Wirkung von Baicalein auf inflammatorische Zellen und Mediatoren des Aortenaneurysmas der Maus

The effect of Baicalein on inflammatory cells and mediators in aortic aneurysm of mice

An abdominal aortic aneurysm (AAA) is defined as a pathological focal dilation of the abdominal aorta. Over 70 per cent of human patients die after a rupture of abdominal aortic aneurysm. This fact shows how important it is to explore the inflammatory development of aortic aneurysms. Nevertheless, the exact pathophysiological mechanisms are not revealed. The aim of this project was to investigate the effect of the anti-oxidative substance Baicalein on aortic aneurysm formation and the inflammation in a mouse model. Also the better understanding of the inflammatory pathway on development of aortic aneurysms should be explored.
The established Angiotensin II induced ApoE-/- -Mouse Model was used. During 4 weeks, 1500 ng/kg/min Angiotensin II was infused via an implanted osmotic pump (ALZET Modell 2004). Animals were classified in 4 groups. Group NaCl BAI- and NaCl BAI+ (n=10) had a saline infusion, Group Ang II BAI- and Ang II BAI+ (n= 30) were perfused with angiotensin II. The Groups NaCl BAI+ and Ang II BAI+ additionally received 1,5 mg/kg/day Baicalein via intraperitoneal injection. The aortic diameter, the peak systolic velocity and the mean velocity were measured weekly through the use of a duplex sonographer. After 4 weeks, the mice were sacrificed and the aortas were dissected. The aortas were stained with histological and immunohistochemical methods to locate the spread of immunological cells, apoptotic cells and the presence of inflammasome components in the aortic wall. Also the degeneration of the media (Grading 0-III) was staged via histological review.
There was no significant effect on mortality, diameter development and the incidence of aortic aneurysms with 30 percent in the verum-group in response to the injection of 1,5 mg/kg/day Baicalein. In addition, Baicalein treatment seems to be associated with the decrease of mortality and incidence of AAAs. Moreover, this dose did not change the presence and distribution patterns of inflammasoms in the aortic wall. Analyses of the medial degeneration seem to show a reduction through Baicalein.
The findings of this study in addition with the inhibition of AAA incidence and the decrease of AAA diameters of other investigations indicate that Baicalein might have an effect on the development of AAA.