Polysaccharide Of Atractylodes Macrocephala Koidz Regulates LPS-mediated Mouse Hepatitis Through The TLR4-MyD88-NFκB Signaling Pathway

Polysaccharide of Atractylodes Macrocephala Koidz(PAMK)is an important component of Atractylodes Macrocephala Koidz.Studies have shown that PAMK could enhance the immune function of animals.However,there is not much research on the anti-inflammatory effects of PAMK,and the molecular mechanism of PAMK regulates animal hepatitis caused by bacteria is not clear.In order to verify whether PAMK could regulate the animal hepatitis caused by bacteria and explore the molecular mechanism of this regulation effect,“water extraction and alcohol precipitation”method was used to extract PAMK.And then 150 4 weeks old mice were pretreated with the extracted PAMK.In order to explore the role of PAMK in LPS-mediated hepatitis in mice,based on hepatitis animal model caused by LPS,histopathological of liver tissue damage in mice was examined,the level of inflammation-related cytokines and oxidative stress in serum were detected by ELISA kit,the levels inflammation-related genes expression and protein expression were detected by qPCR and Western Blot,respectively.The results showed that:(1)The average molecular weight of PAMK was 2.676×10~4 g/mol,with mainly composed of glucose,galactose,arabinose,fructose,and mannose,which accounted for 67.01%,12.32%,9.89%,1.18%and 0.91%;(2)The results of histopathology section showed that the hepatocytes in the LPS group had obvious swelling,hepatic cord structure disorder,a large number of inflammatory cell infiltration and red blood cell exudation.The hepatic cord structure of the LPS+PAMK group was clearer,no obvious cell swelling,and less inflammatory cell infiltration.Apparently,PAMK could relieves LPS-mediated tissue damage;(3)The results of cytokines in serum showed that the levels of IL-1βand IL-6 in serum were significantly increased in the LPS group at 6,12,and 24 h after LPS injection.The levels of IL-1β,IL-6 and TNF-αwere significantly reduced,while the levels of IL-4were significantly increased in the LPS+PAMK group 24 h after LPS injection.It can be shown that PAMK could increase the level of IL-4 by inhibiting the levels of IL-1β,IL-6 and TNF-α,and reduce the inflammation caused by LPS;(4)The results of oxidative stress in serum showed that LPS group could significantly increase the activity of CAT,GSH-PX,SOD,iNOS and the level of MDA in serum 24 h after LPS injection,the activity of GSH-PX and iNOS and the level of MDA were significantly reduced.It can be seen that PAMK could alleviate the oxidative stress damage in the liver of mice caused by LPS by reducing the activity of GSH-PX and iNOS and the level of MDA;(5)The results of the relative expression levels of mRNA and protein of inflammation-related genes in the liver showed that the mRNA and protein expression levels of TLR4,MyD88,IKBαand NFκB in the LPS group were significantly increased.In the LPS+PAMK group,the expression levels of IKBαand NFκB mRNA were significantly reduced and the protein expression levels of MyD88,IKBαand NFκB were significantly increased at 6 h after LPS injection.It is shown that PAMK could activate the TLR4-MyD88-NFκB signaling pathway and up-regulate the mRNA expression levels of IKBαand NFκB and the protein expression levels of MyD88,IKBαand NFκB.In summary,PAMK could activate the TLR4-MyD88-NFκB signaling pathway and regulate downstream cytokines and affect the state of oxidative stress in the body,and has a protective effect on LPS-mediated hepatitis in mice.Outdated farming conditions and technical levels may cause bacterial infections,which could cause severe liver inflammation and liver damage,or even death.In this study,by studying the theory of PAMK regulating LPS-induced hepatitis in mice,the molecular mechanism of PAMK production was deeply understood,which also laid the foundation for the development and application of green feed additives in the animal husbandry industry.