Dietary polyphenols for treatment of Alzheimer's disease--future research and development.

Polyphenols are the most abundant components of our daily food, occupying the major portion of naturally occurring phytochemicals in plants. Currently, polyphenols have received a special attention from the scientific community against health risk because of their antioxidant capacity and the ability to scavenge the free radicals formed during the pathological process like cancer, cardiovascular diseases and neurodegenerative disorders. Alzheimer's disease, one of the common forms of dementia is an intricate, multifactorial mental illness which is characterized by age-dependent memory loss ultimately leading to a steady decline of cognitive function. Extracellular amyloid beta deposition and intracellular tau hyperphosphorylation are the two main alterations occurring in the cells reported to cause neuronal dysfunction during AD. Dietary intake of polyphenols is known to attenuate the progression of the disease by showing strong potential to tackle the alterations and reduce the risk of AD by reversing the cognitive deficits. A large number of polyphenolic compounds showing promising results against AD pathologies have been identified and described in the past decade. Many efforts have been made to unravel the molecular mechanisms and the specific interactions of polyphenols with their targets in the pathway. This review focuses on the therapeutic potential and promising role of dietary polyphenols as nutraceuticals to combat AD.