Cardioprotective actions of two bioflavonoids, quercetin and rutin, in experimental myocardial infarction in both normal and streptozotocin-induced type I diabetic rats.
OBJECTIVE
Revascularization therapy is the mainstay of treatment in the management of myocardial infarction in normal and diabetic patients. We attempted to evaluate the cardioprotective actions of quercetin and rutin in ischaemia-reperfusion-induced myocardial infarction in both normal and diabetic rats.


METHODS
Myocardial infarct size was measured using the staining agent 2,3,5-triphenyltetrazoliumchloride. Serum and tissue malondialdehyde levels and superoxide dismutase and catalase in heart tissue were estimated spectrophotometrically. A lead II electrocardiogram was monitored at various intervals throughout the experiment.


RESULTS
Results demonstrated the larger infarct size, enhanced lipid peroxidation, partial depletion of antioxidant enzymes and drastic drop in heart rate in diabetic hearts subjected to in-vivo ischaemia-reperfusion in comparison to normal rats subjected to ischaemia-reperfusion. Furthermore, quercetin and rutin significantly limit the infarct size in both normal and diabetic animals in a similar fashion. However, rutin offered complete cardioprotection at a dose of 10 mg/kg in terms of limiting infarct size. Both flavonoids could partially but significantly attenuate the lipid peroxidation. In addition, treatment has shown moderate improvement in heart rate in both normal and diabetic rats.


CONCLUSIONS
Our data suggest the possible cardioprotective effects of quercetin and rutin in ischaemia-reperfusion injury in both normal and diabetic rats, and that protection might be in part due to the attenuation of oxidative stress and moderate increment in antioxidant reserves.
Annapurna
Akula
A
University College of Pharmaceutical Sciences, Andhra University, Visakhapatnam, India. annapurnaa@rediffmail.com
Reddy
Challa S
CS
Akondi
Raju B
RB
Rao
Sangana R C
SR
D000818:Animals; D002316:Cardiotonic Agents / Q000627:therapeutic use*; D002374:Catalase / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000150:complications / Q000378:metabolism*; D004562:Electrocardiography / Q000187:drug effects; D005260:Female; D006321:Heart / Q000187:drug effects*; D008297:Male; D008315:Malondialdehyde / Q000097:blood / Q000378:metabolism; D009203:Myocardial Infarction / Q000150:complications / Q000188:drug therapy* / Q000473:pathology; D009206:Myocardium / Q000201:enzymology / Q000473:pathology; D011794:Quercetin / Q000627:therapeutic use*; D051381:Rats; D017208:Rats, Wistar; D012431:Rutin / Q000627:therapeutic use*; D013311:Streptozocin; D013482:Superoxide Dismutase / Q000378:metabolism
D002316:Cardiotonic Agents; D008315:Malondialdehyde; D012431:Rutin; D013311:Streptozocin; D011794:Quercetin; D002374:Catalase; D013482:Superoxide Dismutase