Rooibos (Aspalathus linearis) offers cardiac protection against ischaemia/reperfusion in the isolated perfused rat heart

Abstract

Myocardial ischemia/reperfusion (I/R) occurs following partial or complete cessation of blood circulation to the myocardium. The involvement of oxidative stress in the pathogenesis of myocardial I/R injury has been previously reported, with the generation of reactive oxygen species being one of the major mechanisms underlying myocardial reperfusion injury (McCord et al., 1985, Kloner et al., 1989 and Dhalla et al., 2000). Observational studies have repeatedly shown that diets high in plant-based foods and beverages are associated with a lower risk of chronic diseases such as cardiovascular disease (Hertog et al., 1993, Hollman et al., 1999 and Hu, 2003). In addition, it has been reported that antioxidant-rich oils have cardioprotective effects against IR injury (Esterhuyse et al., 2005 and Bester et al., 2006). Flavonoids possess properties that alleviate ischemia/reperfusion injury by helping to re-establish blood flow in post-ischemic hearts. A number of flavonoids and polyphenolic compounds have shown the capacity to dilate vessels (Achike and Kwan, 2003, Engler and Engler, 2006, Sanchez et al., 2006, Nishioka et al., 2007 and Jochmann et al., 2008). Research has shown that flavonols possess antioxidant, anti-inflammatory and vasorelaxant activities (Chan et al., 2000 and Perez-Vizcaino et al., 2006). Epidemiological studies report an inverse association between dietary flavonol intake and mortality from coronary heart disease (Geleijnse et al., 2002 and Lin et al., 2007).