Long-term resveratrol administration improves diabetes-induced pancreatic oxidative stress, inflammatory status, and ß cell function in male rats

Abstract Diabetes is a metabolic disorder caused by insulin resistance or a defect in the pancreatic beta cells in insulin secretion. The aim of this study was to evaluate the possible effectiveness of long-term administration of resveratrol on inflammatory and oxidative stress markers in the pancreatic tissue of diabetic rats. Male Wistar rats (n = 24) were randomly divided into four groups of six animals, namely a healthy group, a healthy group receiving resveratrol, a diabetic control group, and a diabetic group receiving resveratrol. Diabetes was induced by single dose injection of streptozotocin (50 mg/kg; ip), 15 min after injection of nicotinamide (110 mg/kg; ip). Resveratrol was also administered by gavage (5 mg/kg/day) for 4 months. Administration of resveratrol alleviated hyperglycemia, weight loss and pancreatic ß cell function measured by HOMA-ß. Resveratrol improved oxidative stress (nitrate/nitrite, 8-isoprostane and glutathione) and proinflammatory markers (tumor necrosis factor α, cyclooxygenase 2, interleukin 6 and nuclear factor kappa B) in the pancreatic tissue of diabetic rats. Resveratrol administration had no significant effect on the activity of superoxide dismutase and catalase enzyme. These observations indicate that resveratrol administration may be effective as a beneficial factor in improving pancreatic function and reducing the complications of diabetes

Resveratrol inhibits nicotine-induced conditioned place preference in mice

Abstract Nicotine addiction leads to in a huge burden on public health and the economy worldwide. Resveratrol (3,5,4'-tetrahydroxystilbene) is the most well-known polyphenolic stilbenoid. Resveratrol was shown to exhibit positive effects on numerous mechanisms that are important for drug and substance addiction. Thus, this study aimed to examine the effect of resveratrol on nicotine addiction. Intraperitoneal (i.p.) treatment with nicotine (0.5 mg/kg) significantly enhanced time spent in the nicotine-paired compartment. Resveratrol (50 and 75 mg/kg, i.p.) and varenicline (2 mg/kg, i.p.) co-administered with nicotine during the 3-day conditioning period effectively diminished the acquisition of nicotine-induced conditioned place preference (CPP). On the other hand, the administration of resveratrol (50 and 75 mg/kg, i.p.) and varenicline (2 mg/kg, i.p.) decreased the low dose (0.1 mg/kg, i.p.) nicotine-induced reinstatement. The results suggest that resveratrol and varenicline inhibit the acquisition and reinstatement of nicotine's reward properties. Resveratrol displayed similar results in the CPP phases as obtained with the reference drug varenicline. In conclusion, resveratrol could be beneficial as an adjuvant pharmacotherapy for nicotine addiction; however, more investigation is needed to completely explain this property.

Effect of trans-resveratrol on oxidative stress biomarkers associated with atherosclerosis / Efeito do trans-resveratrol em biomarcadores de estresse oxidativo associados à aterosclerose

Growing evidence indicates that oxidative stress plays an important role in the pathophysiology of many cardiovascular diseases, including atherosclerosis. In this context, the use of bioactive compounds with antioxidant action can bring health benefits, especially in the prevention and control of pathophysiological events. Studies suggest that the polyphenol trans-resveratrol can reduce oxidative stress by acting on the nuclear factor erythroid-2-related factor 2 (Nrf2) and this effect would be associated with dosage. Thus, the present study aimed to investigate the effect of different doses of trans-resveratrol on biomarkers related to atherosclerosis and oxidative stress. In the first step, 27 randomized clinical trials, which evaluated the effect of trans-resveratrol on atherosclerosis-related biomarkers, were classified according to their protocol characteristics and profile of each outcome. Biochemical data from 12 biomarkers were selected to calculate the net change (%). Using multivariate analysis, the trials were distributed into 3 clusters. The studies that composed Clusters II and III were more effective in improving blood pressure and reducing dyslipidemia, respectively. These studies were characterized by a longer intervention time (> 2 months) with doses of around 200-500 mg/day. These results showed that the effects of transresveratrol are mainly related to dosage and intervention time. Based on these results, two doses were selected to apply in an experimental protocol to investigate the effect of trans-resveratrol on hepatic oxidative stress biomarkers mediated by Nrf2 pathway. LDLr(-/-) mice were fed for 8 weeks on a standard diet, followed by over 24 weeks on a Western diet, both containing trans-resveratrol at doses of 250 mg/kg diet/day (low dose resveratrol, LRD) or 400 mg/kg diet/day (high dose resveratrol, HRD). A control group (CONT) was maintained without supplementation. In general, both doses of trans-resveratrol did not affect the body weight and lipid profile of the animals. Only the LRD group showed reduced levels of two important biomarkers of oxidative stress in the liver (GSH/GSSG ratio and malonaldehyde), besides to reduced expression of factor nuclear kappa B (NF-kB). However, contrary to our hypothesis, both doses reduced Nrf2 expression in the liver compared to the CONT group. Regarding inflammatory cytokines, no changes were observed in the levels of TNF-α and IL-10. Furthermore, both doses increased the level of the pro-inflammatory cytokine IL-6. Taken together, our results suggest that trans-resveratrol supplementation at doses lower than 500 mg/day may contribute to the reduction of biomarkers related to atherosclerosis and oxidative stress

Evidências crescentes indicam que o estresse oxidativo desempenha um papel importante na fisiopatologia de muitas doenças cardiovasculares, incluindo a aterosclerose. Nesse contexto, o uso de compostos bioativos com ação antioxidante pode trazer benefícios à saúde, principalmente na prevenção e controle de eventos fisiopatológicos. Estudos sugerem que o polifenol trans-resveratrol pode reduzir o estresse oxidativo atuando na via do fator nuclear eritroide 2 relacionado ao fator 2 (Nrf2) e que esse efeito estaria associado a dosagem. Assim, o presente estudo teve como objetivo investigar o efeito de diferentes doses de trans-resveratrol sobre biomarcadores relacionados à aterosclerose e estresse oxidativo. Na primeira etapa, 27 ensaios clínicos randomizados, que avaliaram o efeito do trans-resveratrol em biomarcadores relacionados à aterosclerose, foram classificados de acordo com suas características de protocolo e perfil de cada resultado. Dados bioquímicos de 12 biomarcadores foram selecionados para calcular a variação líquida (%). Usando análise multivariada, os ensaios foram distribuídos em 3 Clusters. Os estudos que compuseram os Clusters II e III foram mais eficazes na melhora da pressão arterial e na redução da dislipidemia, respectivamente. Esses estudos foram caracterizados por um tempo de intervenção mais longo (> 2 meses) com doses de cerca de 200-500 mg/dia. Esses resultados mostraram que os efeitos do transresveratrol estão relacionados principalmente à dosagem e ao tempo de intervenção. Com base nesses resultados, duas doses foram selecionadas para aplicar em um protocolo experimental para investigar o efeito do trans-resveratrol em biomarcadores de estresse oxidativo hepático mediados pela via do Nrf2. Camundongos LDLr(-/-) foram alimentados por 8 semanas com dieta padrão, seguidos por mais de 24 semanas com Western diet, ambos contendo trans-resveratrol nas doses de 250 mg/kg de dieta/dia (baixa dose de resveratrol, LRD) ou 400 mg/kg de dieta/dia (alta dose de resveratrol, HRD). Um grupo controle (CONT) foi mantido sem suplementação. Em geral, ambas as doses de trans-resveratrol não afetaram o peso corporal e o perfil lipídico dos animais. Apenas o grupo LRD apresentou níveis reduzidos de dois importantes biomarcadores de estresse oxidativo no fígado (razão GSH/GSSG e malonaldeído), além da redução da expressão de fator nuclear kappa B (NF-kB). No entanto, ao contrário da nossa hipótese, ambas as doses reduziram a expressão de Nrf2 no fígado em comparação com o grupo CONT. Em relação às citocinas inflamatórias, não foram observadas alterações nos níveis de TNF-α e IL-10. Além disso, ambas as doses aumentaram o nível da citocina pró-inflamatória IL-6. Em conjunto, nossos resultados sugerem que a suplementação de trans-resveratrol em doses menores de 500 mg/dia podem contribuir para a redução de biomarcadores relacionados à aterosclerose e ao estresse oxidativo

Potential neuroprotective of trans resveratrol a promising agent tempeh and soybean seed coats-derived against betaamyloid neurotoxicity on primary culture of nerve cells induced by 2-methoxyethanol / Potencial neuroprotetor do agente trans-resveratrol em cascas de sementes de soja e tempê derivadas da neurotoxicidade beta-amiloide na cultura primária de células nervosas induzidas pelo 2-metoxietanol

Resveratrol, a natural polyphenol found in tempeh, has not been investigated especially in vitro as a neuroprotective agent against 2-methoxyethanol (2-ME)-induced beta-amyloid cytotoxicity. Beta amyloid peptides (Aβ) could initiate neurotoxic events and neuron-inflammatory response via microglial activation. However, it remains unknown whether the neurotoxic effect of beta-amyloid and/or associated with the potential of 2-ME to induce neurotoxic effects on primary culture of nerve cells induced by 2-ME. This study investigated potential neuroprotective of trans-resveratrol a promising agent tempeh and soybean seed coats-derived against beta amyloid cytotoxicity on primary culture of nerve cells induced by 2-methoxyethanol. Biotium and MTT assays were used to analyze neurons, which were isolated from the cerebral cortex of fetal mice at gestation day 19 (GD-19). A standard solution of 2-methoxyethanol was dosed at 10 μL. The cultured cells were randomly divided into the following groups: (1) 2-ME group + resveratrol standard, (2) 2-ME group + resveratrol isolated from tempeh, (3) 2-ME group + resveratrol isolated from soybean seed coats, and (4) the control group, without the addition of either 2-ME or resveratrol. Exposure of the primary cortical neuron cells to beta-amyloid monoclonal antibody pre-incubated for 24 h with 10 µL of 4.2 µg/mL resveratrol and 7.5 mmol/l 2-methoxy-ethanol additions. Here, we report that the addition of 2-ME and resveratrol (standard and isolated from tempeh) of cell culture at concentrations of 1.4, 2.8 and 4.2 µg/mL showed that the majority of neurons grew well. In contrast, after exposure to 2-ME and Beta-amyloid, showed that glial activated. These findings demonstrate a role for resveratrol in neuroprotective-neurorescuing action.

O resveratrol, um polifenol natural encontrado em tempê, não foi investigado apenas in vitro como agente neuroprotetor contra a citotoxicidade beta-amiloide induzida por 2-metoxietanol (2-ME). Os peptídeos beta amiloides (Aβ) podem iniciar eventos neurotóxicos e resposta inflamatória dos neurônios via ativação microglial. No entanto, permanece desconhecido se o efeito neurotóxico do peptídeo beta-amiloide associado ao potencial do 2-ME causa efeitos neurotóxicos na cultura primária de células nervosas induzidas pelo 2-ME. Este estudo investigou o potencial neuroprotetor do agente trans-resveratrol em cascas de sementes de soja e tempê derivadas da citotoxicidade beta-amiloide na cultura primária de células nervosas induzidas pelo 2-metoxietanol. Ensaios de biotium e MTT foram utilizados para analisar os neurônios isolados do córtex cerebral de camundongos fetais no dia da gestação 19 (GD-19). As células cultivadas foram divididas aleatoriamente nos seguintes grupos: (1) grupo 2-ME + padrão de resveratrol; (2) grupo 2-ME + resveratrol isolado de tempê; (3) grupo 2-ME + resveratrol isolado de cascas de sementes de soja; e (4) grupo controle, sem a adição de 2-ME ou resveratrol. Houve exposição das células primárias dos neurônios corticais ao anticorpo monoclonal beta-amiloide pré-incubado por 24 horas, com 10 µL de 4,2 µg/mL de resveratrol, e adições de 7,5 mmol/l de 2-metoxietanol. A adição de 2-ME e resveratrol (padrão e isolado do tempê) da cultura de células nas concentrações de 1,4, 2,8 e 4,2 µg/mL mostrou que a maioria dos neurônios cresceu bem. Por outro lado, após a exposição ao 2-ME e beta-amiloide, a glia foi ativada. Esses achados demonstram um papel do resveratrol na ação neuroprotetora e de neurorresgate.