Effect of aged garlic extract on APP processing and tau phosphorylation in Alzheimer's transgenic model Tg2576.

Multiple components present in garlic and various garlic preparations are known to exert pleiotropic protective effects as demonstrated in various in vitro and in vivo model systems. However, garlic pleiotropy in relation to Alzheimer's pathophysiology has not been explored extensively. Current study investigated anti-amyloidogenic, anti-inflammatory and anti-tangle effects of dietary aged garlic extract (AGE) (2%) and compared with its prominent constituents, i.e. S-allyl-cysteine (SAC) (20 mg/kg) and di-allyl-disulfide (DADS) (20 mg/kg) in Alzheimer's Swedish double mutant mouse model (Tg2576). Possible cholesterol-dependent and cholesterol-independent mechanisms of actions of AGE, SAC and DADS in exerting anti-amyloidogenic, anti-inflammatory and anti-tangle effects are discussed. Finally, ameliorative effects of dietary interventions were found to be in the order of AGE>SAC>DADS. If validated pre-clinically, dietary intervention with herbal alternative such as AGE having pleiotropic useful properties and least adverse effects may provide greater therapeutic benefit over a single-ingredient synthetic pharmaceutical drug having serious side effects in treating Alzheimer's disease.