| Sedum aizoon L.belongs to the genus Sedum,which is a perennial herb with both medicinal and edible functions.Diabetes is already the world’s third"silent killer"after cancer and cardiovascular disease.China is a big country with diabetes.Studies have shown that flavonoids with antioxidant and free radical scavenging activities can treat pancreaticβ-cell dysfunction and inhibit lipid peroxidation.In this study,Sedum aizoon L.were used as raw material,and the optimal extraction conditions of total flavonoids from Sedum aizoon L.were obtained by response surface methodology.Using Vitamin C as a positive control,DPPH·,·OH,total antioxidant capacity,reducing power,ABTS~+·scavenging rate test and total antioxidant capacity and reducing power determination,analysis of its antioxidant activity.Subsequently,animal experiments were carried out.The STZ-induced I diabetes model C57BL/6 mice were given an oral administration test for 7 consecutive weeks,The biochemical indicators like total cholesterol(TC),triglyceride(TG),glycosylated hemoglobin(GHb),malondialdehyde(MDA),total superoxide dismutase(T-SOD),glutathione(GSH)and catalase(CAT)were measured.Hematoxylin-eosin staining to observe the liver tissue lesions.The expression of nuclear factor erythroid 2-related factor(Nrf2),kelch ECH associated protein 1(Keap1),heme oxygenase-1(HO-1)and NADH quinone oxidoreductase 1(NQO1)were determined by western blotting level.1.The results showed that after optimization of response surface methodology,the optimal extraction conditions were as follows:ethanol concentration 91%,liquid to solid 47:1 m L/g,extraction temperature 78℃,extraction time 3.55 h,the total flavonoid content of Sedum aizoon L.under this process condition was 25.03±0.08 mg/g.2.The total flavonoids of Sedum aizoon L.showed the scavenging ability to DPPH·,ABTS~+·and hydroxyl radicals,and also had better reducing ability,but were weaker than Vc.3.Compared with the blank group,the total flavonoids of Sedum aizoon L.significantly alleviated the symptoms of"three more and one less"in type 1 diabetic mice.In terms of blood lipids,the total flavonoids of Sedum aizoon L.can effectively reduce the contents of TC,TG and GHb in diabetic mice(P<0.05).At the same time,the intervention of total flavonoids of Sedum aizoon L.can increase the content of antioxidant stress related indicators T-SOD,GSH,CAT(P<0.05),reduce the content of MDA(P<0.05),and reduce the production of free radicals in the body,thereby enhancing the body’s antioxidant capacity ability.4.The results of HE staining showed that the cell boundaries in the liver tissue of the mice in the diabetes model group were unclear,some nuclei atrophied or dissolved and disappeared,and the liver was damaged.After the intervention of total flavonoids from Sedum aizoon L.,there was a small amount of granular degeneration in the liver tissue,the liver cords were arranged neatly,and the liver damage was alleviated.5.The results of western blot experiments showed that the total flavonoids of Sedum aizoon L.up-regulated the expression of Nrf2 protein and down-regulated the protein expression of its negative regulator Keap1.Thereby regulating the downstream targets of Nrf2,HO-1 and NQO1,and increasing their protein expression.Thereby maintaining the homeostasis of the body’s internal environment,reducing the oxidative stress of the body caused by diabetes,thereby relieving the symptoms of diabetes.The results of this article provide a theoretical reference for Sedum aizoon L.’s application in assisting the development of blood sugar-lowering functional foods and the oxidative stress of Sedum aizoon L.for improving diabetes. |
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