Ketoprofen Combined with UVA Irradiation Exerts Higher Selectivity in the Mode of Action against Melanotic Melanoma Cells than against Normal Human Melanocytes

An In Vitro Strategy to Evaluate Ketoprofen Phototoxicity at the Molecular and Cellular Levels

Phototoxicity is a significant problem that occurs in a large part of the population and is often caused by commonly used pharmaceuticals, including over-the-counter drugs. Therefore, testing drugs with photosensitizing potential is very important. The aim of this study is to analyze the cytotoxicity and phototoxicity of ketoprofen towards human melanocytes and fibroblasts in three different treatment schemes in order to optimize the study. Cytometric tests (studies of viability, proliferation, intracellular thiol levels, mitochondrial potential, cell cycle, and DNA fragmentation), Western blot analysis (cytochrome c and p44/p42 protein levels), and confocal microscopy imaging were performed to assess the impact of the developed treatments on skin cells. Research on experimental schemes may help reduce or eliminate the risk of phototoxic reactions. In the case of ketoprofen, we found that the strongest phototoxic potential was exhibited in the treatment where the drug was present in the solution during the irradiation of cells, both pigmented and non-pigmented cells. These results indicate that the greatest risk of photosensitivity reactions related to ketoprofen occurs after direct contact with the drug and UV exposure.

The Assessment of Meloxicam Phototoxicity in Human Normal Skin Cells: In Vitro Studies on Dermal Fibroblasts and Epidermal Melanocytes

Meloxicam (MLX), which belongs to the oxicam nonsteroidal anti-inflammatory drug derivatives, is an inhibitor of the cyclooxygenase-2 (COX-2) enzyme. Cutaneous adverse effects caused by interaction between UVA radiation and exogenous factors can manifest as phototoxic reactions. Phototoxicity may be a reason for the accumulation of genetic and molecular changes in long-lived cells with low proliferation potential, leading to tumor development. There are several potentially phototoxic drugs, the active component of which is meloxicam. The research aimed to evaluate the influence of MLX and UVAR on skin cells—fibroblasts and melanocytes homeostasis. The obtained results indicated that co-treatment with MLX and UVAR inhibited skin cell proliferation, proportionally to the drug concentration. The observation was confirmed by cytometric analysis of the cell number and viability. The phototoxic effect of MLX was revealed in morphological changes. It was stated that MLX with UVAR lowered the mitochondrial transmembrane potential and changed the cell cycle profile. Additionally, MLX and UVAR caused the disruption of redox homeostasis by lowering the intracellular level of reduced thiols. The presented study revealed that the phototoxic activity of MLX is associated with oxidative stress induction and disruptions in cell homeostasis. The differences in the phototoxic effects of MLX at the cellular level may be related to the different content of melanin pigments.