Department of Molecular Biology, College of Natural Sciences, Pusan National University, Busan 609-735, South Korea.
J Ethnopharmacol. 2012 Oct 31;144(1):109-17. doi: 10.1016/j.jep.2012.08.037. Epub 2012 Sep 5.
The roots of Achyranthes japonica Nakai have been used in traditional herbal medicine for the treatment of edema and arthritis in Korea.
In this study, we investigated the molecular mechanism responsible for anti-inflammatory effects of the aqueous extract of A. japonica roots (AJ) in LPS-stimulated macrophages.
Nitric oxide (NO) production and as inducible nitric oxide synthase (iNOS) expression were examined in TG-elicited peritoneal macrophages and RAW 264.7 cells. Cell viability was monitored by MTT assay. Protein and mRNA expressions were determined by Western blotting and RT-PCR, respectively. The activity of NF-κB and Nrf2 were examined by EMSA, immunocytochemistry or reporter assay.
AJ inhibited LPS-induced NO secretion as well as iNOS expression, without affecting cell viability. Furthermore, AJ suppressed LPS-induced NF-κB activation, degradation of IκB-α, phosphorylation of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38. Further study demonstrated that AJ induced heme oxygenase-1 (HO-1) gene expression via nuclear translocation and transactivation of Nrf2. In addition, the inhibitory effects of AJ on iNOS expression were abrogated by small interfering RNA-mediated knock-down of HO-1.
These results suggest that AJ suppresses LPS-induced NO production and iNOS expression in macrophages through the inhibition of IκB/NF-κB and MAPK as well as the Nrf2-mediated HO-1 induction. These findings provide the scientific rationale for anti-inflammatory therapeutic use of A. japonica roots.
日本牛膝的根在韩国传统草药医学中被用于治疗水肿和关节炎。
在这项研究中，我们研究了日本牛膝根（AJ）水提物发挥抗炎作用的分子机制，该作用是在 LPS 刺激的巨噬细胞中产生的。
在 TG 诱导的腹腔巨噬细胞和 RAW 264.7 细胞中，检测了一氧化氮（NO）的产生和诱导型一氧化氮合酶（iNOS）的表达。通过 MTT 分析监测细胞活力。通过 Western blot 和 RT-PCR 分别测定蛋白质和 mRNA 的表达。通过 EMSA、免疫细胞化学或报告基因分析检测 NF-κB 和 Nrf2 的活性。
AJ 抑制 LPS 诱导的 NO 分泌和 iNOS 表达，而不影响细胞活力。此外，AJ 抑制 LPS 诱导的 NF-κB 活化、IκB-α降解、细胞外信号调节激酶（ERK）、c-Jun N 末端激酶（JNK）和 p38 的磷酸化。进一步的研究表明，AJ 通过核易位和 Nrf2 的转激活诱导血红素加氧酶-1（HO-1）基因表达。此外，AJ 对 iNOS 表达的抑制作用被 HO-1 的小干扰 RNA 介导的敲低所消除。
这些结果表明，AJ 通过抑制 IκB/NF-κB 和 MAPK 以及 Nrf2 介导的 HO-1 诱导，抑制巨噬细胞中 LPS 诱导的 NO 产生和 iNOS 表达。这些发现为日本牛膝根的抗炎治疗应用提供了科学依据。
