A review on pathophysiology of ischemic-reperfusion injury of heart and ameliorating role of flavonoids and polyphenols

Ischemia-reperfusion (IR) syndrome is defined as injury caused by the restoration of coronary flow after a period of ischemia. The pathophysiology of ischemia-reperfusion injury involves cellular effect of ischemia, reactive oxygen species and inflammatory cascade. Flavonoids and polyphenols possess unique antioxidant properties and other protective activities which are beneficial for ischemia-reperfusion injury. It is found that flavonoids and polyphenols prevent production of reactive oxygen species and thereby inhibit oxidation of cellular components and also block propagation of oxidative reactions. They also increase the activity of endogenous antioxidant enzymes such as superoxide dismutase and catalase during ischemia-reperfusion injury. Flavonoids also possess anti-inflammatory, anti-platelet aggregation and vasodilatory effects through different mechanism. This review scrutinize to what extent flavonoids and polyphenols play a role in moderating ischemia-reperfusion mediated injury with special emphasis on pathophysiology of heart ischemic-reperfusion injury.   Key words: Ischemia, reperfusion, heart, flavonoids, polyphenols, antioxidant.