Values of lipid and DNA damage in dependence to smoking and plasma antioxidant concentrations

Abstract

Marica Krajcovicova-Kudlackova, Martina Valachovicova, Csilla Mislanova, Jana Pribojova

Smoking is one of the major lifestyle factors influencing the health. Cigarette smoke contains many oxidants, pro-oxidants, free radicals, reducing agents and tobacco-specific carcinogens which can be implicated in the pathogenesis of ischemic heart disease, obstructive lung disease and cancer. Oxidants in cigarette smoke generate oxidative stress which causes oxidative damage to lipids, proteins and DNA. The values of lipid and DNA damage (total peroxides, malondialdehyde, oxidized LDL in plasma, lymphocyte oxidized purines and oxidized pyrimidines) as well as the plasma vitamin concentrations (vitamin C, vitamin E, beta-carotene) were measured in two groups of apparently healthy adults of general population (65 non-smokers and 61 light smokers). Each group was divided into two subgroups with optimal vs suboptimal plasma vitamin concentrations (vitamin C > 50 vs < 50 µmol/l, vitamin E/cholesterol > 5.2 vs < 5.2 µmol/mmol, beta-carotene > 0.4 vs < 0.4 µmol/l). The smokers consumed manufactured filter-cigarettes (less than 20 per day) in average number of 9.1 and 8.4 cigarettes per day with duration of smoking for 18 and 16 years for optimal vitamin and suboptimal vitamin groups, respectively. All parameters of lipid and DNA oxidation were found significantly higher in groups of suboptimal vs optimal plasma vitamin concentrations, but in smoking group the increase was more expressed (by 31.6-35.2% vs 8.9-20.9%). Significantly increased values of all oxidative damage values were seen in smokers vs non-smokers with suboptimal vitamin values, while in groups with optimal vitamin concentrations no changes were observed. In conclusion, oxidative stress induced by cigarette smoking increases the lipid and DNA damage at condition of suboptimal, insufficient plasma vitamin values. Optimal vitamin plasma concentrations seem to be protective against harmful effects of free radical in smoke.