Emodin Inhibits Sepsis By Regulating Macrophages To Secret Cytokines

BackgroundIn sepsis,an immune response caused by an invading pathogen that culminates in a pathological syndrome characterized by persistent excessive inflammation and immunosuppression due to the inability to restore homeostasis,in the clinical can lead to systemic multiple organ dysfunction and failure.Inflammatory mediators are known to include complement components,Arachidonic acid metabolites,and Tumor necrosis factors,interleukin,IFN,PAF,MPIC,protease,thromboxane and oxygen free radicals.Activated macrophages are the source of these inflammatory cytokines.In severe bacterial infections,macrophages are activated by the TLR/NF-?B pathway and subsequently secrete proinflammatory cytokine(such as IL-1?,TNF-?)and i NOS,further directing more immune cells to the site of infection,and release a large number of Cytokines,which lead to "cytokine storm" production,as well as the development of fatal Septic Shock Syndrome and multiple organ failure.Therefore,it is very important for the recovery of Sepsis to inhibit the inflammatory state of macrophages and gradually restore their homeostasis.Emodin is a kind of hydroxyanthraquinone with anti-inflammatory,anti-bacterial,anti-viral,anti-fungal and anti-protozoan effects.It has been reported that Emodin can play an anti-inflammatory role in sepsis,however,whether it is directly related to macrophages is not clear,and whether it can regulate the secretion of inflammatory cytokines in macrophages needs further confirmation.Research purposesTo investigate whether emodin can inhibit the development of LPS-induced sepsis in mice,and further explore whether this effect is achieved by regulating the secretion of cytokines by macrophages.Research Methodology1.To explore whether the anti-inflammatory effect of emodin is related to macrophages through in Vivo experiments.A mouse model of sepsis was established by intraperitoneal injection of LPS.Emodin was injected intraperitoneally 2 hours later.After 24 days,the serum was isolated from peripheral blood and used to detect cytokines.Liver and lung tissues were taken for pathological examination,and the degree of injury and inflammatory infiltration were analyzed.After the peritoneal macrophages were purified,the m RNA was extracted and the gene expression of cytokines was detected.2.To analyze the anti-inflammatory mechanism of emodin in vitro.First,BMDM in mice was cultured and emodin of different concentrations was added to investigate whether it could play a regulatory role on macrophages under normal conditions.Secondly,the BMDM of the cultured mice was stimulated with LPS for 2 h,then emodin of different concentrations was added,after 24 h,the supernatant of the cultured cells was taken,and the release of TNF-?,IL-1?,IL-10 and TGF-? were detected by ELISA,the expression of TNF-?,IL-1?,IL-10 and TGF-? was detected by QPCR.Results1.Emodin can inhibit LPS-induced inflammation in miceMice treated with LPS showed signs of acute alveolar injury and inflammation,such as hyperemia,neutrophil accumulation,and marked thickening of the alveolar walls.The LPS add emodin group showed reduced sepsis-induced Lesions,reduced inflammation in the lungs and liver,and even normal histological features.In addition,emodin can reduce the content of TNF-? and increased the content of IL-10 in serum of mice.2.Emodin can reduce the expression of inflammatory cytokines in mice BMDM induced by LPSAt the gene level,emodin had no significant effect on the expression of TNF-?,but decreased the expression of IL-1?,and increased the expression of anti-inflammatory factor IL-10 and TGF.At the protein level,emodin significantly reduced the release of TNF-? and IL-1?,but had no significant effect on IL-10 and TGF-?.3.Emodin can affect the gene expression of TNF-?,IL-1? and TGF-? in BALB/C mice BMDMEmodin could decrease the gene expression of TNF-? and IL-1? in BMDM,and TGF-?,at different concentrations(10u M,20 u M,40 u M),but had no effect on IL-10 expression.ConclusionEmodin inhibits LPS-induced inflammation in mice by directly reducing TNF-? and IL-1? in mouse macrophages and regulating the expression of IL-10 and TGF-? at the gene level.