Featured Research

from universities, journals, and other organizations

Antioxidant Action Of Vitamin E Significantly Reduces Heart Disease In Mice

Date:
September 29, 1998
Source:
University Of Pennsylvania Medical Center
Summary:
In mice genetically manipulated to develop atherosclerosis, scientists at the University of Pennsylvania Medical Center have for the first time conclusively demonstrated that vitamin E confers potent protection from the disease. Atherosclerotic damage to cardiovascular tissues was limited by about 40 percent in at-risk mice receiving doses of the vitamin for only 16 weeks.

In mice genetically manipulated to develop atherosclerosis, scientists at the University of Pennsylvania Medical Center have for the first time conclusively demonstrated that vitamin E confers potent protection from the disease. Atherosclerotic damage to cardiovascular tissues was limited by about 40 percent in at-risk mice receiving doses of the vitamin for only 16 weeks.

The researchers were also able to show that the benefit was due to the antioxidant action of vitamin E, not to other possible effects such as a reduction in blood cholesterol levels. This fact strongly suggests that free radicals do, in fact, play a central role in heart disease, a theory long proposed but never proven. A novel method recently developed by the same group for directly measuring oxidant stress in the body provided the data in support of the observations.

A report on the new findings appears in the October issue of Nature Medicine.

"This study offers powerful evidence for the efficacy of vitamin E as an antioxidant in atherosclerosis," says Garret A FitzGerald, MD, chairman of the department pharmacology and senior author on the report. "Significantly, it also shows that free-radical injury is functionally important in the development of cardiovascular disease."

The innovative measurement technique used in the study was developed in FitzGerald's laboratory in collaboration with Joshua Rokach, PhD, a chemist at the Florida Institute of Technology. It assesses the levels in blood or urine of certain biochemicals called isoprostanes. These isoprostanes are stable byproducts of free-radical catalyzed damage to lipids, or fatty molecules, found in tissues throughout the body, and they serve as quantitative markers for that damage.

The strain of mice used in the experiments has been genetically engineered to lack the apoE gene, resulting in extremely high levels of cholesterol and triglycerides in their blood. Atherosclerotic lesions develop in the cardiovasculature of these mice that are similar to those seen in humans with the disease.

Using the isoprostane assay, the investigators were able to determine not only the degree of oxidant stress at work in the mice but also the precise effects of the vitamin E given as an experimental intervention to counter the corrosive process. The results showed that lesions were reduced from 31.7 percent of the aortic arch surface area in the untreated mice to 19.3 percent in the mice receiving vitamin E for 16 weeks, an improvement of approximately 40 percent.

According to FitzGerald, the measure of lipid oxidation used in these experiments could form the basis for clinical trials to test effectively the use of antioxidants against a range of diseases in humans. In recently published studies, his laboratory has demonstrated that levels of the isoprostanes are also increased in human atherosclerosis.

He notes that trials to date of antioxidants have resulted in conflicted findings, perhaps because it could not be known whether the volunteers were under high oxidant stress to begin and, thus, able to benefit from the antioxidant vitamins and other compounds being tested. Also, because antioxidants like vitamins C and E have been shown in the test tube to act as prooxidants when used at high levels, the assay could be used to determine the doses of an antioxidant that would be beneficial rather than damaging.

"One's responsiveness to an antioxidant is a function of the degree to which the oxidation system is activated," FitzGerald says. "So, in clinical trials where there's no biochemical basis for either selecting a dose or identifying patients susceptible to respond, the results can be skewed and erroneous conclusions can be drawn from them."

He adds: "We need to know which individuals should take an antioxidant like vitamin E, because it's not entirely innocuous, and we need to know what dose would be beneficial for them -- as is the case with any drug."

The lead author on the study was Domenico Pratico, MD, an assistant professor of pharmacology, and Rajendra K. Tangirala, MD, was a coauthor. Daniel J. Rader, MD, an assistant professor of medicine, collaborated on the study. Funding was provided by the National Institutes of Health, the National Science Foundation, the American Heart Association, and the W.W. Smith Charitable Trust.


Story Source:

The above story is based on materials provided by University Of Pennsylvania Medical Center. Note: Materials may be edited for content and length.


Cite This Page:

University Of Pennsylvania Medical Center. "Antioxidant Action Of Vitamin E Significantly Reduces Heart Disease In Mice." ScienceDaily. ScienceDaily, 29 September 1998. <www.sciencedaily.com/releases/1998/09/980929072415.htm>.
University Of Pennsylvania Medical Center. (1998, September 29). Antioxidant Action Of Vitamin E Significantly Reduces Heart Disease In Mice. ScienceDaily. Retrieved July 30, 2014 from www.sciencedaily.com/releases/1998/09/980929072415.htm
University Of Pennsylvania Medical Center. "Antioxidant Action Of Vitamin E Significantly Reduces Heart Disease In Mice." ScienceDaily. www.sciencedaily.com/releases/1998/09/980929072415.htm (accessed July 30, 2014).

Share This




More Health & Medicine News

Wednesday, July 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Health Insurers' Profits Slide

Health Insurers' Profits Slide

Reuters - Business Video Online (July 30, 2014) Obamacare-related costs were said to be behind the profit plunge at Wellpoint and Humana, but Wellpoint sees the new exchanges boosting its earnings for the full year. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
Concern Grows Over Worsening Ebola Crisis

Concern Grows Over Worsening Ebola Crisis

AFP (July 30, 2014) Pan-African airline ASKY has suspended all flights to and from the capitals of Liberia and Sierra Leone amid the worsening Ebola health crisis, which has so far caused 672 deaths in Guinea, Liberia and Sierra Leone. Duration: 00:43 Video provided by AFP
Powered by NewsLook.com
At Least 20 Chikungunya Cases in New Jersey

At Least 20 Chikungunya Cases in New Jersey

AP (July 30, 2014) At least 20 New Jersey residents have tested positive for chikungunya, a mosquito-borne virus that has spread through the Caribbean. (July 30) Video provided by AP
Powered by NewsLook.com
Generics Eat Into Pfizer's Sales

Generics Eat Into Pfizer's Sales

Reuters - Business Video Online (July 29, 2014) Pfizer, the world's largest drug maker, cut full-year revenue forecasts because generics could cut into sales of its anti-arthritis drug, Celebrex. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



      Save/Print:
      Share:

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile: iPhone Android Web
      Follow: Facebook Twitter Google+
      Subscribe: RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins