title: Synthesis of artemiside and its effects in combination with conventional drugs against severe murine malaria.
abstract: This research describes the use of novel antimalarial combinations of the new artemisinin derivative artemiside, a 10-alkylamino artemisinin. It is a stable, highly crystalline compound that is economically prepared from dihydroartemisinin in a one-step process. Artemiside activity was more pronounced than that of any antimalarial drug in use, both in Plasmodium falciparum culture and in vivo in a murine malaria model depicting cerebral malaria (CM). In vitro high-throughput testing of artemiside combinations revealed a large number of conventional antimalarial drugs with which it was additive. Following monotherapy in mice, individual drugs reduced parasitemias to nondetectable levels. However, after a period of latency, parasites again were seen and eventually all mice became terminally ill. Treatment with individual drugs did not prevent CM in mice with recrudescent malaria, except for piperaquine at high concentrations. Even when CM was prevented, the mice developed later of severe anemia. In contrast, most of the mice treated with drug combinations survived. A combination of artemiside and mefloquine or piperaquine may confer an optimal result because of the longer half life of both conventional drugs. The use of artemiside combinations revealed a significant safety margin of the effective artemiside doses. Likewise, a combination of 1.3 mg/kg of body weight artemiside and 10 mg/kg piperaquine administered for 3 days from the seventh day postinfection was completely curative. It appears possible to increase drug concentrations in the combination therapy without reaching toxic levels. Using the drug combinations as little as 1 day before the expected death of control animals, we could prevent further parasite development and death due to CM or anemic malaria. Earlier treatment may prevent cognitive dysfunctions which might occur after recovery from CM.
authors: Department of Pathology and Bosch Institute, The University of Sydney, Sydney, Australia.
authors: Jin
authors: J
authors: Guo
authors: Armand W
authors: AW
authors: Guiguemde
authors: Annael
authors: A
authors: Bentura-Marciano
authors: Julie
authors: J
authors: Clark
authors: Richard K
authors: RK
authors: Haynes
authors: Wing-Chi
authors: WC
authors: Chan
authors: Ho-Ning
authors: HN
authors: Wong
authors: Nicholas H
authors: NH
authors: Hunt
authors: R Kiplin
authors: RK
authors: Guy
authors: Jacob
authors: J
authors: Golenser
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000008:administration & dosage / Q000627:therapeutic use; D037621:Artemisinins / Q000008:administration & dosage* / Q000138:chemical synthesis / Q000627:therapeutic use; D004195:Disease Models, Animal; D004334:Drug Administration Schedule; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D057166:High-Throughput Screening Assays; D006801:Humans; D020128:Inhibitory Concentration 50; D016779:Malaria, Cerebral / Q000188:drug therapy* / Q000401:mortality / Q000469:parasitology; D016778:Malaria, Falciparum / Q000188:drug therapy* / Q000469:parasitology; D015767:Mefloquine / Q000008:administration & dosage / Q000627:therapeutic use; D051379:Mice; D008810:Mice, Inbred C57BL; D008853:Microscopy; D018512:Parasitemia / Q000188:drug therapy / Q000401:mortality; D010962:Plasmodium berghei / Q000187:drug effects / Q000254:growth & development; D010963:Plasmodium falciparum / Q000187:drug effects / Q000254:growth & development; D011804:Quinolines / Q000008:administration & dosage / Q000627:therapeutic use; D055502:Secondary Prevention; D015996:Survival Rate; D010879:Piperazines
chemical_list: D000962:Antimalarials; D037621:Artemisinins; D015767:Mefloquine; D011804:Quinolines; C034759:piperaquine; D010879:Piperazines