1. Introduction
Wormwood (Artemisia annua L.) is an annual aromatic plant that is fast-growing, giant annual with upright, often red stems and bright green, pinnately divided, and saw-toothed leaves. Tiny yellow flowers appear in loose panicles in summer. This antibacterial herb destroys malarial parasites, lowers fevers and checks bleeding. It also possesses also tonic, febrifuge and antibiotic properties. It has been used internally in Chinese medicine – qing hao – for malaria and heat stroke, and externally for nosebleeds, bleeding rashes and sores. Synthetic compounds, namely artefelene and artemether, have been developed from this plant for use in the treatment of drug-resistant species of malaria, notably Plasmodium falciparum (Bown, 2001; Wyk and Wink, 2004).