title: Inhibition of leukotriene synthesis by honokiol in rat basophilic leukemia cells.
abstract: The effects of honokiol, a diphenyl compound extracted from a Chinese herbal medicine, on leukotriene (LT) synthesis were evaluated in rat basophilic leukemia (RBL) cells. The production of LTC4 and LTB4 stimulated by the Ca2+ ionophore A23187 was measured in RBL-1 cells by high-performance liquid chromatography. Honokiol inhibited the production of LTC4 and LTB4 stimulated by A23187 in RBL-1 cells. Honokiol did not inhibit either phospholipase A2 activity, measured by the release of 3H-arachidonic acid (AA), or LTC4 synthase and LTA4 hydrolase activities, measured with LTA4-free acid as substrate. The synthesis of LTC4 and LTB4 from AA in RBL-1 cell lysates in the presence of Ca2+ was inhibited by honokiol. These results indicate that honokiol blocks LT synthesis by inhibiting 5-lipoxygenase activity. Honokiol also inhibited immunoglobulin E-mediated production of these LTs in RBL-2H3 cells, which was measured by a specific radioimmunoassay (RIA). These results suggest that honokiol may exhibit antiallergic actions by inhibiting LT synthesis in immediate-type hyperreactivity.
authors.affiliation: Department of Pediatrics, Saga Medical School, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Hamasaki
authors.forename: E
authors.initials: E
authors.lastname: Muro
authors.forename: S
authors.initials: S
authors.lastname: Miyanji
authors.forename: S
authors.initials: S
authors.lastname: Yamamoto
authors.forename: I
authors.initials: I
authors.lastname: Kobayashi
authors.forename: R
authors.initials: R
authors.lastname: Sato
authors.forename: M
authors.initials: M
authors.lastname: Zaitu
authors.forename: M
authors.initials: M
authors.lastname: Matsuo
authors.forename: T
authors.initials: T
authors.lastname: Ichimaru
authors.forename: H
authors.initials: H
authors.lastname: Tasaki
authors.forename: S
authors.initials: S
authors.lastname: Miyazaki
mesh_terms: D000818:Animals; D018926:Anti-Allergic Agents / Q000494:pharmacology*; D001713:Biphenyl Compounds / Q000494:pharmacology*; D015471:Leukemia, Basophilic, Acute / Q000201:enzymology / Q000378:metabolism*; D020024:Leukotriene Antagonists; D015289:Leukotrienes / Q000096:biosynthesis*; D017705:Lignans; D051381:Rats; D014407:Tumor Cells, Cultured; D000498:Allyl Compounds; D010636:Phenols
chemical_list: D018926:Anti-Allergic Agents; D001713:Biphenyl Compounds; D020024:Leukotriene Antagonists; D015289:Leukotrienes; D017705:Lignans; C005499:honokiol; D000498:Allyl Compounds; D010636:Phenols