Anthocyanidins Found Protective Against Ischemia/Reperfusion Injury.

A new European study published in the April Journal of Nutrition (138:747-752, 2008) found that anthocyanidin consumption was protective against ischemia/reperfusion injury. Reperfusion injury is damage to tissue caused when blood supply returns to tissues after a period of absence, known as ischemia. The restoration of circulation results in inflammation and damage through oxidative stress, rather than restoration of normal function. White blood cells in newly returning blood release a host of inflammatory factors and free radicals in tissue damaged due to oxygen deprivation. Restored blood flow reintroduces oxygen that damages cellular proteins and DNA. Damage to the cell membranes may in turn cause the release of more free radicals, activating apoptosis. Leukocytes also may build up in capillaries, obstructing them and leading to more ischemia. Controlling reperfusion injury is of particular importance in organ transplant surgery. Sub-acute, chronic ischemia/reperfusion injury may be a significant contributor to degenerative conditions in many organ systems, most notably cardiovascular, intestinal, liver, and lungs.Researchers stated that, while the in vitro biological activity of flavonoids is well established, there were no studies showing that dietary intake and absorption of flavonoids actually protected the heart against ischemia-reperfusion injury. They studied the effects in rats of long-term consumption of a class of flavonoids, anthocyanidins, on resistance to myocardial infarction. Rats were fed either an anthocyanidin-rich or anthocyanidin-free diet for a period of 8 weeks. Anthocyanidins were significantly absorbed and detected only in the blood and urine of rats fed the anthocyanidin-rich diet. The hearts of rats fed the anthocyanidin-rich diet were tested and found more resistant to regional ischemia and reperfusion insult. Additionally, infarct size was reduced in rats that ate the anthocyanidin-rich diet compared to those that consumed the anthocyanidin-free diet. Cardio-protection was associated with increased myocardial glutathione levels, suggesting that dietary anthocyanidins may modulate cardiac antioxidant defenses. Researchers stated that their findings suggest important potential health benefits for human health in consumption of foods rich in anthocyanidins. ActiVin® is an all-natural grape seed extract, rich in biologically active flavonoids, in particular anthocyanidins.