| In recent years,the incidence rate of Type 2 diabetes mellitus(T2DM)has been increasing year by year,and the research on the treatment of diabetes mellitus by traditional Chinese medicine has gradually increased.Therefore,it is an important way to select the drugs with hypoglycemic activity from many natural drugs.Urtica plants have a certain effect on the treatment of diabetes.At present,there have been reports on the hypoglycemic activities of different Urticaria,such as Urtica dioica,Urtica angustifolia,Urtica romanica and other Urticaria,plants,but there are few reports on the hypoglycemic activities of Urtica fissa.In this study,it were rearched on the antioxidative and hypoglycemic activities of extract of Urtica fissa.Then the T2DM mice model was constructed to explore its hypoglycemic effects in vivo according to the physiological and biochemical indexes and the changes of tissue morphology.Finally,the hypoglycemic mechanism of Urtica fissa was explained based on metabonomics and molecular biology.(1)Study on the anti oxidation and hypoglycemic activity of Urtica fissa extract in vitroThe extraction of Urtica fissa extract(UFE)was prepared by ethanol reflux method.The content of flavonoids was 12.09mg/g.The maximum scavenging rate of UFE to DPPH radical was 92.76%,IC50 value was 9.96 ?g/mL;the maximum scavenging rate to hydroxyl radical was 98.05%,IC50 value was 1.12mg/mL;total reducing power was increased with increasing the UFE concentration,indicating that UFE have a certain antioxidant activity in vitro.The maximum inhibition rate of UFE to ?-glucosidase was 59.06%,IC50 value was 31.59mg/mL,the maximum inhibition rate to a-amylase was 76.54%,IC50 value was 8.62mg/mL,and the inhibition rate was increased with increasing the UFE concentration,indicating that UFE have a certain hypoglycemic activity in vitro.(2)Study on hypoglycemic activity of Urtica fissa extract in T2DM miceA high-fat and high-sugar diet was combined with intraperitoneal injection of streptozotocin(STZ)75mg/Kg to construct a T2DM mouse model.The diet and water intake,body weight,and fasting blood glucose(FBG)were measured regularly.The results showed that compared with the control group,the mice in the model group had increased food and water intake and had decreased body weight.The FBG value was greater than 11.1mmoL/L,indicateing that the model was successfully constructed.Then the mice in the model group were divided into a model group(DM),a metformin group(Met),a UFE low-dose group(F-L),medium-dose group(F-M),and high-dose group(F-H).Each group of mice and the blank group(Con)Mice were administrated with corresponding drugs.Their diet and water intake,body weight and FBG values were measured regularly.After 5 weeks of continuous administration,the physiological and biochemical indicators were measured.The results of physiological indicators showed that compared with the DM group,the mice in the F-L,F-M,and F-H groups had decreased food and water intake,increased body weight,decreased FBG values,and had a dose-dependent relationship.The results of blood lipid content determination showed that:Compared with the F-L,F-M,and F-H group,the serum total cholesterol(TC),triglyceride(TG),and low density lipoprotein(LDL-C)contents of the mice was decreased,and the high density lipoprotein(HDL-C)contents was increased.The blood lipid improvement effect of the mice in the F-H group was better,and the content of TC,TG,LDL-C and HDL-C in the mice of F-H group was significantly different from DM group(P<0.05 or P<0.01);The results of serum transaminase activity measurement showed that:Compared with the DM group,the serum aspartate aminotransferase(AST)and alanine aminotransferase(ALT)activities of mice in the F-L,F-M,and F-H groups were decreased.The difference beteeen the F-M and DM groups in the serum aminotransferase activity was significantly different(P<0.05).The results of the oxidation index showed that compared with the DM group,the superoxide dismutase(SOD)activity and glutathione(GSH)content in the F-L,F-M,and F-H groups were increased,the content of malondialdehyde(MDA)was decreased,and the difference between the F-H group and the DM group in the oxidative indexes was significant(P<0.05 or P<0.01).The results of the calculation of the organ coefficients showed that compared with the DM group,UFE can improve liver and kidney enlargement in T2DM mice;Histomorphological observations showed that compared with the DM group,UFE have a certain improvement effect on hepatocellular enlargement and necrosis,glomerular atrophy,basement membrane deformation and islet atrophy in T2DM mice;In conclusion,it has been shown that UFE have certain hypoglycemic and lipid-lowering effects,it can reduce oxidative stress levels and aminotransferase activity in T2DM mice,and can repair liver,kidney and pancreas tissue damage in T2DM mice.(3)Study on the hypoglycemic mechanism of Urtica fissa extractBased on UPLC-Q-TOF-MS,the serum metabolites of mice in the Con,DM,Met,and F-H groups were analyzed,and the differences of the metabolites and the metabolic pathways in each group of mice were obtained.Partial least squares discriminant analysis(PLS-DA)results showed that there were a significant differences of serum metabolites in each group of mice,obtained 66 metabolic differences and 8 metabolic pathways.It is glycerophospholipid metabolism and ether lipid metabolism.It is suggested that UFE can improve glucose and lipid metabolism in diabetic mice.The levels of serum fasting insulin(FINS)in each group were measured,and the insulin secretion index(FBCI),insulin resistance index(IRI)and insulin sensitivity index(ISI)were calculated to determine whether the UFE could improve the insulin resistance of diabetic mice.The results showed that compared with DM group,the insulin resistance of mice in the F-L,F-M and F-H group was improved,and the effect of F-H group was the best(P<0.01).Furthermore,Western blot was used to detect the protein expression of adenylate-activated protein kinase(AMPK),phosphatidylinositol 3 kinase(PI-3K),and protein kinase B(AKT)in the liver of Con,DM,Met and F-H group.The results showed that compared with DM group,the AMPK,PI-3K and Akt protein expression in the F-H group was up-regulated.These results indicate that UFE can improve insulin resistance in T2DM mice,This may be due to UFE can regulate metabolic pathways such as glycerophospholipid.In conclusion,UFE can improve the glycolipid metabolism disorder of T2DM mice by regulating the metabolism of glycerophospholipids and ether lipids,and up regulate the expression of AMPK,PI3K and Akt protein to improve insulin resistance.According to the animal experiments in vivo,UFE has a certain degree of protective effect on organ damage in T2DM mice.At the same time,combined with the in vitro anti-oxidation experiment and the detection of oxidation indexes in vivo It was determined that the extract of Urtica fissa had antioxidant effect. |
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