Section of Immunology & Joint Immunology Program, The Second Clinical Medical College of Guangzhou University of Chinese Medicine, Guangdong Provincial Academy of Chinese Medical Sciences, Guangzhou, Guangdong, 510006, China.
Section of Immunology & Joint Immunology Program, The Second Clinical Medical College of Guangzhou University of Chinese Medicine, Guangdong Provincial Academy of Chinese Medical Sciences, Guangzhou, Guangdong, 510006, China.
J Ethnopharmacol. 2020 May 10;253:112656. doi: 10.1016/j.jep.2020.112656. Epub 2020 Feb 6.
Shegan-Mahuang Decoction (SMD), also named Yakammaoto or Shegan-Mahuang Tang, is a classic formula of traditional Chinese medicine with nine herbs, including Asarum sieboldii Miq., Aster tataricus L.f., Ephedra sinica Stapf, Belamcanda chinensis (L.) Redouté, Pinellia ternata (Thunb.) Breit., Schisandra chinensis (Turcz.) Baill., Tussilago farfara L., Zingiber officinale Roscoe, and Ziziphus jujuba Mill. SMD was originally discovered by Zhang Zhongjing in Eastern Han dynasty. It has been widely used as traditional medicine to treat flu-like symptoms in China and Japan for around twenty centuries. It was also utilized for the treatment of the early stage of acute asthma. However, the immune mechanisms underlying its therapeutic effects remain unknown.
This study was set to investigate the effects of SMD on asthmatic airway hyperresponsiveness and its impacts on adaptive immunity in a mouse model of asthma.
The HPLC fingerprint profile of the water extract of SMD recorded 22 peaks, including those equivalent to guanosine, chlorogenic acid, tectoridin, 6-gingerol and wuweizisu B, as described previously (Yen et al., 2014). Airway hyperresponsiveness was assessed by measuring the airway resistance. Cellular infiltration was measured via H&E staining and immunochemistry while gene expression was analyzed using real-time RT-PCR. Treg frequency was determined through flow analysis whereas cytokine production in the supernatant was evaluated using ELISA. Finally, mTOR and NF-kB signalings were analyzed via Western blotting.
We found that SMD largely corrected the imbalance of Th cell subsets in asthmatic mice with a significant inhibition of Th2 and Th17 cytokine production, thereby reducing asthmatic airway hyperresponsiveness. Moreover, lung function tests showed that SMD reduced airway hyperresponsiveness while immunohistochemical analyses demonstrated that SMD attenuated pulmonary infiltration of CD3 and CD4 T cells. Further, we observed a significant increase in the proportion of CD4+Foxp3+ Tregs in SMD-treated asthmatic mice. We also found that SMD downregulated gene expression of GATA3 and ROR-γt in murine lung tissue. In addition, both mTOR- and NF-kB-related protein expressions were reduced in the lung tissue of SMD-treated mice. SMD inhibited Th2/Th17 cytokine production by CD4 T cells and also their mTOR activity in vitro.
Our findings demonstrate that SMD attenuates asthmatic airway hyperresponsiveness by hindering Th2/Th17 differentiation, promoting CD4+FoxP3+ Treg generation and suppressing mTOR and NF-kB activities.
射干麻黄汤（SMD），也称为 Yakammaoto 或射干麻黄汤，是一种含有九种草药的中药经典方剂，包括细辛、紫菀、麻黄、射干、半夏、北沙参、款冬花、生姜和大枣。SMD 最初由东汉张仲景发现，在中国和日本已有约 20 个世纪的历史，被广泛用作治疗流感样症状的传统药物。它也被用于治疗急性哮喘的早期阶段。然而，其治疗效果的免疫机制尚不清楚。
本研究旨在探讨 SMD 对哮喘气道高反应性的影响及其对哮喘小鼠模型适应性免疫的影响。
如 Yen 等人所述（2014 年），通过高效液相色谱指纹图谱记录了 SMD 水提取物的 22 个峰，包括鸟苷、绿原酸、金雀异黄素、6-姜辣素和五味子 B 等峰。气道高反应性通过测量气道阻力来评估。细胞浸润通过 H&E 染色和免疫组织化学测定，基因表达通过实时 RT-PCR 分析。通过流式分析确定 Treg 频率，通过 ELISA 评估上清液中细胞因子的产生。最后，通过 Western 印迹分析 mTOR 和 NF-kB 信号通路。
我们发现 SMD 可显著抑制 Th2 和 Th17 细胞因子的产生，从而纠正哮喘小鼠 Th 细胞亚群失衡，减轻哮喘气道高反应性。此外，肺功能测试显示 SMD 可降低气道高反应性，免疫组织化学分析显示 SMD 可减轻肺组织中 CD3 和 CD4 T 细胞浸润。此外，我们观察到 SMD 治疗的哮喘小鼠中 CD4+Foxp3+Treg 的比例显著增加。我们还发现 SMD 下调了小鼠肺组织中 GATA3 和 ROR-γt 的基因表达。此外，SMD 治疗的小鼠肺组织中 mTOR 和 NF-kB 相关蛋白的表达均降低。SMD 可抑制 CD4 T 细胞 Th2/Th17 细胞因子的产生及其 mTOR 活性。
我们的研究结果表明，SMD 通过抑制 Th2/Th17 分化、促进 CD4+Foxp3+Treg 生成以及抑制 mTOR 和 NF-kB 活性来减轻哮喘气道高反应性。
