ABC | Volume 112, Nº5, May 2019

Original Article Resistance Exercise Modulates Oxidative Stress Parameters and TNF- α Content in the Heart of Mice with Diet‑Induced Obesity Pauline Souza Effting, 1 Stella M. S. Brescianini, 1 Helen R. Sorato, 1 Bruna Barros Fernandes, 1 Giulia dos S. Pedroso Fidelis, 1 Paulo Roberto L. da Silva, 1 Paulo César L. Silveira, 1, 4 R enata T. Nesi, 1 Rolando B. Ceddia, 3 Ricardo A. Pinho 1, 2 Laboratório de Fisiologia e Bioquímica do Exercício (LAFIBE) - Programa de Pós-Graduação em Ciências da Saúde (PPGCS) - Universidade do Extremo Sul Catarinense (UNESC), 1 Criciúma, SC – Brazil Laboratório de Bioquímica do Exercício em Saúde (BioEx) - Programa de Pós-Graduação em Ciências da Saúde (PPGCS) - Pontifícia Universidade Católica do Paraná (PUCPR), 2 Curitiba, PR – Brazil Muscle Health Research Center, School of Kinesiology and Health Center - York University, 3 Toronto, ON – Canadá Laboratório de Fisiopatologia Experimental - Programa de Pós-Graduação em Ciências da Saúde (PPGCS) - Universidade do Extremo Sul Catarinense (UNESC), 4 Criciúma, SC – Brazil Mailing Address: Pauline Souza Effting • Rua Alda Agliardi Colombo, 210. Postal Code 88816-735, Pedro Zanivan, Criciúma, SC – Brazil E-mail: paulinese@gmail.com, paulinese@outlook.com Manuscript received May 29, 2018, revised manuscript August 20, 2018, accepted October 02, 2018 DOI: 10.5935/abc.20190072 Abstract Background: Obesity can be characterized by low-grade chronic inflammation and is associated with an excess production of reactive oxygen species, factors that contribute to coronary heart disease and other cardiomyopathies. Objective: To verify the effects of resistance exercise training on oxidative stress and inflammatory parameters on mice with obesity induced by a high-fat diet (HFD). Methods: 24 Swiss mice were divided into 4 groups: standard diet (SD), SD + resistance exercise (SD + RE), diet-induced obesity (DIO), DIO + RE. The animals were fed SD or HFD for 26 weeks and performed resistance exercises in the last 8 weeks of the study. The insulin tolerance test (ITT) and body weight monitoring were performed to assess the clinical parameters. Oxidative stress and inflammation parameters were evaluated in the cardiac tissue. Data were expressed by mean and standard deviation (p < 0.05). Results: The DIO group had a significant increase in reactive oxygen species levels and lipid peroxidation with reduction after exercise. Superoxide dismutase and the glutathione system showed no significant changes in DIO animals, with an increase in SD + RE. Only catalase activity decreased with both diet and exercise influence. There was an increase in tumor necrosis factor-alpha (TNF- α ) in the DIO group, characterizing a possible inflammatory condition, with a decrease when exposed to resistance training (DIO+RE). Conclusion: The DIO resulted in a redox imbalance in cardiac tissue, but the RE was able to modulate these parameters, as well as to control the increase in TNF- α levels. (Arq Bras Cardiol. 2019; 112(5):545-552) Keywords: Exercise; Oxidative Stress; Obesity; Diet, High-Fat; Mice. Introduction The World Health Organization (WHO) 1 defines obesity as an abnormal or excessive accumulation of fat that brings health risks. The WHO brings data from the Global Health Observatory showing a worldwide prevalence of obesity of 39% in men and women over 18 years of age (2016 updated data). In this scenario, obesity is also a risk factor for lifestyle‑related diseases, such as cardiovascular disease and type 2 diabetes mellitus. 2 It can be characterized by low-grade chronic inflammation and is associated with increased levels of proinflammatory cytokines, as well as an excess production of reactive oxygen species. 3,4 Studies have shown that hyperglycemia and alterations in glucose uptake in diabetes may lead to oxidative stress with consequent mitochondrial dysfunction, as well as to an inflammatory process with the presence of elevated proinflammatory cytokines, such as TNF- α . Both cases may be triggering factors for coronary heart disease and other cardiomyopathies 5 (see review by Adeghate and Singh). Gamez-Mendez et al., 6 also showed that 8 weeks of high-fat diet (HFD) led to an increase in oxidative stress, resulting in an imbalance of vasoactive substances and consequent endothelial dysfunction of the coronary arteries in obese rats. Studies point to physical exercise as an important ally in reducing the risks related to obesity due to its ability to reestablish the balance between pro-anti-inflammatory cytokines and regulate the cell redox state. 7,8 According to Boardman et al., 9 physical exercise is not only an important therapeutic approach in obesity, but it is also crucial for cardiac function improvement and ischemic injury prevention in obese and/or diabetic animals. Although the literature indicates that exercise is important to prevent or complement the treatment of obesity, 10 one should consider the characteristics of the performed exercise, such as: intensity, duration, frequency and type. Based on the aforementioned facts, this study aimed to identify whether resistance exercise (RE) modifies the oxidative stress and inflammation parameters caused by an HFD in an experimental model of obesity. 545