosina (3-NT)] e oxidação do DNA [8-hidroxi-2'-desoxiguanosina (8-OHDG)] em soro de pacientes ostomizados comparados a controles saudáveis. RESULTADOS: Os dados mostraram um aumento de LPO, 8-ISO, 4-HNE, 3-NT e 8-OHDG em soro de pacientes ostomizados em comparação a controles saudáveis. CONCLUSÃO: Os achados sustentam a hipótese de que a ostomia desencadeia o estresse oxidativo observado no sangue coletado destes pacientes.

Chelation therapy with desferrioxamine does not normalize ferritin level but attenuates oxidative damage and improves total antioxidant level in malaysian Chinese β-thalassaemia major patients / La terapia de quelación con deferoxamina no normaliza los niveles de ferritinaa pero atenúa el daño oxidativo y mejora el nivel antioxidante total en los pacientes sinomalayos que padecen de talasemia β

Beta-thalassaemia major causes severe anaemia and patients with it may be transfusion-dependent for life. Regular blood transfusions cause iron-overload that leads to oxidative damage which can hasten mortality. The objective of this research was to study the oxidant-antioxidant indices in β-thalassaemia major patients at the University of Malaya Medical Centre (UMMC) who were on desferrioxaminechelation or without chelation therapy. Blood was collected from 39 Chinese patients and 20 controls. Plasma and peripheral blood mononuclear cell lysates (PBMC) were extracted and biochemical tests to evaluate oxidative stress were performed. Oxidative stress was evident in these patients as advanced oxidized protein products (AOPP) and lipid hydroperoxides were elevated, whereas glutathione peroxidase activity and the ferric reducing antioxidant power (FRAP) were reduced. The catalase activity in the patients' PBMC was elevated, possibly as a compensatory mechanism for the reduced glutathione peroxidase activity in both red blood cells and PBMC. The lower FRAP and higher AOPP levels in the non-chelated patients compared with the chelated patients were indicative of a lower oxidative stress level in the chelated patients. The ferritin levels in the chelated and non-chelated patients were high and the mean levels of liver enzyme activities in the majority of patients were elevated regardless of chelation therapy. In conclusion, this study indicates that desferrioxamine chelation therapy does not normalize ferritin level but attenuates oxidative damage and improves total antioxidant level in Malaysian Chinese β-thalassaemia major patients.

La beta-talasemia mayor causa anemia severa, y los pacientes con este padecimiento pueden hacerse dependientes de las transfusiones de sangre por el resto de sus vidas. Las transfusiones regulares de sangre dan lugar a una sobrecarga de hierro que conduce al dano oxidativo, el cual a su vez puede acelerar la mortalidad. El objetivo de esta investigación fue estudiar las tasas de oxidantesantioxidantes en pacientes de beta-talasemia mayor en el Centro Médico de la Universidad de Malaya, tanto aquellos bajo tratamiento de quelación con deferoxamina, como aquellos sin terapia de quelación alguna. Se recogieron muestras de sangre de 39 pacientes chinos y 20 controles. Se extrajeron plasma y lisados de celulas mononucleares perifericas (CMSP), y se realizaron pruebas bioquimicas para evaluar el estrés oxidativo. El estrés oxidativo era evidente en estos pacientes en forma de productos avanzados de oxidación de proteinas (PAOP), y los hidroperoxidos de lipidos eran elevados, en tanto que la actividad de glutatión peroxidasa y el poder reductor ferrico/antioxidante (FRAP) era reducida. La actividad de la catalasa en los pacientes de CMSP era elevada, posiblemente como un mecanismo compensatorio frente a la actividad de glutatión peroxidasa reducida tanto en los globulos rojos como en las CMSP. Los niveles más bajos de FRAP y los más altos de PAOP en los pacientes no quelados en comparación con los pacientes quelados, indicaban un bajo nivel de estrés oxidativo en los pacientes quelados. Los niveles de ferritina tanto en los pacientes quelados como en los no quelados, eran altos, y los niveles promedio de actividades enzimaticas del higado fueron elevados en la mayoria de los pacientes, independientemente de la terapia de quelación. En conclusión, este estudio indica que la terapia de quelación con deferoxamina no normaliza el nivel de ferritina, pero en cambio atenua el daño oxidativo, y mejora el nivel antioxidante total en los pacientes sinomalayos afectados por la betatalasemia mayor.

Effect of vagus nerve stimulation on serum level of pentraxin-3 at focal transient cerebral ischemia and reperfusion in adult male new zealand rabbits

Regarding that oxidative stress, distinguished by the overproduction of reactive oxygen species [ROS], has been implicated in the pathophysiology of cerebral ischemia. Pentraxin-3 [PTX-3] plays an important role in innate immune responses and in inflammatory disease. However, no study has evaluated PTX3 in animal models with cerebral ischemia and reperfusion. Aim of the work: is to assess the anti-inflammatory and anti-oxidant effect of vagus nerve stimulation [VNS] on focal model of transient cerebral ischemia and reperfusion. Focal transient cerebral I/R was induced by occlusion of right common carotid artery [CCA] for 30 minutes followed by reperfusion for one hour. Stimulating electrodes were implanted on the cervical part of the right vagus nerve. VNS started 15 min after right CCA ligation and lasted 15 min after reperfusion and delivered for 30 s at every 5 min. All the procedures were duplicated but no stimulus was delivered in the control group. Serum level of pentraxin-3, lipid peroxide and total thiols were determined at baseline, at end of ischemia and at end of reperfusion and the animal decapitated and neuronal damage was evaluated. VNS causes reduction of the ischemic features with revival of the cell shape and size, increased serum levels of pentraxin-3 and total thiols whereas the level of lipid peroxide was diminished. The observed diversity in pentraxin-3, lipid peroxide and total thiols levels in cerebral I/R, which may reflect relative roles in the bioactivity of the animal. The anti-inflammatory and anti-oxidant role of vagus nerve stimulation in cerebral I/R in rabbits, may represent a marker of altered cerebral function, that provide potential therapeutic applications

Effects of Urtica dioica on hepatic ischemia-reperfusion injury in rats

OBJECTIVES: To evaluate the effects of Urtica dioica on hepatic ischemia-reperfusion injury. METHODS: Thirty adult male Wistar albino rats were divided into three groups: sham group (group 1), control group (group 2), and Urtica dioica group (group 3). All the rats were exposed to hepatic ischemia for 60 min, followed by 60 min of reperfusion. In group 2, a total of 2 ml/kg 0.9 percent saline solution was given intraperitoneally. In group 3, a total of 2 ml/kg Urtica dioica was given intraperitoneally. At the end of the procedure, liver tissue and blood samples were taken from all rats. Serum aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, ceruloplasmin, catalase, paraoxonase, arylesterase, and lipid hydroperoxide levels were measured. Liver tissue histopathologies were also evaluated by light microscopy. RESULTS: Serum aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase levels were significantly higher in group 2 than in group 1, and significantly lower in group 3 than in group 2. Also, group 2 had higher serum lipid hydroperoxides and ceruloplasmin levels but lower catalase, paraoxonase, and arylesterase levels than group 1. In group 3, serum lipid hydroperoxides and ceruloplasmin levels were significantly lower, and catalase, paraoxonase, and arylesterase levels were higher than those in group 2. Histopathological examination showed that liver tissue damage was significantly decreased in group 3 compared with group 2. CONCLUSIONS: Urtica dioica has a protective effect on the liver in hepatic ischemia-reperfusion-injured rats.

[Effects of green tea extract on experimentally induced toxicosis of carrageenan in male albino rats]

Green tea extract [GTE] is rich in polyphenolic compounds whose antioxidant activity is several fold higher than that of vitamins C and E. In the present study, the effect of GTE on the carrageenan toxicosis in male albino rats using intra-articular injection of 0.1 ml of carrageenan solution was investigated. Three groups of 10 rats each were used: Control, Carrageenan alone, and carrageenan plus GTE. After one week of treatment, the plasma levels of lipid -peroxides and nitric oxide as well as total thiol were measured. The histopathological examination of the liver, spleen and kidneys of the three groups were performed .Animals treated with carrageenan alone showed significant increase value in the levels of both lipid peroxides and nitric oxide in comparison to the control group. In rats that received GTE, the changes in plasma levels of lipid peroxides and nitric oxide were not statistically present from the control group, while the total thiol levels in the GTE group were significantly increased [p<0.05] in comparison with carrageenan only and control groups

study of lipid peroxidation status in patients of stroke

During past few years identification of many molecules that participate in neuronal death and particularly apoptosis by various experimental studies, has contributed to the information on pathogenesis of ischemic brain injury and oxidative stress has been regarded as one of the mechanisms. The present study has been undertaken to evaluate a free radical, as a measure of lipid peroxidation in patients with cerebral infarction and haemorrhage and also to correlate its level with lesion size and its outcome in the patient. The study included 50 patients of stroke [25 each with infarction and haemorrhage] while 25 comparable subjects served as control. Serum malondialdehyde [SMDA] levels was estimated on the first day of admission in both the study groups as a measure of lipid peroxidation status in these subjects and the lesion size was measured by computed tomography. The mean SMDA level in thrombotic and haemorrhagic group was 4.16 +/- 0.04 nmol/dL and 4.03 +/- 1.1 nmol/dL while it was 1.9 +/- 0.4 nmol/dL in control. The difference in the mean SMDA levels in the controls and study subjects were statistically significant [p<0.001], while the difference between the thrombotic and haemorrhagic groups was statistically insignificant. The mean size of large lesion in thrombotic group was 13.6 +/- 3.0 cm[2] while it was 5.0 +/- 1.4 cm[2] for small lesions. The corresponding values of SMDA with these lesions were 4.98 +/- 0.9 nmol/dL and 3.23 +/- 0.4 nmol/dL. In haemorrhagic group mean size of large lesion was 13.3 +/- 1.9 cm[2] while that of small lesion was 6.6 +/- 1.9 cm[2]. The respective SMDA levels were 5.0 +/- 0.7 nmol/dL and 3.13 +/- 0.2 nmol/dL. There was marked statistical significance [p<0.001] in the SMDA levels between the small and large lesions in both study groups. A significant correlation existed between serum MDA levels, lesion size and early outcome in patients with stroke [p<0.001]. It is, therefore, concluded that the SMDA levels are raised in patients with acute stroke and hence are an indicator of the involvement of lipid peroxidation in its pathophysiology and can also be used as a prognostic markers in subjects with stroke

Estado oxidante/antioxidante total em recém-nascidos ictéricos antes e depois da fototerapia / Total oxidant/antioxidant status in jaundiced newborns before and after phototherapy

OBJETIVO: Avaliar o efeito da fototerapia no estado oxidante e antioxidante no soro de recém-nascidos a termo com hiperbilirrubinemia. MÉTODO: Trinta e quatro recém-nascidos a termo com idades entre 3 e 10 dias submetidos a fototerapia foram avaliados. O estado antioxidante do soro foi determinado pela capacidade antioxidante total e por componentes antioxidantes individuais: vitamina C, ácido úrico, albumina, concentração de tiol e bilirrubina total. O estado oxidante foi avaliado através do estado oxidante total, índice de estresse oxidativo e componentes oxidantes individuais: malondialdeído e níveis de hidroperóxido lipídico. RESULTADOS: As concentrações de vitamina C, ácido úrico, bilirrubina total e malondialdeído foram significativamente mais baixas, enquanto que o estado oxidante total, níveis de hidroperóxido lipídico e o índice de estresse oxidativo foram significativamente maiores após a fototerapia (p < 0,05). Houve correlações positivas significativas entre a bilirrubina sérica total e a concentração de malondialdeído (r = 0,434, p = 0,001). CONCLUSÕES: Embora a concentração de malondialdeído tenha diminuído após a fototerapia, esta exerce um efeito negativo sobre as diversas partes do sistema de defesa oxidante/antioxidante em recém-nascidos a termo ictéricos, expondo-os a um possível estresse oxidativo.

OBJECTIVE: To assess the effect of phototherapy on serum oxidant and antioxidant status in hyperbilirubinemic full-term newborns. METHOD: Thirty-four full-term infants from 3 to 10 days of age exposed to phototherapy were studied. The serum antioxidant status was assessed by measuring the total antioxidant capacity (TAC) and individual antioxidant components: vitamin C, uric acid, albumin, thiol contents and total bilirubin. The oxidant status was assessed by determining the total oxidant status (TOS), oxidative stress index (OSI) and individual oxidant components: malondialdehyde (MDA), and lipid hydroperoxide levels. RESULTS: Vitamin C, uric acid, total bilirubin and MDA concentration were significantly lower, whereas serum TOS, lipid hydroperoxide and OSI levels were significantly higher after phototherapy (p < 0.05). There were significant positive correlations between serum total bilirubin and MDA (r = 0.434, p = 0.001). CONCLUSIONS: Although the MDA level was reduced after phototherapy, phototherapy has a negative impact on numerous parts of the oxidant/antioxidant defense system in jaundiced full-term newborns, exposing them to potential oxidative stress.

Liver and kidney toxicity in chronic use of opioids: an experimental long term treatment model.

In this study, histopathological and biochemical changes due to chronic usage of morphine or tramadol in liver and kidney were assessed in rats. Thirty male Wistar rats (180-220 g) were included and divided into three groups. Normal saline (1 ml) was given intraperitoneally as placebo in the control group (n = 10). Morphine group (n = 10) received morphine intraperitoneally at a dose of 4, 8, 10 mg/kg/day in the first, second and the third ten days of the study, respectively. Tramadol group (n = 10), received the drug intraperitoneally at doses of 20, 40 and 80 mg/kg/day in the first, second and the third ten days of the study, respectively. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), creatinin, blood urea nitrogen (BUN) and malondialdehyde (MDA) levels were measured in the serum. Liver and kidney specimens were evaluated by light microscopy. Serum ALT, AST, LDH, BUN and creatinin levels were significantly higher in morphine group compared to the control group. Serum LDH, BUN and creatinin levels were significantly increased in the morphine group compared to the tramadol group. The mean MDA level was significantly higher in morphine group compared to the tramadol and control groups (P < 0.05). Light microscopy revealed severe centrolobular congestion and focal necrosis in the liver of morphine and tramadol groups, but perivenular necrosis was present only in the morphine group. The main histopathologic finding was vacuolization in tubular cells in morphine and tramadol groups. Our findings pointed out the risk of increased lipid peroxidation, hepatic and renal damage due to long term use of opioids, especially morphine. Although opioids are reported to be effective in pain management, their toxic effects should be kept in mind during chronic usage.

Protective effect of Terminalia chebula against experimental myocardial injury induced by isoproterenol.

Cardioprotective effect of ethanolic extract of Terminalia chebula fruits (500 mg/kg body wt) was examined in isoproterenol (200 mg/kg body wt) induced myocardial damage in rats. In isoproterenol administered rats, the level of lipid peroxides increased significantly in the serum and heart. A significant decrease was observed in the activity of the myocardial marker enzymes with a concomitant increase in their activity in serum. Histopathological examination was carried out to confirm the myocardial necrosis. T. chebula extract pretreatment was found to ameliorate the effect of isoproterenol on lipid peroxide formation and retained the activities of the diagnostic marker enzymes.

Effect of a polyherbal formulation, Ambrex, on butylated hydroxy toluene (BHT) induced toxicity in rats.

Effect of polyherbal formulation Ambrex was evaluated in butylated hydroxytoluene (BHT) induced toxicity of lungs and liver in rats. Toxicity was produced by administering BHT (500 mg/kg/day) for 3 days. Lung damage was evidenced by elevated levels of broncho alveolar lavage fluid (BAL) parameters such as protein, lactate, lactate dehydrogenase (LDH), alkaline phosphatase (ALP), acid phosphatase (ACP) and glucose-6-phosphate dehydrogenase (G6PDH). Liver damage was proved by elevated levels of serum protein and markers such as LDH, ALP, aspartate amino transferase (AST), alanine amino transferase (ALT), decreased level of lipid peroxides (LPO) in serum and glutathione (GSH) in liver. Administration of aqueous suspension of Ambrex (50 mg/kg orally) retained these elevated levels of BAL-protein, lactate, LDH, ALP, ACP, G6PDH and serum-protein, LDH, ALP, AST and ALT at near normal values. Decreased level of liver GSH was retained at near normalcy in Ambrex pretreated BHT-administered animals. There was no change in liver LPO in all the four groups.

Oxidative stress and anti-oxidant status in leprosy patients.

Severe oxidative stress has been reported in leprosy patients because of malnutrition and poor immunity. The purpose of this study was to investigate the serum lipid peroxidation products, serum LDH and important free radical scavenging enzymes, i.e. superoxide dismutase (SOD), and catalase and anti-oxidant glutathione levels and total anti-oxidant status, in different types of leprosy patients. The subjects for this study were normal human volunteers (NHVs, n=14), paucibacillary leprosy patients (PB, n=18), untreated MB patients (MB1, n=18), MB patients under treatment (MB2, n=19), and MB patients released from treatment (RFT) (MB3, n=28). The levels of lipid peroxidation product, malondialdehyde (MDA), and LDH increased significantly (p<0.001) in MB (MB1, MB2, MB3) patients, and both gradually decreased with clinical improvement following MDT. The levels of SOD, catalase and glutathione, and the total anti-oxidant status decreased significantly in MB (MB1, MB2, MB3) patients (p<0.001), in comparison with NHVs. They gradually increased with clinical improvement with MDT. There was no significant variation of these parameters in PB leprosy patients in comparison with healthy volunteers. High free radical activity and low anti-oxidant levels observed in MB (MB1, MB2, MB3) leprosy patients indicate that there is an oxidative stress in MB cases, irrespective of the treatment status and suggest a suitable anti-oxidant therapy to prevent possible tissue injury.

Plasma lipoperoxides: a preliminary reference range.

We measured lipoperoxides, as malonaldehyde (MDA) by thiobarbituric acid reaction in serum from 80 male and 120 female volunteers to establish reliable reference values and to compare possible sex- and age- related differences. In the present study women had higher MDA concentration in serum than do men (p<0.05) and older subjects had higher values (p<0.05). These age related results support the suggestions that lipid peroxidation increases with increasing age.

Hypoglycemic effect of methanol extract of Phyllanthus amarus Schum & Thonn on alloxan induced diabetes mellitus in rats and its relation with antioxidant potential.

Methanolic extract of P. amarus was found to have potential anti-oxidant activity as it could inhibit lipid peroxidation, and scavenge hydroxyl and superoxide radicals in vitro. The amount required for 50% inhibition of lipid peroxide formation was 104 microg/ml and the concentrations needed to scavenge hydroxyl and superoxide radicals were 117 and 19 microg/ml respectively. The extract was found to reduce the blood sugar in alloxan diabetic rats at 4th hr by 6% at a dose level of 200 mg/kg body wt and 18.7% at a concentration of 1000 mg/kg body wt. Continued administration of the extract for 15 days produced significant (P < 0.001) reduction in blood sugar. On 18th day after alloxan administration values were almost similar to normal in the group taking 1000 mg/kg body wt.

Hypolipidemic and antiperoxidative effect of coconut protein in hypercholesterolemic rats.

Effect of coconut protein in rats fed high fat cholesterol containing diet on the metabolism of lipids and lipid peroxides was studied. In addition, effect of coconut protein were compared with rats fed L-arginine. The results indicate that those fed coconut protein and those fed L-arginine showed significantly lower levels of total cholesterol, LDL+ VLDL cholesterol, Triglycerides and Phospholipids in the serum and higher levels of serum HDL cholesterol. The concentration of total cholesterol, triglycerides and phospholipids in the tissues were lower in these groups. There was increased hepatic cholesterogenesis which is evident from the higher rate of incorporation of labeled acetate into free cholesterol. Increased conversion of cholesterol to bile acids and increased fecal excretion of bile acids were observed. Feeding coconut protein results in decreased levels of Malondialdehyde in the heart and increased activity of Superoxide dismutase and Catalase. Supplementation of coconut protein causes increased excretion of urinary nitrate which implies higher rate of conversion of arginine into nitric oxide. In the present study, the arginine supplemented group and the coconut protein fed group produced similar effects. These studies clearly demonstrate that coconut protein is able to reduce hyperlipidemia and peroxidative effect induced by high fat cholesterol containing diet and these effects are mainly mediated by the L-arginine present in it.

Influence of rice bran oil on serum lipid peroxides and lipids in human subjects.

To study the effect of rice bran oil (RBO) on serum lipids and lipid peroxides in human volunteers. Nine healthy volunteers, aged between 42 to 57 years were given 75 ml of RBO thrice daily as the cooking medium with break fast, lunch and dinner for a period of 50 days. At the beginning and at the end of 50 days, 5 ml of blood were drawn from an ante cubital vein. Serum lipids and lipid peroxides levels were estimated from the blood sample. There was a significant decrease in the levels of lipid peroxides, triglycerides, LDL, VLDL, and total cholesterol in human volunteers who switched over to RBO. RBO has evidently antioxidant and antilipidemic activities in human subjects.

Comparison of antioxidant efficacy of vitamin E, vitamin C, vitamin A and fruits in coronary heart disease: a controlled trial.

OBJECTIVE: To determine the efficacy of various antioxidant vitamins and a major dietary source of antioxidants (fruits) we performed a randomized controlled trial. METHODS: 175 successive patients with coronary heart disease (CHD) presenting to our centre were recruited and using a Latin-square design divided into five groups of 35 each. The groups were matched for age, lifestyle and dietary variables, clinical diagnosis and drug treatment status. None of the patients was on lipid-lowering drugs. Supplemental vitamins were stopped for one month before study began and American Heart Association Step II dietary advice was given to all. At baseline, total cholesterol, triglycerides, HDL and LDL cholesterol and lipid peroxide measured as thiobarbaturic acid reactive substances (TBARS) were determined. Group I received placebo capsules; Group II vitamin E 400 units/day; Group III vitamin C 1,000 mg; Group IV vitamin A 25,000 IU; Group V received 400 gm of fruit daily. Lipids and lipid peroxide levels were determined at 30 days follow-up. RESULTS: Response rate in various groups varied form 86% to 91%. No significant changes in total, HDL, LDL cholesterol and triglyceride levels were seen in Groups I, II, III and IV (paired t-test p > 0.05). In Group V there was a significant decrease in total cholesterol (-7.8 +/- 11.1%), and LDL cholesterol (-11.2 +/- 25.4%) and increase in HDL cholesterol (+12.9 +/- 20.1%) (paired t-test p < 0.01). Lipid peroxide levels decreased significantly in all the treatment groups (p < 0.01). This decrease was the highest in Group II (vitamin E; -36.4 +/- 17.7%) as compared to Group III (vitamin C -19.8 -/+ 10.8%); Group IV (vitamin A -5.4 +/- 17%) and Group V (fruits -13.1 +/- 12.0%). CONCLUSIONS: All the antioxidant vitamins and fruits significantly decrease lipid peroxide levels and oxidant load in CHD patients. However, fruits are the best choice as they also favourably modify the lipid profile.

Diferencias en antioxidantes plasmáticos según nivel socioeconómico en mujeres chilenas / Differences in plasma antioxidants according to socioeconomic level in chilean women

Background: Free radical-mediated oxidative damage is a known initial event in atherogenesis. Cardiovascular disease is frequent in the Chilean population showing differences in the prevalence of risk factors of the disease according to socioeconomic level (SEL). Aim: To determine levels of antioxidants and lipid peroxides in Chilean women from different SEL. Patients and methods: Blood samples were taken from 81 women for measurements of plasma ascorbic acid, ß-carotene, a-tocopherol, licopene, ubiquinol, glutathione, total plasma antioxidant capacity, and lipid peroxides (TBARS). Results:Individuals in the lower SEL showed reduced levels of plasma ß-carotene, ascorbic acid, a-tocopherol, and ubiquinol compared to women in the higher SEL. There were no differences between groups in the plasma levels of glutathione, total antioxidant capacity, or TBARS. Conclusions: The results could be explained in part by the higher consumption of fruits and vegetables in women from the upper SEL

Raised platelet thiobarbituric acid-reacting substances in proliferative Eales' disease.

BACKGROUND: Platelets are an elective site for oxidative stress owing to their high content of polyunsaturated fatty acid. Increased lipid peroxidation and elevated platelet thiobarbituric acid-reacting substances (TBARS) signal oxidative stress. This possibly leads to retinal neovascularization in Eales' disease. METHODS: TBARS levels were estimated in consecutive cases of Eales' disease with neovascularisation (n = 26), Eales' disease without neovascularisation (n = 17) and healthy controls (n = 17). RESULTS: Platelet TBARS levels in the cases of Eales' disease with neovascularisation, Eales' disease without neovascularisation, and healthy controls were 0.66 +/- 0.1, 0.57 +/- 0.11 and 0.42 +/- 0.14 n moles TBARS formed/hour/10(8) platelets respectively. Student's t-test showed a significant increase in platelet TBARS levels in cases with neovascularisation as compared to cases without neovascularization (p < 0.05) and healthy controls (p < 0.01). CONCLUSION: The increase in platelet TBARS levels in proliferative Eales' disease is consistent with an emerging view that lipid peroxides may be associated with retinal neovascularisation.