[Retracted] 5-Aminolevulinic Acid-Based Photodynamic Therapy Pretreatment Mitigates Ultraviolet A-Induced Oxidative Photodamage

Figure 3

ALA-PDT pretreatment inhibits cytotoxicity and apoptosis of cells irradiated with UVA. Cells were treated with a sublethal dose of ALA-PDT, then these cells were irradiated with 10 J/cm² of UVA light. (a) The cell viability was detected by CCK-8 assay at 450 nm. (b) The apoptosis of HaCaT cells was measured by using Annexin-V and PI in conjunction with flow cytometry; Annexin-V(+)/PI(−) cells were early-stage apoptotic cells. (c) Early apoptosis was indicated by a decrease in mitochondrial membrane potential. When the fluorescence probe JC-1 underwent a transition from red light to green light, it indicated a decrease in cell membrane potential. This was an indicator of early apoptosis. The fluorescence intensity of the green/red ratio was determined by a fluorescence microplate reader. Data were expressed as mean ± SD, for each group, , .

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