Anti-inflammatory constituents from the root of Litsea cubeba in LPS-induced RAW 264.7 macrophages

• Published in: Pharmaceutical biology Vol. 54; no. 9; pp. 1741 - 1747
• Main Authors: Lin, Bing, Sun, Lian-Na, Xin, Hai-Liang, Nian, Hua, Song, Hong-Tao, Jiang, Yi-Ping, Wei, Zhen-Qiao, Qin, Lu-Ping, Han, Ting
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis 01.09.2016
• Subjects: Animals; Anti-arthritic; Anti-Inflammatory Agents - isolation & purification; Anti-Inflammatory Agents - pharmacology; Cyclooxygenase 2 - genetics; Cyclooxygenase 2 - metabolism; Cytokines - metabolism; IKKβ; Inflammation - genetics; Inflammation - immunology; Inflammation - metabolism; Inflammation - prevention & control; Inflammation Mediators - metabolism; IκBα; Lipopolysaccharides - pharmacology; Litsea - chemistry; Macrophages - drug effects; Macrophages - immunology; Macrophages - metabolism; Mice; Molecular Structure; NF-kappa B - metabolism; Nitric Oxide Synthase Type II - genetics; Nitric Oxide Synthase Type II - metabolism; p38 Mitogen-Activated Protein Kinases - metabolism; Phosphorylation; Phytotherapy; Plant Roots; Plants, Medicinal; Proto-Oncogene Proteins c-akt - metabolism; RAW 264.7 Cells; rheumatoid arthritis; RT-PCR; Signal Transduction - drug effects; Traditional Chinese Medicine; IKKβ; rheumatoid arthritis; RT-PCR; Anti-arthritic; IκBα; Traditional Chinese Medicine
• ISSN: 1388-0209; 1744-5116
• DOI: 10.3109/13880209.2015.1126619

Context Litsea cubeba (Lour.) Pers. (Lauraceae) has long been used as a folk remedy in Traditional Chinese Medicine (TCM) for the treatment of rheumatic diseases. Previous studies from our laboratory indicated that L. cubeba extract showed anti-arthritic activity in rats. Objective To study L. cubeba chemically and biologically and to find the potential constituents responsible for its anti-arthritic effect. Materials and methods The compounds were isolated from the root of L. cubeba by column chromatography which eluted with PE:EtOAc gradient system, and the structures were elucidated by detailed spectroscopic data analysis; the anti-inflammatory activity of the isolated compounds was evaluated by lipopolysaccharide (LPS)-induced RAW 264.7 cells and the TNF-α and NO level were measured by ELISA (commercial kit); The iNOS and COX-2 mRNA expression were measured by RT-PCR and the phosphorylation of IκBα, IKKβ, P38 and Akt were determined by western blots. Results A novel 9-fluorenone, 1-ethoxy-3,7-dihydroxy-4,6-dimethoxy-9-fluorenone (1), together with 4 known compounds, namely pinoresinol (2), syringaresinol (3), 9,9′-O-di-(E)-feruloyl-meso-5,5′-dimethoxysecoisolariciresinol (4) and lyoniresinol (5) were isolated from the root of L. cubeba for the first time. The IC 50 for NO inhibition on compounds 1 and 4 were 56.1 ± 1.2 and 32.8 ± 2.3 μM, respectively. The IC 50 for TNF-α inhibition were 28.2 ± 0.9 and 15.0 ± 1.0 μM, respectively. Both 1 and 4 suppress mRNA expression of iNOS, COX-2 and protein phosphorylation of IκBα, IKKβ in LPS-induced RAW 264.7 cells. Discussion and conclusion Compounds 1 and 4 isolated from L. cubeba exhibited potent anti-inflammatory activity through the NF-κB signal pathway.