Additive In Vitro Antiplasmodial Effect of N-Alkyl and N-Benzyl-1,10-Phenanthroline Derivatives and Cysteine Protease Inhibitor E64

Table 2

Combination index of N-alkyl and N-benzyl-1,10-phenanthroline derivatives with E64 or with chloroquine on P. falciparum FCR3 in vitro.

Compound combination			Combination Index (CI)	Interaction
(1)-N-methyl-1,10-phenanthrolinium sulfate	--	E64	1.00 ± 0.26	Additive
(1)-N-ethyl-1,10-phenanthrolinium sulfate	--	E64	0.89 ± 0.18	Additive
(1)-N-benzyl-1,10-phenanthrolinium chloride	--	E64	1.07 ± 0.18	Additive
(1)-N-benzyl-1,10-phenanthrolinium iodide	--	E64	0.99 ± 0.03	Additive
Chloroquine	--	E64	1.17 ± 0.19	Additive
(1)-N-methyl-1,10-phenanthrolinium sulfate	--	Chloroquine	1.28 ± 0.30	Additive
(1)-N-ethyl-1,10-phenanthrolinium sulfate	--	Chloroquine	1.54 ± 0.96	Additive
(1)-N-benzyl-1,10-phenanthrolinium chloride	--	Chloroquine	1.56 ± 0.58	Additive
(1)-N-benzyl-1,10-phenanthrolinium iodide	--	Chloroquine	1.53 ± 0.44	Additive