TABLE 1.

Trypanocidal activity of alkaloids and digitonin alone and in combinations

Drug	IC50 ± SD of the serially diluted drug alone (μM)	IC50 ± SD of the drug in combination with (μM)a:
		Berberine (1.87)	Chelerythrine (0.07)	Emetine (0.005)	Homoharringtonine (0.002)	Piperine (14)	Vinblastine (0.04)	Digitonin (0.94)
Berberine	6.85 ± 0.82		2.80 ± 0.85	6.09 ± 0.82	4.18 ± 0.35	6.05 ± 1.60	3.31 ± 0.91	2.64 ± 0.63
Chelerythrine	0.33 ± 0.006	0.30 ± 0.04		0.27 ± 0.04	0.30 ± 0.06	0.20 ± 0.04	0.25 ± 0.04	0.27 ± 0.06
Emetine	0.03 ± 0.007	0.02 ± 0.002	0.02 ± 0.001		0.01 ± 0.002	0.02 ± 0.002	0.01 ± 0.004	0.01 ± 0.001
Homoharringtonine	0.01 ± 0.0002	0.009 ± 0.002	0.009 ± 0.002	0.007 ± 0.002		0.01 ± 0.003	0.009 ± 0.001	0.009 ± 0.002
Piperine	72.40 ± 2.43	31.88 ± 2.37	57.47 ± 11.70	16.83 ± 1.94	53.31 ± 2.40		35.03 ± 1.71	55.09 ± 6.75
Vinblastine	0.21 ± 0.06	0.12 ± 0.007	0.22 ± 0.02	0.13 ± 0.02	0.22 ± 0.01	0.03 ± 0.01		0.02 ± 0.006
Digitonin	6.89 ± 0.57	4.02 ± 1.09	8.39 ± 0.55	11.47 ± 0.85	6.80 ± 0.90	7.03 ± 0.84	8.13 ± 1.01

^aA fixed concentration (indicated in parentheses) was chosen for each combination partner.