Sensitive spectrofluorimetric and mass spectroscopic methods for the determination of nucleic acid damage induced by photosensitized anti-inflammatory drugs: Comparative study.

Anti-inflammatory drugs are reported to induce changes in nucleic-acids upon UV-irradiation. Such changes have the potential to cause apoptosis, carcinogenesis, and mutagenesis. In this work, the kinetics of the damage induced in DNA by some anti-inflammatory drugs were compared after UV-irradiation. Five commonly used anti-inflammatory drugs; diclofenac, ketoprofen, leflunomide, piroxicam and tolmetin, were studied. Simple, sensitive and eco-friendly methods for the analysis of DNA-damage were proposed including absorption spectroscopy, MALDI-TOF mass spectrometry and fluorescence using TbCl3. Results show that all drugs induced DNA-damage after UV-irradiation. Absorption spectroscopy results demonstrated hyperchromic shift in the absorption band characteristic to DNA, indicating distortion of the double-strand. Mass spectra showed a significant decrease of the molecular-ion-peak of DNA, together with peaks of smaller m/z that indicated the formation of DNA strand-breaks. TbCl3 fluorescence was observed to increase with incubation time of each drug with DNA, indicating the presence of more single-stranded regions in DNA due to damage. TbCl3 fluorescence was used to obtain the kinetics of the induced damage. Results show that DNA-damage occurred via photoinduced oxidative mechanism. Also, the potency of the studied drugs was examined on calf-thymus real DNA samples using TbCl3 fluorescence with ketoprofen and leflunomide being the most photogenotoxic anti-inflammatory drugs.