MONDAY, April 10, 2006 (HealthDay News) -- The heart-protective effect of the cholesterol-lowering drug probucol (Lorelco) has nothing to do with its antioxidant activities, Australian researchers conclude.
The drug was pulled off the market in the United States due to adverse side effects -- a tendency to lower HDL "good" cholesterol as well as LDL "bad" cholesterol, and the potential to induce irregular heartbeat. However, the drug is still available in Europe and Canada.
This study, expected to be published online Monday in the Journal of Experimental Medicine, involved laboratory rodents with heart disease. Researchers at the University of New South Wales in Sydney concluded that probucol's protective effect had nothing to do with its antioxidant activities, and that a different part of the probucol molecule provided the benefit in the rodents.
Drugs closely related to probucol that contained this part of the drug -- but not the antioxidant component -- provided just as much heart protection to the rodents as the original drug. If these probucol relatives (one is currently being tested in humans) are free of side effects, they may provide a new treatment option.
It's believed that antioxidants, such as vitamin E and beta carotene, help protect the heart by preventing oxidation of bad cholesterol, a process thought to contribute to the buildup of fatty deposits on artery walls.
More information
The American Heart Association has information about antioxidant vitamins.
