Polyphenols and depression: from chemistry to medicine.

Polyphenols are an extensive group of substances present in plants. Animals and humans achieve them through the diet. Polyphenols have been related to several processes, such as oxidative stress and signaling pathways modulating gene expression that promote an anti-inflammatory environment. Moreover, polyphenols also have a possible role in the protection of several diseases, including major depression. Depression is an important public-health problem with a multifactorial etiology and lots of pathways that can be altered in affected subjects. Moreover, this disease can be affected by exercise, sleep and diet. There are animal works studying polyphenols and depression, but human studies are scarce. This review summarizes recent evidences in relation to the effects of polyphenols as antidepressant agents in the depression.