Post-upper respiratory tract infection related olfactory dysfunction typically occurs due to neural damage after an upper respiratory tract infection associated with a common cold or influenza. At present, Tokishakuyakusan, a Japanese traditional Kampo medicine, has been found to be effective for post-viral olfactory dysfunction. However, the pharmacodynamics of Tokishakuyakusan in the treatment of post-viral olfactory dysfunction remains unresolved. We investigated the effects of Tokishakuyakusan on the regeneration of olfactory neurons and expression of nerve growth factor (NGF) in neural systems, using in vivo murine studies and in vitro cell culture studies. Eight-week-old BALB/C female mice were fed a pellet diet with or without Tokishakuyakusan. Degeneration of cells in olfactory epithelium was induced by intraperitoneal methimazole injection. Regeneration of olfactory neurons was observed by histological and immunohistochemical procedures. NGF expression in the olfactory bulb was measured by enzyme-linked immunosorbent assay. NGF gene and protein expression were measured using rat primary cultured astrocytes by real-time polymerase chain reaction and enzyme-linked immunosorbent assay. We found that olfactory marker protein, Ki-67, and NGF were more highly expressed in the olfactory epithelium during the regeneration period in mice receiving Tokishakuyakusan. In cultured astrocytes, Tokishakuyakusan as well as its individual components, Atractylodes lancea rhizome and Japanese angelica root, increased NGF expression. Screening assays revealed that NGF production was increased by atractylodin and levistolide A, which are ingredients in Atractylodes lancea rhizome and Japanese angelica root, respectively. These results suggest that Tokishakuyakusan promotes regeneration of olfactory neurons by increasing NGF expression in the olfactory bulb.

中文翻译：

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Tokishakuyakusan对体内和体外鼠嗅神经元再生的影响。

上呼吸道后感染相关的嗅觉功能障碍通常是由于与普通感冒或流感相关的上呼吸道感染后的神经损伤而发生的。目前，已发现日本传统的汉方药物Tok​​ishakuyakusan对病毒后嗅觉功能障碍有效。然而，Tokishakuyakusan在治疗病毒后嗅觉功能障碍中的药效学仍未解决。我们使用体内鼠研究和体外细胞培养研究，调查了Tokishakuyakusan对嗅觉神经元再生和神经系统中神经生长因子（NGF）表达的影响。给八周大的BALB / C雌性小鼠喂食含或不含Tokishakuyakusan的颗粒饲料。腹腔内注射他巴唑可诱导嗅觉上皮细胞变性。通过组织学和免疫组织化学方法观察到嗅觉神经元的再生。通过酶联免疫吸附测定法测量嗅球中的NGF表达。使用大鼠原代培养的星形胶质细胞通过实时聚合酶链反应和酶联免疫吸附测定法测量NGF基因和蛋白质表达。我们发现嗅觉标记蛋白，Ki-67和NGF在接受Tokishakuyakusan的小鼠再生期间在嗅觉上皮中表达更高。在培养的星形胶质细胞中，Tokishakuyakusan及其单个成分，白术白术和日本当归根，增加了NGF的表达。筛选试验表明，白术素和去甲内酯A分别增加了白术根和日本当归的成分，从而增加了NGF的产生。这些结果表明，Tokishakuyakusan通过增加嗅球中NGF的表达来促进嗅神经元的再生。