Cardiovascular properties of catechin

Catechin is a flavonoid with antioxidant and anti-inflammatory properties, found in various vegetables commonly included in the daily diet. However, there are few studies reporting on its effects and cardiovascular safety. The effects of catechin on isolated, perfused rat hearts were measured using the Langendorff method. The amplitude of the cardiac contraction force and the QT, QTc, QRS, and RR intervals of the electrocardiogram were assessed. The results (control group and groups treated with different concentrations of catechin) were compared using a paired-sample t-test (p < 0.05), after verifying that the data met the assumptions of normality. The catechin vascular effects on aortic contraction, at different concentrations, were assessed in endothelium-denuded rat aortic rings pre-contracted with 60 mmol·L-1 of KCl and with 10 µmol·L-1 of phenylephrine. Catechin increased the QRS interval only at the highest concentration studied (10 μmol/L) and prolonged the RR interval across the entire concentration range; however, it did not significantly affect the QTc interval. In a concentration-dependent manner, this compound exhibited a negative inotropic effect on isolated hearts. The estimated concentration for 50% inhibition of myocardial contractility was 5.36 ± 3.22 μmol/L. Conclusions: Direct cardiovascular effects of catechin were observed, with a good margin of cardiovascular safety. Catechin induced a concentration-dependent relaxation in endothelium-denuded rat aortic rings with an IC50 of 45.8 ± 2.1 μmol·L−1 and 13.9 ± 3.5 μmol·L−1 in the aortic rings precontracted with 60 mmol·L−1 of KCl and 10 µmol·L−1 of phenylephrine, respectively. Conclusions: The mode of action of the vasorelaxant effect caused by this flavonoid is endothelium-independent.