Comparison of DNA Damage Photoinduced by Ketoprofen, Fenofibric Acid and Benzophenone via Electron and Energy Transfer¶

Abstract

Ketoprofen (KP) and fenofibrate, respectively, anti-inflammatory and hypolipidemiant agents, promote anormal photosensitivity in patients and may induce photoallergic cross-reactions correlated to their benzophenone-like structure. Here, their ability to photosensitize the degradation of biological targets was particularly investigated in DNA. The photosensitization of DNA damage by KP and fenofibric acid (FB), the main metabolite of fenofibrate, and their parent compound, benzophenone (BZ), was examined on a 32 P-end-labeled synthetic oligonucleotide in phosphatebuffered solution using gel sequencing experiments. Upon irradiation at Ͼ 320 nm, piperidine-sensitive lesions were induced in single-stranded oligonucleotides by KP, FB and BZ at all G sites to the same extent. This pattern of damage, enhanced in D 2 O is characteristic of a Type-II mechanism. Spin trapping experiments using 2,2,6,6-tetramethyl-4-piperidone have confirmed the production of singlet oxygen during drug photolysis. On double-stranded oligonucleotides, highly specific DNA break occurred selectively at 5-G of a 5-GG-3 sequence, after alkali treatment. Prolonged irradiation led to the degradation of all G residues, with efficiency decreasing in the order 5-GG Ͼ 5-GA Ͼ 5-GC Ͼ 5-GT, in good agreement with the calculated lowest ionization potentials of stacked nucleobase models supporting the assumption of a Type-I mechanism involving electron transfer, also observed to a lesser extent with adenine. Cytosine sites were also affected but the action of mannitol which selectively inhibited cytosine lesions suggests, in this case, the involvement of hydroxyl radical, also detected by electronic paramagnetic resonance using 5,5-dimethyl-1pyrrolidine-1-oxide as spin trap. On a double-stranded 32 P-end-labeled 25-mer oligonucleotide containing TT and TTT sequences, the three compounds were found to photosensitize by triplet-triplet energy transfer the ¶Posted on the website on formation of cyclobutane thymine dimers detected using T4 endonuclease V.

Photosensitizing Mechanism and Identification of Levofloxacin Photoproducts at Ambient UV Radiation

“…The cutaneous phototoxicity is a common health problem caused by the interaction of sunlight and drugs are absorbed either locally into the skin or via the systemic circulation and become the substrate for photochemical reactions in the skin (33). Previous studies have shown that low to moderately pigmented human skin may be vulnerable to phototoxic effects (34,35).…”

Establishment of murine model of allergic photocontact dermatitis to ketoprofen and characterization of pathogenic T cells

“…To prepare first strand cDNA, 1 mg of RNA was incubated in 100 ml of buffer containing 10 mM dithiothreitol, 2.5 mM MgCl 2 , dNTP mix, 200 U of reverse transcriptase II (Invitorogen, Carlsbad, CA, USA) and 0.1 mM oligo (dT) [12][13][14][15][16][17][18] (Invitorogen). To prepare first strand cDNA, 1 mg of RNA was incubated in 100 ml of buffer containing 10 mM dithiothreitol, 2.5 mM MgCl 2 , dNTP mix, 200 U of reverse transcriptase II (Invitorogen, Carlsbad, CA, USA) and 0.1 mM oligo (dT) [12][13][14][15][16][17][18] (Invitorogen).…”

“…In addition to the high incidence of occurrence of photocontact dermatitis, KP is an interesting drug in its cross-photoreactivity with thiaprofenic acid, suprofen, phenofibrate, and benzophenone-3 [7][8][9][10][11]. These substances have a photohaptenic moiety [2] as well as a phototoxic ability [12,13].…”

Effect of Basic Amino Acids on Photoreaction of Ketoprofen in Phosphate Buffer Solution

“…From the viewpoint of pharmacology, their photostability, photochemistry and phototoxicity are key factors. Many NSAIDs contain a chromophore such as naphthalene and benzophenone, and can undergo photosensitization reaction that would give rise to undesired phototoxic and photoalleregic effects on human skin (1)(2)(3)(4)(5)(6)(7)(8). The information on the photoreaction mechanism of NSAIDs should be required to understand their photosensitization on human skin.…”