Efeitos de diferentes modalidades de exercícios e intervenção nutricional sobre biomarcadores de estresse oxidativo e aspectos histopatológicos musculares: evidências de estudos pré-clínicos na obesidade e isquemia e reperfusão

Abstract

High-fat diets (HFD) and sedentary lifestyles are directly associated with obesity, which leads to skeletal muscle dysfunction and increased risk of cardiovascular disease. On the other hand, the inclusion of functional foods, such as chia oil, recognized for its anti-inflammatory and antioxidant properties, can mitigate these negative effects. In parallel, regular physical exercise significantly influences oxidative stress levels, promoting muscle benefits and cardioprotective effects. The objective of this thesis was to develop two studies: 1) to evaluate the effects of aerobic physical exercise alone or in combination with chia oil supplementation on the modulation of oxidative stress and histopathological parameters in skeletal muscle in experimental models of obesity; and 2) to perform a systematic review with meta-analysis to evaluate the effects of high-intensity interval training (HIIT) in animals with ischemia-reperfusion injury in relation to cardiac oxidative stress. In the first study, 35 60-day-old male Wistar rats were randomly divided into five groups: (1) control (C), fed a standard chow diet; (2) HFD, fed a high-fat diet ad libitum; (3) HFD+Ex, fed HFD and swimming three times a week; (4) HFD+CO, receiving HFD with chia oil supplementation via gavage at a dose of 1 mL/day, three times a week; and (5) HFD+Ex+CO, fed HFD, swimming and supplemented with chia oil. After 8 weeks, the rats were euthanized and the soleus muscles were collected, weighed and processed for histopathological, morphometric and oxidative stress analyses. Chia oil supplementation reduced collagen accumulation and protein carbonylation, while aerobic exercise alone improved collagen deposition but increased protein carbonylation. The combination of both interventions effectively reduced weight gain and adipose stores. Furthermore, in the second article, a meta-analysis examined the effects of HIIT on markers of oxidative stress in ischemia-reperfusion (IR) injury, a condition characterized by transient interruption of blood flow followed by reperfusion, leading to cellular damage. Six studies with 88 rats were analyzed, revealing that HIIT significantly increased the levels of antioxidant enzymes, such as superoxide dismutase and catalase. However, no significant differences were observed in the levels of glutathione peroxidase, reduced glutathione, malondialdehyde, and myeloperoxidase. Although HIIT appears beneficial in increasing antioxidant defenses, more high-quality studies are needed to confirm these findings. In conclusion, both aerobic training combined with chia oil and HIIT demonstrate potential benefits in improving muscle and cardiac parameters related to oxidative stress. These findings highlight the importance of functional nutrition supplementation and structured exercise programs to combat metabolic disorders and skeletal and cardiac muscle dysfunction.