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Planta Med 1999; 65(3): 222-226
DOI: 10.1055/s-1999-13984
Original Paper

Georg Thieme Verlag Stuttgart · New York

Magnolol Inhibits Leukotriene Synthesis in Rat Basophilic Leukemia-2H3 Cells

Yuhei Hamasaki, Ikuko Kobayashi, Masafumi Zaitu, Kosuke Tsuji, Michiko Kita, Rika Hayasaki, Eriko Muro, Shuichi Yamamoto, Muneaki Matsuo, Tomohiro Ichimaru, Sumio Miyazaki
  • Department of Pediatrics, Saga Medical School, Saga-City, Japan
Further Information

Publication History

June 3, 1998

November 22, 1998

Publication Date:
31 December 1999 (online)

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Abstract:

We have observed an inhibitory action of magnolol on the production of leukotriene (LT) C4 and LTB4, important lipid mediators in allergy and inflammation. IgE- and A23187-stimulated production of LTC 4 and LTB4 was measured by radioimmunoassay (RIA) in the absence or presence of various concentrations of magnolol in intact rat basophilic leukemia (RBL)-2H3 cells. Magnolol dose-dependently inhibited synthesis of LTC4 and LTB4. Magnolol inhibited the IgE-mediated increase of intracellular calcium ion concentration, resulting in the inhibition of cytosolic phospholipase A2 (cPLA2) and possibly 5-lipoxygenase (5-LO), both calcium ion-dependent enzymes. In cell-free studies magnolol inhibited LTC4 synthase activity. LTA4 hydrolase activity was only inhibited at the higher concentration (2.5 × 10-5 M). These results indicate that magnolol inhibits production of LTs by inhibiting PLA2, 5-LO, LTC4 synthase and LTA 4 hydrolase which are essential for LT-synthesis. Magnolol may have anti-allergic effect by blocking LT-synthesis.

Key words:

Magnolol - leukotriene (LT) - rat basophilic leukemia-2H3 cell (RBL-2H3) - cytosolic phospholipase A2 (PLA2) - 5-lipoxygenase (5-LO) - Magnolia obovata Thunberg