Inhibition of [methyl-3H]diazepam binding to rat brain membranes in vitro by dinatin and skrofulein.
Two flavones, 4',5,7-trihydroxy-6-methoxy flavone (dinatin) and 4',5-dihydroxy-6, 7-dimethoxy flavone (skrofulein), were extracted from Artemisia herba alba L. Dinatin and skrofulein inhibited the binding of [methyl-3H]diazepam to rat brain membranes in vitro with IC50 of 1.3 and 23 mumol.L-1, respectively. The GABA-ratios (the ratio of IC50 values in the absence/presence of GABA in the binding assay) were 1.1 and 1.2 for dinatin and skrofulein, respectively. Both flavones induced a slight increase in [35S] TBPS binding. The data suggest that the flavones are antagonists or partial agonists of benzodiazepine receptors.
Shen
X L
XL
Department of Biochemistry, St Hans Hospital, Roskilde, Denmark.
Nielsen
M
M
Witt
M R
MR
Sterner
O
O
Bergendorff
O
O
Khayyal
M
M
D000818:Animals; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D003975:Diazepam / Q000378:metabolism*; D047309:Flavones; D005419:Flavonoids / Q000302:isolation & purification / Q000494:pharmacology*; D058785:GABA-A Receptor Agonists; D058787:GABA-A Receptor Antagonists; D010946:Plants, Medicinal / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar
D047309:Flavones; D005419:Flavonoids; D058785:GABA-A Receptor Agonists; D058787:GABA-A Receptor Antagonists; C007072:cirsimaritin; C055957:hispidulin; D003975:Diazepam