( Antioxidants such as beta-carotene and...)Free-radical busting antioxidants might not promote healthy hearts

Antioxidants, such as beta-carotene and Vitamin E, have been touted for their ability to protect against heart disease. This protective effect is attributed to their ability to prevent the oxidation of bad cholesterol by free radicals—a process thought to contribute to the build-up of disease-causing fatty deposits on artery walls. But a new study, published online on April 10 in The Journal of Experimental Medicine, suggests that the heart-healthy effect of one antioxidant has little to do with cholesterol oxidation.

A group of researchers at the University of New South Wales in Australia, led by Roland Stocker, studied a cholesterol-lowering drug called Probucol (Lorelco) in laboratory rodents with vascular disease. Probucol reduces the risk of heart disease in humans, but is no longer prescribed in the US and Australia because of adverse side effects: a tendency to lower good cholesterol along with the bad and the potential to induce an irregular heartbeat. Probucol is still available in Canada and Europe.

In their new study, Stocker and his colleagues show that the protective effect of probucol has nothing to do with its ability to scavenge oxygen free radicals, as the free radical-busting part of the drug alone was ineffective in protecting animals against heart disease. Instead, a different part of the probucol molecule was doing the beneficial work.

In fact, contrary to widely accepted opinion, the group found no relationship between the levels of oxidized cholesterol in blood vessels and the severity of heart disease. This might help explain the disappointing results of clinical trials with other free radical-scavenging antioxidants, such as Vitamin E, which have shown no protective effect against heart disease in humans.

The protective effect of these compounds depended on the induction of a cellular enzyme called heme oxygenase-1 (HO-1). HO-1 is known to protect against atherosclerosis in animal models, although the mechanism
'"/>

Source:Journal of Experimental Medicine

Page: 1 2
Related biology news :

1. York researchers develop pollution-busting plants to clean up contaminated land
2. Clot-busting drug helps revive cardiac arrest patients
3. Red delicious, Northern Spy apples have most antioxidants, chemists find
4. Unique tomatoes tops in disease-fighting antioxidants
5. Honeydew honeys are better antioxidants than nectar honeys
6. Pistachios lower cholesterol, provide antioxidants
7. Antibiotic might fight HIV-induced neurological problems
8. Newly discovered pathway might help in design of cancer drugs
9. Compound might defeat African sleeping sickness, clinical trial beginning this month
10. Stem cells electric abilities might help their safe clinical use
11. Software might revolutionize glucose monitoring in critically ill patients