The antiplasmodial and radical scavenging activities of flavonoids of Erythrina burttii

The acetone extract of the root bark of Erythrina burttii showed in vitro antiplasmodial activity against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum with IC50 values of 0.97 +/- 0.2 and 1.73 +/- 0.5 mu g/ml respectively. The extract also had radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical with an EC50 value of 12.0 mu g/ml. The isoflav-3-enes burttinol-A and burttinol-C, and the 2-arylbenzofuran derivative burttinol-D were identified as the most active antiplasmodial (IC50 <10 mu M) and free radical scavenging (EC50 ca. 10 mu m) principles. The acetone extract of E. burttii at 800 mg/kg/day, in a 4-day Plasmodium berghei ANKA suppressive test, showed in vivo antimalarial activity with 52% chemosuppression. In the same in vivo test, marginal activities were also observed for the extracts of the root and stem bark of Erythrina abyssinica and the root bark of Erythrina sacleuxii. (C) 2012 Elsevier B.V. All rights reserved.