Still, WHO has approved the use of synthetic derivatives, produced in Europe, to be used in cases of drug-resistant malaria, especially the chloroquine resistant malaria that has developed in Brazil and parts of Asia as a result of such widespread use of this drug.

In addition to antimalarial effects, artemisinin was found to have promise in treating the parasitic diseases schistosomiasis and clonorchiasis (common in China and Africa, affecting over 200 million people each year) caused by trematodes (blood flukes). Artemether is now being used for prophylaxis against schistosomiasis; in combination therapy with praziquantel it is used to treat the disease (22). Ching-hao is included in effective treatments for leptospirosis, a bacterial disease that usually infects humans from animal waste contaminating water supplies. It has been shown in laboratory studies to inhibit Toxoplasma gondii, an organism that mainly affects persons with compromised immunity, acquired from pets or from eating contaminated meat, and Leishmania major, a protozoa that infects the macrophages. As described earlier, ching-hao was indicated in ancient times for topical treatment of skin parasites. In post-revolutionary China, an antiseptic fumigant was developed using the combination of moxa leaves plus atractylodes (cangzhu). This combination, burned to produce a cleansing smoke, was reported to serve as protection from viruses and bacteria in hospitals; both herbs contributed to the action (4). Recent investigations of the chemical constituents of ching-hao and other Artemisia species have focused on antifungal activity. An oil produced from the herb after its artemisinin was removed, called huanghua oil (yellow flower oil; huanghuahao is another name for ching-hao) was shown to be strongly anti-fungal for all skin fungi tested (26).

IMMUNOLOGICAL EFFECTS
Ching-hao appears to regulate T-cell responses and antibody production to inhibit autoimmune reactions (13), with artemisinin being the main active component. Artesunate, which has the same functions as artemisinin, was evaluated in laboratory animal studies and found to suppress allergic contact dermatitis and enhance specific suppressor T-cell activity (24).

Clinically, both ching-hao and artemisinin have been used in the treatment of systemic lupus since 1979, with claimed positive effects in recent trials (12). The dose of artemisinin that has been used clinically for lupus has ranged from 0.2-0.6 grams per day; this corresponds to a dose of ching-hao of about 20-30 grams, the same as used to treat malaria. Treatment time is typically about 3 months. Ching-hao has also been applied in treatment of discoid lupus and was deemed successful (25).

references on request.