title: Parasite mitochondria as a target of chemotherapy: inhibitory effect of licochalcone A on the Plasmodium falciparum respiratory chain.
abstract: Parasites have exploited unique energy metabolic pathways as adaptations to the natural host habitat. In fact, the respiratory systems of parasites typically show greater diversity in electron transfer pathways than do those of host animals. These unique aspects of parasite mitochondria and related enzymes may represent promising targets for chemotherapy. Natural products have been recognized as a source of the candidates of the specific inhibitors for such parasite respiratory chains. Chalcones was recently evaluated for its antimalarial activity in vitro and in vivo. However, its target is still unclear in malaria parasites. In this study, we investigated that licochalcone A inhibited the bc1 complex (ubiquinol-cytochrome c reductase) as well as complex II (succinate ubiquinone reductase, SQR) of Plasmodium falciparum mitochondria. In particular, licochalcone A inhibits bc1 complex activity at very low concentrations. Because the property of the P. falciparum bc1 complex is different from that of the mammalian host, chalcones would be a promising candidate for a new antimalarial drug.
authors.affiliation: Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Fumika
authors.initials: F
authors.lastname: Mi-Ichi
authors.forename: Hiroko
authors.initials: H
authors.lastname: Miyadera
authors.forename: Tamaki
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Shinzaburo
authors.initials: S
authors.lastname: Takamiya
authors.forename: Seiji
authors.initials: S
authors.lastname: Waki
authors.forename: Susumu
authors.initials: S
authors.lastname: Iwata
authors.forename: Shoji
authors.initials: S
authors.lastname: Shibata
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Kita
mesh_terms: D000818:Animals; D000977:Antiparasitic Agents / Q000494:pharmacology; D047188:Chalcones / Q000494:pharmacology*; D045304:Cytochromes c / Q000187:drug effects / Q000378:metabolism; D007887:Fabaceae; D008928:Mitochondria / Q000187:drug effects*; D008930:Mitochondria, Liver / Q000187:drug effects; D010101:Oxygen Consumption / Q000187:drug effects*; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000648:ultrastructure; D051381:Rats; D014451:Ubiquinone / Q000494:pharmacology*
chemical_list: D000977:Antiparasitic Agents; D047188:Chalcones; D014451:Ubiquinone; D045304:Cytochromes c; C070840:licochalcone A