Non-pharmacological strategies have been rarely described in the treatment of
infectious diseases. Although exercise training has been recently incorporated in the clinical management of
Chagas disease, the rationale basis that supports this indication is poorly understood. Thus, we investigated the effect of an aerobic exercise on the parasitism,
inflammation and oxidative tissue damage in a murine model of Trypanosoma cruzi-induced skeletal
myositis. Wistar rats were randomized into four groups: trained not infected (TNI) and infected (TI), sedentary not infected (SNI) and infected (SI). A running training program was administered 5days/week for 9 weeks. Then, infected animals were inoculated with T. cruzi and followed up for another 9 weeks. Exercise training induced beneficial adaptations by increasing time to
fatigue and
lactate threshold in TNI and TI animals. SI animals presented higher
parasitemia, skeletal muscle parasitism, cell
necrosis, leukocyte infiltration,
cytokines levels,
reactive oxygen species and
nitric oxide production,
thiobarbituric acid reactive substances, carbonyl
proteins,
myosin heavy chain I depletion, and increased
catalase (CAT) and
superoxide dismutase (SOD) activities. Beyond attenuation in all these variables, TI animals showed reduced TNF-α, CCL-2/MCP-1 and CX3CL1, and increased
IL-10 muscle levels. Furthermore, these animals presented higher CAT and SOD activities and reduced
lipid and
protein oxidation. Taken together, our findings indicated that exercise training induced a protective phenotype in T. cruzi-infected mice, enhancing host defenses against the parasite and attenuating the pathological remodeling associated with skeletal
myositis, aspects potentially associated to an improved immunological and redox balance in infected animals.