Fig. 6. Intracellular ROS production and phototherapeutic activity.
a HeLa cells were treated with BTI, T1, T2, or T3 (500 nM) and incubated at 37 °C for 24 h. Afterwards, the cells were incubated with CellROXTM green reagent (5 µM, green signal) for 30 min at 37 °C, and where indicated, blue light generated by a LED light cube (excitation = 470/22 nm, 23 mW cm−2) was applied to the cells for 10 min. Hoechst 33342 (500 nM, blue signal) was added to the cells for 30 min at 37 °C before imaging. Hoechst 33342: λexc/λem: 405/430–460 nm and CellROXTM: λexc/λem: 490/510–670 nm. Scale bar 10 µm. Cytotoxicity studies of BTI, T1, T2, and T3 on HeLa cells in the absence (b) or presence (c) of blue light (excitation = 470/22 nm, 23 mW cm−2) irradiated for 6 min. n = 3 independent experiments. Mean ± SD is indicated.