Magnolol inhibits leukotriene synthesis in rat basophilic leukemia-2H3 cells

Planta Med. 1999 Apr;65(3):222-6. doi: 10.1055/s-1999-13984.


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 LTC4 and LTB4 was measured by radio-immunoassay (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 x 10(-5)M). These results indicate that magnolol inhibits production of LTs by inhibiting PLA2, 5-LO, LTC4 synthase and LTA4 hydrolase which are essential for LT-synthesis. Magnolol may have anti-allergic effect by blocking LT-synthesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biphenyl Compounds / pharmacology*
  • Enzyme Inhibitors / pharmacology
  • Epoxide Hydrolases / antagonists & inhibitors
  • Glutathione Transferase / antagonists & inhibitors
  • Leukemia, Basophilic, Acute / enzymology
  • Leukemia, Basophilic, Acute / metabolism*
  • Leukemia, Basophilic, Acute / pathology
  • Leukotriene B4 / biosynthesis*
  • Leukotriene C4 / biosynthesis*
  • Lignans*
  • Lipoxygenase Inhibitors
  • Rats
  • Tumor Cells, Cultured


  • Biphenyl Compounds
  • Enzyme Inhibitors
  • Lignans
  • Lipoxygenase Inhibitors
  • magnolol
  • Leukotriene B4
  • Leukotriene C4
  • Glutathione Transferase
  • Epoxide Hydrolases
  • leukotriene-C4 synthase
  • leukotriene A4 hydrolase