Human serum paraoxonase (PON1) is an esterase that is bound to high-density
lipoproteins (HDLs). It can hydrolyze organophosphates and its activity is
inversely related to atherosclerosis. Some studies also suggest that a rel
ationship exists between polymorphisms of the gene that encodes paraoxonase
and coronary heart disease (CHD), whereas other studies, in different popu
lations, have not found such an association. One mechanism by which certain
PON1 allozymes might protect against atherosclerosis is by inhibition of t
he oxidation of HDL and low-density lipoprotein (LDL). Experimental studies
suggest that this protection is associated with the ability of PON1 to hyd
rolyze specific lipid peroxides in oxidized lipoproteins. interventions tha
t preserve or enhance PON1 activity, as well as manipulations of Pont polym
orphisms, might help delay the onset of CHD.