| Type 2 Diabetes Mellitus(T2DM)is a comprehensive disease in which the body’s glucose,lipid and protein metabolism is disrupted due to insufficient or ineffective insulin secretion from beta pancreatic islet cells.Agrocybe aegirita(AA)is a high dietary fiber,low fat edible of Agrocybe aegirita on glucolipid metabolism from both in vitro and in vivo aspects with high edible and medicinal value.It has been confirmed that polysaccharides and polyphenols are the main functional factors of fungal ingredients.However,fewer reports on the functional factors of Agrocybe aegirita can be found.Therefore,this study explored the modulatory effects of water-extracted polysaccharides,alkali-extracted polysaccharides and polyphenols of Agrocybe aegirita on glucolipid metabolism from both in vitro and in vivo aspects.The main studies and conclusions are as follows:1.In vitro evaluation of the efficacy of functional factors of Agrocybe aegirita in regulating blood glucose has been done.Three functional factors,Agrocybe aegirita water extract polysaccharide(SAAP),Agrocybe aegirita alkali extract polysaccharide(JAAP)and polyphenol(AA-P),were obtained from the Agrocybe aegirita by water extraction,alkaline alcohol precipitation and ethanol extraction,respectively.The gastrointestinal environment was first simulated in vitro to compare the effects of three functional factor on glucose diffusion,the activity ofα-amylase,pepsin and pancreatic lipase,and the binding of bile acid salts and the disruption of cholesterol gels.The results showed that SAAP could inhibit the diffusion of glucose under solution conditions to some extent.And JAAP and SAAP inhibitedα-amylase activity more significantly,with an inhibition rate of about 20%,While SAAP and AA-P had strong inhibitory effects on pepsin activity,with inhibition rates of 51%and 50%at a concentration of 10 mg/m L,respectively.AA-P had a better inhibitory effect on pancreatic lipase activity,with 20%inhibition at a concentration of 1.25 mg/m L.The results on the binding ability of bile salts showed that SAAP and JAAP were more effective in binding glycocholate,and SAAP and AA-P were more effective in binding taurocholate.The results on the destruction effect of cholesterol gels showed that the destruction rate of each functional factor did not change significantly at different concentrations.2.The intervention effect of functional factors of Agrocybe aegirita on glucolipid metabolism in type 2 diabetic mice.A type 2 diabetic mouse model was established by high-fat diet and intraperitoneal injection of streptozotocin(STZ),and the interventions of aqueous polysaccharide,alkaline polysaccharide and polyphenols of Agrocybe aegirita were given respectively.It was found that SAAP,JAAP and AA-P could slow down the rate of weight loss and effectively reduce the dietary waterintake of diabetic mice;enhance the glucose tolerance.They significantly reduced the insulin resistance index as well as the serum TG concentration in type 2diabetic mice.In addition,SAAP and JAAP could effectively reduce HDL-C concentration in serum,while aqueous polysaccharide also had the effect of down-regulating TC concentration in serum.AA-P could significantly reduce TNF-α,IL-1βand IL-6 content,and SAAP and JAAP could significantly reduce TNF-αand IL-6content.The pathological section results also showed that the three functional factors could also alleviate vacuolar degeneration and hepatocyte cord arrangement disorder in mice to different degrees,with the most significant effect in the polyphenol group.SAAP,JAAP and AA-P groups could improve islet cell injury,vacuolar degeneration and islet cell atrophy.Thus,it was hypothesized that the aqueous polysaccharide,alkaline polysaccharide and polyphenols of Agrocybe aegirita have potential effects in regulating glucolipid metabolism.3.To investigate the effect of functional factors of Agrocybe aegirita on intestinal flora of type 2 diabetic mice.The results of the intestinal flora analysis showed that the phylum Bacteroidetes and Proteobacteria were significantly reduced and the phylum Firmicutes was significantly up-regulated after the intervention of Agrocybe aegirita polyphenols at the phylum level.And the phylum Proteobacteria was significantly decreased after the intervention of Agrocybe aegirita aqueous and alkaline polysaccharides.The abundance of Proteobacteria phylum was significantly decreased after the intervention of aqueous and alkaline polysaccharides of Agrocybe aegirita.At the genus level,the abundance of the genus Muribaculaceae was significantly increased in the JAAP group,and the abundance of the genus Lachnospiraceae＿NK4A136＿group was significantly increased in the AA-P group.The abundance of Bacteroides,Parabacteroides,and Enterobacteriaceae was significantly decreased in the JAAP and AA-P groups,and the abundance of Enterobacteriaceae was significantly decreased in the SAAP group.The abundance of Enterobacteriaceae,Bacteroides was significantly reduced.It indicates that the functional factor intervention can improve the disorder of intestinal flora in type 2diabetic mice to some extent.4.Based on the results of the above study,a fat-reducing and sugar-reducing functional yogurt was developed using Agrocybe aegirita as raw material.Through sensory evaluation of the yogurt,the optimum addition amount of Agrocybe aegirita extract was determined to be 4%.The color of this yogurt was light yellow,acidity 88.18°T,p H 4.37;soluble solids content was 13.76%,protein content was3.26g,which was higher than the protein content of many commercially available yogurts;fat content was 2.87g and total lactic acid bacteria was 1.251×10~9,all of which met the standards in the national standard of GB19302-2010. |
PDF Full Text Request