Antinociception, tolerance and withdrawal symptoms induced by 7-hydroxymitragynine,
an alkaloid from the Thai medicinal herb Mitragyna speciosa
Kenjiro Matsumotoa, Syunji Horiea,Hiromitsu Takayamab, Hayato Ishikawab, Norio Aimib, Dhavadee Pongluxc, Toshihiko Murayamad and Kazuo Watanabed.
Laboratory of Pharmacolgy, Faculty of Pharmaceutical Sciences, Josai International University, Japan
Laboratory of Molecular Structure and Biological Function, Graduate School of Pharmaceutical Sciences, Chiba University, Japan. Faculty of Pharmaceutical Sciences, Chulalongkorn University, Thailand
19 June 2004
7-Hydroxymitragynine is a potent opioid analgesic alkaloid isolated from the Thai medicinal herb Mitragyna speciosa. In the present study, we investigated the opioid receptor subtype responsible for the analgesic effect of this compound. In addition, we tested whether development of tolerance, cross-tolerance to morphine and naloxone-induced withdrawal signs were observed in chronically 7-hydroxymitragynine-treated mice.