Ethyl linoleate from garlic attenuates lipopolysaccharide-induced pro-inflammatory cytokine production by inducing heme oxygenase-1 in RAW264.7 cells

• DOI: 10.1016/j.intimp.2014.01.017
• Publication Date: 2014-02-04T16:47:31Z
• Authors: Sun Young Park; Rajasekar Seethar...; Min Jung Ko; Do Yeon Kim; Tae Hoon Kim; Moo Kyoung Yoon; Jung Ho Kwak; Sang Joon Lee; Yoe Sik Bae; Young Whan Choi
• Keywords: Lipopolysaccharides; 0301 basic medicine; Anti-Inflammatory Agents; NF-kappa B; Membrane Proteins; Nitric Oxide Synthase Type II; Nitric Oxide; Cell Line; Mice; 03 medical and health sciences; Linoleic Acids; Cyclooxygenase 2; Animals; Cytokines; Mitogen-Activated Protein Kinases; Garlic; Heme Oxygenase-1

In the present study, an essential fatty acid, ethyl linoleate (ELA), was isolated from the cloves of Allium sativum, and its structure was elucidated by NMR and GC-MS analyses. In vitro systems were used to evaluate the anti-inflammatory activity of ELA. Our results indicate that ELA down-regulates inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression and thereby reduces nitric oxide (NO) and prostaglandin E2 production in lipopolysaccharide (LPS)-activated RAW 264.7 cells. Immunofluorescent microscopy and western blot analyses revealed that these effects were mediated by impaired translocation of nuclear factor (NF)-κB and inhibition of phosphorylation of mitogen activated protein kinases. Furthermore, ELA exerted its anti-inflammatory activity by inducing heme oxygenase-1 (HO-1) expression, as determined by HO-1 small interfering (Si) RNA system. Si RNA-mediated knock-down of HO-1 abrogated the inhibitory effects of ELA on the production of NO, TNF-α, IL-1β, and IL-6 in LPS-induced macrophages. These findings indicate the potential therapeutic use of ELA as an anti-inflammatory agent.