Artemisinin, also known as
qinghaosu, is a
sesquiterpene lactone endoperoxide extracted from the plant Artemisia annua L, an herb employed in
traditional Chinese medicine.
Artemisinin and its two main derivatives
artemether and
artesunate have been shown to be effective against both
malaria and
schistosomiasis, and therefore, they were described by Liu et al (Parasitol Res 110:2071-2074, 2012b) as the gifts from
traditional Chinese medicine not only for
malaria control but also for
schistosomiasis control. However, another
artemisinin derivative
dihydroartemisinin (DHA) cannot be neglected.
Dihydroartemisinin, a derivative of
artemisinin with the C-10
lactone group replaced by hemiacetal and the active metabolite of all
artemisinin compounds, was firstly identified as an
antimalarial agent, and the
dihydroartemisinin-
piperaquine combination has been recommended as a first-line treatment of uncomplicated
Plasmodium falciparum malaria by the WHO. It has been recently found that administration of
dihydroartemisinin at a single dose of 300 mg/kg 2 h or 3, 5, 7, 10, 14, 18, 21, 28, or 35 days post-
infection reduces total worm burdens by 1.1-64.8% and female worm burden reductions by 11.9-90.5%, and the in vivo activity of
dihydroartemisinin against S. japonicum is enhanced by the use of multiple doses. However, a combination of
praziquantel and
dihydroartemisinin appears no more effective against S. japonicum schistosomulum than treatment with
dihydroartemisinin alone. In mice experimentally infected with S. mansoni, administration with
dihydroartemisinin at a single dose of 300 mg/kg on days 1, 7, 14, 21, 28, 35, 42, 49, or 56 post-
infection results in total worm burden reductions of 13.8-82.1% and female worm burden reductions of 13-82.8%, and a clear-cut dose-response relationship of
dihydroartemisinin against the schistosomula and adult worms of S. mansoni is observed. In addition,
dihydroartemisinin was found to cause damages to the reproductive system of female S. mansoni worms, reduce the oviposition of survival worms, and inhibit the formation of
granulomas around tissue-trapped eggs. More interestingly, no reduced sensitivity to
dihydroartemisinin is detected in
praziquantel non-susceptible S. japonicum, which provides a new option for the treatment of S. japonicum and S. mansoni
infections, notably in endemic foci with
praziquantel resistance or insensitivity detected. It is therefore considered that
dihydroartemisinin is another gift from the
traditional Chinese medicine not only for
malaria control but also for
schistosomiasis control.