Voluntary exercise improves pulmonary inflammation through NF-κB and Nrf-2 in type 2 diabetic male rats

Objective(s): This study aimed to evaluate the effects of voluntary exercise as an anti-inflammatory intervention on the pulmonary levels of inflammatory cytokines in type 2 diabetic male rats. Materials and Methods: Twenty-eight male Wistar rats were divided into four groups (n=7), including control (Col), diabetic (Dia), voluntary exercise (Exe), and diabetic with voluntary exercise (Dia+Exe). Diabetes was induced by a high-fat diet (4 weeks) and intraperitoneal injection of streptozotocin (35 mg/kg), and animals did training on the running wheel for 10 weeks as voluntary exercise. Finally, the rats were euthanized and the lung tissues were sampled for the evaluation of the levels of pulmonary interleukin (IL)-10, IL-11, and TNF-α using ELISA, and the protein levels of Nrf-2 and NF-κB using western blotting and tissue histopathological analysis.  Results: Diabetes reduced the IL-10, IL-11, and Nrf2 levels (P 0.001 to P 0.01) and increased the levels of TNF-α and NF-κB compared to the Col group (P 0.001). Lung tissue levels of IL-10, IL-11, and Nrf2 in the Dia+Exe group enhanced compared to the Dia group (P 0.001 to P 0.05), however; the TNF-α and NF-κB levels decreased (P 0.001). The level of pulmonary Nrf2 in the Dia+Exe group was lower than that of the Exe group while the NF-κB level increased (P 0.001). Moreover, diabetes caused histopathological changes in lung tissue which improved with exercise in the Dia+Exe group.  Conclusion: These findings showed that voluntary exercise could improve diabetes-induced pulmonary complications by ameliorating inflammatory conditions.