TABLE 5.
In vitro interaction of 4-chlorothymol with chloroquine at different concentrations against chloroquine-resistant strain (K1) of P. falciparum.
| Fix ratio | *IC50 (µg/ml) | *FIC50 | ƩFIC50 | #Interactions | ||
|---|---|---|---|---|---|---|
| Chloroquine | 4-Chlorothymol | Chloroquine | 4-Chlorothymol | |||
| 5:0 | 0.130 ± 0.04 (0.252 µM) | – | – | – | – | – |
| 4:1 | 0.057 ± 0.010 (0.110 µM) | 0.287 ± 0.078 (1.559 µM) | 0.438 ± 0.078 | 0.119 ± 0.032 | 0.558 | Synergistic |
| 3:2 | 0.041 ± 0.011 (0.079 µM) | 0.600 ± 0.119 (3.260 µM) | 0.320 ± 0.091 | 0.250 ± 0.049 | 0.570 | Synergistic |
| 1:1 | 0.027 ± 0.002 (0.052 µM) | 0.745 ± 0.268 (4.048 µM) | 0.207 ± 0.022 | 0.310 ± 0.111 | 0.518 | Synergistic |
| 2:3 | 0.023 ± 0.008 (0.044 µM) | 0.875 ± 0.166 (4.755 µM) | 0.179 ± 0.006 | 0.364 ± 0.069 | 0.544 | Synergistic |
| 1:4 | 0.015 ± 0.002 (0.029 µM) | 1.225 ± 0.132 (6.657 µM) | 0.117 ± 0.020 | 0.510 ± 0.055 | 0.628 | Synergistic |
| 0:5 | – | 2.40 ± 0.42 (13.043 µM) | – | – | – | – |
FIC50 = IC50 in combination/IC50 of drug alone and ƩFIC50 = FIC50 values of chloroquine + FIC50 values of 4-chlorothymol at different ratio. *IC50 and *FIC50 expressed as mean ± SEM (n = 3), and #Σ FIC <1 synergism, Σ FIC ≥1 and <2 additive, Σ FIC ≥2 and <4 antagonism.