Ginsenoside Rf, a trace component of ginseng root, produces antinociception in mice

Brain Res. 1998 May 11;792(2):218-28. doi: 10.1016/s0006-8993(98)00133-4.


Ginseng root, a traditional oriental medicine, contains more than a dozen biologically active saponins called ginsenosides, including one present in only trace amounts called ginsenoside-Rf (Rf). Previously, we showed that Rf inhibits Ca2+ channels in mammalian sensory neurons through a mechanism requiring G-proteins, whereas a variety of other ginsenosides were relatively ineffective. Since inhibition of Ca2+ channels in sensory neurons contributes to antinociception by opioids, we tested for analgesic actions of Rf. We find dose-dependent antinociception by systemic administration of Rf in mice using two separate assays of tonic pain: in the acetic acid abdominal constriction test, the ED50 was 56+/-9 mg/kg, a concentration similar to those reported for aspirin and acetaminophen in the same assay; in the tonic phase of the biphasic formalin test, the ED50 was 129+/-32 mg/kg. Rf failed to affect nociception measured in three assays of acute pain: the acute phase of the formalin test, and the thermal (49 degrees C) tail-flick and increasing-temperature (3 degrees C/min) hot-plate tests. The simplest explanation is that Rf inhibits tonic pain without affecting acute pain, but other possibilities exist. Seeking a cellular explanation for the effect, we tested whether Rf suppresses Ca2+ channels on identified nociceptors. Inhibition was seen on large, but not small, nociceptors. This is inconsistent with a selective effect on tonic pain, so it seems unlikely that Ca2+ channel inhibition on primary sensory neurons can fully explain the behavioral antinociception we have demonstrated for Rf.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Abdominal Muscles / physiology
  • Analgesics / pharmacology*
  • Animals
  • Behavior, Animal / drug effects
  • Body Temperature / drug effects
  • Calcium Channel Blockers / pharmacology
  • Calcium Channels / physiology
  • Dose-Response Relationship, Drug
  • Formaldehyde
  • Ginsenosides*
  • Hot Temperature
  • Locomotion / drug effects
  • Mice
  • Neurons, Afferent / chemistry
  • Neurons, Afferent / drug effects
  • Neurons, Afferent / physiology
  • Nociceptors / drug effects*
  • Pain / drug therapy*
  • Panax
  • Patch-Clamp Techniques
  • Plants, Medicinal
  • Saponins / pharmacology*
  • Tail


  • Analgesics
  • Calcium Channel Blockers
  • Calcium Channels
  • Ginsenosides
  • Saponins
  • Formaldehyde
  • ginsenoside Rf