Natural antioxidants in prevention and management of Alzheimer's disease.

Alzheimer's disease (AD) is the most common neurodegenerative disease that causes dementia in the elderly. As the aging population increases, the prevalence of AD has increased remarkably worldwide and AD has become one of the leading causes of disability and death among the elderly. A number of drugs have been approved for the treatment of AD; however, they produce only modest benefits and have a wide range of side effects. Therefore, extensive studies are underway to identify effective drugs that are free of undesirable side effects. As accumulating evidences have implicated oxidative stress in the initiation and progression of AD, the potential of using nature antioxidants for prevention and treatment of AD has attracted considerable attention. The present review discusses the involvement of oxidative stress in the pathogenesis of AD and the neuroprotective effects of natural antioxidants, such as Ginkgo biloba flavonoids, soybean isoflavones, theanine and nicotine in cell culture and AD transgenic animal models, specifically, their inhibition on Abeta-induced neurotoxicity and the underlined molecular mechanisms.