Inhibition of acetylcholine-mediated effects by borneol

Biochem Pharmacol. 2003 Jan 1;65(1):83-90. doi: 10.1016/s0006-2952(02)01444-2.


We previously reported that the aqueous extract from a medicinal plant Dryobalanops aromatica specifically inhibits the nicotinic acetylcholine receptor (nAChR) (Oh et al. Pharmacol Res 2000;42(6):559-64). Here, the effect of borneol, the main constituent of D. aromatica, on nAChR activity was investigated in bovine adrenal chromaffin cells. Borneol inhibited a nAChR agonist 1,1-dimethyl-4-phenylpiperazinium iodide (DMPP)-induced calcium increase with a half maximal inhibitory concentration (IC(50)) of 56+/-9 microM. In contrast, borneol did not affect the calcium increases induced by high K+, veratridine, and bradykinin. The sodium increase induced by DMPP was also inhibited by borneol with similar potency (49+/-12 microM), suggesting that the activity of nAChRs is inhibited by borneol. Borneol inhibited DMPP-induced secretion of [3H]norepinephrine with an IC(50) of 70+/-12 microM. Carbon-fiber amperometry also confirmed the inhibition of DMPP-induced exocytosis by borneol in single chromaffin cells. [3H]nicotine binding, however, was not affected by borneol. The inhibitory effect by borneol is more potent than the effect by lidocaine, a commonly used local anesthetic. The data suggest that borneol specifically inhibits the nAChR-mediated effects in a noncompetitive way.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcholine / antagonists & inhibitors*
  • Anesthetics, Local / pharmacology
  • Animals
  • Calcium / metabolism
  • Camphanes / pharmacology*
  • Cattle
  • Chromaffin Cells / drug effects*
  • Chromaffin Cells / metabolism
  • Drug Interactions
  • Exocytosis
  • Lidocaine / pharmacology
  • Nicotine / antagonists & inhibitors
  • Nicotine / pharmacology
  • Receptors, Nicotinic / drug effects
  • Receptors, Nicotinic / metabolism
  • Signal Transduction
  • Sodium / metabolism


  • Anesthetics, Local
  • Camphanes
  • Receptors, Nicotinic
  • Nicotine
  • Lidocaine
  • Sodium
  • isoborneol
  • Acetylcholine
  • Calcium