Anti-amyloidogenic effect of Allium sativum in Alzheimer’s transgenic model Tg2576

Abstract

High levels of cholesterol are implicated in potentiating Alzheimer's disease (AD). Therefore, the use of cholesterol-lowering agents such as statins has attracted considerable interest in treating AD. However, statins stimulate inflammatory response, which may aggravate AD-pathology. Although garlic (Allium sativum) is historically known for its hypocholesterolemic effects in relation to cardiovascular functions, no reports indicate its use in treating AD. Current study tested the feasibility of using dietary garlic on the reduction of amyloid burden in a transgenic mouse model of AD that overexpresses the human amyloid precursor protein 695 carrying Swedish double mutation (K670N/M671L) (Tg2576). Animals were treated with aged garlic extract (40 mg/kg/d/4 wks). Cerebral levels of sAPPalpha, sAbeta40, sAbeta42 were analyzed by sandwich ELISA. Results show 64% reduction of sAPPalpha, and approximately 21-fold elevation of Abeta40 and Abeta42 in untreated Tgs compared to wild type and littermate controls. Dietary garlic increased sAPPalpha by 25% and decreased Abeta40 and Abeta42 by 31% and 32%, respectively, compared to untreated Tgs. These results suggest a simple and non-invasive dietary therapy for reducing risk of AD in probable cases and reducing preexisting amyloid burden in clinically diagnosed AD cases.