Inhibitory effects of the methanol extract of Ganoderma lucidum on mosquito allergy-induced itch-associated responses in mice.
Recently, we showed that a methanol extract of Ganoderma lucidum inhibits scratching, an itch-related response, induced by intradermal injections of some pruritogens in mice. The present study investigated whether G. lucidum extract would inhibit allergic itch. In mice sensitized with an extract of salivary gland of mosquito (ESGM), an intradermal injection of ESGM elicited scratching, which was suppressed by oral administration of G. lucidum extract (100 and 300 mg/kg). The scratching was inhibited by the H₁ histamine-receptor antagonist azelastine, but not by the peripherally acting H₁-antagonist terfenadine, at the oral dose of 30 mg/kg. In sensitized mice, ESGM increased the activity of cutaneous nerve, which was suppressed by G. lucidum extract (300 mg/kg). Although terfenadine (30 mg/kg) inhibited plasma extravasation induced by ESGM in the sensitized mice, G. lucidum extract (300 mg/kg) was without effect. These results suggest that G. lucidum extract relieves allergic itch through a peripheral action. The results support the idea that mast cells and H₁ histamine receptors are not the primary sites of the antipruritic action of G. lucidum extract.
Department of Applied Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan.
Tsugunobu
T
Andoh
Qun
Q
Zhang
Takumi
T
Yamamoto
Manabu
M
Tayama
Masao
M
Hattori
Ken
K
Tanaka
Yasushi
Y
Kuraishi
D000818:Animals; D000982:Antipruritics / Q000276:immunology / Q000494:pharmacology*; D009033:Culicidae / Q000276:immunology*; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D005638:Fruit; D006632:Histamine / Q000494:pharmacology; D039563:Histamine H1 Antagonists, Non-Sedating / Q000494:pharmacology; D006636:Histamine Release / Q000187:drug effects; D006967:Hypersensitivity / Q000276:immunology; D007271:Injections, Intradermal; D008297:Male; D008407:Mast Cells / Q000187:drug effects / Q000276:immunology; D000432:Methanol / Q000494:pharmacology; D051379:Mice; D008813:Mice, Inbred ICR; D010793:Phthalazines / Q000494:pharmacology; D008517:Phytotherapy; D011537:Pruritus / Q000188:drug therapy* / Q000276:immunology; D011968:Receptors, Histamine / Q000378:metabolism; D020940:Reishi; D012867:Skin / Q000187:drug effects / Q000276:immunology / Q000294:innervation; D016593:Terfenadine / Q000494:pharmacology
D000982:Antipruritics; D004365:Drugs, Chinese Herbal; D039563:Histamine H1 Antagonists, Non-Sedating; D010793:Phthalazines; D011968:Receptors, Histamine; D016593:Terfenadine; D006632:Histamine; D000432:Methanol; C020976:azelastine