Table 1. The IC50 and CI of different treatments in PC3 cells.
| Treatments | IC50 (μM) |
|---|---|
| Orlistat group | 80 |
| Enzalutamide group | 100 |
| Combination group | 35 |
| CI | 0.79 |
The CI of combination treatment in PC3 cells was calculated according to Chou and Talalay [38] as CI = (D)C/(DX)1 + (D)C/(DX)2 (36). (D)C, (DX)1 and (Dx)2 stand for IC50 of the combination treatment, orlistat alone and enzalutamide alone, respectively. It is synergistic when CI < 1, additive when CI = 1, and antagonistic when CI > 1. Here the CI was calculated as (35/80) + (35/100) = 0.79 (<1), and was identified as synergistic.