Planta Med 2002; 68(9): 794-798
DOI: 10.1055/s-2002-34396
Original Paper
Pharmacology
© Georg Thieme Verlag Stuttgart · New York

Antinociceptive Mechanisms of Platycodin D Administered Intracerebroventricularly in the Mouse

Seong-Soo Choi1 , Eun-Jung Han1 , Tae-Hee Lee2 , Jin-Koo Lee1 , Ki-Jung Han1 , Han-Kyu Lee1 , Hong-Won Suh1
  • 1Department of Pharmacology, College of Medicine and Institute of Natural Medicine, Hallym University, Chunchon, Kangwon-Do, South Korea
  • 2Department of Formulae Pharmacology, Oriental Medical School, Kyungwon University, Seong-Nam, Kyunggi-Do, South Korea
Further Information

Publication History

Received: November 30, 2001

Accepted: March 16, 2002

Publication Date:
30 September 2002 (online)

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Abstract

Platycodin D administered intracerebroventricularly (i. c. v.) showed an antinociceptive effect in a dose-dependent manner as measured by the tail-flick assay. The antinociception induced by platycodin D was maintained at least 1 h. MK-801 [(±)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate], a competitive N-methyl-D-aspartic acid (NMDA) receptor antagonist, or CNQX (6-cyano-7-nitroquinoxaline-2,3-dione), a non-NMDA receptor antagonist, muscimol (a GABAA receptor agonist), or baclofen (a GABAB receptor antagonist), or sulfated cholecystokinin (CCK-8 s; CCKA receptor agonist), injected i. c. v. significantly reduced the inhibition of the tail-flick response induced by platycodin D administered i. c. v. Additionally, intrathecal (i. t.) pretreatment with yohimbine (an α2-adrenergic receptor antagonist) or methysergide (a serotonin receptor antagonist) dose-dependently attenuated inhibition of the tail-flick response induced by i. c. v. administered platycodin D. However, naloxone (an opioid receptor antagonist) did not affect the inhibition of the tail-flick response induced by platycodin D. Our results suggest that platycodin D has an antinociceptive effect when it is administered supraspinally, and supraspinal GABAA, GABAB, NMDA and non-NMDA receptors are involved in platycodin D-induced antinociception. Furthermore, platycodin D administered supraspinally produces antinociception by stimulating descending noradrenergic and serotonergic, but not opioidergic, pathways.

References

Hong-Won Suh, Ph. D., Associate professor

Department of Pharmacology and Institute of Natural Medicine

College of Medicine, Hallym University

1 Okchun-Dong, Chunchon, Kangwon-Do, 200-702, South Korea

Phone: +82-33-240-1654

Fax: +82-33-240-1652

Email: hwsuh@hallym.ac.kr