Electrochemical oxidation of the antitumor antibiotic mitomycin C and in situ evaluation of its interaction with DNA using a DNA-electrochemical biosensor

• Published in: Microchemical journal 2017-07, Vol.133, p.81-89
• Main Authors: Bruzaca, Evellin Enny S., Lopes, Ilanna C., Silva, Elizaura Hyeda C., Carvalho, Paulina Andréa V., Tanaka, Auro A.
• Format: Article
• Language: English
• Subjects: DNA; DNA oxidative damage; DNA-electrochemical biosensor; Mitomycin C
• ISSN: 0026-265X; 1095-9149
• DOI: 10.1016/j.microc.2017.03.030

The electrochemical behaviour of the antitumor drug mitomycin C (MMC) was investigated on carbon paste electrode over a wide pH range and using voltammetric techniques. The MMC undergoes diffusion-controlled irreversible oxidation in two different processes, one pH-independent for 2.2˂pH˂4.5 and one pH-dependent for 4.5˂pH˂12.0, and does not involve the formation of any electroactive oxidation product. Upon incubation in different pH electrolytes, chemical degradation of MMC was electrochemically detected by the appearance of a new oxidation peak at a lower potential. The chemically degraded MMC undergoes an irreversible, pH-dependent oxidation for 3.4˂pH˂5.4, and its redox products are reversibly oxidised. The spontaneous degradation of MMC in aqueous solution was confirmed by UV–Vis spectrophotometry. Moreover, a multilayer dsDNA-electrochemical biosensor was used to evaluate the interaction between MMC and DNA. The results have clearly proven that MMC interacts and binds to dsDNA strands immobilized onto a glassy carbon electrode surface and its metabolite(s) cause oxidative damage to DNA. •Chemical degradation of mitomycin C was electrochemically detected.•A multilayer dsDNA-electrochemical biosensor was used to evaluate the interaction between MMC and DNA.•Mitomycin C interacts and binds to dsDNA strands and its metabolite(s) cause oxidative damage to DNA.