Role of Plant Polyphenols in Alzheimer's Disease

Alzheimer's disease (AD) is the most common neurodegenerative disease, characterized by notable memory loss, cognitive impairment, and personality disorders accompanied with structural abnormalities in the brain of aged population. Currently approved drugs for AD offer symptomatic relief without preventing the progression of the disease and having limited efficacy. Many experiments and clinical trials have shown that the traditional herbal medicine, which has multiple targets, could provide effective treatment of AD. Increasing evidence suggests that the plant derived polyphenols plays a key role in improving cognitive functions and preventing/delaying the onset of certain neurodegenerative diseases including AD. Although several biological effects based on experimental studies could be scientifically explained, the way to bring natural polyphenols into routine clinical application against neurodegeneration seems to be long, because of its low average daily intake, poor availability and few adverse effects. So the better knowledge about intestinal absorption, excretion, intestinal and hepatic metabolism, plasma kinetics, the nature of circulating metabolites, transport, cellular uptake, intracellular metabolism, and accumulation in tissues including brain will facilitate current scientific understanding and offer great hope for the prevention of AD.