Our objective was to establish a diabetes mellitus type 2 (DM2) model in rats using a highfat diet and streptozotocin (HF-STZ). Male Wistar rats (240-250g) were divided into a control group (commercial feed), and HF-STZ group, (66.5%-commercial feed, 13.5%-lard, and 20%-sugar). STZ (40mg/kg i.p.) or vehicle was administered on the 13 th day. An oral glucose tolerance test (OgTT) was performed (2.5mg of glucose/kg v.o.) on both groups. After 39 days of treatment, blood and tissue samples were collected for analyses. The weight gain after STZ administration was lower in the HF-STZ group than in the control group with reductions in muscle mass and adipose tissue. The HF-STZ group showed hyperglycemia after STZ administration (glucose on day 39: HF-STZ: 499 ± 60; control: 134 ± 9mg/ dl). Serum glucagon was 23% lower, and insulin levels were unaltered. The HOMA index was 4-times higher in the HF-STZ. The HF-STZ group showed increased post-prandial (330%) and fasting (125%) triglycerides, and while glycogen content in the liver and muscles decreased (70-80%). The area under the curve (OgTT) was 282% higher in the HF-STZ group. The combination of high-fat diet with STZ (i.p) generated rats with hyperglycemia associated with hypertriglyceridemia and introduced many other alterations present in human DM2.

Brazil nuts (BN) (Bertholletia excels, Bonpl.), are of great importance because of their nutritional properties and economic value. They can be consumed in natura or as flour (BNF). In this study, we evaluated the effects of BNF and BN intakes (Both 5% and 15%) on metabolic parameters of rats for 15 days. Serum Selenium (Se) levels were higher in BN‐15% and BNF‐15% groups. Lipid content was reduced in retroperitoneal and epididymal adipose tissues in all groups and in the BN‐5% group in the liver. However, liver lipids increased in the BNF‐15% group. The levels of carbonylated proteins and lipid peroxidation in the liver were not altered. The data reveal that the increase in hepatic lipids in the BNF‐15% group probably occurred due to the high concentration of free fatty acids present in the flour. The Se bioavailability in the diet contributed to the preservation of the liver function in rats. Practical implications The consumption of BN is common in the population. However, changes in eating habits have led to a more frequent consumption of vegetable derivatives, such as drinks and oils. The cake residue generated after processing is still considered of high nutritional value, since it is a source of protein and minerals such as Se. Because of its low cost, the use of pie at the industrial level is becoming increasingly more interesting for the development of new products, and the Brazil nut flour (BNF) is considered a good option. Our study showed that just like BN, BNF can be a source of selenium for the body, although changes in lipid metabolism and physiological parameters can be observed depending on the amount used. We believe that the results of this investigation can be used to guide the development of new technologies and products containing BN.

ResumoSabe-se a importância do fornecimento adequando de zinco (Zn) no desenvolvimento inicial da cultura do milho, dessa forma conhecer os sintomas de deficiência e de excesso bem como a interação do micronutriente com outros elementos é essencial. Objetivou-se avaliar concentrações de Zn em solução nutritiva na nutrição e no desenvolvimento inicial da cultura do milho. Utilizou-se delineamento inteiramente casualizado com quatro concentrações de Zn: 0; 0,733; 1,465; 2,930 ou 5,861 µmol L -1 . Após 30 dias, avaliou-se o comprimento de parte aérea e raiz, diâmetro de colmo, volume de raiz, massa seca de parte aérea e de raiz e teor micronutrientes (zinco, manganês (Mn), ferro (Fe) e boro (B)). Evidenciou-se que a ausência de zinco na solução nutritiva resultou em menor crescimento da planta e sintomas visuais de deficiência. Estes resultados contribuem para a diagnose foliar a campo de forma a identificar a deficiência nos estágios iniciais do crescimento da cultura. Além disso, verificou-se interações com outros nutrientes, havendo relação inversa entre teores foliares de Mn, Fe e B com teores de Zn. Este resultado demonstra o desbalanço nutricional provocado tanto pela ausência quanto pelo excesso de zinco e sugere uma possível interação ainda não conhecida com o B.

No abstract

In soaked soils there is an increase in the availability of iron and manganese. Thus, it becomes important to investigate the tolerance levels of plants to excess of these nutrients. The objective was to evaluate the tolerance of Urochloa brizantha cv. Marandu cultivated in nutrient solution with different levels of iron and manganese. The experimental design was completely randomized with seven treatments and four replications. The treatments consisted of a nutrient solution and consisted of: 1- adequate concentration of Fe (8.22 mM) and Mn (2.05 mM); 2– Fe, four times the adequate concentration; 3– Fe, eight times the adequate concentration; 4– Mn, four times the adequate concentration; 5– Mn, eight times the adequate concentration; 6– Fe and Mn, four times the appropriate concentration, and; 7– Fe and Mn, eight times the appropriate concentration. The variables evaluated were visual diagnosis (symptomatology), shoot height, root volume, Fe and Mn content in shoots and dry mass production. Grass plants were not tolerant to excess Fe and Mn. The excess of nutrients promoted less development of the root system, with a reduction in volume and dry mass, and the treatment with the highest dose of nutrients resulted in the lowest values. Grass plants were sensitive to the increase in nutrient concentrations, showing reductions in total dry mass production of 55% for treatment with the application of the highest concentration of nutrients in relation to the adequate dose of Fe and Mn.