MECHANISM OF PHOTOSENSITIZATION OF GLIOBLASTOMA AND NEUROBLASTOMA-CELLS BY MEROCYANINE-540 - A LIPID-PEROXIDATION STUDY

Mechanism of merocyanine 540 (MC540) mediated photosensitization in gl ioblastoma (U-87MG) and neuroblastoma (Neuro 2a) cells was investigate d. Photoinduced lipid peroxidation was measured in the presence of mec hanistic probes-deuterium oxide (D2O), sodium azide, superoxide dismut ase (SOD), mannitol and sodium benzoate. In both the types of cells, t he photoinduced lipid peroxidation was enhanced in D2O whereas it show ed inhibition in the presence of sodium azide. SOD also inhibited the lipid peroxidation while sodium benzoate and mannitol had no effect. T hese results suggest that photosensitization of U-87MG and Neuro 2a ce lls by MC 540 involves both type I (free radical mediated) and type II (singlet oxygen mediated) mechanisms.