Role of dietary polyphenols in attenuating brain edema and cell swelling in cerebral ischemia.

Polyphenols are natural substances with variable phenolic structures and are enriched in vegetables, fruits, grains, bark, roots, tea, and wine. There are over 8000 polyphenolic structures identified in plants, but edible plants contain only several hundred polyphenolic structures. Recent interest in polyphenols has increased greatly due to their potential antioxidant effects. In addition, some polyphenols also have insulin-potentiating, anti-inflammatory, anti-carcinogenic, anti-viral, anti-ulcer, and anti-apoptotic properties although some of these properties may be a consequence of their anti-oxidant effects. Given that oxidative stress and inflammation are hypothesized to contribute to increased neural damage in ischemia, polyphenols appear to have a tremendous potential in attenuating such injuries. One important consequence of ischemia is brain edema and oxidative stress and inflammation are implicated in its pathogenesis. Brain edema is defined as an abnormal accumulation of fluid in the brain parenchyma resulting in a volumetric enlargement of the cells or tissue and can cause further ischemic damage. The purpose of this article is to review the current literature on brain edema and/or cell swelling in ischemic injury with the goal to identify newer approaches to attenuate brain edema. A review of currently known mechanisms underlying edema/cell swelling will be undertaken and the potential of dietary polyphenols to reduce edema will be critically reviewed with the discussion of some recent patents.