Antinociceptive profiles of platycodin D in the mouse.
Platycodin D (PD), one of several triterpene saponins, was isolated from roots of Platycodon grandiflorum. We previously reported that intracerebroventricular (i.c.v.) administration of PD showed an antinociceptive effect as measured by the tail-flick assay. However, its exact role in the regulation of antinociception in the various types of pain models has not yet been characterized. Thus, we attempted to find antinociceptive profiles of PD in various pain models. PD administered intraperitoneally (i.p.), i.c.v. or intrathecally (i.t.) showed antinociceptive effects in dose-dependent manners as measured by the tail-flick, writhing and formalin tests. In the tail-flick test, PD at the low doses reached the peak after 15 minutes and returned to the control level after 60 minutes. However, higher doses of PD showed a strong antinociception at least for 1 hour. PD administered i.t. showed stronger antinociception than that induced by i.c.v. administration PD in both tail-flick and writhing tests. In the formalin test, PD administered i.p., i.c.v. or i.t. showed antinociceptive effects during both the first (direct nociceptive stimulation) and second (late inflammatory) phases. Pretreatment with naltrexone i.p., i.c.v. or i.t. did not affect PD-induced inhibition of the tail-flick response. Our results suggest that PD shows a strong antinociceptive effect on the tail-flick, writhing and formalin tests, acting on central nervous system. However, PD-induced antinociception may not be mediated by the opioid receptors.
Choi
Seong-Soo
SS
Department of Pharmacology, College of Medicine and Institute of Natural Medicine, Hallym University, Chunchon, South Korea.
Han
Eun-Jung
EJ
Lee
Tae-Hee
TH
Han
Ki-Jung
KJ
Lee
Han-Kyu
HK
Suh
Hong-Won
HW
D000818:Animals; D029422:Campanulaceae / Q000737:chemistry; D002552:Cerebral Ventricles; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D010146:Pain / Q000188:drug therapy*; D010147:Pain Measurement; D012503:Saponins / Q000008:administration & dosage / Q000494:pharmacology*; D013623:Tail / Q000502:physiology; D014315:Triterpenes / Q000008:administration & dosage / Q000494:pharmacology*
D012503:Saponins; D014315:Triterpenes; C108953:platycodin D