Agonistic Activities to the Benzodiazepine Receptor by Extracts of Medicinal Plants(II). -Activities of component and Active Fraction from Gastrodia elata-

생약의 Benzodiazepine 수용체 효능활성 검색 (II). -천마성분 및 유효분획의 활성-

In order to find active ingradients having an agonistic activity to benzodiazepine receptor from Gastrodia elata Blume (Orchidaceae) which has been used as an anticonvulsant in oriental medicine, one component and some fractions were separated from the butanol extract of the rhizomes of this plant and evaluated for their activities on GABA/benzodiazepine receptor in vitro. As a result, one crude mixture (F4f) obtained from the most active fraction (F4) inhibited significantly the binding of $[^3H]Ro15-1788$, a selective benzodiazepine receptor antagonist, to benzodiazepine receptor of rat cortices. GABA significantly enhanced the inhibition of $[^3H]flunitrazepam$ binding by F4f, and this positive GABA shift supported the strong possibility of the agonistic activity of F4f to benzodiazepine receptor.