Hypolipemic and antioxidant activities from Tamarindus indica L. pulp fruit extract in hypercholesterolemic hamsters

Dietary modifications may significantly reduce cardiovascular disease (CVD) risk factors, including cholesterol and atherosclerosis. The present study addressed the effects of the crude extract from the pulp fruit of Tamarindus indica L. on lipid serum levels and early atherosclerotic lesions in hypercholesterolemic hamsters in vivo, and the extract's antioxidant action, in vitro. Animals were fed on either chow or atherogenic diet during 10 weeks and concomitantly received either water or T indica L. extract for drinking. Treatment of hypercholesterolemic hamsters with the T. indica pulp fruit extract (5%) led to a decrease in the levels of serum total cholesterol (50%), non-HDL cholesterol (73%) and triglyceride (60%), and to an increase of high-density lipoprotein (HDL) cholesterol levels (61%). In vitro, the extract presented radical scavenging ability, as assessed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radicals assays, and led to decreased lipid peroxidation in serum, as assessed by the thiobarbituric acid reactive substances (TBARS) assay. In vivo, the extract improved the efficiency of the antioxidant defense system, as assessed by the superoxide dismutase, catalase and glutathione peroxidase activities. Together these results indicate the potential of tamarind extracts in diminishing the risk of atherosclerosis development in humans. (c) 2005 Elsevier Ltd. All rights reserved.

Capacidade antioxidante e qualidade pós-colheita de abacate 'Fuerte'

A capacidade antioxidante e a qualidade pós-colheita do abacate 'Fuerte' foram avaliadas. Os frutos foram mantidos sob temperatura ambiente (24 ± 1 ºC) e sob refrigeração em 10 ± 1 ºC e 90±5% UR e avaliados durante 15 dias. Determinaram-se a perda de massa e a taxa respiratória. As características físico-químicas avaliadas foram acidez total titulável (AT), sólidos solúveis (SS), ratio, pH, firmeza, atividade da enzima polifenoloxidase (PPO), cor (L, a* e b*), fenólicos totais e atividade antioxidante (AA) por DPPH·. Nas duas condições de armazenamento, o pico respiratório ocorreu no 9º dia.Os frutos mantidos sob temperatura refrigerada apresentaram menor perda de massa e maior firmeza em relação àqueles em temperatura ambiente. O comportamento respiratório refletiu na redução dos valores de AT e no conteúdo de SS que diminuíram a partir do pico de respiração. Os valores de pH aumentaram como consequência da diminuição da AT. Os valores de luminosidade mantiveram-se elevados, observando-se diminuição do componente de cor verde na polpa com o armazenamento. A atividade da PPO diminuiu com o armazenamento. Os valores de AA variaram de 17,6 a 68,7%. O conteúdo de fenólicos totais diminuiu após o pico respiratório, e valores crescentes de AA foram observados mesmo após o 9º dia.

Chemical Composition and Antioxidant and Antimycobacterial Activities of Bromelia balansae (Bromeliaceae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Comparative effects of acute and subacute lycopene administration on chromosomal aberrations induced by cisplatin in male rats

Lycopene is a natural carotenoid, free radical scavenger, and presents protective effects by inhibiting oxidative DNA damage. The objective of the current study was to investigate the cytogenetic effects of a single acute and four daily gavage administrations of lycopene, and to examine possible protective effects on chromosomal damage induced by the antitumor drug cisplatin (cDDP) in rat bone marrow cells. The animals were divided into treatment groups, with three lycopene doses in the acute treatment (2, 4, and 6 mg/kg b.w.), three lycopene doses in the subacute treatment (0.5, 1.0, and 1.5 mg/kg b.w.) with and without cDDP (5 mg/kg b.w. i.p.), and respective controls. The results indicated that lycopene is neither cytotoxic nor clastogenic when compared with the negative controls (P > 0.01). cDDP-treated animals submitted to acute and subacute treatments with different lycopene doses showed a significant reduction (p < 0.01) in the number of abnormal metaphases when compared with the animals treated only with cDDP. The protective effects of lycopene on cDDP-induced chromosomal damage may be attributed to its antioxidant activity. These results suggest that this carotenoid may prove useful in reducing some of the toxic effects associated with certain classes of chemotherapeutic agents. (c) 2006 Elsevier Ltd. All rights reserved.

Metabolismo mitocondrial, radicais livres e envelhecimento

O envelhecimento pode estar associado ao maior acúmulo de lesões celulares decorrentes das espécies reativas do oxigênio e do nitrogênio derivadas do metabolismo mitocondrial. Com a progressão da idade, há acúmulo de proteínas, lipídeos, carboidratos e DNA oxidados em relação a organismos jovens, de acordo com a teoria dos radicais livres. Entretanto, nem sempre os idosos ou animais envelhecidos apresentam maior estresse oxidativo que os jovens. Este artigo discute o paradoxo da teoria dos radicais livres de acordo com a teoria da biogênese da manutenção adequada do metabolismo mitocondrial. Diversos fatores podem contribuir para a redução do estresse oxidativo, como a hormese induzida pela prática regular de exercícios físicos, a restrição calórica, a ingestão de antioxidantes nutricionais e o aumento da produção de antioxidantes celulares que. em conjunto, estes promovem a expressão das sirtuínas e das proteínas do choque térmico, protegendo a integridade e funcionalidade mitocondriais, reduzindo o estresse oxidativo e nitrosativo, o que está associado à redução do envelhecimento e aumento da longevidade.

Protection of insulin-producing cells against toxicity of dexamethasone by catalase overexpression

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeito da complexação de metais aos antiinflamatórios na ação contra agentes oxidativos e radicais livres: ação do cetoprofeno

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Interconverting flavanone glucosides and other phenolic compounds in Lippia salviaefolia Cham. ethanol extracts

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Tomate salada: uma alternativa como fonte de antioxidante para uso tópico

Tomato Salad: An Alternative as Antioxidant Source for Topic Use. Tomato is the principal source of lycopene, a carotenoid with high antioxidant activity which can be used topically as a phytocosmetic to combat skin aging. The aim of this study was to get a lycopene-rich extract from salad tomato pulp. The extract was analyzed using UV/vis spectroscopy, thin layer chromatography and high performance liquid chromatography. Oxidant activity was analyzed using the free radical DPPH method. The presence of lycopene in the salad tomato was confirmed. It was present in the apolar fraction rich in carotenoids, which was 96.70% lycopene. In the evaluation of the antioxidant activity, using the radical DPPH, the extract showed activity (IC(50) = 0,311 mg/mL). We conclude that the salad tomato can be used as a source of antioxidants for topic use.

Evaluation of DNA damage and lipoperoxidation of propofol in patients undergoing elective surgery

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Trimetazidine and N-acetylcysteine in attenuating hind-limb ischemia and reperfusion injuries: experimental study in rats

Aim. Lower-limb traumatic injury associated with ischemia and followed by reperfusion (I/R) is a common severe situation in muscle lesions due to trauma and hypoxia followed by local and systemic injuries induced by oxygen-derived free radical release during reperfusion. The aim of this study was to evaluate the attenuating effects of trimetazidine (TMZ) and N-acetylcysteine (NAC) in such situation.Methods. The muscles at the root of the right hind limb of Wistar rats were cross-sectioned, preserving femoral vessels and nerves and clamping the femoral artery for four hours. The clamp was then released and the femoral artery has been reperfused for 2 hours. Rats were randomly divided in groups of ten as follows: Group 1: sham I/R, treated with saline; Group 2: I/R, treated with saline; Group 3: sham I/R, treated with TMZ (7.5 mg/kg/dose); Group 4: sham I/R, treated with NAC (375 mg/kg/dose); Group 5: I/R treated with TMZ (7.5 mg/kg/dose); Group 6: I/R treated with NAC (375 mg/kg/dose). All rats received two intravenous bolus injections of the drugs, one before ischemia and one before reperfusion. Oxidative stress in plasma (MDA, total, oxidized and reduced glutathione), creatinephosphokinase (CPK), optical and electron microscopy and pelvic extremity circumference and volume were studied.Results. No statistical differences were found between the groups for MDA or total and reduced glutathione. Oxidized glutathione increased significantly in groups 5 and 2. Limb circumference as well as limb volume increased in all groups over time, mainly in groups 5, 2 and 1. CPK increased in all groups, being highest in groups 5, 6 and 2. Histological lesions were present in all but sham groups, being less severe in group 6. Soleus muscle analyses at electron microscopy exhibit some degree of alteration in all groups.Conclusion. This experimental model simulated severe limb trauma associated with ischemia and reperfusion, and, as such, it was aggressive, causing severe injury and local inflammatory reaction. The model did not show antioxidant action from NAC, and possible antioxidant action from TMZ was insufficient to attenuate tissue injuries. [Int Angiol 2009;28:412-7]

Decreased oxidative stress in patients with ulcerative colitis supplemented with fish oil omega-3 fatty acids

OBJECTIVE: the potential pathogenicity of free radicals may have a pivotal role in ulcerative colitis. Fish oil omega-3 fatty acids exert anti-inflammatory effects on patients with ulcerative colitis (UC), but the precise mechanism of the action of fish oil on oxidative stress is still controversial. The aim of the present work was to verify the blood oxidative stress in patients with UC and determine whether the association of sulfasalazine to fish oil omega-3 fatty acids is more effective than isolated use of sulfasalazine to reduce the oxidative stress.METHODS:, Nine patients (seven female and two male; me. an age = 40 +/- 11 y) with mild or moderate active UC were studied in a randomized crossover design. In addition to their usual medication (2 g/d of sulfasalazine), they received fish oil omega-3 fatty acids (4.5 g/d) or placebo for 2-mo treatment periods that were separated by 2 mo, when they only received sulfasalazine. Nine healthy individuals served as control subjects to study the oxidative stress status. Disease activity was assessed by laboratory indicators (C-reactive protein, alpha(1)-acid glycoprotein, alpha(1)-antitrypsin, erythrocyte sedimentation rate, albumin, hemoglobin, and platelet count), sigmoidoscopy, and histology scores. Analysis of oxidative stress was assessed by plasma chemiluminescence and erythrocyte lipid peroxidation, both induced by tert butyl hydroperoxide (t-BuOOH) and by plasma malondialdehyde. Antioxidant status was assayed by total plasma antioxidant capacity (TRAP) and microsomal lipid peroxidation inhibition (LPI). Superoxide dismutase (SOD) and catalase erythrocyte enzymatic activities were also determined.RESULTS: No significant changes were observed in any laboratory indicator or in the sigmoidoscopy or histology scores, with the exception of erythrocyte sedimentation rate, which decreased with both treatments. Oxidative stress was demonstrated by significant decreases in TRAP and LPI levels, increased chemiluminescence induced by t-BuOOH, and higher SOD activity in patients with UC. Treatment with fish oil omega-3 fatty acids reverted the chemiluminescence induced by t-BuOOH and LPI to baseline levels but that did not occur when patients received only sulfasalazine. Levels of plasma malondialdehyde, erythrocyte lipid peroxidation, and catalase were not different from those in the control group.CONCLUSIONS: the results indicated that plasma oxidative stress occurs in patients with UC, and there was a significant decrease when the patients used sulfasalazine plus fish oil omega-3 fatty acids. However, there was no improvement in most laboratory indicators, sigmoidoscopy, and histology scores. The results suggested that omega-3 fatty acids may act as free radical scavengers protecting the patients against the overall effect of oxidative stress. (C)Elsevier B.V. 2003.