In a mouse model of Ang II-induced Abdominal Aortic Aneurysm (AAA), dietary supplementation with Celastrol, a pentacyclic triterpene derived from the root extracts of the Chinese herb Tripterygium wilfordii, resulted in increased abdominal aortic dilatation, elastin degradation, and activation of MMP-9. This evidence concerns the gene MMP9 and abdominal aortic aneurysm.