In-Vitro Study of DNA Adduct 8-Hydroxy-2'-Deoxyguanosine Formation from 2'-Dexoyguanosine Exposure Against Benzo[a]pyrene and Ni(II) Compounds Through Fenton-Like Reactions

This research was performed to study the process of 8-hydroxy-2'-deoxyguanosine (8-OHdG) adduct formation as biomarker that used for early cancer detection in humans. This in-vitro study was conducted by reacting 2'-deoxyguanosine as one of the bases of DNA against benzo[a]pyrene (B[a]P) as xenobiotic, Ni(II), and H₂O₂, to study the effects of 2'- deoxyguanosine (2'-dG) exposure against xenobiotic through Fenton-like reaction. The reaction was incubated at 37°C for 18 hours in a shaker incubator. The reactions were varied at pH 7.4 and 8.4. The reaction products were then analyzed by using reverse phase HPLC with UV-Vis detector. The mobile phase used was a mixture of phosphate buffer and methanol with composition of 90:10. It was observed that exposure of 2'-dG against B[a]P and H₂O₂ and also B[a]P, Ni(II), and H₂O₂ both produced 8-OHdG. The higher 8-OHdG yield was obtained from the exposure of 2'-dG against B[a]P, Ni(II), and H₂O₂ compared to exposure against B[a]P and H₂O₂, which can be attributed to stronger effects from Fenton-like reaction. It was also observed that at similar exposure conditions, the 8-OHdG formation was higher at pH 7.4 compared to pH 8.4.