Antony Ellman, Natural Resources Institute, in the first of two articles on this important anti-malarial describes the potential of Artemisia annua cultivation for artemisinin production in the fight against malaria. In the next issue Elspeth Bartlett will describe efforts to increase the yield of the drug in the crop
Introduction The malaria parasite Plasmodium falciparum is one of the world’s most lethal pests, accounting for over a million deaths per year. 90% of cases are in Sub-Saharan Africa, 85% in children under five. For over 50 years the main tool for controlling the malaria parasite1 has been chloroquine, a synthetic derivative of the plant-based extract quinine. Chloroquine acts as both prophylactic and cure and has the advantage of very low cost ($0.10 per treatment), but unfortunately in much of Africa as well as South-East Asia it is no longer effective due to the emergence of resistant strains of the malaria parasite. The best hope for a replacement treatment lies with drugs based on artemisinin, a chemical extracted from the leaves of the plant Artemisia annua.
Artemisia annua is an annual shrub indigenous to China, but able to grow in a wide range of sub-tropical and temperate environments. Its use in treating malaria has been known in China for over 2000 years. The active ingredient, artemisinin, was isolated by Chinese scientists in 19722 . Derivatives which are more effective than artemisinin itself have been developed over the last 20 years. Attempts to produce synthetic and semi-synthetic artemisinin are ongoing, but the viability of this approach is not yet clear. Resistance to artemisinin drugs will inevitably appear in time, but the plant-based extract is still believed to have a useful life of at least 10 years3 .
This article describes programmes for expanding cultivation of Artemisia annua in Africa and Asia, and analyses Keywords: Artemisia annua, smallholder cultivation, artemisinin extraction, malaria control, China, East Africa prospects for extraction, manufacture and distribution of artemisinin-based anti-malarial drugs in the light of the WHO target of halving the incidence of malaria by 2015 and eliminating the disease thereafter.