Antagonistic effects of methanolic extract of Polygala telephioides on morphine responses in mice.
The present study was undertaken to investigate the antagonistic effects of the methanolic extract of Polygala telephioides (PT) on morphine responses in mice. Single administration of PT tended to antagonize the morphine-induced analgesia in a hot-plate test. Moreover, PT (300 mg/kg, p.o.) improved the morphine-induced memory impairment in an elevated plus maze test. However, PT alone had no effect on behaviors in the open-field, hot-plate and elevated plus maze tests. We investigated the effects of PT on naloxone-induced jumping (as withdrawal sign) in morphine-dependent mice. To induce dependence, mice were twice daily treated with morphine (10-45 mg/kg, s.c.) for 5 days. Co-administrations of PT (10, 100 and 300 mg/kg, p.o.) during repeated morphine treatments significantly suppressed the naloxone (10 mg/kg, i.p.)-induced jumping. However, the naloxone-induced jumping was not affected by a single large administration of PT on the 5th day. The inhibitory effect of PT on the naloxone-induced jumping was due to the development of dependence rather than expression of withdrawal sign. Moreover, single administration of PT (30 mg/kg, p.o.) decreased the morphine levels in plasma. These results indicate that PT may be useful in facilitating narcotic detoxification.
Egashira
Nobuaki
N
Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Nanakuma 8-19-1, Fukuoka city, Fukuoka, 814-0180 Fukuoka, Japan.
Li
Jian-Chen
JC
Mizuki
Ai
A
Yamauchi
Keita
K
Matsuda
Tomoko
T
Osajima
Megumi
M
Matsushita
Michihiko
M
Mishima
Kenichi
K
Iwasaki
Katsunori
K
Hara
Shuji
S
Ono
Nobufumi
N
Nishimura
Ryoji
R
Nohara
Toshihiro
T
Fujiwara
Michihiro
M
D000818:Animals; D004305:Dose-Response Relationship, Drug; D008297:Male; D000432:Methanol / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009020:Morphine / Q000494:pharmacology*; D009292:Narcotic Antagonists / Q000302:isolation & purification / Q000494:pharmacology*; D010147:Pain Measurement / Q000187:drug effects / Q000379:methods; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology; D031801:Polygala; D011930:Reaction Time / Q000187:drug effects* / Q000502:physiology
D009292:Narcotic Antagonists; D010936:Plant Extracts; D009020:Morphine; D000432:Methanol