Effects of consumption of mauritia flexuosa fruits on renal and hepatic functions in growing rats

INTRODUCTION: Previous studies have reported that buriti (Mauritia flexuosa L. f.) is a typical fruit from the Brazilian cerrado ecosystem and an important food source for low-income populations. Its composition is rich in carotenoid polyphenols, monounsaturated fatty acids, and ascorbic acid. However, studies on the biological effects resulting from the consumption of this fruit are scarce. OBJECTIVE: To evaluate the effects of a diet supplemented with buriti (Mauritia flexuosa L. f.) on kidney and liver functions in growing rats. METHODS: Determination of centesimal composition, carotenoids, and fatty acids content for buriti pulp, standard chow, and butiti-supplemented chow were performed. Then, Wistar rats of both sexes were fed a standard diet or supplemented with buriti pulp. Blood samples were collected at the end of the experiment to determine biochemical parameters. The unpaired t-test was applied, and differences were considered significant when p<0.05. RESULTS: A diet enriched with buriti pulp did not interfere with kidney function and most markers of liver function in animals. Alkaline phosphatase showed significantly higher plasma concentration in female rats, and albumin and uric acid showed lower concentrations in male rats in both experimental groups. CONCLUSION: The changes observed in biochemical markers did not provide evidence of adverse effects of buriti pulp supplementation on liver function. Thus, the intake of buriti pulp can be encouraged as it is a low-cost food source for the general population.

Restrição dietética de magnésio associada à dieta hiperlipídica: implicações sobre a homeostase do mineral e sensibilidade à insulina / Dietary magnesium restriction associated with a high-fat diet: implications on mineral homeostasis and insulin sensitivity

A resistência dos tecidos à ação da insulina é uma das principais complicações do excesso de peso. O aumento da gordura corporal, decorrente do consumo excessivo de nutrientes, é acompanhado por um quadro de inflamação crônica de baixa intensidade que está relacionado com a fisiopatologia da resistência à insulina. O magnésio (Mg) é um mineral envolvido com diversos processos fisiológicos e bioquímicos, especialmente aqueles relacionados ao metabolismo energético e ao controle glicêmico. Apesar de a deficiência deste mineral estar relacionada com condições pré-diabéticas, não está claro se a inadequação dietética promove alterações na sensibilidade à insulina e/ou se condições de resistência à insulina causam distúrbios na homeostase de Mg. O objetivo deste trabalho foi investigar os efeitos da restrição dietética de Mg e sua associação com o excesso de lipídios sobre a homeostase do mineral e a sensibilidade à insulina. Ratos Wistar, machos, com peso entre 97-123 g, permaneceram em gaiolas individuais por 24 semanas. Os animais receberam rações normolipídicas (CON, 7% de lipídios) ou hiperlipídicas (HL, 32% de lipídios), adequadas (CON e HL Mg; 500 mg de Mg/kg de ração; n = 6 para cada grupo) ou com restrição de Mg (Mg[50] e HL Mg[50]; 50 mg de Mg/kg de ração; n = 6 para cada grupo). O consumo da dieta HL promoveu maior acúmulo de tecido adiposo e maior ganho de peso corporal (p < 0,05). Os animais que consumiram rações com restrição de Mg apresentaram hipomagnesemia (p<0,01), menor excreção urinária (p < 0,01) e fecal (p < 0,001) de Mg e menor concentração óssea desse mineral (p < 0,001). No entanto, não foram observadas alterações no Mg muscular (p > 0,05). O grupo HL Mg[50] apresentou maior concentração de Mg no eritrócito quando comparado aos outros grupos. A restrição dietética de Mg, isoladamente, não promoveu alterações na sensibilidade à insulina (avaliada pelo teste de tolerância à insulina). Quando associada à dieta hiperlipídica, resultou em aumento da glicemia de jejum e em redução da sensibilidade à insulina, após 16 semanas (p < 0,01). Em nível molecular, a fosforilação da proteína quinase B (Akt) no músculo e no fígado foi significantemente menor no grupo HL Mg[50] (p < 0,05). A restrição dietética de Mg induziu ao aumento do conteúdo proteico dos canais TRPM6 e TRPM7 no rim, independentemente da sensibilidade à insulina. Os resultados deste estudo apontam que a deficiência de Mg tende a agravar as repercussões metabólicas do consumo de dietas hiperlipídicas na sensibilidade à insulina e que a resistência à insulina altera a compartimentalização do Mg

Insulin resistance is one of the main complications of overweight. Increase body fat, due to excessive consumption of nutrients is accompanied by a chronic low-grade inflammation related to insulin resistance pathophysiology. Magnesium (Mg) is a mineral involved in many physiological and biochemical processes, especially those related to energy metabolism and glycemic control. Although Mg deficiency is related to pre-diabetic conditions, it is unclear whether dietary inadequacy promotes changes in insulin sensitivity and/or if conditions of insulin resistance cause disturbances in Mg homeostasis. This work aimed to investigate the effects of dietary Mg restriction and its association with high-fat diet on mineral homeostasis and insulin sensitivity. Male Wistar rat (97-123 g) remained in individual cages for 24 weeks. Animals received normolipid diet (CON, 7% lipid) or high-fat diet (HF, 32% lipid), adequate (CON and HF, 500 mg Mg / kg diet, n = 6 for each group) or Mg restricted (Mg[50] and HF Mg[50], 50 mg of Mg / kg of diet, n = 6 for each group). High-fat diet promoted a greater adipose tissue excess and body weight gain (p<0.05). Animals with Mg restricted diet had hypomagnesemia (p<0.01), lower Mg urinary (p<0.01) and faecal loss (p<0.001) and lower bone Mg concentration (p<0.001). However, no changes were observed in muscle Mg (p>0.05). HF Mg[50] group presented higher concentration of erythrocyte Mg when compared to the other groups. Singly, dietary Mg restriction did not induce changes in insulin sensitivity (as assessed by the insulin tolerance test). When associated with high-fat diet, dietary Mg restriction resulted in higher fasting glycemia and lower insulin sensitivity after 16 weeks (p<0.01). At the molecular level, protein kinase B (Akt) phosphorylation in muscle and liver was significantly lower in HFMg [50] group (p<0.05). Dietary Mg restriction induced increased protein content of renal TRPM6 and TRPM7 channels, regardless of insulin sensitivity. The results of this study indicate that Mg deficiency worsens metabolic effects of high-fat diet on insulin sensitivity. In addition, insulin resistance changes Mg compartmentalization

Mg status in inflammation, insulin resistance, and associated conditions

Magnesium (Mg), an essential ion for the human body, is involved in various enzymatic reactions, particularly those related to energy transfer, storage, and transport. Longitudinal studies show that hypomagnesaemia (Mg serum concentration <0.75 mmol/L) and Mg dietary inadequacy (daily intake < EAR (Estimated Average Requirement) for age/gender) are conditions related to metabolic disorders of the immune and cardiovascular system and often occur in obese and diabetic individuals. Poor eating habits, reduced Mg content in food and water are the main causes of the decrease in Mg intake by the general population. In clinical practice, the serum concentration of this mineral is the most widely used marker for diagnosing deficiency. However, the serum concentration does not reflect the nutritional Mg status since it can be maintained by mobilization of body storage, mainly the bone. Thus, the use of serum concentration as the only routine biomarker of Mg status may hinder the diagnosis of Mg deficiency. In clinical and experimental research, different methods for Mg status assessment are proposed (plasma, erythrocyte, urine), but they are seldom used in clinical routine. In some countries (such as USA and Brazil) the average daily Mg dietary ingestion of more than 60% of the adult population is lower than the Estimated Average Requirement for age and gender, and these data are not too different for individuals with chronic non-communicable diseases. It is unclear whether it is an actual reduction of Mg consumption or if the recommendations are overestimated. If we assume that the recommendations are correct, the question is if this condition constitutes a risk factor for chronic diseases or the hypomagnesemia described in some diseases is a consequence of physiopathological changes. This review has the latest information of human and animal studies about Mg status evaluated from plasma, erythrocyte and urine, dietary inadequacy, and its relation to inflammation and to components of metabolic syndrome.

A formação do profissional nutricionista na percepção do docente / Professional nutritionists education from the perception of the teacher / La formación del profesional nutricionista en la percepción del docente

Este estudo avaliou a formação do profissional de nutrição na percepção dos docentes nutricionistas de uma instituição de Ensino Superior do nordeste brasileiro. Trata-se de pesquisa qualitativa realizada com vinte professores nutricionistas que ministraram disciplinas do ciclo profissional no período de 1980 a 2008. A principal limitação foi a deficiência de infraestrutura física, de material e de equipamentos, sobretudo para a realização de aulas práticas. Limitações relacionadas à atividade docente e ao conhecimento adquirido pelos estudantes foram mencionadas. Apesar das dificuldades apontadas, melhorias estruturais foram referidas. Adequações adicionais são necessárias na infraestrutura, bem como medidas voltadas para melhor planejamento do trabalho docente e para conscientização do corpo discente do seu papel no processo ensino-aprendizagem, possibilitando a formação de profissionais mais capacitados para o mercado de trabalho.

This study evaluated the nutrition professionals education from the perception of nutrition teachers at a higher education institution in northeastern Brazil. This was a qualitative study among twenty nutrition teachers who were giving classes within disciplines in the professional cycle between 1980 and 2008. The main limitations faced were deficiencies in physical infrastructure, material and equipment, especially for conducting practical classes. Limitations relating to teaching activities and the knowledge acquired by students were mentioned. In spite of the difficulties, structural improvements were reported. Additional adjustments to infrastructure are required, along with measures aimed at better planning of teaching work and greater awareness among students regarding their role in the teaching-learning process, thereby enabling the education of professionals who are better qualified for the labor market.

Este estudio evaluó la formación del profesional de nutrición en la percepción de los docentes nutricionistas de una institución de Enseñanza Superior del nordeste brasileño. Se trata de encuesta cualitativa realizada con veinte profesores nutricionistas que dictaran asignaturas del ciclo de profesionalización en el período de 1980 a 2008. La principal limitación fue la deficiencia de infraestructura física, de material y de equipos, principalmente para la realización de clases prácticas. Se mencionaron las limitaciones relacionadas con la actividad docente y con el conocimiento adquirido por los estudiantes. A pesar de las dificultades señaladas, se refirieron mejoras estructurales. Son necesarias adecuaciones adicionales en la infraestructura, así como medidas enfocadas en una mejor planificación del trabajo docente y para la toma de conciencia del cuerpo discente de su papel en el proceso enseñanza-aprendizaje, posibilitando la formación de profesionales más capacitados para el mercado de trabajo.