Toxicity risk assessment in tobacco chewers, cigarette smokers and alcohol consumers using urinary DNA adduct and exfoliated buccal cells micronuclei as non-invasive biomarkers

Abstract

To assess the toxicity amongst alcohol consumers, tobacco chewers and cigarette smokers using non invasive biomarkers such as urinary DNA adduct and buccal cell micronuclei. Fifty subjects aged between (20-40 years) of different social habits (alcoholics, tobacco chewers and cigarette smokers) of Meerut City (India), were registered for this study. Similarly non-alcoholics, non-tobacco chewers and non-smokers were also selected. Each volunteer completed a health and occupational questionnaire that included information on food habit, smoking habit and consumption of alcohol. Samples were collected in white sterilized plastic bottles and transported in an ice box to the laboratory and stored at −20 0 C (Remi, India) for further analyses of specific gravity of urine, creatinine (Toro and Ackerman, 1975), urinary DNA adduct (8-OHdG) and exfoliated buccal cell micronuclei. ELISA kit was used to determine 8–OHdG in the urine samples of selected subjects. The results showed that minimum amount of 8–OHdG was present in the urine samples of control subjects, whereas maximum value of 8–OHdG was found in tobacco. Alcoholics showed lower values than smokers. Subjects with all the three habits showed further lower value for 8–OHdG. Microscopical examination of the buccal epithelium showed the presence of MN. The least number of cells with micronuclei was recorded in control subjects. Whereas, maximum number of cells with MN was found in tobacco chewers followed by smokers and alcoholics. It is concluded that intake of alcohol, cigarette smoke and tobacco promote generation of reactive oxygen species in the buccal epithelium exposing their DNA to continuous oxidative stress which finally leads to DNA damage and MN formation. Additionally, DNA adducts and micronuclei formation in human tissue can be use as a simple tool and non invasive toxicity biomarkers.