Inhibition of leukotriene synthesis by honokiol in rat basophilic leukemia cells.
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.
Hamasaki
Y
Y
Department of Pediatrics, Saga Medical School, Japan.
Muro
E
E
Miyanji
S
S
Yamamoto
S
S
Kobayashi
I
I
Sato
R
R
Zaitu
M
M
Matsuo
M
M
Ichimaru
T
T
Tasaki
H
H
Miyazaki
S
S
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
D018926:Anti-Allergic Agents; D001713:Biphenyl Compounds; D020024:Leukotriene Antagonists; D015289:Leukotrienes; D017705:Lignans; C005499:honokiol; D000498:Allyl Compounds; D010636:Phenols