Discovery of artemisinin in Artemisia annua, its current production, and relevance to sub-Saharan Africa
Barend Jacobus Lee, Morné Weyers, Richard K. Haynes, Frank van der Kooy
Abstract
Fifty years ago, in 1972, artemisinin was first isolated as a pure compound from Artemisia annua L. (Asteraceae) and was shown to possess potent antimalarial properties. This review aims to present a concise account of the history of the discovery of artemisinin and the development of artemisinin combination therapies. This is followed by the current production techniques (isolation and purification) to supply the growing global demand and finally the possibility to produce artemisinin in South Africa is discussed. Artemisinin and its derivatives are now used worldwide for treatment of malaria, largely in combinations with other antimalarial drugs known as artemisinin combination therapies (ACTs). The main source of artemisinin still relies on extraction from A. annua, with Vietnam and China presently providing over 80% of the global supply. However, the production of artemisinin is not sufficient to meet requirements for global treatment of malaria, and demand continues to outstrip supply. This supply problem will be exacerbated once artemisinin and its derivatives are adopted for treatment of other diseases including cancer, other parasitic diseases, and viral infections. Thus, higher yielding A. annua cultivars coupled with development of novel extraction and purification techniques are required for meeting the enhanced demands. One significant development involves the use of a pressurised hot water system to efficiently extract artemisinin. From a South African perspective, little work has been conducted on the production of A. annua and optimization of supply of artemisinin. A recent pilot study simulating an agrophotovoltaic (APV) system where the land area utilised is associated with both production of solar energy as well as the cultivation and growing of A. annua indicated that the plant produced roughly 20% more artemisinin when grown under these conditions as compared to the control group. Current activities focussing on production of artemisinin in South Africa to serve the Sub-Saharan African region are also discussed.