BIOMARKERS OF OXIDATIVE STRESS AS INDICATORS OF THE TOXIC HARM OF TOBACCO SMOKING

Cigarette smoke contains a number of oxidising compounds, reactive oxygen species, and carcinogens damaging genome, membranes and cellular macromolecules. Oxidative stress causes lipid peroxidation, protein modification and DNA damage. The aim of this study was to investigate changes in antioxidant status and parameters of structural damages induced by chronic cigarette smoking in healthy subjects. We examined the blood samples of healthy subjects, both smokers (n=25) and non-smokers (n=29). The activities of 5 antioxidant enzymes: glutathione peroxidase (GPx), glutathione transferase, glutathione reductase (GR), superoxide dismutase (SOD), and catalase were measured. Parameters of oxidative damages of cellular structure (level of malonic dialdehyde, membrane microviscosity in erythrocytes and numbers of leukocyte DNA breaks) were determined. The results show a statistically significant increase in GPx and SOD activity in smokers compared to non-smokers. There were GPx and SOD activity and the number of DNA breaks increase and GR activity decrease in smokers of high intensity compared to smokers of low intensity and non-smokers. In the ex-smokers all these parameters were lower than in high intensity smokers. The data obtained show the increased oxidative stress in healthy smokers compared to healthy non-smokers and the relationship between smoking intensity and the extent of damage.