The Possible Involvement of GABAA Systems in the Antinarcotic Effect of Majonoside-R2, a Major Constituent of Vietnamese Ginseng, in Mice

摘要

References(13) Cited-By(7) 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 Cl- 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.