Abstract 13343: Green Tea Polyphenol Attenuates Experimental Abdominal Aortic Aneurysm Progression in a Rat Model
Introduction: Destruction of elastin in the media layer is thought to play an important role in the development of abdominal aortic aneurysm (AAA). It has been reported that a major component of green tea, epigallocatechin-3-gallate (EGCG), enhances the stabilization of elastin and facilitates the regeneration of elastin in vitro. However, it is unknown whether EGCG attenuates AAA development in vivo.
Hypothesis: We aimed to prove the hypothesis that administration of EGCG can attenuate AAA development.
Methods: We divided 48 male SD rats into two groups: the control group (n=24) and the EGCG group (n=24). A 1.0 mmol/L EGCG solution was administered orally for 2 weeks prior to the induction of AAAs in the EGCG group until sacrifice, while tap water was given to the control group. AAAs were induced by administration of intraluminal elastase and extraluminal calcium chloride. Immediately before the induction of the AAAs (on day 0) and on day 7 after their induction, 6 rats were sacrificed in each group. In addition, 12 rats were sacrificed in each group on day 28. The aortic size was measured and aortic tissues underwent biochemical and histological evaluation.
Results: The abdominal aortic size on day 28 was significantly smaller in the EGCG group than in the control group (2.34 ± 0.12 vs 2.86 ± 0.19mm, p<.0001). The thickness of the media layer increased significantly in the EGCG group compared with that of the control group (68.4 ± 13.6 vs 46.9 ± 13.6μm, p<0.001). The elastin content of the media layer was significantly greater in the EGCG group than in the control group (20.3 ± 4.8 vs 9.6 ± 3.7%, p<.0001). The lysyl oxidase (LOX) mRNA level in the aortic tissues on day 0 was significantly higher in the EGCG group than in the control group (p<0.05). Transmission electron microscopy images showed the growth of new elastic fibers in the EGCG group. On immunohistochemical staining, the LOX-positive area was significantly larger in the EGCG group than in the control group (p<0.01).
Conclusions: Oral treatment with EGCG attenuated AAA progression in a rat model via organization and stabilization of elastin in the media layer by increasing LOX production. Thus, the green tea polyphenol EGCG has the potential to serve as a pharmacological agent to treat and prevent AAAs.
Author Disclosures: S. Setozaki: None. K. Minakata: None. S. Hirao: None. T. Ikeda: None. R. Sakata: None.
- © 2015 by American Heart Association, Inc.