Regulatory effects and molecular mechanism of Trigonostemon reidioides on lipopolysaccharide-induced inflammatory responses in RAW264.7 cells

Abstract

Trigonostemon reidioides (Kurz) Craib has been traditionally used for the treatment of vomiting and asthma in Cambodia. However, the underlying molecular mechanisms of the anti-inflammatory effect of T. reidioides extract remains unknown. The present study investigated the anti-inflammatory activity and molecular action of an ethanol extract of T. reidioides (ETR) in lipopolysaccharide (LPS)-induced RAW264.7 macrophage cells. Nitric oxide assays, ELISA, reverse transcription-quantitative polymerase chain reaction and western blot analysis were used. ETR treatment inhibited the production of nitric oxide by downregulating inducible nitric oxide synthase expression, while exhibiting no significant cytotoxicity compared with macrophages treated with LPS-alone. Consequently, ETR decreased the production of certain proinflammatory cytokines, including interleukin (IL)-1β, IL-6 and tumor necrosis factor-α. Additionally, ETR inhibited the activation of mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated kinase, c-Jun N-terminal kinase and p38 MAPK, as well as the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. These effects were mediated by inhibition of the nuclear localization of nuclear factor κ-B (NF-κB). Taken together, the results of the present study demonstrate that ETR may exert an anti-inflammatory effect by inhibiting the expression of inflammatory mediators and cytokines via downregulation of the NF-κB, PI3K/Akt and the MAPK signaling pathways in LPS-stimulated macrophages. Based on these results, we hypothesize that ETR may be a potential therapeutic agent for the treatment of inflammatory disorders.

Anti-inflammatory activity of the dietary supplement Houttuynia cordata fermentation product in RAW264.7 cells and Wistar rats

“…LPS from gram-negative bacteria has been shown to possess a dose-dependent cytotoxic activity in RAW264.7 cells [13], therefore, the non-toxic concentration of LPS was predetermined (Data not shown). LPS at concentration of 1 μg/ml was used in the present study, and not toxic to RAW264.7 cells, consistent with the result from previous study [27].…”

Water-separated part of Chloranthus serratus alleviates lipopolysaccharide- induced RAW264.7 cell injury mainly by regulating the MAPK and Nrf2/HO-1 inflammatory pathways

“…Inflammation is generally divided into acute and chronic inflammation, which can lead to a series of inflammatory diseases such as rheumatoid arthritis and gastritis. If not treated in time, inflammation may further develop into various cancers [3, 4].…”

“…The occurrence of inflammation is accompanied by the production of inflammatory mediators such as prostaglandin E 2 (PGE 2 ), interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α) and nitric oxide (NO). The over-expression of these inflammatory mediators may cause serious damage to cells and tissues, even resulting in organ failure [3, 5]. Moreover, two pro-inflammatory enzymes, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), play synergistic roles in inflammatory diseases, and drugs with dual inhibitory effects on iNOS and COX-2 mRNA have great anti-inflammatory potential [6].…”

Monoterpenoids from the Fruits of Amomum tsao-ko Have Inhibitory Effects on Nitric Oxide Production

“…IL-1β and IL-6 are the most important pro-inflammatory cytokines in an inflammatory response. The inhibition of pro-inflammatory cytokine, such as IL-1β and IL-6 is essential for the control of an inflammatory response [ 29 ]. We measured the levels of the relevant mRNAs via reverse transcription polymerase chain reaction (RT-PCR) [ 30 ].…”