Moderate-intensity Exercise Alleviates Rat's Systemic Inflammation Induced by Repeated Exposure to Lipopolysaccharide

The protective impacts of physical activity against inflammatory and oxidative stress conditions have been demonstrated. In this study, the impacts of moderate-intensity exercise on oxidative stress-associated factors and proinflammatory cytokines levels as well as the count of white blood cells (WBC) were assessed in a lipopolysaccharide (LPS)-triggered model of inflammation. Wistar rats were randomized into these groups (8 rats in each): (1) control; (2) LPS; (3) moderate exercise (EX); and (4) moderate exercise + LPS (EX+LPS). Exercise groups were trained for 8 weeks (30 min, 6 days/week) at 15 m/min speed. During the final week of the experiment, 1 mg/kg/day of intraperitoneal LPS was administered for 5 days. On day 56, from the rats' hearts, peripheral blood was taken for biochemical evaluation. LPS enhanced serum levels of C-reactive protein (CRP), interleukin (IL)- 1β, tumor necrosis factor-α (TNF-α), metabolites of nitric oxide, and malondialdehyde (MDA), as well as the counts of total WBC, monocytes, neutrophils, and eosinophils, but decreased serum levels of thiol as well as superoxide dismutase (SOD) and catalase (CAT) activity versus the control rats. Moderate exercise reduced the levels of thiol, CAT, and SOD, but increased TNF-α level, and total WBC, neutrophils, eosinophils, and monocytes counts versus the control group. In the EX+LPS group, moderate exercise decreased cell counts and diminished MDA, TNF-α, IL-1β, and CRP levels, while increasing thiol level, CAT, and SOD versus the LPS group. In our study, exercise preconditioning reduced inflammation induced by LPS by ameliorating inflammatory cytokine levels, WBC counts, and oxidative damage, while improving antioxidant defenses.