Endothelial dysfunction and inflammation are both common events occurring during the development of atherosclerosis. Previous studies have shown that urolithins, the intestinal microflora metabolites of ellagitannin, exhibit anti-inflammation and antioxidative properties. This study aims to investigate the protective effect of urolithin A (UA) on ox-LDL-induced (where ox-LDL is oxidized low-density lipoprotein) endothelial dysfunction and possible modes of action.