TABLE 3.
Combination index (CI) value of a two-drug combination between resveratrol, and other antibabesial drugs on the in vitro growth of B. bovis, B. bigemina, and T. equi.
| Drug combinations a | CI value at | Weighted average CI values b | Degree of synergism c | |||
|---|---|---|---|---|---|---|
| IC50 | IC75 | IC90 | IC95 | |||
| Diminazene aceturate | ||||||
| B. bovis | >10 | >10 | >10 | 10.21 | >10 | Antagonism |
| B. bigemina | 13.12 | 10.29 | 8.08 | 6.86 | 9.58 | Antagonism |
| T. equi | >10 | >10 | 7.67 | 3.13 | >10 | Antagonism |
| Imidocarb dipropionate | ||||||
| B. bovis | >10 | >10 | >10 | >10 | >10 | Antagonism |
| B. bigemina | >10 | >10 | >10 | >10 | >10 | Antagonism |
| T. equi | 0.11 | 0.24 | 14.62 | 8.74 | 5.92 | Antagonism |
| MMV396693 | ||||||
| B. bovis | >10 | >10 | >10 | >10 | >10 | Antagonism |
| B. bigemina | >10 | >10 | >10 | >10 | >10 | Antagonism |
| T. equi | >10 | >10 | >10 | >10 | >10 | Antagonism |
CI, value, combination index value; IC50, 50% inhibition concentration.
a
Two-drug combination between resveratrol, and other antibabesial drugs at a concentration of approximately 0.25 x IC50, 0.5 x IC50, IC50, 2 x IC50 and 4 x IC50 (constant ratio).
b
The higher inhibition is preferable; thus, the weighted average CI, value was calculated with the formula [(1 x IC50) + (2 x IC75) + (3 x IC90) + (4 x IC95)]/10.
c
The degree of synergism was determined based on the Chou-Talalay method.