Malaria and Bitter-wood

Bitter-wood (Quassia amara) is a shrub that can eventually grow into a small tree of about seven meters. It has leaves that can reach 25 centimeters en blooms with bright red flowers that white on the inside. The small fruit is a drupe that colours from green to almost black. Bitter-wood is endemic in South-American countries such as Costa Rica, Nicaragua, Panama, Brasil, Peru, Venezuela, Suriname, Colombia, Argentina, French Guyana and (British) Guyana.

With a name like bitter-wood every reader shall probably understand that this shrub will be tasting rather bitter and the reader is right in thinking that. Scientists believe that bitter-wood is so extremely bitter that it is just about maximum level a human can endure.

That bitterness is the result of two substances that hide in the wood of the bitter-wood: quassin (0.09 to 0.17%) and neoquassin (0.05 to 0.11%). Extracts of the wood and the bark are used as an insecticid. Research has shown that bitter-wood offers a very good protection against a host of insects that can ravage a crop. And, most importantly, tea from bitter-wood is very effective against the development of the larvae of mosquitoes in ponds, while not damaging the fishes.

Traditionally, bitter-wood is used to treat fever and to combat flees and lice in hair. Research has shown conclusively that two substances in this species, Simalikalactone D en Simalikalactone E, are a potent cure against malaria. In French Guyana, a tea from fresh young leaves is a traditional antimalarial medicine[1][2]. Experiments showed that this tea highly inhibited the development of the malaria parasites, Plasmodium yoelii yoelii and Plasmodium falciparum. It seems that a tea from dried young leaves gets an even better results than fresh young leaves[3].

All very positive news, you might be thinking at this moment. Mosquitoes and malaria parasites are getting increasingly resistant against nearly every medication and therapy we throw at them. Bitter-wood might be a feasible alternative. But all is not well in the State of Denmark because an extract of bitter-wood greatly reduced the fertility of rats[4]. Good for a potential rat infestation, but not for us humans.

[1] Bertani et al: Simalikalactone D is responsible for the antimalarial properties of an amazonian traditional remedy made with Quassia amara L. (Simaroubaceae) in Science Direct – 2006
[2] Cachet et al: Antimalarial activity of simalikalactone E, a new quassinoid from Quassia amara L. (Simaroubaceae) in AntimicrobialAgents and Chemotherapy – 2009
[3] Bertani et al: Quassia amara L. (Simaroubaceae) leaf tea: effect of the growing stage and desiccation status on the antimalarial activity of a traditional preparation in Journal of Ethnopharmacology – 2007
[4] Raji et al: Antifertility activity of Quassia amara in male rats — In vivo study in Science Direct – 1997