The Effect of Curcumin on Aβ, Akt, and GSK3β in Brain and Retina of APP/PS1 Mice and Blood of Alzheimer’s Patients With Early Stage Disease

Abstract BackgroundCurcumin has multifunctional pharmacological properties, including anti-oxidant, anti-inflammatory, and anti-diabetic properties. We investigated whether curcumin can improve pathological changes associated with Alzheimer's disease, including amyloid β (Aβ), protein kinase B (PKB, also termed Akt), and glycogen synthase kinase 3β (GSK3β) levels and expression. MethodsAlzheimer’s transgenic APPSWE/PS1ΔE9 mice and wild type mice were treated with curcumin by intragastric administration for 2 weeks at 2 and 5 months of age. Aβ plaques and contents in the brain and retina were measured by immunohistochemistry and enzyme-linked immune sorbent assay, respectively, while the expression of Akt and GSK3β was tested by RNA isolation and quantitative real-time poly merase chain reaction. Bloods of patients with AD and age-matched health controls were used to determine the contents of Aβ, Akt and GSK3β. ResultsCurcumin treatment decreased Aβ accumulation in the early stages of AD at 5 months (p < 0.001). It also improved AD-associated pathological changes, including upregulation of Akt (p < 0.01) and downregulation of GSK3β (p < 0.01). In addition to AD-associated changes, the proinflammatory cytokine IL-1β was significantly decreased by curcumin treatment (p < 0.05). ConclusionsCurcumin can suppress Aβ accumulation during the early stages of AD, upregulate the expression of Akt, downregulate the expression of GSK3β, and inhibit the proinflammatory cytokine IL-1β. Curcumin can be used to improve pathological features of AD in the early stages of disease