Inhibitory Effects Of Taraxacum Extractive On LPS-induced Inflammation Via Regulating NF-?B Pathways In RAW264.7 Cells

Taraxacum plant is commonly used in clinical Chinese herbal medicine,it is one of the national medicine to protect species in China.Taraxacum bitter,sweet,cold,Taraxacum because it has choleretic,diuretic and anti-inflammatory medicinal effect so long been used as medicine.Macrophages act as innate immune cells that cause inflammation and immune responses in macrophages that protect the body from invasion by foreign invaders.When stimulated by LPS,macrophages are activated and release a variety of inflammatory mediators and cytokines,which may lead to extensive tissue damage and pathological changes.In this process,macrophages produce many inflammatory mediators such as interleukin(IL)-6,tumor necrosis factor(TNF)-?,nitric oxide(NO),prostaglandins.Produce a variety of mediators caused by a variety of physiological disorders,including tumor formation,autoimmune response and inflammatory diseases.Lipopolysaccharide(LPS)is an effective inducer of monocytes and macrophages and is a key medium for natural immune responses.LPS-stimulated RAW264.7 macrophages lead to intracellular signaling,and ultimately lead to cytokines and other inflammatory mediators constitute proinflammatory media production and secretion.Therefore,this study induced LPS-stimulated macrophages as an in vitro inflammatory model.In order to improve the medicinal value of Taraxacum and further increase the application of Taraxacum in clinical application,the anti-inflammatory effect of ethanol extract,glycoprotein and saponin of Taraxacum was studied in detail.The anti-inflammatory activity of Taraxacum extract,glycoprotein and saponin in vitro was studied by using RAW264.7 macrophages induced by lipopolysaccharide(LPS)in vitro.The proliferation activity of RAW264.7 cells was detected by MTT assay,Griess reagent was used to detect the secretion of NO,IL-6 and tumor necrosis factor(TNF)-? and iNOS mRNA were detected by RT-PCR.The levels of IL-6 and TNF-? were measured by ELISA.Western blot was used to detect I?B-? protein phosphorylation level,To study the inhibitory effect of ethanol extract,glycoprotein and saponin of Taraxacum on NF-?B signal transduction pathway.The results showed that the alcohol extract,glycoprotein and saponin of Taraxacum had no obvious effect on the proliferation activity of the cells in the range of 0-5000?g / mL,0-1000?g / mL and 0-1000?g / mL,respectively.The results of RT-PCR showed that the contents of TNF-?,IL-6 and iNOS mRNA were inhibited by different concentrations of ethanol extract,glycoprotein and saponin,and then use the ELISA assay verified that the extract of Taraxacum,glycoprotein and saponin could inhibit the secretion of TNF-? and IL-6,which was consistent with the expression of mRNA in a dose-dependent manner.In addition,Taraxacum extract,glycoprotein and saponin can inhibit the synthesis of NO.Above experimental data show that Taraxacum alcohol extract,glycoprotein and saponin able to regulate the secretion of cytokines and inflammatory mediators exert anti-inflammatory effects in vitro.We further analyzed the mechanism of LPS-induced cytokines and inflammatory mediators,and found that NF-?B,the most common signaling pathway,plays a key role in inflammatory signaling pathways.In this study,the effects of ethanol extract,glycoprotein and saponin of Taraxacum on NF-?B signaling pathway were measured by LPS-induced RAW264.7 macrophages.The results showed that LPS could significantly upregulate the phosphorylation level of I?B-?,while the Taraxacum extract,glycoprotein and saponin could inhibit the phosphorylation of I?B-? protein in a dose-dependent manner,Thus indirectly proved through its regulation of NF-?B signaling pathway,inhibiting the secretion of TNF-? and IL-6,and the expression of TNF-?,IL-6 and iNOS mRNA and the synthesis of NO in order to exert its anti-inflammatory effect.In this study,it was proved that the alcohol extract of Taraxacum had anti-inflammatory effect,and the glycoprotein and saponin in the alcohol extract also played an anti-inflammatory effect.The anti-inflammatory molecular mechanism of Taraxacum glycoprotein in cell inflammatory factors was found and proved for the first time.This provides a basis for the anti-inflammatory mechanism of Taraxacum,but also provides a new idea for the study of the anti-inflammatory molecular mechanism of glycoprotein,and also provides a theoretical basis for the development of anti-inflammatory drugs for glycoprotein.