The antiplasmodial and radical scavenging activities of flavonoids of Erythrina burttii.

Abstract

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 _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 _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 _M) and free radical scavenging (EC50 ca. 10 _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.