| Type 2 diabetes is a systemic disease characterized by insulin resistance and relative insulin deficiency,which can lead to hyperglycemia and various physiological and metabolic abnormalities.Its pathogenesis may be related to oxidative stress,immune disorder and intestinal flora disorder.At present,there are many side effects of first-line medication in type 2 diabetes and the intervention effect on systemic damage caused by type 2 diabetes is limited.if a natural product with no toxic side effects and hypoglycemic effect can be found,it may provide a new way for the adjuvant treatment of type 2 diabetes.Tremella fuciformis has the functions of tonifying kidney and protecting liver.It has been reported that Tremella fuciformis has hypoglycemic effect on type 2 diabetic mice induced by high sugar.Other studies have shown that natural products homologous to medicine and food,such as kelp,balsam pear,pumpkin,dandelion,inulin and so on,can enhance physique and regulate blood sugar.In the animal model used to test the hypoglycemic effect of natural products,Drosophila has the advantages of simple operation,short reproductive cycle,low cost,and the insulin signal pathway is highly similar to that of humans.At present,the means of using Drosophila to prepare insulin resistance and to study the mechanism of occurrence and development of type 2 diabetes have been more mature and have been used more and more.The purpose of this experiment is to screen a natural product with the lowest side effects,and to explore its hypoglycemic function and mechanism through the model of high-sugar Drosophila,so as to provide experimental basis for enriching the intervention mechanism of diabetes and lay a foundation for the development of hypoglycemic functional food.Objectives:The safest natural products were screened and its hypoglycemic effect was proved.It was proved that the hypoglycemic mechanism was related to the improvement of antioxidant capacity,immune function and regulation of intestinal flora of Drosophila melanogaster,and had a positive effect on insulin signal pathway.Methods:The main experimental contents include three parts: screening hypoglycemic natural products,determining their health-promoting and hypoglycemic effects,and exploring the mechanism of action.The specific methods are as follows: Drosophila melanogaster was fed with high sugar medium for 14 days,and the model of high sugar Drosophila melanogaster was established.The safest one was selected from 6 kinds of natural products through life test.Drosophila melanogaster was randomly divided into negative control group,high glucose model group and natural product intervention group.The trehalose content,life span and body weight of each group were compared,and the activity of Drosophila melanogaster was detected by Drosophila behavior detector to verify the hypoglycemic function of Tremella fuciformis and the effect of Tremella fuciformis on related physiological indexes of Drosophila melanogaster.Detection of antioxidant capacity: malondialdehyde(MDA)content and superoxide dismutase(SOD)activity are important indicators of antioxidant capacity.After Drosophila melanogaster was homogenized,MDA content and SOD activity were detected by kit.Detection of immune ability: the intestinal tract of Drosophila melanogaster was dissected under microscope,and the apoptosis of intestinal cells was detected by 7-AAD staining.At the same time,the contents of IL-6 and TNF-α in Drosophila homogenate were detected by Western Blotting.Detection of intestinal microflora: DNA was extracted from Drosophila melanogaster,and 16srDNA gene sequencing technology was used to detect the intestinal microflora of Drosophila melanogaster.Bioinformatics and statistical methods were used to explore the changes of intestinal flora.Detection of genes related to insulin signal pathway: the expression of PI3K,PDK and FOXO in Drosophila homogenate was detected by Western Blotting.Results:1.Through the life experiment,it was found that Tremella,kelp,pumpkin,balsam pear,dandelion and chrysanthemum powder were beneficial to the survival of Drosophila melanogaster.Among them,Tremella fuciformis has the strongest ability to improve the physiological index of Drosophila melanogaster,the lowest side effect.The optimum concentration is 1%.2.Compared with the negative control group,the trehalose(equivalent to human blood glucose)content in the high glucose model group was significantly increased,the life span was shortened,the body weight was significantly reduced and the activity became lower.In contrast,Tremella fuciformis had antagonistic effect on the above changes.3.Compared with the high glucose model group,the content of malondialdehyde(MDA)in tissue homogenate of Drosophila melanogaster in Tremella fuciformis group decreased,the activity of superoxide dismutase(SOD)increased,the number of apoptotic cells in intestinal tract decreased,the expression of IL-6 and TNF-α in tissue homogenate decreased,and the structure of intestinal flora was closer to that of negative control group.These results suggest that Tremella fuciformis can strengthen the ability of antioxidation,improve immune function and regulate intestinal flora.4.Compared with the high glucose model group,the expression of PI3K,PDK and FOXO in tissue homogenate of Drosophila melanogaster in Tremella fuciformis group increased in different degrees,which indicated that Tremella fuciformis could promote insulin signal transduction.Conclusions1.In the appropriate concentration of Tremella,kelp,pumpkin,balsam pear,dandelion,chrysanthemum powder are beneficial to the survival of fruit flies,of which 1%concentration of Tremella is the best.2.Tremella fuciformis can reduce blood sugar,prolong life,increase body weight and increase activity.3.The hypoglycemic mechanism of Tremella fuciformis on high candy flies may be through improving the ability of antioxidation,enhancing immune function and improving intestinal flora,so as to regulate the transduction of insulin signal pathway and reduce blood glucose. |
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