Allicin Reduces Adhesion Molecules and NO Production Induced by γ-irradiation in Human Endothelial Cells

Background: Inflammation is a frequent reaction following therapeutic irradiation. Since the upregulation of adhesion molecules on endothelial cell surface is known to be associated with inflammation, the expression of adhesion molecules is an important therapeutic target. Methods: Treatment of human umbilical endothelial cells (HUVECs) with γ-irradiation (γIR) induces the expression of adhesion proteins such as intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin. Changes in the expression of these proteins on γ-irradiated HUVECs which had been treated previously with allicin were measured by ELISA. Results: In the present study, we demonstrate that allicin inhibits the γIR induced expression of ICAM-1, VCAM-1, and E-selectin on HUVEC in a dose-dependent manner. Allicin was also found to inhibit theγIR induced production of nitric oxide (NO). Conclusion: These data suggest that allicin has a therapeutic potential for the treatment of various inflammatory disorders associated with increase numbers of endothelial leukocyte adhesion molecules. (Immune Network 2002;2(1):6-11)