Oxidative stress, antioxidants and neurodegenerative diseases.

It is widely accepted that oxidative stress increases with age, and that age is a major risk factor for several neurodegenerative diseases such as Parkinson's disease and Alzheimer's disease. An inbalanced overproduction of reactive oxygen species can induce neuronal damage, leading to neuronal death by necrosis or apoptosis. Antioxidants are consequently considered to be a promising approaches to neuroprotection. Although experimental data are consistent in demonstrating a neuroprotective effects of antioxidants in vitro and in animal models, the clinical evidence that antioxidants agents may prevent or slow the course of these diseases is still relatively unsatisfactory, and unsufficient to strongly modify the clinical practice. This review summarizes the available data from experimental studies and clinical trials on antioxidant neuroprotection in Parkinson's and Alzheimer's disease.