Neuropharmacological actions of Pluchea indica Less root extract in socially isolated mice.
The effects of Pluchea indica Less root extract (PI-E) on locomotor activity and pentobarbital-induced sleep, social isolation-induced aggressive behavior, motor coordination in the rotarod test, pentylenetetrazole-induced convulsion and nociceptive responses in the tail-pinch test were examined in mice. Socially isolated mice showed higher locomotor activity and shorter duration of pentobarbital sleep than group-housed mice. PI-E (50-100 mg/kg, p.o.) significantly decreased locomotor activity and prolonged pentobarbital sleep in a dose-dependent manner in isolated mice but not in group-housed mice. At a large dose (400 mg/kg, p.o.), PI-E not only decreased locomotor activity but also prolonged pentobarbital sleep in group-housed mice. The reference drug diazepam, at 0.5 mg/kg, also suppressed the locomotor activity in isolated mice but not in group-housed mice. Moreover, diazepam, at 0.1 and 0.5 mg/kg, significantly prolonged pentobarbital sleep in both isolated mice and group-housed mice. The effects of PI-E and diazepam on pentobarbital sleep in isolated mice were significantly attenuated by flumazenil (1 mg/kg, i.v.). PI-E (50-100 mg/kg), as well as diazepam (0.5-5 mg/kg, p.o.), dose-dependently suppressed social isolation-induced aggressive behavior, but it had no effect on pentylenetetrazole-induced convulsion, motor coordination in the rotarod test, or nociceptive response in the tail pinch test in group-housed mice. These results suggest that PI-E attenuates pathophysiological changes caused by social isolation stress in mice, and that the GABAergic system is partly involved in the action of PI-E on a social isolation-induced decrease in pentobarbital sleep.
Thongpraditchote
S
S
Division of Pharmacology, Research Institute for Wakan-Yaku (Oriental Medicines), Toyama Medical and Pharmaceutical University, Japan.
Matsumoto
K
K
Temsiririrkkul
R
R
Tohda
M
M
Murakami
Y
Y
Watanabe
H
H
D000374:Aggression / Q000187:drug effects; D000700:Analgesics / Q000494:pharmacology; D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology; D001208:Asia; D001522:Behavior, Animal / Q000187:drug effects*; D004347:Drug Interactions; D006993:Hypnotics and Sedatives / Q000494:pharmacology; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009043:Motor Activity / Q000187:drug effects; D010424:Pentobarbital / Q000494:pharmacology; D010936:Plant Extracts / Q000494:pharmacology*; D018517:Plant Roots / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D004856:Postural Balance / Q000187:drug effects; D012890:Sleep / Q000187:drug effects; D012934:Social Isolation
D000700:Analgesics; D000927:Anticonvulsants; D006993:Hypnotics and Sedatives; D010936:Plant Extracts; D010424:Pentobarbital