Anti-inflammation of Methanol Extract of Salix pseudolasiogyne in LPS stimulated RAW 264.7 Macrophage Cells

Abstract

Inflammation is the innate immune system's response to harmful stimuli. However, Uncontrolled acute inflammation develops into chronic inflammation, which causes various inflammatory diseases. Representative anti-inflammatory treatments including non-steroidal anti-inflammatory drugs (NSAIDs) cause various side effects. Accordingly, the development of natural anti-inflammatory treatments is necessary. In this study, the methanol extract of Salix Pseudolasiogyne, a Korean native plant, was conformed to inhibit NO production and RNA, protein expression of iNOS, an inflammatory mediator synthase, in LPS-stimulated RAW 264.7 murine macrophages. Additionally, a decrease in the production of inflammatory cytokines (tumor necrosis factor-α; TNF-α) and chemokines (monocyte chemoattractant protein-1; MCP- 1) and mRNA expression levels of IL-6, IL-1β, and TNF-α was confirmed in the MESP-treated group. The phosphorylation levels of NF-κB, a major transcription factor in the inflammatory response, and MAPK, an upstream factor of NF-κB, decreased in the MESP-treated group. Additionally, production of intracellular ROS was reduced due to increased KEAP-1/Nrf-2/HO- 1, a major antioxidant enzyme, protein expression in the MESP-treated group. Therefore, MESP can inhibit inflammation by inhibiting pro-inflammatory enzymes, cytokines, chemokines, and transcription factors and by decreasing intracellular ROS formation by increasing the expression of antioxidant enzymes in LPS-induced RAW 264.7 murine macrophages. GC-MS analysis of the MESP was used to confirm the chemical compounds that reported anti-inflammatory effects. This study shows that MESP has the potential to be used as a remedy for inflammatory diseases caused by chronic inflammation.