Effect Of Salidroside On Macrophage Polarization And Lipid Accumulation In Macrophages

With the changes in health concepts and changes in medical models,traditional Chinese medicine has increasingly shown its unique advantages and irreplaceable effects.Rhodiola as a permanent application history of Chinese medicine,is known as"Snow ginseng".Salidroside is the main active ingredient of Rhodiola root and has many pharmacological functions.It plays an important role in anti-inflammation and lipid metabolism,but the mechanism is not yet clear.Macrophages are important immune cells in the body and can exert anti-inflammatory or pro-inflammatory effects depend on its polarization.At the same time,macrophage lipid metabolism is closely related to macrophage function.Studies have shown that the fat mass and obesity-associated?FTO?gene inhibit pro-inflammatory cytokine expression.In order to better understand the function of macrophages and explore the potential medicinal functions of salidroside,this study investigated the effects of salidroside on macrophage polarization and the important regulators of lipid metabolism in macrophages.This study uses mouse RAW264.7 macrophage as a research model.After pretreatment with salidroside?100?M?for 1 h,macrophages were induced to polarize to M1 or M2 by LPS?1?g/mL?or IL-4?20 ng/mL?.The RT-qPCR method was used to detect the mRNA expression levels of the M1 polarization marker genes iNOS,IL-6,IL-1?and M2 polarized marker genes ARG1,MRC and MGL.The results showed that the relative expression levels of iNOS,IL-6,and IL-1?were significantly down-regulated in the LPS alone group,whereas the relative expression levels of ARG1,MRC,and MGL were up-regulated in comparison with the IL-4 alone group,indicating that salidroside inhibit macrophage M1 polarization and promote macrophage M2 polarization.The phosphorylation level of Akt S⁴⁷³ was detected by Western blot.Salidroside can inhibit the phosphorylation of Akt S⁴⁷³ in LPS,and salidroside regulate macrophage polarization through macrophage Akt signaling pathway.Macrophages were pretreated with salidroside and stimulated with Poly?I:C??5?g/mL?to detect mRNA expression levels of iNOS,IL-6 and TNF-?.The results showed that the mRNA expression levels of iNOS,IL-6,and TNF-?were significantly reduced,indicating that salidroside may also have protective effects on inflammation caused by viral infection.Overexpression of FTO in macrophages,pretreatment with salidroside,and LPS stimulation were used to detect the mRNA relative expression levels of IL-6,TNF-?and IL-1?.The results showed that the relative mRNA expression levels of IL-6,TNF-?and IL-1?were significantly decreased,indicating that overexpression of FTO can inhibit the expression of inflammatory factors induced by LPS and further affect the anti-inflammatory effects of macrophages.To further investigate the effect of salidroside on macrophage lipid metabolism,salidroside was pretreated with cells and then stimulated with LPS or Poly?I:C?to detect the mRNA expression level of FTO.The results showed that the mRNA level of FTO was decreased,and salidroside had a regulatory effect on FTO in macrophage inflammation.Pretreatment with salidroside,stimulation with LPS or Poly?I:C?,followed by detection of SREBP1c and CIDEc mRNA expression levels in the FTO/SREBP1c/CIDEc signaling pathway.The results showed that salidroside can inhibit the expression of key genes SREBP1c and CIDEc in the process of fat accumulation,which may reduce lipid accumulation in macrophages.In conclusion,our results show that salidroside can regulate the macrophage polarization and affect the expression of important regulatory molecules related to lipid metabolism in macrophages,thereby regulating the body's inflammatory response.