Chemical Properties
White Solid
Uses
An antioxidant, anti-inflammatory, and hypocholesterolemic agent which inhibits atherogenesis in murine models.
Uses
anti-hyperlipoproteinemic
Uses
Probucol is an antilipemic.
Definition
ChEBI: A dithioketal that is propane-2,2-dithiol in which the hydrogens attached to both sulfur atoms are replaced by 3,5-di-tert-butyl-4-hydroxyphenyl groups. An anticholesteremic drug with antioxidant and anti-inflammatory properties, it is used to treat high l
vels of cholesterol in blood.
Brand name
Lorelco (Sanofi Aventis).
Biological Functions
Probucol (Lorelco) is a hypocholesterolemic drug with
few side effects that modestly (15–30%) decreases elevated
plasma LDL cholesterol levels. The marginal LDL-lowering action plus reports that it can lower
HDL cholesterol resulted in its discontinuation as a
hypocholesterolemic drug. However, it still may reduce
the risk of CHD because it is a powerful antioxidant.
The oxidation hypothesis of atherosclerosis states
that oxidation of lipids in LDL is required for LDL uptake
by macrophages and smooth muscle cells in the intima
of arteries, leading to their transformation to foam cells, an early event in atherogenesis. A recent clinical
trial reported that use of probucol decreased the rate of
restenosis of coronary arteries by 50% in patients who
underwent angioplasty. Fluvastatin also has potent antioxidant
properties that may contribute to its antiatherosclerotic
effects.These findings suggest that reducing
high plasma lipids may not be the only approach to retarding
the progression of atherosclerosis and decreasing
the risk of coronary heart disease.
General Description
Probucol, 4,4＇ -[(1-methylethylidene)bis(thio)]bis[2,6-bis(1,1-dimethylethyl)phenol], DH-581(Lorelco), is a chemical agent that was developed for the plasticsand rubber industry in the 1960s. The probucol moleculehas two tertiary butylphenol groups linked by a dithiopropylidenebridge, giving it a high lipophilic character with strongantioxidant properties. In humans, it causes reduction of bothliver and serum cholesterol levels, but it does not alter plasmatriglycerides. It reduces LDL and (to a lesser extent) HDLlevels by a unique mechanism that is still not clearly delineated.The reduction of HDL may be caused by the ability ofprobucol to inhibit the synthesis of apoprotein A-1, a majorprotein component of HDL. It is effective at reducing levelsof LDL and is used in hyperlipoproteinemias characterized byelevated LDL levels.
Biological Activity
Antioxidant, anti-inflammatory and hypocholesterolemic agent. Inhibits atherogenesis in genetically hypercholesterolemic rabbits (Watanabe) and attenuates ischemia/reperfusion-induced cardiomyocyte apoptosis.
Mechanism of action
Probucol reduces the overall level of cholesterol—primarily low-density lipoproteins—
without having an effect on triglycerides and very low-density lipoproteins. It has been
suggested that it inhibits synthesis of cholesterol itself and increases removal of bile salts.
Upon using this drug, a fraction of low-density proteins is reduced; however, even more
significant is the reduction of high-density proteins. From the epidemiological point of
view, this is dangerous, because lowering the concentration of high-density proteins means
less cholesterol is removed from tissues. However, in any case, probucol lowers the level
of cholesterol in the plasma by 10–15%. Moreover, it has been shown that probucol facilitates
reduction of necrotic zones in myocardial ischemia.
Pharmacology
Being a lipophilic compound,
it is easily distributed into fatty tissue and, as a result, approximately 20% of its maximum
concentration in the blood is still maintained for 6 months.
Synthesis
Probucol, bis(3,5-tert-butyl-4-hydroxyphenyl)mercaptol acetone (20.2.6), is
synthesized by thioketalizing acetone with 2,6-di-tert-butyl-4-mercaptophenol in the presence
of hydrogen chloride.
