Protective effects of different exercise modalities in an Alzheimer's disease-like model

Abstract

Our aim was to investigate the probable protective effects of aerobic, resistance and combined exercise methods on ovariectomy and D-galactose induced Alzheimer's Disease (AD)-like model. D-galactose (100 mg/kg) or saline were administered intraperitoneally for 6 weeks to ovariectomized or sham-operated rats (n = 8/group). Aerobic (AE), resistance (RE) and combined exercises (CE) (aerobic + resistance) were performed for 3 times a week for 6 weeks. Anxiety level and cognitive functions were evaluated via hole-board and object recognition tests. Brain myeloperoxidase, malondialdehyde, nitric oxide activity, lucigenin-enhanced chemiluminescence, glutathione and serum insulin like growth factor-I (IGF-I) assays were done. Hippocampal mRNA levels of nerve growth factor (NGF), brain derived neurotrophic factor (BDNF), and amyloid precursor protein 695 (APP695) were measured. Amyloid Beta (A beta), NGF, BDNF, IGF-I immunoreactive neurons were evaluated. Freezing time were increased in AD like model and decreased back with AE (p <0.05). Deteriorated working memory in AD-like model was improved with all exercise types (p < 0.05-0.001). Reduced glutathione levels in AD-like model were increased and increased malondialdehyde levels were reduced and serum IGF-I levels were increased by all exercises (p < 0.05-0.001). Increased APP mRNA levels in AD-like model were decreased via CE (p < 0.05). Elevated AP scores in AD-like model were decreased by RE and CE (p < 0.01) in hippocampus and by all exercise types in cortex (p < 0.05-0.01). Decreased cortical NGF immunocytochemical scores of AD-like model were increased by CE (p < 0.05). Different exercise models may have protective effects in development stage of AD via reducing oxidative stress and A beta scores, and by improving antioxidant system and brain plasticity. (C) 2017 Elsevier B.V. All rights reserved.