Exercise-induced hippocampal anti-inflammatory response in aged rats

Aging is often accompanied by cognitive decline, memory impairment and an increased susceptibility to neurodegenerative disorders. Most of these age-related alterations have been associated with deleterious processes such as changes in the expression of inflammatory cytokines. Indeed, higher levels of pro-inflammatory cytokines and lower levels of anti-inflammatory cytokines are found in the aged brain. This perturbation in pro-and anti-inflammatory balance can represent one of the mechanisms that contribute to age-associated neuronal dysfunction and brain vulnerability. We conducted an experimental study to investigate whether an aerobic exercise program could promote changes in inflammatory response in the brains of aged rats. To do so, we evaluated the levels of tumor necrosis factor alpha (TNF alpha), interleukin 1 beta (IL1 beta), interleukin 6 (IL6) and interleukin 10 (IL10) in the hippocampal formation of 18 month old rats that underwent treadmill training over 10 consecutive days. Quantitative immunoassay analyses showed that the physical exercise increased anti-inflammatory cytokine levels IL10 in the hippocampal formation of aged rats, when compared to the control group. the hippocampal levels of pro-inflammatory cytokines IL1 beta, IL6 and TNF alpha were not statistically different between the groups. However, a significant reduction in IL1 beta/IL10, IL6/IL10 and TNF alpha/IL10 ratio was observed in the exercised group in relation to the control group. These findings indicate a favorable effect of physical exercise in the balance between hippocampal pro-and anti-inflammatory during aging, as well as reinforce the potential therapeutic of exercise in reducing the risk of neuroinflammation-linked disorders.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Instituto Nacional de Neurociencia Translacional (INNT) (Brazil)Universidade Federal de São Paulo, Dept Fisiol, BR-04023900 São Paulo, BrazilFac Clube Naut Mogiano, BR-08773000 Mogi Das Cruzes, BrazilUniversidade Federal de São Paulo, Dept Neurol & Neurosurg, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Microbiol Immunol & Parasitol, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Fisiol, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Neurol & Neurosurg, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Microbiol Immunol & Parasitol, BR-04023900 São Paulo, BrazilWeb of Scienc