RESUMO
BACKGROUND: Alzheimer's disease (AD) is an age-associated neurodegenerative disorder that is associated with a progressive impairment of cognition. Acupuncture has protective effects, although the molecular mechanisms are largely unknown. The activation of peroxisome proliferator activated receptor γ (PPAR-γ) has an impact on the pathogenesis of AD. OBJECTIVE: To test the hypothesis that electroacupuncture (EA) confers therapeutic benefits through activation of PPAR-γ in a rat model of AD. METHODS: 80 male Sprague-Dawley rats were randomly divided into four groups (n=20 each): Control (healthy control group), Sham (sham-operated group), AD (untreated AD model group), and AD+EA (AD model group treated with EA). The AD model was induced in the latter two groups by injection of amyloid-ß (Aß)1-40 into the hippocampal CA1 area bilaterally. EA was administered at GV20 and BL23 six times per week for 4â weeks. The rats' behaviour was examined using the Morris water maze test, and protein expression of Aß, hyperphosphorylated tau protein (p-Tau), PPAR-γ, and hyperphosphorylated p38 mitogen activated protein kinase (p38MAPK) in the hippocampal CA1 region was examined by immunohistochemistry and Western blotting. RESULTS: EA significantly improved cognitive deficits and reduced Aß and p-Tau Ser404 protein concentrations in the hippocampal CA1 region. AD decreased PPAR-γ and increased p-p38MAPK, while EA significantly upregulated PPAR-γ expression and significantly downregulated p-p38MAPK expression. CONCLUSIONS: Acupuncture at GV20 and BL23 might have a beneficial effect on rats with AD via activation of PPAR-γ and inhibition of p-p38MAPK expression.