Cnidilide, an alkylphthalide isolated from the roots of Cnidium officinale, suppresses LPS-induced NO, PGE(2), IL-1 beta, IL-6 and TNF-alpha production by AP-1 and NF-kappa B inactivation in RAW 264.7 macrophages

摘要

Cnidilide, an alkyl phthalide isolated from the rhizome of Cnidium officinale, has been reported to possess antispasmodic and sedative effects. However, the anti-inflammatory capacity and molecular mechanism of cnidilide have not been studied to date. In the present study, we investigated the inhibitory effects of cnidilide on LPS-induced pro-inflammatory mediators and the underlying molecular mechanisms in RAW 264.7 macrophages. Our results indicated that cnidilide potently inhibits inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression at the protein and mRNA levels and their promoter activities, causing attendant decreases in the production of nitric oxide (NO) and prostaglandin E-2 (PGE(2)). In addition, cnidilide reduced LPS-induced production and mRNA expression of interleukin (IL)-1 beta, IL-6, and tumor necrosis factor-alpha (TNF-alpha) in a dose-dependent manner. Molecular data revealed that cnidilide inhibited LPS-induced transcriptional activity of activator protein-1 (AP-1) by reducing the phosphorylation and nuclear translocation of c-Fos and c-Jun. In addition, cnidilide attenuated LPS-induced transcriptional activity of nuclear factor-kappa B (NF-kappa B), and this reduction was accompanied by parallel reduction in the phosphorylation, but not in the translocation of p65 NF-kappa B. In addition, cnidilide inhibited LPS-induced phosphorylation of p38 mitogen-activated protein kinase (MAPK) and mitogen-and stress-activated protein kinase 1(MSK-1), a downstream kinase. Moreover, the phosphorylation of c-Jun N-terminal kinase (INK) was suppressed by cnidilide in a concentration-dependent manner, whereas it did not inhibit the extracellular signal-regulated kinase (ERK) phosphorylation in LPS-stimulated RAW 264.7 macrophages. Taken together, our findings suggest that cnidilide has anti-inflammatory properties by inhibiting p38 MAPK, JNK, AP-1, and the NF-kappa B pathway in LPS-stimulated RAW 264.7 macrophages. (C) 2016 Elsevier B.V. All rights reserved.