Department of Applied Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan.
J Pharmacol Sci. 2010;114(3):292-7. doi: 10.1254/jphs.10180fp. Epub 2010 Oct 8.
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.
最近，我们发现灵芝甲醇提取物可抑制某些致痒原皮内注射引起的小鼠搔抓，这一与瘙痒相关的反应。本研究旨在探讨灵芝提取物是否可抑制过敏性瘙痒。在经蚊子唾液腺提取物（ESGM）致敏的小鼠中，ESGM 皮内注射可诱发搔抓，灵芝提取物（100 和 300 mg/kg）口服可抑制搔抓。H₁ 组胺受体拮抗剂氮卓斯汀（30 mg/kg）可抑制搔抓，但外周作用的 H₁ 拮抗剂特非那定（30 mg/kg）无此作用。在致敏小鼠中，ESGM 增加皮肤神经活性，灵芝提取物（300 mg/kg）可抑制其增加。特非那定（30 mg/kg）可抑制致敏小鼠中 ESGM 引起的血浆外渗，但灵芝提取物（300 mg/kg）无此作用。这些结果提示灵芝提取物通过外周作用缓解过敏性瘙痒。结果支持这样一种观点，即肥大细胞和 H₁ 组胺受体并非灵芝提取物止痒作用的主要部位。
