Dendrobium moniliforme Stem Extract Inhibits Lipoteichoic Acid-Induced Inflammatory Responses by Upregulation of Heme Oxygenase-1

• Published in: Journal of microbiology and biotechnology Vol. 28; no. 8; pp. 1310 - 1317
• Main Authors: Lee, Young Ji, Kim, Ji-Hee, Kim, YoungHee
• Format: Journal Article
• Language: English
• Published: Korea (South) 한국미생물·생명공학회 28.08.2018
• Subjects: Active Transport, Cell Nucleus - drug effects; Animals; Anti-Inflammatory Agents - pharmacology; Dendrobium - chemistry; Gene Expression Regulation - drug effects; Gene Knockdown Techniques; Heme Oxygenase-1 - genetics; Inflammation - genetics; Lipopolysaccharides - adverse effects; Macrophages - drug effects; Macrophages - metabolism; Mice; NF-E2-Related Factor 2 - metabolism; Nitric Oxide - metabolism; Nitric Oxide Synthase Type II - genetics; Phosphorylation - drug effects; Plant Extracts - pharmacology; Plant Stems - chemistry; RAW 264.7 Cells; RNA, Small Interfering - genetics; Signal Transduction - drug effects; Teichoic Acids - adverse effects; 생물학; heme oxygenase-1 (HO-1); lipoteichoic acid; Dendrobium moniliforme; NF-E2-related factor 2 (Nrf2); inducible nitric oxide synthase (iNOS)
• ISSN: 1017-7825; 1738-8872
• DOI: 10.4014/jmb.1807.07024

The stems of have been used in traditional herbal medicine for the treatment of fever and lack of body fluid in Korea. In this study, we investigated anti-inflammatory effects of the aqueous extract of stems (DM) in response to lipoteichoic acid (LTA), a major constituent of the cell wall of Gram-positive bacteria. DM inhibited LTA-induced expression of a pro-inflammatory mediator inducible nitric oxide synthase (iNOS) in the murine macrophages. And DM induced expression of heme oxygenase-1 (HO-1) at the transcriptional level. Conversely, the knockdown of HO-1 expression by siRNA markedly reversed the inhibitory effects of DM on LTA-induced iNOS expression. We also demonstrated that nuclear translocation of Nrf2 was increased following treatment with DM. In addition, DM-mediated Nrf2 activation and HO-1 expression were suppressed by PI3K/Akt and p38 inhibitors; treatment with DM also resulted in phosphorylation of Akt and p38. These results suggest that DM inhibits the expression of iNOS in LTA-stimulated macrophages, and that these effects are mediated by the upregulation of HO-1 expression via PI3K/Akt/p38-Nrf2 signaling.