Effects of hop extracts on nasal rubbing and sneezing in BALB/c mice.
The effects of hop extracts (Humulus lupulus L.) on histamine release from rat peritoneal mast cells and human basophilic KU812 cells were studied. Hop water extract (HWE) and XAD-4 50% methanol fraction of HWE (MFH) inhibited histamine release from rat mast cells induced by compound 48/80 at concentrations of 100 and 10 mug/ml, respectively. Almost the same findings were observed with A23187-induced histamine release from KU812 cells. Next, we studied the effects of hop extracts on antigen-induced nasal rubbing and sneezing in sensitized BALB/c mice. HWE caused a significant inhibition of nasal rubbing and sneezing at a dose of 500 mg/kg. MFH also inhibited nasal rubbing and sneezing dose-dependently. A significant difference was observed from 100 mg/kg in nasal rubbing and 200 mg/kg in sneezing. The effects of both extracts became clear after repeated administration. HWE and MFH significantly inhibited both nasal rubbing and sneezing, respectively, after consecutive treatment for 15 d at smaller doses compared with single administration. This finding indicates that the active component of hop is included in MFH, which was absorbed to Amberlite XAD-4 and eluted with 50% methanol. These results clearly demonstrated that hop extracts may be effective in the relief of symptoms of allergic rhinitis.
Takubo
Miho
M
Department of Medicinal Pharmacology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Japan.
Inoue
Toshio
T
Jiang
Shuishi
S
Tsumuro
Tae
T
Ueda
Yuhki
Y
Yatsuzuka
Rie
R
Segawa
Shuichi
S
Watari
Junji
J
Kamei
Chiaki
C
D000818:Animals; D018926:Anti-Allergic Agents; D001491:Basophils / Q000187:drug effects / Q000378:metabolism; D001522:Behavior, Animal / Q000187:drug effects; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D005260:Female; D006636:Histamine Release / Q000187:drug effects; D027582:Humulus / Q000737:chemistry*; D008407:Mast Cells / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D010936:Plant Extracts / Q000494:pharmacology; D051381:Rats; D006255:Rhinitis, Allergic, Seasonal / Q000188:drug therapy* / Q000523:psychology; D012912:Sneezing / Q000187:drug effects*
D018926:Anti-Allergic Agents; D010936:Plant Extracts