Mitochondrial function in response to cardiac ischemia-reperfusion after oral treatment with quercetin.

Polyphenolic compounds present in red wines, such as the flavonol quercetin, are thought capable of cardioprotection through mechanisms not yet clearly defined. It has been established that mitochondria play a critical role in myocardial recovery from ischemia-reperfusion (I-R) damage, and in vitro experiments indicate that quercetin can exert a variety of direct effects on mitochondrial function. The effects of quercetin at concentrations typically found in 1-2 glasses of red wine on cardiac I-R and mitochondrial function in vivo are not known. Quercetin was administered to rats (0.033 mg/kg per day by gavage for 4 d). Isolated Langendorff perfused hearts were subjected to I-R, and cardiac functional parameters determined both before and after I-R. Mitochondria were isolated from post-I-R hearts and their function assessed. Compared to an untreated control group, quercetin treatment significantly decreased the impairment of cardiac function following I-R. This protective effect was associated with improved mitochondrial function after I-R. These results indicate that oral low dose quercetin is cardioprotective, possibly via a mechanism involving protection of mitochondrial function during I-R.