5-Hydroxytryptamine2A receptor binding activity of compounds from Litsea sessilis.
A 96-well microplate filtration based 5-HT(2A) receptor-radioligand binding assay was optimized and adopted to carry out a bioassay-guided fractionation of the methanol extract of the leaves of Litsea sessilis. This purification led to the isolation of two compounds identified as (+)-boldine (1) and (+)-dehydrovomifoliol (2). (+)-Boldine binds to 5-HT(2A) receptors at high concentrations with a K(i) value of 2.16 microm. However, (+)-dehydrovomifoliol showed minimal competitive inhibition on the binding of [(3)H]ketanserin to the same receptor with a K(i) value of 2.06 mm. These results suggest that (+)-boldine influences the activity of 5-HT(2A) receptors through competitive binding as an agonist or antagonist.
Department of Pharmacy, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia. chungly@hotmail.com
Lip Yong
LY
Chung
Mee Wah
MW
Lo
Muhammad Rais
MR
Mustafa
Swee Hock
SH
Goh
Zamrie
Z
Imiyabir
D001060:Aporphines / Q000494:pharmacology*; D001667:Binding, Competitive; D003512:Cyclohexanones / Q000494:pharmacology*; D007650:Ketanserin / Q000494:pharmacology; D032862:Litsea / Q000737:chemistry*; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D011869:Radioligand Assay; D044402:Receptor, Serotonin, 5-HT2A / Q000187:drug effects / Q000378:metabolism*
D001060:Aporphines; D003512:Cyclohexanones; D010936:Plant Extracts; D044402:Receptor, Serotonin, 5-HT2A; C539425:dehydrovomifoliol; C011686:boldine; D007650:Ketanserin