Malaria and Coffeewood

Malaria parasites have the annoying habit of circumventing our medicine to combat malaria. They mutate, become resistant and medication like quinine or artimisine are becoming more and more ineffective.

The current main therapy is ACT (artemisinin-based combination treatment), introduced when the parasite became resistant to chloroquine, a quinine derivative. Now artemisinin resistance is becoming increasingly common and no new class of antimalarial has been introduced since 1996.

That means that the search is on for other therapies. One of these is coffeewood (Caesalpinia pluviosa)[1].

Coffeewood is a legume within the Fabaceae family with numerous local medicinal uses, many of which have some rational basis. The plant is antiviral, antimicrobial, anti-inflammatory and antioxidant. Apparently, it is also anti-malarial. In previous research, the crude extract proved inactive. The current research started in vitro testing various extracts against Plasmodium. Finding the hoped for activity, research moved to in vivo research in infected mice.

In the in vitro test, two fractions were significantly effective. The crude extract was not. In mice, the crude extract was somewhat effective, though not as effective against chloroquine resistant malaria. The ethanol extract was effective against both. What’s more, it was synergistic with the artemisinin based drug artesunate, so the two together are more effective than the combined effect of both. The plant extract alone was around 50% effective, artesunate around 60% and the combination around 80%.

Chemical analysis showed that a novel active molecule, most likely an isomer of quercetin, appears to be the most active compound against malaria.

[1] Kayano et al: In vitro and in vivo assessment of the anti-malarial activity of Caesalpinia pluviosa in Malaria Journal - 2011. See here.