CPP-1 Improves Inflammation And Oxidative Stress Research In Aging Mice Through "Gut-liver" Axis

Codonopsis pilosula,a traditional Chinese medicine,is commonly used in clinic to treat spleen and lung weakness,shortness of breath,palpitation,internal heat and thirst.C.pilosula polysaccharide(CPs),as the main component of C.pilosula,has various pharmacological activities,and has a wide range of sources,and low prices.In our previous study,polysaccharides from C.pilosula(Franch.)Nannf were extracted and characterized,and it was found that acidic polysaccharides from C.pilosula(Franch.)Nannf showed potential antioxidant activity in vitro.Based on the above research background,this topic uses the same extraction,separation and purification methods as previous studies to obtain the acidic polysaccharide of the root of C.pilosula(CPP-1),and explore whether CPP-1 can improve the inflammation and oxidative stress of aging mice by regulating the intestine-liver axis.1 Effects of CPP-1 on antioxidant and anti-inflammatory indicators in the intestine of aging miceBased on the results of our previous study,an acidic polysaccharide named CPP-1 was isolated from C.pilosula root by water extraction and ethanol precipitation.Aging mice were divided into two groups: high dose groups(20 mg/kg),low dose group(10 mg/kg)and blank control group(saline).The daily weight and food intake of mice was recorded and the histopathology morphology of ileum and jejunum was observed by H&E staining;qRT-PCR method was applied for detecting inflammatory factors(IL-6、IL-1β、TNF-ɑ)and antioxidant enzymes(SOD,CAT,GSH-Px)and tight junction proteins(ZO-1,OCC),TLR4,NRF2,in various intestinal tissues.The activity of antioxidant enzymes(SOD,CAT,GSH-Px),ROS,MDA were detected by ELISA.The results showed that there was no significant difference in body weight and organ index of mice in each group,indicating that CPP-1 had no adverse effect on naturally aging mice,and it was safe to gavage.Pathological examination of the intestine showed that CPP-1 can reduce the degree of intestinal tissue necrosis in aging mice and improve intestinal permeability.CPP-1 can enhance the expression of NRF2 signaling pathway in the duodenum of naturally aging mice,significantly increased the mRNA expression of CAT,GSH-Px,SOD in the duodenum,jejunum,and ileum tissues of naturally aging mice,and significantly increased the expression of ZO-1 and OCC in the duodenum and jejunum of naturally aging mice.And CPP-1 can significantly reduce the content of IL-6,IL-1β and TNF-ɑ in the duodenum,jejunum,and ileum tissues of naturally aging mice.CPP-1can significantly reduce the mRNA expression of TLR4 in the duodenum,indicating that CPP-1 has a certain antioxidant function in the intestines of naturally aging mice,and can also alleviate age-related intestinal inflammation.It also protects the barrier and permeability functions of the intestinal mucosa in aging mice to a certain extent,thereby exerting its anti-aging function.2 Effects of CPP-1 on antioxidant and anti-inflammatory indicators in the liver of aging miceLiver function biochemical indicators in the serum of naturally aging mice were detected by using a fully automated biochemical analyze.qRT-PCR method was applied for detecting inflammatory factors(IL-6,IL-1β,TNF-ɑ)and antioxidant enzymes(SOD,CAT,GSH-Px)and TLR4,NRF2,in the liver of aging mice.The activity of antioxidant enzymes(SOD,CAT,GSH-Px),ROS,MDA and ROS were detected by ELISA,and histopathology of liver were examined.The results of histopathology examination showed that CPP-1 could improve the damage of liver pathological cells in aging mice.It can also increase the activity of T-AOC,GSH-Px,CAT,and SOD in the liver tissue of aging mice,and reduce the concentration of inflammatory factors IL-1β,IL-6 and TNF-α in the liver tissue of aging mice.The levels of ALT,AST and NEFA in aging mice serum were improved,indicating that it can improve the apoptosis of inflammatory cells and improve the state of inflammatory aging by increasing antioxidant levels and reducing the concentration of pro-inflammatory cytokines in the liver.3 CPP-1 improves inflammation and oxidative stress in aging mice through "gut-liver" axisThe “gut-liver” axis was analyzed after administration of CPP-1 to aging mice.Through cluster analysis of operational taxonomic units on the feces of experimental mice,the results showed that at the phylum level,Firmicutes,Bacteroidetes,and Proteobacteria were important phyla in the mouse intestinal microbiota.The relative abundance of Bacteroidetes in the group treated with CPP-1 increased while the relative abundance of Firmicutes,Proteobacteria,Desulfobacteria and Acidobacteria decreased.At the genus level,the relative abundance of beneficial bacteria such as Bacteroides,Eubacterium and Bifidobacterium increased significantly,while the relative abundance of harmful bacteria such as Staphylococcus,Pseudomonas and Clostridium lactis decreased significantly.α-Diversity analysis found that the Chao index of the administration group increased,indicating that CPP-1,a polysaccharide from Codonopsis pilosula,can increase the abundance of gut microbiota in aging mice.In this study,we found that CPP-1 can indirectly reduce intestinal epithelial mucosal damage by inhibiting pro-inflammatory cytokines and promoting the expression of anti-inflammatory cytokines in the liver and intestine,to protect intestinal mucosal function.It can also be achieved by regulating the gut microbiota of aging mice,increasing the abundance of Bacteroidetes and decreasing the abundance of Desulfobacteria in the intestine can increase SCFAs,and by regulating the LPS-TLR4 pathway,the content of LPS in serum is reduced,thereby exerting antioxidant and anti-inflammatory effects on aging mice through the "gut liver" axis.