Proanthocyanidins are a class of polyphenolic compounds widely existing in plants. They are known for their strong antioxidant activity,and recognized as the most effective natural antioxidants to scavenge free radicals. Numerous in vitro and in vivo studies have demonstrated that proanthocyanidins have potential applications in improving body function,such as reducing inflammation,improving oxidative stress,anti-cancer and regulating immunity. In this paper,the chemical structure,extraction methods,biological function and current a...