title: Anti-malarial activity of leaf-extract of hydrangea macrophylla, a common Japanese plant.
abstract: To find a new anti-malarial medicine derived from natural resources, we examined the leaves of 13 common Japanese plants in vitro. Among them, a leaf-extract of Hydrangea macrophylla, a common Japanese flower, inhibited the parasitic growth of Plasmodium falciparum. The IC50 of Hydrangea macrophylla leaf extract to Plasmodium falciparum was 0.18 microg/ml. The IC50 to NIH 3T3-3 cells, from a normal mouse cell line, was 7.2 microg/ml. Thus, selective toxicity was 40. For the in vivo test, we inoculated Plasmodium berghei, a rodent malaria parasite, to ddY mice and administered the leaf-extract of Hydrangea macrophylla (3.6 mg/0.2 ml) orally 3 times a day for 3 days. Malaria parasites did not appear in the blood of in the treated mice, but they did appear in the control group on day 3 or 4 after inoculation with the parasites. When leaf extract was administered to 5 mice 2 times a day for 3 days, malaria parasites did not appear in 4 of the mice but did appear in 1 mouse. In addition, the leaf-extract was administered orally 3 times a day for 3 days to Plasmodium berghei infected mice with a parasitemia of 2.7%. In the latter group, malaria parasites disappeared on day 3 after initiating the treatment, but they appeared again after day 5 or 6. Although we could not cure the mice entirely, we confirmed that the Hydrangea macrophylla leaf extract did contain an anti-malarial substance that can be administered orally.
authors.affiliation: Department of Parasitology, School of Medicine, Teikyo University, Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Kamei
authors.forename: H
authors.initials: H
authors.lastname: Matsuoka
authors.forename: S I
authors.initials: SI
authors.lastname: Furuhata
authors.forename: R I
authors.initials: RI
authors.lastname: Fujisaki
authors.forename: T
authors.initials: T
authors.lastname: Kawakami
authors.forename: S
authors.initials: S
authors.lastname: Mogi
authors.forename: H
authors.initials: H
authors.lastname: Yoshihara
authors.forename: N
authors.initials: N
authors.lastname: Aoki
authors.forename: A
authors.initials: A
authors.lastname: Ishii
authors.forename: T
authors.initials: T
authors.lastname: Shibuya
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000494:pharmacology* / Q000627:therapeutic use; D007564:Japan; D008288:Malaria / Q000188:drug therapy; D051379:Mice; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use; D010946:Plants, Medicinal; D010962:Plasmodium berghei / Q000187:drug effects; D010963:Plasmodium falciparum / Q000187:drug effects
chemical_list: D000962:Antimalarials; D010936:Plant Extracts