RESUMO
OBJECTIVE: Brain stroke is the third most important cause of death in developed countries. We studied the effect of different dietary lipids on the outcome of a permanent ischemic stroke rat model. METHODS: Wistar rats were fed diets containing 7% commercial oils (S, soybean; O, olive; C, coconut; G, grape seed) for 35 d. Stroke was induced by permanent middle cerebral artery occlusion. Coronal slices from ischemic brains and sham-operated animals were supravitally stained. Penumbra and core volumes were calculated by image digitalization after 24, 48, and 72 h poststroke. Homogenates and mitochondrial fractions were prepared from different zones and analyzed by redox status, inflammatory markers, ceramide, and arachidonate content, phospholipase A2, NOS, and proteases. RESULTS: Soybean (S) and G diets were mainly prooxidative and proinflammatory by increasing the liberation of arachidonate and its transformation into prostaglandins. O was protective in terms of redox homeostatic balance, minor increases in lipid and protein damage, conservation of reduced glutathione, protective activation of NOS in penumbra, and net ratio of anti-to proinflammatory cytokines. Apoptosis (caspase-3, milli- and microcalpains) was less activated by O than by any other diet. CONCLUSION: Dietary lipids modulate NOS and PLA2 activities, ceramide production, and glutathione import into the mitochondrial matrix, finally determining the activation of the two main protease systems involved in programmed cell death. Olive oil appears to be a biological source for the isolation of protective agents that block the expansion of brain core at the expense of penumbral neurons.
Assuntos
Antioxidantes/uso terapêutico , Encéfalo/efeitos dos fármacos , Gorduras na Dieta , Inflamação/prevenção & controle , Estresse Oxidativo/efeitos dos fármacos , Óleos de Plantas/uso terapêutico , Acidente Vascular Cerebral , Animais , Antioxidantes/farmacologia , Apoptose , Biomarcadores/metabolismo , Encéfalo/citologia , Encéfalo/metabolismo , Isquemia Encefálica/dietoterapia , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , Cocos , Dieta , Gorduras na Dieta/efeitos adversos , Gorduras na Dieta/metabolismo , Gorduras na Dieta/farmacologia , Gorduras na Dieta/uso terapêutico , Inflamação/etiologia , Inflamação/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Masculino , Neurônios , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Óxido Nítrico Sintase/metabolismo , Olea , Oxirredução , Óleos de Plantas/efeitos adversos , Óleos de Plantas/farmacologia , Ratos Wistar , Espécies Reativas de Oxigênio/efeitos adversos , Glycine max , Acidente Vascular Cerebral/dietoterapia , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/metabolismo , Acidente Vascular Cerebral/patologia , VitisRESUMO
The effect of the simultaneous exposure to transition metals and natural antioxidants frequently present in food is a question that needs further investigation. We aimed to explore the possible use of the natural polyphenols caffeic acid (CA), resveratrol (RES) and curcumin (CUR) to prevent damages induced by copper-overload on cellular molecules in HepG2 and A-549 human cells in culture. Exposure to 100µM/24h copper (Cu) caused extensive pro-oxidative damage evidenced by increased TBARS, protein carbonyls and nitrite productions in both cell types. Damage was aggravated by simultaneous incubation with 100µM of CA or RES, and it was also reflected in a decrease on cellular viability explored by trypan blue dye exclusion test and LDH leakage. Co-incubation with CUR produced opposite effects demonstrating a protective action which restored the level of biomarkers and cellular viability almost to control values. Thus, while CA and RES might aggravate the oxidative/nitrative damage of Cu, CUR should be considered as a putative protective agent. These results could stimulate further research on the possible use of natural polyphenols as neutralizing substances against the transition metal over-exposure in specific populations such as professional agrochemical sprayers and women using Cu-intrauterine devices.