Nicotine-enhanced oxidation of low-density lipoprotein and its components by myeloperoxidase/H2O2/Cl- system

Abstract

In this study, the effect of nicotine on the LDL oxidation by the MPO/H 2 O 2 /Cl -system and the effect of HOCl on LDL and some of its components, such as methyl linoleate, vitamin E and the amino acid tryptophan were explored. Nicotine, in micromolar concentrations, enhanced the tryptophan oxidation, either present in LDL or free, in solution. Nicotine also decreased the formation of conjugated dienes and oxygen consumption in a methyl linoleate / HOCl system, and there was evidence to suggest an increase in chlorohydrin formation. Acceleration of the vitamin E oxidation by HOCl was also observed in the presence of nicotine. These data show that the interaction of nicotine and HOCl can promote significant biochemical modifications in LDL particle and some of its components involved in the pathogenesis of cardiovascular and other diseases.