Flavonoid glycosides extracted from hop (Humulus lupulus L.) as inhibitors of chemical mediator release from human basophilic KU812 cells.
The antiallergic properties of hop water extract (HWE) were studied by evaluating histamine release from human basophilic KU812 cells induced by calcium ionophore A23187. HWE significantly inhibited histamine release, but boiling water extract and chloroform-methanol extract did not show any inhibitory effect on it. A 50% methanol-eluted fraction separated from HWE by XAD-4 column chromatography (MFH) had a strong inhibitory effect as compared with HWE. Quercetin glycosides and kaempherol glycosides were identified in MFH, of which quercetin glycosides contributed to the inhibition of histamine release. Most quercetin in HWE existed in glycoside form and its quercetin content, obtained by acid hydrolysis, was about 200 mug/g. HWE and MFH significantly inhibited protein kinase C, which plays a pivotal role in the degranulation of chemical mediators. These results indicate that HWE can inhibit type-I allergic reactions.
Segawa
Shuichi
S
Frontier Laboratories of Value Creation, Sapporo Breweries. syuuichi.segawa@sapporobeer.co.jp
Yasui
Kazuhisa
K
Takata
Yoshihiro
Y
Kurihara
Toshio
T
Kaneda
Hirotaka
H
Watari
Junji
J
D001491:Basophils / Q000187:drug effects* / Q000378:metabolism; D002460:Cell Line; D002853:Chromatography, Liquid; D005419:Flavonoids / Q000302:isolation & purification* / Q000494:pharmacology; D006027:Glycosides / Q000302:isolation & purification* / Q000494:pharmacology; D006801:Humans; D027582:Humulus / Q000737:chemistry*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D047428:Protein Kinase Inhibitors / Q000302:isolation & purification / Q000494:pharmacology
D005419:Flavonoids; D006027:Glycosides; D047428:Protein Kinase Inhibitors; D011493:Protein Kinase C