Enhancing the efficiency of 5-aminolevulinic acid-mediated photodynamic therapy using 5-fluorouracil on human melanoma cells

• Mel-Rm cells survival decreases with increasing concentration of 5-fluorouracil.
• Mel-Rm cells survival decreases with increasing concentration of 5-ALA.
• 5-FU enhances efficiency of 5-ALA mediated photodynamic therapy on Mel-Rm cells.
• 5-FU decreases effective illumination time in 5-ALA mediated photodynamic therapy.

Background5-Aminolevulinic acid-mediated photodynamic therapy (ALA–PDT) is an effective and noninvasive modality for treatment of several types of non-melanoma skin cancers. This in-vitro study attempted to know whether the killing effect of ALA–PDT on the human melanoma cells (Mel-Rm cell line) could be increased by the presence of 5-fluorouracil (5-FU).MethodsTo evaluate the effect of ALA–PDT in combination with 5-FU on viability of human melanoma Mel-Rm cells, the cells incubated with 5-ALA and 5-FU for 3 h in nontoxic concentrations, and subsequently illuminated with a 630 nm light-emitting diode array. The cells viability and cytotoxicity determined by mitochondrial activity and lactate dehydrogenase assays.ResultsCombination of ALA–PDT and 5-FU (FU–ALA–PDT) showed a considerable growth inhibition according to the results of MTT assay compared to ALA–PDT. The results of LDH assay also showed a cytotoxicity effect in ALA–PDT; however, the FU–ALA–PDT showed no significantly enhancement in cytotoxicity compared to ALA–PDT using LDH assay.ConclusionThe Mel-Rm cells incubation with 5-FU before PDT enhances the efficiency of 5-Aminolevulinic acid-mediated photodynamic therapy.