Jaboticaba berry peel intake prevents insulin-resistance-induced tau phosphorylation in mice

The hyperphosphorylation of microtubule-associated protein tau (tau) in the hippocampus can be caused by central and peripheral insulin resistance and these alterations are related to the development of tauopathies, such as Alzheimer's disease. In this study, we used a high-fat diet to induce obesity and insulin resistance in adult Swiss mice and checked whether supplementation with Myrciaria jaboticaba berry peel for 10 weeks could improve insulin sensitivity, learning/memory performance, and prevent tau phosphorylation in the hippocampus. Furthermore, adipocytokines, inflammatory markers, and oxidative stress were assessed. Myrciaria jaboticaba peel has phenolic compounds (e.g., cyanidin, ellagic acid), dietary fiber and carotenoids, which contribute to great antioxidant capacity. Supplementation of the high-fat diet with 4% M. jaboticaba peel prevented fat weight gain and reduced peripheral insulin resistance. The treated group also showed lower tau phosphorylation in the hippocampus corroborating better learning/memory performance in the Morris water maze test. Maintenance of neuronal viability, lower levels of hippocampal inflammatory markers, and improved brain antioxidant defenses were also related to the consumption of M. jaboticaba peel. These findings contribute to a better understanding of how a high-fat diet supplemented with jaboticaba berry peel counteracts the impairment of cognitive functions caused by high-fat diet intake and diet-induced insulin resistance.610CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP300533/2013-6 ; 305099/2011-6Sem informação2010/05262-5 ; 2015/50333-

Reduced graphene oxide: nanotoxicological profile in rats

We have previously demonstrated that reduced graphene oxide (rGO) administered intravenously in rats was detected inside the hippocampus after downregulation of the tight and adherens junction proteins of the blood-brain barrier. While down-regulators of junctional proteins could be useful tools for drug delivery through the paracellular pathway, concerns over toxicity must be investigated before clinical application. Herein, our purpose was to trace whether the rGO inside the hippocampus triggered toxic alterations in this brain region and in target organs (blood, liver and kidney) of rats at various time points (15 min, 1, 3 h and 7 days). Results: The assessed rGO-treated rats (7 mg/kg) were clinically indistinguishable from controls at all the time points. Hematological, histopathological (neurons and astrocytes markers), biochemical (nephrotoxicity and hepatotoxicity assessment) and genotoxicological based tests showed that systemic rGO single injection seemed to produce minimal toxicological effects at the time points assessed. Relative to control, the only change was a decrease in the blood urea nitrogen level 3 h post-treatment and increases in superoxide dismutase activity 1 h and 7 days post-treatment. While no alteration in leukocyte parameters was detected between control and rGO-treated animals, time-dependent leukocytosis (rGO-1 h versus rGO-3 h) and leukopenia (rGO-3 h versus rGO-7 days) was observed intra-treated groups. Nevertheless, no inflammatory response was induced in serum and hippocampus at any time. Conclusions: The toxic effects seemed to be peripheral and transitory in the short-term analysis after systemic administration of rGO. The effects were self-limited and non-significant even at 7 days post-rGO administration.141CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP305099/2011-6 ; 486142/2012-42012/24782-

Jaboticaba berry peel intake increases short chain fatty acids production and prevent hepatic steatosis in mice fed high-fat diet

In this study, a preventive model was proposed to check whether the intake of Myrciaria jaboticaba berry peel (MJP) could avoid harmful effects caused by a high-fat diet. The intake of the high-fat diet supplemented with MJP (HM mice) down-regulated pro-inflammatory cytokines in adipose tissue and prevented adipose tissue growth and accumulation. In addition, the intake of the high-fat diet supplemented with MJP prevented weight gain, increased the excretion of triglycerides, reduced hepatic steatosis area and stimulated the production of short chain fatty acids (SCFA) by the large intestinal microbiota. Furthermore, hepatic mRNA PPAR-α level was lowered in non-fasted animals of the HM mice, indicating lower oxidation of both fatty acids and lipotoxic metabolites by the liver. In conclusion, MJP intake induces higher production of the gut SCFA, compounds known to counteract obesity markers, as shown by the lowering of adipose tissue inflammation, weight gain, dyslipidemia and hepatic steatosis.48266274CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP301108/2016-1 ; 403328/2016-0 ; 305099/2011-6Sem informação2015/50333-