College of Korean Medicine, Daejeon University, Daejeon, 300-716, Republic of Korea.
In Vitro Cell Dev Biol Anim. 2013 Dec;49(10):805-14. doi: 10.1007/s11626-013-9670-9. Epub 2013 Aug 16.
Magnolia species have been used for the treatment of allergic diseases in Asia as folk medicine; however, the cellular and molecular mechanisms of its anti-allergic effects have rarely been investigated. In this study, we demonstrated that a methanolic extract of the fructus of Magnolia denudata has suppressive effects on Th2 cytokine production such as IL-4 and IL-13, but not IFN-γ and IL-17, produced by both phorbol 12-myristate 13-acetate/ionomycin (PI)- and CD3/CD28-stimulated EL-4 T cells. Moreover, the mRNA expression of Th2 cytokines was significantly inhibited, and luciferase activity in cells transiently transfected with IL-4 or IL-13 promoter reporter plasmids was suppressed by M. denudata, indicating that M. denudata may regulate these expression at the transcriptional level. Western blot analysis for transcription factors involved in the cytokine gene expression indicated that the activation of c-Jun was significantly downregulated in the nucleus of cells, while the activations of nuclear factor of activated T cells, nuclear factor kappa B and c-Fos, were not affected. Furthermore, the mRNA expression and nuclear translocation of GATA-binding protein 3, a key transcriptional factor for Th2 commitment and Th2 cytokine expression, but not T-bet and RORγt, were dramatically downregulated by M. denudata. Treatment with M. denudata suppressed the phosphorylation of p38 mitogen-activated protein kinase; however, the PI-induced phosphorylation of extracellular signal-related kinase and c-Jun N-terminal kinase was unaffected. Taken together, our study indicated that M. denudata inhibited IL-4 and IL-13 expression, possibly through regulation of p38 mitogen-activated protein kinase phosphorylation and selective transcription factors, such as GATA-3 and c-Jun, in EL-4 T cells.
玉兰属植物在亚洲被用作治疗过敏性疾病的民间药物；然而，其抗过敏作用的细胞和分子机制很少被研究。在这项研究中，我们证明了厚朴的甲醇提取物对由佛波醇 12-肉豆蔻酸 13-醋酸盐/离子霉素（PI）和 CD3/CD28 刺激的 EL-4 T 细胞产生的 Th2 细胞因子（如 IL-4 和 IL-13）的产生具有抑制作用，但对 IFN-γ和 IL-17 没有抑制作用。此外，Th2 细胞因子的 mRNA 表达显著受到抑制，并且用 IL-4 或 IL-13 启动子报告质粒瞬时转染的细胞中的荧光素酶活性受到抑制，表明厚朴可能在转录水平上调节这些表达。涉及细胞因子基因表达的转录因子的 Western blot 分析表明，细胞核中 c-Jun 的激活明显下调，而激活的 T 细胞核因子、核因子 kappa B 和 c-Fos 不受影响。此外，GATA 结合蛋白 3 的 mRNA 表达和核易位，一种 Th2 承诺和 Th2 细胞因子表达的关键转录因子，而不是 T-bet 和 RORγt，被厚朴显著下调。厚朴处理抑制了 p38 丝裂原活化蛋白激酶的磷酸化；然而，PI 诱导的细胞外信号相关激酶和 c-Jun N 末端激酶的磷酸化不受影响。总之，我们的研究表明，厚朴通过调节 p38 丝裂原活化蛋白激酶的磷酸化和选择性转录因子，如 GATA-3 和 c-Jun，抑制 EL-4 T 细胞中 IL-4 和 IL-13 的表达。
