TABLE 3

Effects of AmB, allicin, and their combination on the multiplication of intracellular amastigotes of Leishmania infantum in J774 cellsa

Drug combination nonconstant ratio (μM)% infectionb% growth inhibitionbCIDRI
AmBAllicinAmBAllicin
0064.7 ± 2.50
0.0567.0 ± 3.57.3 ± 5.5
0.07564.7 ± 4.525.8 ± 5.1
0.158.3 ± 2.150.1 ± 5.5
0.0560.3 ± 2.11.3 ± 4.2
161.7 ± 5.715.7 ± 4.6
556.7 ± 3.124.9 ± 1.8
1063.0 ± 4.432.8 ± 3.9
0.050.0562.7 ± 3.126.1 ± 3.1**0.75 (moderate synergism)1.5111.28
160.0 ± 4.028.5 ± 4.4**0.80 (moderate synergism)1.556.04
556.7 ± 1.534.2 ± 6.3***1.30 (moderate antagonism)1.671.42
1056.3 ± 1.545.6 ± 8.5***1.58 (antagonism)1.910.94
0.0750.0556.0 ± 9.547.4 ± 4.5***0.82 (moderate synergism)1.2919.68
154.0 ± 8.255.8 ± 10.9***0.79 (moderate synergism)1.4211.96
559.0 ± 4.454.8 ± 2.0***1.13 (nearly additive)1.412.34
1059.0 ± 2.654.0 ± 3.6***1.58 (antagonism)1.391.15
0.10.0547.3 ± 3.861.4 ± 3.8*0.90 (slight synergism)1.1327.58
153.3 ± 3.861.5 ± 3.3*0.95 (nearly additive)1.1313.86
553.0 ± 3.664.5 ± 5.0**1.18 (slight antagonism)1.173.00
1047.7 ± 1.564.9 ± 0.9**1.50 (antagonism)1.181.51
  • a Drugs were combined at a nonconstant ratio and their dose-effect relationships assessed by the Chou-Talalay method (17) using CalcuSyn software. CI was calculated by the combination index equation. CI of <1, 1, and >1 indicate synergism, additive effect, and antagonism, respectively, at the different drug combination doses. Synergistic effects (CI < 1) are in bold. DRI indicates the fold dose reduction allowed in a drug combination at the different data points compared with each drug alone. Statistical differences between the effects of AmB alone and the combination of AmB plus allicin are indicated as follows: *, P < 0.05; **, P < 0.001; and ***, P < 0.0001.

  • b Values are means ± standard deviations.