Probucol

Probucol, sold under the trade name Lorelco among others, is an anti-hyperlipidemic drug initially developed for the treatment of coronary artery disease. Clinical use was discontinued in some countries after it was found that the drug may have the undesired effect of lowering HDL in patients with a previous history of heart disease. It may also cause QT interval prolongation.

Probucol was originally developed as an industrial antioxidant added to tires to maximize their longevity.

Mechanism of action
Probucol lowers the level of cholesterol in the bloodstream by increasing the rate of LDL catabolism. Additionally, probucol may inhibit cholesterol synthesis and delay cholesterol absorption. Probucol is a powerful antioxidant which inhibits the oxidation of cholesterol in LDLs; this slows the formation of foam cells, which form atherosclerotic plaques.

Probucol has also been shown to inhibit ABCA1-dependent cholesterol transport, which may contribute to its known effect of lowering HDL.

Research
Probucol has been found to have antioxidant and anti-inflammatory properties via several different mechanisms. These properties have led to research into the drug's potential capacity to treat sensorineural hearing loss related to oxidative stress, as well as formulations to improve the delivery of the drug into the ear.

After promising test results in mouse models, probucol is under study at Weston Brain Institute of McGill University as a possible aid in delaying the onset of Alzheimer's disease.