Central inhibitory effects of water extract of Acori graminei rhizoma in mice.
The present study evaluated in mice the central inhibitory effects of a water extract of shichangpu (Acori graminei rhizoma (AGR), the dry rhizome of Acorus gramineus Soland. (Araceae)). AGR (0.5-5.0 g/kg) dose-dependently decreased the locomotor activity and increased the pentobarbital-induced sleeping time, but had no significant effect on the treadmill performance. AGR also dose-dependently inhibited the intensity of apomorphine-induced stereotypic behavior. At the highest dose (5.0 g/kg), AGR had a weak anticonvulsant effect on the pentylenetetrazol-induced seizures. Receptor binding assays showed that AGR competed with [3H]SCH-23390 and [3H]YM-09151-2 for specific binding to striatal dopamine D1 and D2 receptors with Ki values of 5.6 and 4.2 mg/ml, respectively. AGR also competed with [3H]muscimol for specific binding to the gamma-aminobutyric acid (GABA) binding site of cortex GABA(A) receptors with a Ki value of 0.31 mg/ml. It also increased the specific binding of [3H]flunitrazepam to the benzodiazepine binding site of the GABA(A) receptors, suggesting a GABA agonist-like action. These results suggested that the central inhibitory effects of AGR were probably effected through an action on the central dopamine receptors and GABA(A) receptors. The principle of AGR acting at these ligand binding sites was not alpha-asarone, one of the important principles of AGR, since that alpha-asarone (10(-6)-10(-4) M) had no significant interactions with these binding sites.
Department and Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan, ROC. jfliao@ym.edu.tw
J F
JF
Liao
S Y
SY
Huang
Y M
YM
Jan
L L
LL
Yu
C F
CF
Chen
D000818:Animals; D001058:Apomorphine / Q000037:antagonists & inhibitors; D002490:Central Nervous System / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004365:Drugs, Chinese Herbal / Q000302:isolation & purification / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009043:Motor Activity / Q000187:drug effects; D010424:Pentobarbital / Q000819:agonists; D010433:Pentylenetetrazole / Q000494:pharmacology; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology; D011954:Receptors, Dopamine / Q000187:drug effects; D018079:Receptors, GABA / Q000187:drug effects; D012640:Seizures / Q000139:chemically induced; D012890:Sleep / Q000187:drug effects; D013239:Stereotyped Behavior / Q000187:drug effects
D004365:Drugs, Chinese Herbal; D010936:Plant Extracts; D011954:Receptors, Dopamine; D018079:Receptors, GABA; D010424:Pentobarbital; D001058:Apomorphine; D010433:Pentylenetetrazole