Abstract 421: Anti-Atherosclerotic Effect of Ellagic Acid

Abstract

Introduction Abnormal proliferation and migration of medial vascular smooth muscle cells (VSMC) of vessel wall result in atherosclerotic plaque growth. Targeting proliferation of VSMC could reduce atherosclerotic complications. Therefore, the objective was to study the anti-proliferative effect of Ellagic acid (EA) on primary rat aortic smooth muscle cells (RASMCs) against an atherogenic agonist PDGF in vitro and also anti atherosclerotic effect in streptozotocin (STZ) induced diabetic rats. Methods Proliferation of cells was measured via Alamar blue assay and through propidium iodide based cell cycle analysis in flow cytometer. Reactive oxygen species (ROS) were measured via 2’, 7’-dichlorofluorescin diacetate (DCF-2DA) and Amplex red methods. Expression of proliferation markers and activation of kinases were assessed by immunoblot analysis. Immunohistochemistry was done on aortic tissue sections obtained from in vivo experiments. Results Co-treatment of primary cultures of RASMCs with 25μmol/L of EA significantly reduced PDGF-BB (20ng/ml) induced proliferation by blocking S-phase entry. EA effectively blocked PDGF receptor-β (PDGFR-β) tyrosine phosphorylation, intracellular ROS and downstream activation of extra cellular signal-regulated kinase 1/2. It also blocked PDGF-BB induced expression of cyclin D1. Docking analysis with AutoDock4 revealed two binding pockets for EA in the PDGF-BB-PDGFR-β complex with predicted free energy of bindings similar to known inhibitor, AG1295. In diabetic rats, supplementation of diet with 2% EA significantly blocked diabetes-induced medial thickness, and lipid and collagen deposition in the arch of aorta as well as proliferation marker cyclin D1 expression. Conclusion Therefore, EA is effective as anti atherogenic nutrient therapy.