(Photo)cytotoxicity (IC50, μM) of complexes 1–4 towards various cancer cell lines. The cells were first incubated without or with TCO-OH (100 μM) for 2 h and then with the complexes for 6 h, and incubated for 12 h in fresh medium, which was followed by incubation in the dark or upon irradiation at 450 nm (20 mW cm−2, 20 min), and further incubated in the dark for 24 h.
| Complex | Treatment | MDA-MB-231 | HepG2 | NCI-H460 | |||
|---|---|---|---|---|---|---|---|
| IC50,dark (μM) | IC50,light (μM) | IC50,dark (μM) | IC50,light (μM) | IC50,dark (μM) | IC50,light (μM) | ||
| 1 | − TCO-OH | 14.4 ± 2.8 | 6.9 ± 0.4 | 16.9 ± 2.4 | 11.8 ± 0.9 | 33.0 ± 7.0 | 17.7 ± 2.1 |
| + TCO-OH | 20.4 ± 1.2 | 9.2 ± 0.5 | 17.1 ± 1.0 | 13.1 ± 2.6 | 35.4 ± 4.2 | 21.9 ± 5.7 | |
| 2 | − TCO-OH | 28.2 ± 3.8 | 12.4 ± 0.2 | 11.9 ± 1.4 | 11.2 ± 1.0 | 7.1 ± 0.4 | 1.7 ± 0.1 |
| + TCO-OH | 35.6 ± 6.7 | 5.6 ± 0.6 | 11.5 ± 0.7 | 8.7 ± 0.8 | 6.6 ± 0.2 | 1.1 ± 0.8 | |
| 3 | − TCO-OH | 8.0 ± 1.1 | 0.7 ± 0.1 | 2.3 ± 0.5 | 0.9 ± 0.1 | 4.1 ± 0.2 | 0.9 ± 0.1 |
| + TCO-OH | 5.4 ± 0.4 | 0.5 ± 0.1 | 3.4 ± 0.6 | 0.9 ± 0.1 | 4.2 ± 0.1 | 0.7 ± 0.1 | |
| 4 | − TCO-OH | 68.2 ± 1.2 | 3.8 ± 0.3 | 73.7 ± 6.5 | 4.8 ± 0.8 | 51.1 ± 1.2 | 13.6 ± 0.6 |
| + TCO-OH | 18.3 ± 1.4 | 0.6 ± 0.3 | 15.5 ± 2.0 | 3.2 ± 0.6 | 20.9 ± 0.9 | 4.6 ± 0.1 | |