Reducción de la esteatosis hepática, insulino resistencia y pérdida de la defensa antioxidante en ratones alimentados con dieta alta en grasa suplementados con AGPICL n-3 más aceite de oliva extra virgen / Reduction of hepatic steatosis, insulin resistance and loss of antioxidant defense in high fat diet fed mice suplemented with n-3 LCPUFA more extra virgin olive oil

Non-alcoholic fatty liver disease (NAFLD) is directly associated with insulin resistance and oxidative stress. In NAFLD is established a reduction in n-3 LCPUFA (EPA + DHA) levels and hepatic activity of transcription factor PPAR-alpha. EPA and DHA inhibit lipogenesis and stimulate fatty acid oxidation in the liver. Extra virgin olive oil (EVOO) has important antioxidant properties. This study evaluated the prevention of insulin resistance and prevention of depletion of hepatic antioxidant defense inC57BL/6J mice fed high-fat diet (HFD), supplemented with n-3 LCPUFA plus EVOO. HFD generated insulin resistance and hepatic steatosis, together with significant reduction in i) n-3 LCPUFA hepatic levels, ii) DNA binding activity of PPAR-alpha, iii) activity of antioxidant enzymes (catalase and superoxide dismutase), respect to control group (fed with control diet). Supplementation with n-3 LCPUFA plus EVOO prevent development insulin resistance and attenuate increased of fat in liver (p < 0.05), together with a normalization of i) DNA binding activity of PPAR-á, ii) activity of antioxidant enzymes (catalase and superoxide dismutase) and iii) reducing depletion of n-3 LCPUFA levels in liver tissue, compared to the control group (p < 0.05). Supplementation with n-3 LCPUFA plus EVOO reduced hepatic steatosis and prevent development of insulin resistance, along with preserving the antioxidant defense in liver. Projecting the use of this mixture of AGPICL n-3 plus EVOO as a potential treatment of NAFLD.

Effect of covalent attachment of neomycin on conformational and aggregation properties of catalase.

The carboxylic groups of glutamic acid and aspartic acid residues of catalase (CAT) were chemically modified using the treatment of the enzyme with 1-ethyl-3-(3'-dimethylamino) carbodiimide hydrochloride (EDC) and neomycin. The effect of covalent attachment of neomycin on the enzymatic activity, conformational and aggregation properties of CAT was investigated. The modification of CAT with different concentrations of neomycin showed two different types of behavior, depending up on the concentration range of neomycin. In the concentration range from 0.0 to 5.2 mM, neomycin-modified CAT, compared to the native enzyme exhibited higher α-helix content, reduced surface hydrophobicity, little enhancement in CAT activity and a better protection against thermal aggregation, whereas at concentrations greater than 5.2 mM, the modified enzyme exhibited a significant decrease in CAT activity and an increase in random coil content which may result in disorder in the protein structure and increase in thermal aggregation. This modification is a rapid and simple approach to investigate the role of aspartate and glutamate residues in the structure, function and folding of CAT.

Sistema antioxidante enzimático e indicadores de daño oxidativo en pacientes diabéticos tipo 2 / Antioxidant enzymatic system and oxidative damage indicators in patients with type 2 diabetes

Several biological processes are involved in the oxidative stress present in diabetes mellitus; among them we can find glucose autooxidation, proteins glycation and decreased antioxidant defenses. Free radicals yielded at mitochondrial level could be a trigger to unchain the vicious circle of the oxidative stress in diabetes mellitus. Aims: to determine antioxidant system’s alterations and indicators of oxidative damage on lipids and proteins in patients with type II Diabetes and a control group. Materials and Methods: It was analyzed 120 serum samples; 60 from patients that suffer type II diabetic from endocrinology surgery belonging “Casa de atención al paciente diabético”in Santa Clara, Villa Clara and 60 samples from healthy individuals used as control group. Spectrofotometric techniques were used to assess levels of Superoxide dismutase and Catalase activity as well as concentrations of reduced glutathione, malonildialdehide and advanced products of proteins Oxidation. Results were compared using the statistical software SPSS. Results: Diabetes type 2 patients showed decreased of Superoxide Dismutase and Catalase enzymatic activity (p = 0,003) and (p = 0,013) respectively as well as and reduced Glutathione levels (p = 0,038). Malondialdehide and Advanced Products of Proteins Oxidation were increased (p = 0,000) in diabetics patients compared with control group. Conclusions: it was found redox alterations in patients that suffer type 2 Diabetes. These alterations are evidenced by a reduced antioxidant enzymatic system and damage on macromolecules such as lipids and proteins...

Tratamento pós-menopausa reduz a atividade da catalase e atenua o risco cardiovascular / Postmenopausal therapy reduces catalase activity and attenuates cardiovascular risk

FUNDAMENTO: A menopausa pode levar a alterações na saúde feminina, com mudanças no estado oxidativo de mulheres pós-menopausadas, para as quais são limitadas as informações relativas à influência da hormonioterapia (HT) sobre as atividades das enzimas antioxidantes. OBJETIVO: Avaliar a influência da HT sobre a atividade da catalase, concentrações de lipídeos e lipoproteínas, proteína de transferência de colesteril éster, substâncias reativas ao ácido tiobarbitúrico, nitratos, proteína C-reativa ultrassensível e espessura da carótida em mulheres pós-menopausadas. MÉTODOS: Foram alocadas 94 mulheres para um de quatro grupos com ou sem HT. O último grupo foi subdividido em mulheres sendo tratadas com estrógeno e outras com estrógeno mais progestágeno. Foram realizadas medidas de parâmetros bioquímicos plasmáticos e da espessura da íntima-média da carótida. RESULTADOS: A HT antagonizou a redução na atividade da catalase após a menopausa, mas não teve efeito sobre os níveis da proteína de transferência de colesteril éster, substâncias reativas ao ácido tiobarbitúrico, peróxido lipídico, nitrato e proteína C reativa ultrassensível, nem sobre a espessura da íntima-média da carótida. A análise multivariada mostrou que a HT baseada em estrógeno atenuou a relação entre os fatores de risco cardiovasculares e a espessura da íntima-média da carótida comum. CONCLUSÃO: Este estudo mostra que a HT em mulheres pós-menopausadas produz efeitos antioxidantes e antiateroscleróticos benéficos por melhorar as concentrações séricas de lipídios e lipoproteínas, aumentar a atividade da catalase sérica e atenuar a associação entre os fatores de risco cardiovasculares e a aterosclerose precoce.

BACKGROUND: Menopause can lead to alterations in women's health, with changes in the oxidative status of postmenopausal women in whom information regarding the influence of hormone therapy (HT) on antioxidant enzyme activities is limited. OBJECTIVE: To evaluate the influence of HT on catalase activity; concentrations of lipids and lipoprotein, cholesteryl ester transfer protein, thiobarbituric acid-reactive substances, nitrates, high-sensitivity C-reactive protein and carotid thickness in postmenopausal women. METHODS: Ninety-four consecutive women were allocated to one of four groups, without HT and with HT. The latter group was subdivided into women using estrogen and those using estrogen plus progestogen therapy. Plasma biochemical parameters and common carotid intima-media thickness measurements were performed. RESULTS: HT antagonized the decrease in catalase activity after menopause, but had no effect on the levels of cholesteryl ester transfer protein, thiobarbituric acid-reactive substances, lipid peroxide, nitrate, high-sensitivity C-reactive protein, or on the common carotid intima-media thickness. Multivariate analysis showed that estrogen-based HT attenuated the relationship between cardiovascular risk factors and the intima-media thickness of the common carotid. CONCLUSION: This study indicates that HT in postmenopausal women produces beneficial antioxidant and anti-atherosclerotic effects by ameliorating the plasma lipid and lipoprotein profiles, increasing plasma catalase activity and attenuating the association between cardiovascular risk factors and early atherosclerosis.

Wound healing activity of Ocimum sanctum Linn with supportive role of antioxidant enzymes.

The present study was performed to evaluate the wound healing and antioxidant effect of aqueous extract of Ocimum sanctum Linn. (O. sanctum) in rats. Albino rats of either sex were divided into 2 groups. Group I: Wounded control rats; Group II: Wounded rats administered O. sanctum aqueous extract. Wound breaking strength in incision wound model, epithelization period and percent wound contraction in excision wound model were studied. Using dead space wound model, granulation tissue breaking strength, granulation tissue dry weight, hydoxyproline level in dry granulation tissue, superoxide dismutase (SOD) and catalase levels in wet granulation tissue were estimated in both the groups. Increased wound breaking strength, decreased epithelization period, increased percent wound contraction, increased granulation tissue weight and hydroxyproline concentrations were observed. The increased activity of antioxidant enzymes such as SOD, catalase level in extract treated group compared to controls. Granulation tissue was subjected to histopathological examination to determine the pattern of lay-down for collagen using Haematoxylin and Eosin stains which confirm the results. Owing to wound healing and antioxidant activities, O. sanctum may be useful in the management of abnormal healing such as keloids and hypertrophic scars.

Indicadores del metabolismo oxidativo en primates no humanos viejos / Levels oxidative metabolism markers during aging in non-human primates

En condiciones fisiológicas las células aeróbicas producen cantidades de Especies Reactivas de Oxígeno. La supervivencia celular depende del balance entre los procesos oxidativos y las defensas antioxidantes. Esta interacción determina si la célula se encuentra en estrés oxidativo o no. Recientes estudios sugieren que una reducida capacidad en el metabolismo oxidativo así como estados proinflamatorios contribuyen a cambios neurodegenerativos relacionados con la edad en los humanos. Por tal motivo en el presente estudio nosotros comparamos los niveles séricos de la actividad de la superóxido dismutasa (SOD), Catalasa (CAT) y también los niveles de malonildialdehido (MDA) y el factor de necrosis tumoral a (TNFa) en primates no humanos jóvenes y viejos. Nuestros resultados sugieren relación entre las alteraciones del metabolismo oxidativo con los cambios neurodegenerativos que ocurren en los monos.

Biochemical aspects of cellular antioxidant systems

Aerobic life is characterized by a steady generation of reactive oxygen species balanced by a similar rate of their consumption by antioxidants. To maintain homeostasis, there is a requirement for the continuous regeneration of antioxidant capacity, and if this is not met, oxidative stress occurs, resulting in pathophysiological events. Cellular protection against oxidative stress is organized at multiple levels. Defense strategies include prevention, interception, replacement, and repair. These mechanisms are coupled to the intermediary metabolism for a continuous supply of energy, reducing equivalents, and precursors, and depend on the dietary supply of metabolic fuels and essential molecules to allow an optimal cellular functioning