Anti-malarial activity of indole alkaloids isolated from Aspidosperma olivaceum

Malaria Journal

Table 1 In vitro activity of Aspidosperma olivaceum extracts and fractions against P. falciparum chloroquine-resistant blood parasites (W2 clone), cytotoxicity (MDL ₅₀ ) to a human hepatoma cell line (HepG2), and selectivity index (SI), the ratio between the MDL ₅₀ and IC ₅₀

Compound*	MDL₅₀(μg/mL)	IC₅₀(μg/mL)**		SI***
Compound*	MDL₅₀(μg/mL)	[³H]-hypoxanthine	Anti-HRPII	SI***
Bark extract and fractions
Crude bark extract	177 ± 4.0	10.6 ± 3.0	9.9 ± 4.5	17
Acid fraction	330 ± 54.0	6.4 ± 2.3	5.5 ± 2.5	52
Neutral fraction	20 ± 3.0	2.0 ± 0.2	2.1 ± 0.5	10
Basic fraction	27 ± 0.0	4.3 ± 2.5	3.8 ± 0.4	<6
Neutral precipitate (NP)	455 ± 100.0	6.7 ± 3.3	5.0 ± 2.5	68
Leaf extract and fractions
Crude leaf extract	904 ± 135.4	7.2 ± 2.3	9.2 ± 5.4	126
Basic residue	415 ± 98.8	4.5 ± 0.7	2.0 ± 1.5	92
Acid fraction	441 ± 59.0	8.5 ± 3.5	5.3 ± 1.1	52
Pure substance from extracts*
(1) Aspidoscarpine #	301 ± 24.0	5.4 ± 2.5	4.4 ± 0.8	56
(2) Uleine	52 ± 10.0	7.0 ± 0.0	3.2 ± 1.8	18
(3) Apparacine	41 ± 2.8	3.0 ± 1.4	3.2 ± 2.7	14
(5 N-methyl-tetrahydrolivacine	126 ± 6.0	5.7 ± 3.3	4.0 ± 2.8	22

*The steps for the bio-fractionation of the extracts are summarized in Figure 1.
**IC₅₀ = dose inhibiting 50% of parasite growth, evaluated in three or four different experiments for each test.
*** SI = values obtained using the [³H]-hypoxanthine test; toxicity considered present at an SI <10.
#Compound (1) was isolated from the leaves and bark. The compounds are numbered 1, 2, 3, and 5 as in Figure 2; their complete names and structures are listed in Figure 1.

ISSN: 1475-2875