title: Evidence that ginsenosides prevent the development of opioid tolerance at the central nervous system.
abstract: The analgesic effect of ginsenosides or morphine was first determined following intrathecal (i.t.) administration in rat tail-flick test. The effect of chronic i.t. co-administration of ginsenosides with morphine on the development of opioid tolerance were also examined using rat tail-flick test. Administration of ginsenosides (i.t.) produced a weak antinociception in a dose-dependent manner. Administration of morphine (i.t.) also produced antinociception in a dose-dependent manner. The ED50 was 1.20 microg (1.14-1.29 microg). However, acute i.t. co-administration of ginsenosides with morphine was not additive in antinociception. Repeated i.t. co-administration of 200 microg ginsenosides with 10 microg morphine inhibited the development of tolerance induced by 10 microg morphine in rat tail-flick test, although i.t. co-administration of 50 or 100 microg ginsenosides with morphine was without effect. In conclusion, these results indicate that i.t. administered ginsenosides produce an antinociception in rat tail-flick test and also prevent opioid tolerance caused by chronic treatment with morphine at the spinal sites.
authors.affiliation: Dept of Physiology, College of Veterinary Medicine, Chonnam National University, Kwangju, Korea.
authors.forename: S
authors.initials: S
authors.lastname: Choi
authors.forename: S Y
authors.initials: SY
authors.lastname: Jung
authors.forename: H
authors.initials: H
authors.lastname: Rhim
authors.forename: S W
authors.initials: SW
authors.lastname: Jeong
authors.forename: S M
authors.initials: SM
authors.lastname: Lee
authors.forename: S Y
authors.initials: SY
authors.lastname: Nah
mesh_terms: D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004361:Drug Tolerance; D036145:Ginsenosides; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012503:Saponins / Q000494:pharmacology*; D013116:Spinal Cord / Q000187:drug effects*
chemical_list: D000701:Analgesics, Opioid; D036145:Ginsenosides; D012503:Saponins; D009020:Morphine