Detection of acetaldehyde derived N2-ethyl-2′-deoxyguanosine in human leukocyte DNA following alcohol consumption

Epidemiological studies have shown an association between alcohol (ethanol) consumption and increased cancer risk. The effect of alcohol consumption on the levels and persistence of N2-ethylidene-2′-deoxyguanosine (N2-ethylidene-dG) formed by acetaldehyde, the oxidative metabolite of ethanol, in human leukocyte DNA was investigated. DNA was isolated from venous blood samples obtained from 30 male non-smoking individuals before consumption of alcohol (0 h) and subsequently at 3-5 h following the consumption of 150 mL of vodka (containing 42% pure ethanol). Additional samples were collected 24 h and 48 h post-alcohol consumption. The levels of N2-ethyl-2′-deoxyguanosine (N2-ethyl-dG) in the DNA were determined following reduction of N2-ethylidene-dG with sodium cyanoborohydride using a liquid chromatography-tandem mass spectrometry selected reaction monitoring method. A slight time-dependent trend showing an increase and decrease in the levels of N2-ethyl-dG was observed following consumption of alcohol compared to time 0 h, however, the differences were not statistically significant. The average levels of N2-ethyl-dG observed at 0 h, 3-5 h, 24 h and 48 h time points following ingestion of alcohol were 34.6 ± 21.9, 35.1 ± 21.0, 36.8 ± 20.7 and 35.6 ± 21.1 per 108 2′-deoxynucleosides, respectively. In conclusion, alcohol consumption that could be encountered under social drinking conditions, does not significantly alter the levels of the acetaldehyde derived DNA adduct, N2-ethyl-dG in human leukocyte DNA from healthy individuals.