| In the environment,acrylamide(AA)is a potentially toxic pollutant and widely used in a variety of industries.What’s more,it can also be produced in high-temperature food,causing potential physiological toxicity to the human body.Previous reports on AA-induced liver tissue damage were few and the research was not deep enough.In addition,Ganoderma atrum polysaccharide is the main active ingredient of Ganoderma lucidum.Preliminary studies have proved that Ganoderma atrum polysaccharide has multiple biological activities like immune regulation,anti-aging,anti-tumor,anti-diabetic,myocardial protection and so on.At present,there is no study on the intervention of Ganoderma lucidum polysaccharides on acrylamide-induced liver injury in rats.Therefore,in this study,the intervention effect of Ganoderma atrum polysaccharides on rat liver injury was evaluated by establishing the model of rat liver injury induced by acrylamide and giving rats dietary supplement of Ganoderma atrum polysaccharides.The possible mechanism of Ganoderma atrum polysaccharides in alleviating the toxicity of acrylamide was explored from the two aspects of intestinal flora and metabonomics.This provides a theoretical basis for the mechanism of liver injury induced by AA in different aspects and prevents the early toxicity of AA.And it is also of great significance and practical value.The main research contents are as follows:(1)In order to study the protective effects of Ganoderma atrum polysaccharides on liver tissue induced by AA(20mg/kg)in rats.We established a rat model in vivo,observed the rat state and liver pathological sections,and determined the biochemical indexes of serum and liver tissue.The results showed that the toxic effects of AA began to manifest in 20 days,and the pathological results showed that Ganoderma atrum polysaccharide can significantly alleviate AA-induced hepatocyte necrosis and liver tissue structure destruction.In addition,Ganoderma atrum polysaccharides can significantly alleviate the damage of liver and kidney function induced by AA.Such as,Ganoderma atrumum polysaccharides can significantly reduce the levels of serum AST,ALT,TG,TC,BUN,CR and ALP activity in rats exposed to AA.And the activities of antioxidant enzymes in Ganoderma atrum polysaccharides group,such as SOD,GSH-Px,CAT,GSH and GSH was increased significantly,while the content of MDA decreased significantly,compared with AA group.What’s more,Ganoderma atrum polysaccharides can down-regulate the expression of pro-inflammatory factors IL-1β,IL-2 and TNF-α,increase the content of anti-inflammatory factors IL-10 in the body,then alleviate the inflammation caused by acrylamide.It also significantly decreased the level of serum 8-OHdG and reversed the DNA damage caused by AA.In conclusion,Ganoderma atrum polysaccharides can inhibit the oxidative damage caused by acrylamide by maintaining the balance of oxidation/antioxidation in rats,reducing inflammation,restoring liver and kidney function,alleviating DNA damage and so on.(2)Based on UPLC-Q-TOF/MS,the effects Ganoderma atrum polysaccharides on serum and urine metabolites of AA-damaged rats was investigated.The results showed that serum and urine samples of different treatment groups were significantly separated in PCA coordinates;AA damage induced significant changes in glycerolipid metabolism,arachidonic acid metabolism,butyric acid metabolism,ether lipid metabolism,conversion of pentose and glucuronates,lysine degradation,ascorbic acid metabolism,biotin metabolism,tyrosine metabolism and other metabolic pathways in rats.And Bilirubin,Proline betaine,LysoPC(22 1(13Z),Glycerophosphocholine,Palmitic amide,LysoPC(20:0),LysoPC(14:0),N-Undecanoylglycine,Arginyl-Valine,Lysinoalanine,L-gamma-glutamyl-L-isoleucine,Phenylalany 1-Threonine,L-cis-Cyclo(aspartylphenylalanyl),L-glutamic-L-valine,Deoxyinosine,Acetaminophen glucuronide,Oxoglutaric acid were considered the biomarkers in AA-induced rats.The intervention of Ganoderma atrum polysaccharides had significant effects on phenylalanine metabolism,phenylalanine,tyrosine,tryptophan biosynthesis,glycerophospholipid metabolism,butyric acid metabolism,ether lipid metabolism,mutual transformation of pentose and glucuronates,and lysine degradation pathway.And 20-hydroxy LTB4,112-oxo-20-dihydroxy-leukotriene B4,L-Phenylalanine,27-Nor-5b-cholestane-3a,7a,12a,24,25-pentol,LysoPC(16:1(9Z)),Indoleacetic acid,Arachidonate were considered the biomarkers in PSG administration rats.(3)Analysis of the changes of intestinal flora in rats by Illumina high-throughput sequencing.The PLS-DA results showed that the intestinal flora of rats in different treatment groups was significantly isolated in the figure.In addition,the results of Alpha diversity showed that neither AA nor Ganoderma atrum polysaccharides had a significant effect on the intestinal microbial diversity of rats,but significantly changed the proportion and number of microflora at the phylum level.Compared to control group,the balance between Bacteroidetes and Firmicutes was broken,and the levels of Ruminococcus and Desulfovibrio bacteria decreased significantly,while the levels of Prevotella,Rothia and Bacteroides increased in AA group.When compared to AA,the intervention of Ganoderma atrum polysaccharides significantly increased the levels of Ruminococcus.Lactobacillus and Lachnobacterium.And the KEGG results predicted by ICRUSt show that the Ganoderma atrum polysaccharides intervention and AA damage caused significant differences in the types of metabolism include carbohydrate metabolism,energy metabolism and metabolism of catotors vitamins.In addition,compared with the AA group,Ganoderma atrum polysaccharide significantly increased the levels of acetic acid,propionic acid,butyric acid,isobutyric acid,and total SCFAs in feces of rats which was important for the health of the host.(4)The proteomics(iTRAQ)results showed that 266 proteins had significant changes in acrylamide induced liver tissues,among which 167 were up-regulated and 99 were down-regulated;GO functional analysis showed that normal catabolism of liver tissues,such as catabolism of fatty acids,was mainly affected in the process of liver injury induced by acrylamide damage,as well as cytoplasmic components and protein-binding function;and KEGG pathway analysis showed that the major pathways were retinol metabolism,dilated myocarditis,steroid biosynthesis and other metabolic processes;and the protein-protein interation network showed that the proteins with high connectivity are Actal,Mylpf,Myhl,My13,Myh4,Ugt2a3,Ugt2b,Cyp2c13,Cyp4a2,Adh6,etc.Accordingly,a total of 247 proteins showed significant changes in PSG intervention,of which 75 were up-regulated and 172 were down-regulated;PSG intervention mainly affects the organism’s biological processes of organic cyclic compounds and oxidant reduction,and at the same time changes the cytoplasmic components and protein binding and catalytic enzyme active molecular functions,as well as metabolic transfer processes such as xanol metabolism,chemical carcinogenesis,steroid hormone biosynthesis,and degradation;Finally,the proteins that the connectivity transduced were Cyp3a1,Cyp3a18,Hsd3b5,Cyp4a2,Cyp2c13,Cyp2c7,Alox15,Cyp2d3,Ugt1al,Adh6.In conclusion,the study showed that a natural edible ingredient,Ganoderma atrum polysaccharides,plays an important protective role in preventing dietary AA toxicity and alleviating liver injury caused by AA.At the same time,it not only provides new insights into liver injury caused by AA at the level of metabolism and intestinal microorganisms,but also provides a theoretical basis for the further development of Ganoderma atrum polysaccharides products. |
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