Blood biomarkers of nicotine-induced toxicity in healthy males

Abstract

Abstract Background Smoking enhances oxidative stress by causing an oxidant/antioxidant imbalance in the body leading to deleterious effects on various tissues and organs. 8-hydroxy-2′-deoxyguanosine (8-OHdG) is a predominant form of free radical-induced oxidative lesions, and is widely used as a biomarker of oxidative stress. Objectives This study aimed to estimate blood 8-OHdG level in active, passive and non-smokers and its relation with some lifestyle determinants as well as to assess smoking effects on oxidant/antioxidant status. Participants and methods The current work included 90 male participants who were classified into 3 groups; 20 non-smokers, 30 passive smokers, and 40 active smokers. Data were collected by answering a premade questionnaire. Peripheral venous blood samples were withdrawn then 8-OHdG, cotinine, superoxide dismutase (SOD), and total antioxidant capacity (TAC) levels were estimated in plasma using ELISA kits, while malondialdehyde (MDA) was estimated by colorimetry. Results There were highly statistically significant higher levels of 8-OHdG, cotinine and MDA and lower levels of SOD and TAC in active smokers compared to both passive and non-smokers (p 0.05). There were no significant differences between 8-OHdG level and smoking habits, age, exercise, tea and coffee consumption, and body mass index (BMI) among the 3 studied groups. Conclusion Smoking induces oxidative stress not only through the production of reactive oxygen radicals and increasing blood 8-OHdG levels but also through weakening of the antioxidant defense systems. Further studies are required to reach a consensus on the background level of 8-OHdG and understand which factors determine it and to further differentiate between passive and non-smokers.

Keywords

• Smoking
• Oxidative
• Stress
• Antioxidant
• 8-OHdG