Differential effects of ganodermic acid S on the thromboxane A2-signaling pathways in human platelets

Biochem Pharmacol. 1999 Aug 15;58(4):587-95. doi: 10.1016/s0006-2952(99)00136-7.


Ganodermic acid S (GAS) [lanosta-7,9(11),24-triene-3beta,15alpha-diacetoxy-26-oic acid], isolated from the Chinese medicinal fungus Ganoderma lucidum (Fr.) Karst (Polyporaceae), exerted a concentration-dependent inhibition on the response of human gel-filtered platelets (GFP) to U46619 (9,11-dideoxy-9alpha,11alpha-methanoepoxyprostaglandin F2alpha), a thromboxane (TX) A2 mimetic. GAS at 2 microM inhibited 50% of cell aggregation. GAS at 7.5 microM inhibited 80% of Ca2+ mobilization, 40% of phosphorylation of myosin light chain and pleckstrin, 80% of alpha-granule secretion, and over 95% of aggregation. GAS also strongly inhibited U46619-induced diacylglycerol formation, arachidonic acid release, and TXB2 formation. An immunoblotting study of protein-tyrosine phosphorylation showed that GAS inhibited the formation of phosphotyrosine proteins at the steps involving the engagement of integrin alphaIIbbeta3 and aggregation. However, GAS did not inhibit U46619-induced platelet shape change or the inhibitory effect of U46619 on the prostaglandin E1-evoked cyclic AMP level in GFP. It is concluded that GAS inhibits platelet response to TXA2 on the receptor-Gq-phospholipase Cbeta1 pathway, but not on the receptor-G1 pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid / pharmacology
  • Adenylyl Cyclase Inhibitors
  • Adenylyl Cyclases / metabolism
  • Arachidonic Acid / metabolism
  • Blood Platelets / drug effects*
  • Blood Platelets / metabolism
  • Calcium / metabolism
  • Cyclic AMP / metabolism
  • Drugs, Chinese Herbal / chemistry
  • Humans
  • Lanosterol / analogs & derivatives*
  • Lanosterol / pharmacology
  • Phosphorylation
  • Platelet Aggregation / drug effects
  • Reishi
  • Signal Transduction / drug effects*
  • Thromboxane A2 / metabolism*
  • Tyrosine / metabolism
  • Vasoconstrictor Agents / pharmacology


  • Adenylyl Cyclase Inhibitors
  • Drugs, Chinese Herbal
  • Vasoconstrictor Agents
  • ganodermic acid S
  • Lanosterol
  • Arachidonic Acid
  • Tyrosine
  • Thromboxane A2
  • 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid
  • Cyclic AMP
  • Adenylyl Cyclases
  • Calcium