The use of flavonoids in central nervous system disorders

Neurodegenerative, neurological and psychiatric diseases are a group of pathologies with huge social and economic impacts. Since brain disorders continue to be pathological conditions for which corrective surgery cannot be widely used, treatments are based on drugs that only alleviate the symptoms. Despite all efforts in finding more efficient therapeutic agents, the requirement for neuroprotective drugs able to cross the blood-brain barrier (BBB) has been a hard challenge to overcome. Flavonoids are known by their antioxidant activities thus preventing oxidative stress, which is believe to be one of the causes of disorders affecting the central nervous system. Moreover, they can also modulate both enzymes and receptors activities, being regarded as multi-target botanical therapeutics or drugs. This review will give emphasis to the benefits of flavonoids found in the diet in the treatment of Alzheimer's disease, Parkinson's disease, epilepsy, depression, and schizophrenia. The antioxidant effect of several flavonoids, as well as their effects not related with antioxidant activity, in the above mentioned diseases will be reviewed. Aspects concerning structure-activity relationships, but also the bioavailability of these compounds in the brain will be referred.