title: Cytotoxic screening of medicinal and edible plants in Okinawa, Japan, and identification of the main toxic constituent of Rhodea japonica (Omoto).
abstract: The cytotoxic activity of ethanol extracts from 53 parts of 36 species of medicinal and edible plants cultivated in Okinawa was measured by using K562 human leukemia cells by a flow cytometric method. Two extracts from Rhodea japonica and Hypericum chinense were cytotoxic at a concentration of 10 microg/ml. The main cytotoxic constituent of Rhodea japonica was isolated and identified to be rhodexin A, which has been isolated as a cardetonic agent of the plant. The IC(50) value for rhodexin A against the growth of K562 cells was 19 nM, this activity being much stronger than that of ouabain (IC(50), 60 nM).
authors.affiliation: Faculty of Integrated Arts and Sciences, University of Tokushima, Tokushima 770-8502, Japan. masuda@ias.tokushima-u.ac.jp
authors.forename: Toshiya
authors.initials: T
authors.lastname: Masuda
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Oyama
authors.forename: Natsuko
authors.initials: N
authors.lastname: Yamamoto
authors.forename: Chisato
authors.initials: C
authors.lastname: Umebayashi
authors.forename: Hiromi
authors.initials: H
authors.lastname: Nakao
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Toi
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Takeda
authors.forename: Katsuo
authors.initials: K
authors.lastname: Nakamoto
authors.forename: Hideki
authors.initials: H
authors.lastname: Kuninaga
authors.forename: Yukari
authors.initials: Y
authors.lastname: Nishizato
authors.forename: Akira
authors.initials: A
authors.lastname: Nonaka
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor; D005434:Flow Cytometry; D006801:Humans; D020902:Hypericum / Q000737:chemistry; D020128:Inhibitory Concentration 50; D007564:Japan; D020014:K562 Cells; D010936:Plant Extracts / Q000032:analysis; D010945:Plants, Edible / Q000737:chemistry* / Q000633:toxicity; D010946:Plants, Medicinal / Q000737:chemistry* / Q000633:toxicity; D014118:Toxins, Biological / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D000970:Antineoplastic Agents; D010936:Plant Extracts; D014118:Toxins, Biological