Polyphenols and neuroprotection against ischemia and neurodegeneration.

Neuroprotection of polyphenols in medical plants is getting attention in the world. Scutellaria baicalensis, paeonia veitchii and paeonia suffruticosa have been extensively studied in the last 10 years and show multi-function. They are neuroprotectants, antioxidants, anti-inflammatory and antithrombic agents as well as vasoconstriction inhibitors and amyloid-peptide (Aβ) cleaners by means of their polyphenols: baicalin, baicalein, wogonin (in scutellaria), and paeonol, paeonoside, paeoniflorin (PF) and 1, 2, 3, 4, 6-Penta-O-galloyl-beta-D-glucose (PGG) (in paeonia veitchii and paeonia suffruticosa). Other 4 medical plants: astragali, ligusticum wallichii, angelica sinensis and carthamus tinctorius (saffron) have been the major medicines to treat ischemia for hundreds of years in China, Korea and Japan. Our recent experimental studies demonstrated the neuroprotective efficacy of the combination of these phyotmedicines on mitigating brain infarction and global ischemia as well as preventing the neurodegeneration following ischemia. Owing to their multi-function, including improving cerebral blood circulation, they therefore have the potential to alleviate the symptoms of degenerative diseases, Alzheimer's disease (AD) and Parkinson's disease (PD). Pharmacology of the 7 herbs and their major relative polyphenols is depicted in the article.