Neuroprotective effect of physical exercise in a mouse model of Alzheimer's disease induced by β-amyloid₁₋₄₀ peptide

This study was designed to investigate the potential neuroprotective effect of exercise in a mouse model of Alzheimer's disease (AD) induced by intracerebroventricular (i.c.v.) injection of beta-amyloid₁₋₄₀ (Aβ₁₋₄₀) peptide. For this aim, male Swiss Albino mice were submitted to swimming training (ST) with progressive increase in intensity and duration for 8 weeks before Aβ₁₋₄₀ administration (400 pmol/animal; 3 μl/site, i.c.v. route). The cognitive behavioral, oxidative stress, and neuroinflammatory markers in hippocampus and prefrontal cortex of mice were assessed 7 days after Aβ₁₋₄₀ administration. Our results demonstrated that ST was effective in preventing impairment in short- and long-term memories in the object recognition test. ST attenuated the increased levels of reactive species and decreased non-protein thiol levels in hippocampus and prefrontal cortex induced by Aβ₁₋₄₀. Also, Aβ₁₋₄₀ inhibited superoxide dismutase activity and increased glutathione peroxidase, glutathione reductase, and glutathione S-transferase activities in hippocampus and prefrontal cortex-alterations that were mitigated by ST. In addition, ST was effective against the increase of tumor necrosis factor-alpha and interleukin-1 beta levels and the decrease of interleukin-10 levels in hippocampus and prefrontal cortex. This study confirmed the hypothesis that exercise is able to protect against some mechanisms of Aβ₁₋₄₀-induced neurotoxicity. In conclusion, we suggest that exercise can prevent the cognitive decline, oxidative stress, and neuroinflammation induced by Aβ₁₋₄₀ in mice supporting the hypothesis that exercise can be used as a non-pharmacological tool to reduce the symptoms of AD.