Changes of the body weight in rats following administration of artemisinin and artesunate. (A) The groups administered artesunate; and (B) the groups administered artemisinin. The rats were divided into a normal group (n = 4) and experimental groups (n = 8/artesunate two groups, n = 8/artemisinin two groups, n = 4/each group). The rats were orally administered with two different doses (1.75 and 3.5 mg/kg) of artemisinin and artesunate, once a day for four weeks, respectively, and additionally observed for seven days. The results were expressed as a percentage of the normal group and presented as the mean ± S.D.