The aim of the study was to investigate the photodynamic effect of the novel
photosensitizer chlorophyllin e4 against human
bladder cancer cells. T24 and 5637
bladder cancer cell lines were incubated with
chlorophyllin e4 and irradiated with a 650-nm
laser light. The controls included cells treated with
chlorophyllin e4 but without light as well as cells exposed to
laser light without
chlorophyllin e4. Photocytotoxicity was monitored with MTT assay and apoptosis was measured by flow cytometry. In addition, confocal
laser scanning microscopy was used to assess the subcellular localization of
chlorophyllin e4.
Chlorophyllin e4 exhibited significant photocytotoxicity in both T24 and 5637 cells, which resulted in a maximum of 82.43 and 85.06% cell death, respectively. Treatment with
chlorophyllin e4 or
laser light alone did not induce cytotoxicity. In addition,
chlorophyllin e4-mediated
PDT induced a significantly higher percentage of apoptosis in T24 and 5637 cells compared to the control groups (p<0.01). Moreover, confocal
laser scanning microscopy revealed that
chlorophyllin e4 co-localized with mitochondria in both cell lines. In conclusion, the remarkable photocytotoxicity, natural abundance and inexpensive composition of
chlorophyllin e4 suggest that this compound may be a novel, effective
photosensitizer for the treatment of human superficial
bladder cancer.