Prooxidant activity of norbixin in model of acute gastric ulcer induced by ethanol in rats.

Free radicals and oxidative stress play a central role in gastric injuries caused by ethanol (EtOH). Antioxidant strategies to counteract EtOH toxicity are highly desirable. Norbixin (NBIX) is a carotenoid with antioxidant potential largely used in the food industry. This study evaluated the NBIX effects in a model of gastric ulcer induced by EtOH in rats. Male Wistar rats received NBIX doses of 0, 10, and 25 mg/kg by gavage 1 h after EtOH administration (0 or 75% solution, 1 mL/200 g of animal). The animals were euthanized 1 h after the NBIX administration, and their stomachs were removed for macroscopic and histopathological analyses, quantification of nonprotein sulfhydryl (NPSH) groups, lipid peroxidation (LPO) levels, and catalase (CAT) activity determination. NBIX increased LPO in gastric mucosa and caused CAT inhibition and NPSH depletion in EtOH-treated animals. Results showed that NBIX did not protect gastric tissue against EtOH damage, and this could be associated to a prooxidant effect.

Estabilidade oxidativa e perfil de ácidos graxos do leite de vacas suplementadas com óleo de linhaça na dieta associado ou não ao selenito de sódio injetável / Oxidative stability and fatty acid profile content of milk from cows fed linseed oil diet with or without injectable sodium selenite

Avaliou-se o efeito da suplementação com óleo de linhaça na dieta, com ou sem injeção de selenito de sódio, sobre o perfil de ácidos graxos e sobre a estabilidade oxidativa do leite de vacas leiteiras. Catorze vacas foram distribuídas em três tratamentos: as do grupo 1, que receberam diariamente 400mL de óleo de linhaça (LIN); as do grupo 2, 400mL de óleo de linhaça + 0,2mg/kg de selenito de sódio IM (LINSe); e as do grupo 3 (controle), que não foram tratadas (C). O óleo foi fornecido diariamente após 15 dias da aplicação única de selenito de sódio, e o experimento teve duração de quatro semanas. Os animais suplementados com o óleo de linhaça produziram leite com altas porcentagens de ácido linoleico conjugado (CLA) e de ômega 3, contudo mais suscetível à oxidação. A aplicação injetável de selenito de sódio mostrou-se eficaz ao impedir a oxidação prematura do leite. Concluiu-se que a inclusão do óleo de linhaça na dieta de vacas leiteiras resulta em aumento do CLA, do ômega 3 e, consequentemente, da oxidação do leite, necessitando, assim do uso de substâncias antioxidantes ou promotores antioxidantes, como o selenito de sódio injetável.

The aim of the present study was to evaluate the effect of dietary linseed oil supplementation with or without injectable sodium selenite on the fatty acid profile and oxidative stability of milk from dairy cows. Fourteen cows were allocated into four treatment groups: Group 1 which received 400mL of linseed oil daily (LIN); Group 2, 400mL of linseed oil + 0,2mg/BW sodium selenite IM (LINSe); Group 3, untreated controls (C). The oil was supplied daily after 15 days of a single application of sodium selenite and during 4 weeks. Animals supplemented with linseed oil produced milk with higher levels of conjugated linoleic acid (CLA) and omega 3, but were also more susceptible to oxidation. The application of sodium selenite was effective to prevent premature oxidation of milk. We concluded that the supplementation of a cow's diet with linseed oil promoted increased CLA and omega 3 in milk, which in turn becomes more susceptible to oxidation, requiring the use of antioxidants or promoters of antioxidant activity such as injectable sodium selenite.

Could dietary trans fatty acids induce movement disorders? Effects of exercise and its influence on Na⁺K⁺-ATPase and catalase activity in rat striatum.

The influence of trans fatty acids (FA) on development of orofacial dyskinesia (OD) and locomotor activity was evaluated. Rats were fed with diets enriched with 20% soybean oil (SO; n-6 FA), lard (L; saturated FA) or hydrogenated vegetable fat (HVF; trans FA) for 60 weeks. In the last 12 weeks each group was subdivided into sedentary and exercised (swimming). Brains of HVF and L-fed rats incorporated 0.33% and 0.20% of trans FA, respectively, while SO-fed group showed no incorporation of trans FA. HVF increased OD, while exercise exacerbated this in L and HVF-fed rats. HVF and L reduced locomotor activity, and exercise did not modify. Striatal catalase activity was reduced by L and HVF, but exercise increased its activity in the HVF-fed group. Na(+)K(+)-ATPase activity was not modified by dietary FA, however it was increased by exercise in striatum of SO and L-fed rats. We hypothesized that movement disorders elicited by HVF and less by L could be related to increased dopamine levels in striatum, which have been related to chronic trans FA intake. Exercise increased OD possibly by increase of brain dopamine levels, which generates pro-oxidant metabolites. Thus, a long-term intake of trans FA caused a small but significant brain incorporation of trans FA, which favored development of movement disorders. Exercise worsened behavioral outcomes of HVF and L-fed rats and increased Na(+)K(+)-ATPase activity of L and SO-fed rats, indicating its benefits. HVF blunted beneficial effects of exercise, indicating a critical role of trans FA in brain neurochemistry.