Abstract

A Plasmodium falciparum in vitro drug sensitive study was conducted in order to evaluate artemisinin in combination with potential anti-malarial drug from the stem bark of Erythrina abyssinica. Abyssinone-v was isolated and thus identified as a potential partner for a fixed combination therapy. Bioassay guided chromatographic separation of Ethyl acetate extract of Erythrina abyssinica led to the isolation of Abyssinone-v with IC₅₀ value of 3.19 µg/ml against chloroquine-sensitive (D6) P. falciparum parasites. The structure of abyssinone-v was determined using nuclear magnetic resonance (NMR) and mass spectroscopic technique. The interaction of artemisinin and abyssinone-v was analyzed using combination ratios of 10:90 to 90:10 respectively against P. falciparum parasites. This led to the identification of anti-malarial combination therapy of artemisinin and abyssinone-v with sum of fraction inhibiting concentration (FIC) of 0.79 at a ratio of 2:3, respectively.

Key words: Erythrina Abyssinica, Plasmodium falciparum, abyssinone-v, artemisinin and combination therapy.