| The amount of chaff produced by the production and cultivation of edible fungi is large,and the direct waste is easy to cause environmental pollution and other problems.The chaff contains polysaccharides active substances,so the extraction of polysaccharides in chaff can not only effectively use chaff,reduce environmental pollution,but also optimize the industrial chain of edible fungi.In this study,the extraction conditions of polysaccharides from Agrocybe cylindracea residue(PACR)were optimized.The structure of PACR was preliminarily analyzed,such as the monosaccharide composition.Besides,the improvement effect of PACR on liver and colon of T2 DM mice based on p38 MAPK signaling pathway were analyzed.The main research results are as follows:(1)Extraction optimization of PACR.By designing PB test and corresponding surface test,when the optimal extraction conditions of PACR were extraction temperature 89.98?,number of extraction 1.46,p H=8.02,the predicted yield of polysaccharide was 2.24%.In order to facilitate experimental operation,the extraction conditions were set as extraction temperature90?,number of extraction 1,p H=8,the theoretical yield of PACR was 2.24%.The actual yield was 2.23%.PACR was purified by deproteinization,depigmentation,dialysis and freeze drying.(2)Structure analysis and monosaccharide composition of PACR.PACR is composed of mannose,ribose,rhamnose,glucuronic acid,galacturonic acid,glucose,galactose,xylose,arabinose and fucose,and its composition ratio is 13.69: 4.23: 4.61: 6.31: 1.98: 17.33: 24.03:8.78: 11.18: 7.86.Mannose,glucose and galactose were the main monosaccharides in PACR.FT-IR of PACR showed that PACR had carboxyl group(-COOH),cycloether bond(C-O-C)stretching vibration and carboxyl group(C-O-H)variable angle vibration,and was pyrantose.(3)Antioxidant effect of PACR.The scavenging rates of PACR on superoxide anion,DPPH and hydroxyl radical were 22.40±1.50%,25.50±1.13% and 28.30±1.09%,and reducing power reached 0.08±0.01.In vitro antioxidant capacity of PACR was positively correlated with dose concentration,which was the higher the concentration,the stronger the antioxidant capacity of PACR in vitro.(4)Improvement of liver and colon in T2 DM mice by PACR.(1)After high dose PACR(400 mg/kg)intervention,the activities of antioxidant enzymes SOD,CAT and GSH-Px in vivo were enhanced and the content of MDA was decreased.This also suggested that PACR can reduce the damage of liver and colon,and played a certain role in maintaining redox balance.(2)PACR can reduce liver and colon index.H?E histopathological observation showed that PACR could reduce inflammatory cell infiltration in liver cells,repair nuclear membrane and hepatic lobule structure disorder.In addition,PACR could repair the colon and intestinal glands,and had a certain repair effect on the muscle layer of the colon,improving the disorder of cell arrangement.(3)PACR could improve the level of insulin restistance(IRS1,IRS2)in liver and colon and reduced the express of inflammatory factors(IL-6,IL-1?).(4)Immunofluorescence test suggested that T2 DM stimulated the p38 MAPK signaling pathway,and the expression of p-p38 was down-regulated after PACR intervention.(5)Western-blot analysis also showed that PACR inhibited the activation of p38 MAPK signaling pathway,down-regulated p-p38 level,and reduced the p-p38/p38 ratio.PACR also reduced the expression level of TNF-?,thus playing an anti-inflammatory,anti-oxidant and hypoglycemic role.Based on the above conclusions,the results indicated that PACR had certain antioxidant,anti-inflammatory and diabetic effects,and could repair and improve the damaged liver and colon to some extent by inhibiting the activation of p38 MAPK signaling pathway,which also provided a new idea for the development of natural hypoglycemic drugs. |
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