Quercetin, a flavonoid with anti-inflammatory activity, suppresses the development of abdominal aortic aneurysms in mice

Inflammation has been implicated as a contributing factor in the development of abdominal aortic aneurysms (AAA). Quercetin, a natural flavonoid with anti-inflammatory properties, is known for its beneficial effects on vascular disease. In this study, we examined the effects of quercetin to inflammatory cell infiltration, subsequent expression of cytokines and activation of proteases on the expansion of experimental AAA. Aneurysms were induced by abluminal application of calcium chloride in C57/BL6 mice. Quercetin (60 mg/kg) was administered once daily by gavage beginning 2 weeks before AAA induction and continuing for 8 weeks. Mice treated with quercetin exhibited a 32.7% reduction in aortic size compared with vehicle-treated controls. Prevention of AAA was associated with preservation of medial structure, as well as a relative reduction in macrophage and CD3(+) T cell infiltration in aortic tissue, inflammatory cytokines release and nuclear factor kappa B activation. Quercetin also reduced the expression of matrix metalloproteinase (MMP)-2, MMP-9, cathepsin B, and cathepsin K in aortic tissue. In addition, quercetin treatment increased tissue inhibitors of metalloproteinases (TIMP)-1 gene expression. These data indicate that quercetin may be useful for the prevention and treatment of AAA via blocking the inflammatory response and inhibiting the proteases involved in the pathogenesis of this disease. (C) 2012 Elsevier B.V. All rights reserved.