Impact of physical exercise on metabolic dysfunction-associated fatty liver disease (MAFLD)

Obesity is a chronic multifactorial disease characterized by excess adiposity. Adipose tissue hypertrophy favors lipid deposition in ectopic tissues, such as the liver, which favors the development of the metabolic dysfunction-associated fatty liver disease (MAFLD), characterized by excessive accumulation of lipids in the cytoplasm of hepatocytes (fatty liver). Triglyceride overload in hepatocytes observed in obesity is associated with inflammation and insulin resistance status. Non-pharmacological strategies, such as the practice of physical exercise, seem to be an effective in reducing inflammatory markers and improving insulin sensitivity in obese individuals with MAFLD attenuating hepatocellular steatosis. Thus, this review aims to demonstrate the factors involved in the development of hepatic steatosis, as well as investigate the impact of physical exercise on insulin sensitivity and inflammatory markers in the condition of obesity-associated MAFLD

Influência de diferentes dietas hipercalóricas sobre o estresse oxidativo cardíaco/ Influence of different hypercaloric diets on cardiac oxidative stress

A alta ingestão de dietas hipercalóricas vem sendo mundialmente observada, acarretando aumento do tecido adiposo abdominal com concomitante quadro inflamatório sistêmico de baixo grau, desequilíbrio de citocinas, complicações metabólicas e cardiovasculares. Além disso, observa-se aumento da produção de radicais livres, que associado a diminuição das defesas antioxidantes, resultam em estresse oxidativo. Essa revisão sistemática objetiva analisar estudos que utilizam intervenções nutricionais por meio de dietas hipercalóricas e sua influência no estresse oxidativo cardíaco. A busca virtual foi realizada nas bases de dados Medline, via Pubmed e Bireme, ScienceDirect, Lilacs, e Scielo utilizando como descritores “oxidative stress”, “heart”, “myocardial”, “cardiac”, “high-fat diet”, “high-carbohydrate diet” e “diet”. Foram identificados 739 artigos, os quais após critérios de elegibilidade resultaram em 19 estudos. Estes foram separados em estudos experimentais envolvendo diferentes protocolos de dietas hipercalóricas ricas em gordura e/ou carboidratos.  Os estudos demonstram relação entre consumo de dietas hipercalóricas e estresse oxidativo cardíaco, baseadas em gorduras saturadas ou insaturadas, acrescidas ou não de açúcar observado pelo aumento da lipoperoxidação, carbonilação proteica e elevação das espécies reativas de oxigênio in situ, reporta-se possível envolvimento da enzima NADPH oxidase neste processo, bem como redução das defesas antioxidantes porém há carência de informações sobre as possíveis vias sinalizadoras envolvidas nesse processo.

High‐fat, high‐sucrose, and combined high‐fat/high‐sucrose diets effects in oxidative stress and inflammation in male rats under presence or absence of obesity

Abstract The study examines the influence of three types of hypercaloric diets on metabolic parameters, inflammatory markers, and oxidative stress in experimental model. Male Wistar rats (n = 40) were randomized in control (C), high‐sucrose (HS), high‐fat (HF), and high‐fat with sucrose (HFHS) for 20 weeks. Nutritional, metabolic, hormonal, and biochemical profiles, as well as histological analysis of adipose and hepatic tissues were performed. Inflammation and oxidative stress were determined. HF model caused obesity and comorbidities as glucose intolerance and arterial hypertension. In relation to hormonal and biochemical parameters, there was no significant difference between the groups. All groups showed increased deposition of fat droplets in the hepatic tissue, even though adipocyte areas were similar. Biomarkers of oxidative stress in serum and adipose tissues were similar among the groups. HF model was effective in triggering associated obesity and comorbidities in male rats, but all hypercaloric diets were unable to promote oxidative stress and inflammation