Hypothesis. The present study evaluates the hypothesis that sour cherry seed extract (SCSE) protects against cardiovascular
disease and inflammation in hypercholesterolemic rabbits, and that this protection correlates with SCSE-induced activity of heme oxygenase-
1 (HO-1), a cytoprotective enzyme contributing to oxidative stress responses.
Methods: 18 New Zealand white rabbits were divided into three groups receiving: I. cholesterol-free rabbit chow; II. chow containing 2%
cholesterol; or III. 2% cholesterol plus SCSE for 16 weeks. Heart functions were monitored by echocardiography 0, 4, and 16 weeks after
the initiation of cholesterol-supplemented feeding. At the 16-week time-point, isolated hearts were subjected to ischemia-reperfusion
(I/R), followed by measurement of heart rate (HR), aortic flow (AF), coronary flow (CF), aortic pressure (AoP), and left ventricular developed
pressure (LVDP). Myocardial infarct size was determined using triphenyl tetrazolium chloride (TTC). Quantification of fatty
streaks was assessed using Sudan-III staining. Western blot analysis was used to determine the content of cytochrome c oxidase III (COX
III), vascular endothelial growth factor (VEGF), and HO-1 in the myocardium.
Results: Relative to cholesterol-treated animals not receiving SCSE, SCSE-treated animals exhibited significantly improved cardiac function
and improved peak early diastolic velocity to peak atrial velocity ratio (E'/A'), along with decreased atherosclerotic plaque formation
and infarct size. Increased HO-1 and COX III protein expression and COX activity were also noted in hearts from SCSE-treated rabbits.
Conclusions: This study demonstrates SCSE cardioprotective effects on hypercholesterolemic hearts. Correlation of these outcomes with
HO-1 expression suggests that the effect may be mediated by activity of this enzyme. However, definitive proof of HO-1 dependence requires