Novel indices of oxidant stress in cardiovascular disease: specific analysis of F2-isoprostanes

Vitamin E inhibits abdominal aortic aneurysm formation in angiotensin II-infused apolipoprotein E-deficient mice

BACKGROUND

Abdominal aortic aneurysms (AAAs) in humans are associated with locally increased oxidative stress and activity of NADPH oxidase. We investigated the hypothesis that vitamin E, an antioxidant with documented efficacy in mice, can attenuate AAA formation during angiotensin II (Ang II) infusion in apolipoprotein E-deficient mice.

METHODS AND RESULTS

Six-month-old male apolipoprotein E-deficient mice were infused with Ang II at 1000 ng/kg per minute for 4 weeks via osmotic minipumps while consuming either a regular diet or a diet enriched with vitamin E (2 IU/g of diet). After 4 weeks, abdominal aortic weight and maximal diameter were determined, and aortic tissues were sectioned and examined using biochemical and histological techniques. Vitamin E attenuated formation of AAA, decreasing maximal aortic diameter by 24% and abdominal aortic weight by 34% (P<0.05, respectively). Importantly, animals treated with vitamin E showed a 44% reduction in the combined end point of fatal+nonfatal aortic rupture (P<0.05). Vitamin E also decreased aortic 8-isoprostane content (a marker of oxidative stress) and reduced both aortic macrophage infiltration and osteopontin expression (P<0.05, respectively). Vitamin E treatment had no significant effect on the extent of aortic root atherosclerosis, activation of matrix metalloproteinases 2 or 9, serum lipid profile, or systolic blood pressure.

CONCLUSIONS

Vitamin E ameliorates AAAs and reduces the combined end point of fatal+nonfatal aortic rupture in this animal model. These findings are consistent with the concept that oxidative stress plays a pivotal role in Ang II-driven AAA formation in hyperlipidemic mice.

A phase I study of vitamin E, 5-fluorouracil and leucovorin for advanced malignancies

Six patients with incurable malignancies were originally treated with vitamin E, 3200 IU/day for fourteen days, followed by the same dose of vitamin E daily plus LCV (20 mg/m2 i.v. bolus daily x 5) with 5FU (425 mg/m2 i.v. bolus immediately following LCV). The same schedule of LCV and 5FU was repeated 4 weeks later, then every 5 weeks indefinitely. When 3 of the first 6 had grade 3/4 toxicity, six more patients were treated on the identical drugs and schedule. Seven of twelve total patients had one or more grade 3/4 toxicities. Neutropenia, abdominal pain, and diarrhea were most common. No patient had a documented response, though seven patients did have stable disease. Though the combination of vitamin E and chemotherapy was toxic, this trial demonstrated maximal therapeutic doses of vitamin E can be combined with standard 5FU and LCV, without significantly increasing the side effects of the chemotherapy itself.