Schistosomiasis is among the most prevalent human parasitic diseases, affecting more than 200 million people worldwide. The aetiological agents of this disease are trematode flatworms (Schistosoma) that live and lay eggs within the vasculature of the host. These eggs lodge in host tissues, causing inflammatory responses that are the primary cause of morbidity. Because these parasites can live and reproduce within human hosts for decades, elucidating the mechanisms that promote their longevity is of fundamental importance.
To determine whether artemether, a derivative of the antimalarial agent qinghaosu, is therapeutically active against Schistosoma mansoni, we determined the in vitro, in vivo, and histopathologic effects of the drug on S. mansoni worms. In vitro, toxic effects of artemether on S. mansoni were not seen at concentrations of less than 100 micrograms/ml. However, in vivo, 30 and 50% reductions in the lengths of male and female worms, respectively, were observed 14 days after treatment. By 56 days worm dimensions had returned to control values.
The action of the ether of artemisinin (artemether) on Schistosoma mansoni in mice and hamsters experimentally infected with the LE strain was studied. In mice, the drug showed high schistosomicidal activity using a single intramuscular dose of 100 mg/kg/day. By the oral route, this dose showed a low activity. Mice treated with a single intramuscular dose of 200 mg/kg/day, and examined 15 days after treatment, presented 100% alteration of the oogram; when examined 45 days after treatment, the oogram was normal.
A group of 110 individuals with Schistosoma mansoni infection was investigated. Patients were allocated to one of three treatment groups and given artesunate or praziquantel alone or both in combination. Combined artesunate-praziquantel significantly increased the number of individuals cured at 5 weeks post-treatment, but at 12 weeks was only better than artesunate alone and at 24 weeks there was no statistically significant difference between the three groups. Egg count reduction rate was similar to the rate obtained with praziquantel used alone.
OBJECTIVE: To evaluate the effect of intramuscular injection of artemether in mice experimentally infected with Schistosoma mansoni, at the time of infection, during schistosomula maturation and after the beginning of egg-laying. METHODS: Eighty adult females Balb/c mice were divided into 8 groups with 10 animals each. Seven groups were infected with S. mansoni using 60 cercariae for each animal, inoculated subcutaneously, and the remaining group was maintained without infection.
The American Journal of Tropical Medicine and Hygiene
Artemether, a methyl ether derivative of dihydroartemisinin, not only exhibits antimalarial properties, but also possesses strong activity against schistosomula, the immature stages of a parasitic worm that can cause schistosomiasis. To test if the effect would be similar to that of irradiation with respect to the induction of immunologic protective responses, groups of mice were infected with Schistosoma mansoni cercariae and treated with artemether at 1-3 weeks post-infection.
We report the in vitro activities of trioxaquines against larval and adult-stage schistosomes at 5 and 50 microg/ml, respectively. Such activities are equivalent to that of praziquantel, the major and rather unique drug currently used for the treatment of schistosomiasis. In this range of concentrations, artemisinin derivatives (artesunate and artemether) have no activity.
INTRODUCTION: The distribution of both malaria and schistosomiasis exhibits a large geographical overlap in tropical environments, particularly in sub-Saharan Africa. This part of the world currently harbours more than 85% of the estimated global burden of these diseases. Studies showed that artemisinin derivatives used for the treatment of malaria also have an antischistosomal effect.
Mirazid® is a patented preparation from a plant that had been used in folk medicine since ancient Egyptians (Myrrh). It was registered in Egypt for the treatment of schistosomiasis and fascioliasis. Over 32 independent studies for efficacy of Mirazid had been reviewed and their results analyzed. The majority of these studies reported higher than 90% cure rates, that even higher in mixed than single trematodal infections in humans and in farm animals.