Antiplasmodial activity of the andiroba (Carapa guianensis Aubl., Meliaceae) oil and its limonoid-rich fraction.
BACKGROUND
From seeds of Carapa guianensis the Amazon native people extracts the andiroba oil, which is traditionally used as febrifuge, anti-malarial, insecticidal and repellant. The non-saponifiable fraction separated from the oil is rich in limonoids, which assigns its pharmacological effects.


METHODS
The andiroba oil and its limonoid-rich fraction were submitted to in vitro antiplasmodial bioassay using W(2) and Dd(2) strains of Plasmodium falciparum. The acute toxicity of andiroba oil was evaluated. The limonoid-rich fraction was subjected to fractionation and identified its major constituents.


RESULTS
Andiroba oil and its limonoid-rich fraction inhibited the growth of W(2) clone in 100%, between 24 and 72 h, at concentrations of 8.2 μg/mL and 3.1 μg/mL, respectively. Under the same conditions, the parasitaemia of Dd(2) clone provoked by the andiroba oil showed inhibition of 31% (IC(50) >82 μg/mL) with a time-dependent relationship of 24h and inhibition of 88% (IC(50) 8.4 μg/mL) after 72 h, while for the limonoid-rich fraction the inhibition of Dd(2) clone was 56% (IC(50) 2.8μg/mL) at 24h and 82% (IC(50) 0.4 μg/mL) after 72 h. Andiroba oil in acute toxicity test with a fixed dose (LD(50) >2000 mg/kg) was not toxic The limonoids identified in the oil were gedunin, 6α-acetoxygedunin, 7-deacetoxy-7-oxogedunin, 7-deacetylgedunin, 1,2-dihydro-3β-hydroxy-7-deacetoxy-7-oxogedunin and andirobin. Gedunin and derivatives has been reputed as anti-malarials.


CONCLUSIONS
The results support the traditional use of andiroba oil as antiplasmodial, which additionally proved not to be toxic in bioassays conducted with mice.
Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Pará, 66075-900 Belém, PA, Brazil.
Raimundo Nonato Cardoso
RN
Miranda Júnior
Maria Fâni
MF
Dolabela
Milton Nascimento
MN
da Silva
Marinete Marins
MM
Póvoa
José Guilherme S
JG
Maia
D000818:Animals; D000962:Antimalarials / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D004912:Erythrocytes / Q000382:microbiology; D005260:Female; D036701:Limonins / Q000032:analysis / Q000494:pharmacology* / Q000633:toxicity; D029582:Meliaceae; D051379:Mice; D010938:Plant Oils / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D010963:Plasmodium falciparum / Q000187:drug effects
D000962:Antimalarials; D036701:Limonins; D010938:Plant Oils