[Antimalarial activity of hydroalcoholic extract from Bixa orellana L].

Introduction: Bixa orellana L. is one species used in traditional herb medicine in several continents. Among the medicinal properties attributed to this plant, the antimalarial action has been included.

Objective: to evaluate in vitro and in vivo antimalarial activity of extract from B. orellana grown in Cuba.

Methods: the antimalarial activity of the hydroalcoholic extract fro Bija seeds was evaluated in vitro against Plasmodium falciparum Ghana strain and in vivo using a model of murine malaria, that is, Balb/c mice infected with Plasmodium berghei ANKA strain. Citotoxicity was determined against MRC-5 human fibroblasts. Additionally, phytochemical composition of the studied extract was preliminarily informed.

Results: the extract exhibited IC50 (medium inhibitory concentration) of 11.6 microg/mL, CC50 (medium citotoxic concentration) of 60.2 microg/mL and SI (selectivity index) of 5.1. Subcutaneous administration of the extract at a 500 mg/kg dose caused parasitemia reduction of 50.3 +/- 5.8 % on infected animals compared with that of the controls. Phytochemical screening was consistent with detection of triterpenoids and/or steroids, alkaloids, lactonic compounds, phenols, tanins and flavonoids.

Conclusions: the hydroalcoholic extract from B. orellona seeds grown in Cuba showed in vitro and in vivo moderate antimalarial activity. Bioassay-guided fractioning will allow identifying the molecules responsible for the exhibited extract activity and re-evaluating the potentialities of this extract.