Baicalein protects against the development of angiotensin II-induced abdominal aortic aneurysms by blocking JNK and p38 MAPK signaling.

An abdominal aortic aneurysm (AAA) is a permanent, localized dilatation of the abdominal aorta. In western countries, the morbidity of AAA is approximately 8%. Currently, pharmacotherapies for AAA are limited. Here, we demonstrate that baicalein (BAI), the main component of the Chinese traditional drug "Huang Qin", attenuates the incidence and severity of AAA in Apoe (-/-) mice infused with angiotensin II (AngII). Mechanically, BAI treatment decreases AngII-induced reactive oxygen species (ROS) production in the aortic wall. Moreover, BAI inhibits inflammatory cell accumulation in the aortas of mice infused with AngII. It also inhibits AngII-induced activation of matrix metalloproteinase 2 (MMP-2) and MMP-9 to maintain elastin content in vivo. In addition, it blocks AngII cascade by downregulating angiotensin type 1 receptor (AT1R) and inhibiting mitogen-activated protein kinases (MAPKs). Taken together, our findings show that BAI is an effective agent for AAA prevention.