Curcumin inhibits Homocysteine-induced endothelial dysfunction in porcine coronary arteries

Background. Curcumin, a yellow polyphenolic compound from the plant Curcuma ionga, has anti-tumor, anti-inflammatory, and anti-oxidant activities. The aim of this study was to determine the effect of curcumin on homocysteine (HCY)-induced endothelial dysfunction and superoxide anion production in a porcine coronary artery model. Methods. Five-millimeter porcine coronary artery rings from 8 hearts were incubated for 24 h as either controls, with HCY (50 μM), curcumin (5 μM), or a combination of curcumin (5 μM) and HCY (50 μM). Following this, vasomotor function was analyzed with a myograph device in response to thromboxane A₂ analogue U466419, bradykinin, and sodium nitroprusside (SNP), respectively. Additionally, superoxide anion production was determined by lucigenin-enhanced chemiluminescence assay. Results. All groups of porcine coronary artery rings showed no difference in maximal contraction in response to U46619. However, endothelium-dependent relaxation (bradykin) was 40% in the HCY-treated group as compared to 73% in controls (P = 0.03, n = 8). The curcumin plus HCY group showed a significant improvement of endothelium-dependent relaxation as compared to the HCY-treated group (P = 0.04), but no difference over controls. Curcumin alone showed no difference with controls. All groups showed no difference in endothelium-independent relaxation. Superoxide levels was 13.3 ± 2.1 RLU/s/mm² in control vessels, 40.5 ± 8.7 RLU/s/mm² in HCY-treated vessels, 20.0 ± 2.2 RLU/s/mm² in curcumin treated vessels, and 10.0 ± 1.9 RLU/s/mm² in HCY plus curcumin-treated vessels. Conclusion. These results show that curcumin effectively reverses the endothelial dysfunction induced by HCY. Additionally, curcumin also significantly decreases HCY-induced superoxide production. This study may suggest a therapeutic role of dietary curcumin for patients with hyperhomocysteinemia, thereby reducing cardiovascular morbidity and mortality.