The possible involvement of GABAA systems in the antinarcotic effect of majonoside-R2, a major constituent of Vietnamese ginseng, in mice

Jpn J Pharmacol. 1996 Aug;71(4):345-9. doi: 10.1254/jjp.71.345.

Abstract

The effect of majonoside-R2 on morphine- and U-50,488H-induced antinociception was examined by the tail-pinch test in mice and compared with that of diazepam. Majonoside-R2 and diazepam inhibited the morphine- and U-50,488H-induced antinociception, and the actions were antagonized by the benzodiazepine receptor antagonist flumazenil and the GABA-gated CI- channel blocker picrotoxin. Diazepam but not majonoside-R2 exhibited a protective activity against convulsion caused by the GABAA antagonists bicuculline and picrotoxin. These results indicate that GABAA systems are involved in the effect of majonoside-R2 on the opioid-induced antinociception and suggest that the mechanisms of action of majonoside-R2 may differ from those of diazepam.

MeSH terms

  • 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer
  • Analgesics / antagonists & inhibitors
  • Analgesics, Opioid / antagonists & inhibitors
  • Analysis of Variance
  • Animals
  • Convulsants
  • Diazepam / antagonists & inhibitors
  • Diazepam / pharmacology
  • Dose-Response Relationship, Drug
  • Flumazenil / pharmacology
  • GABA Modulators / antagonists & inhibitors
  • GABA Modulators / pharmacology
  • Ginsenosides*
  • Male
  • Mice
  • Morphine / antagonists & inhibitors
  • Pain Measurement / drug effects*
  • Picrotoxin
  • Pyrrolidines / antagonists & inhibitors
  • Saponins / antagonists & inhibitors
  • Saponins / pharmacology*

Substances

  • Analgesics
  • Analgesics, Opioid
  • Convulsants
  • GABA Modulators
  • Ginsenosides
  • Pyrrolidines
  • Saponins
  • Picrotoxin
  • Flumazenil
  • 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer
  • Morphine
  • majonoside R2
  • Diazepam