|Life Extension Update Exclusive |
Vitamin E reduces abdominal aortic aneurysm in mice
The August 1 2005 issue of the American Heart Association journal Arteriosclerosis, Thrombosis and Vascular Biology (http://atvb.ahajournals.org/) published the findings of researchers from the University of Iowa that vitamin E administered to mice helped protect against the formation of abdominal aortic aneurysm. Abdominal aortic aneurysm is a ballooning of the abdominal portion of the body’s largest blood vessel, the aorta, and occurs in approximately 3 percent of humans over the age of 65. When enlarged, these aneurysms are subject to rupture, which can have life-threatening consequences. Recent research suggests that inflammation secondary to increased local levels of oxidative stress is involved in the development of this condition.
The current study utilized apolipoprotein E-deficient mice in which angiotensin II (which constricts the blood vessels) was infused, a procedure that results in the development of abdominal aortic aneurysms in 90 to 100 percent of treated animals. The mice received normal diets or diets enhanced vitamin E, while a group of apoplipoprotein E-deficient mice infused with saline rather than angiotensin II served as controls.
After four weeks of angiotensin II infusion, the aorta of the mice were examined for abdominal aortic aneurysm. As expected, the condition was found in 90 percent of mice treated with angiotensin II, however vitamin E supplementation lowered the incidence to 60 percent. In the group who received vitamin E, aneurysms were 24% percent smaller in diameter and weighed 34 percent less than those of the group who did not receive the vitamin. Additionally, vitamin E supplementation was associated with a 44 percent reduction in the number of animals who died before the study’s conclusion of fatal aneurysm rupture combined with those who had evidence of nonfatal rupture at the end of the study.
The oxidative stress marker, 8-isoprostane, was reduced in the vitamin E group, as was macrophage infiltration, an indicator inflammation, supporting the theory that oxidative stress may be involved in the development of abdominal aortic aneurysm.