Table 1. Icaritin enhances the radiosensitivity of murine 4T1 breast cancer cells.
Icaritin | D0 (Gy) | SF2 | ER | CI* | DRI* |
0 µM | 5.5 | 0.87 | |||
1.5 µM | 4.8 | 0.85 | 1.30 | 4.95 | 0.20 |
3 µM | 4.7 | 0.83 | 1.18 | 0.39 | 2.51 |
6 µM | 3.7 | 0.62 | 1.28 | 0.19 | 5.07 |
D0, incremental dose required for reducing the fraction of colonies to 37%, indicative of single-event killing; SF2, surviving fraction of exponentially growing cells when irradiated at the clinically relevant dose of 2 Gy; ER, enhancement ratio; CI, combination index; DRI, dose reducing index.
CI <1 and DRI >1 indicate a synergistic cytotoxic effect of icaritin and radiation.