| Gynura divaricata (L.) DC. is an important folk medicine. The leaf of Gynura divaricata is a commonly tea for reducing blood glucose. It could significantly decrease the blood glucose of diabetic patient.The experiment determined some validation sections of Gynura divaricata (L.) DC. that could reduce the blood glucose in the model animals. In the advanced study, 4g/kg of the 90% alcohol eluted fractionⅤand the n-butanol extract fraction F of Gynura medica reducing blood glucose were better than other.The chemical constituents of the plant were studied. Various modern chromatographic techniques, spectral methods as well as physical and chemical means were used to isolate and identify constituents from Gynura divaricata. 25 compounds were obtained. 23 were determined to be 1-O-β-D-glucopyranosyl-(2S,3S,4R,10Z)-2-[(2′R)-2′-hydroxylignocenoyl-amino]-10-octadecene- 1,3,4– triol ( 1 ),1-O-β-D-glucopyranosyl-(2S,3S,4R,10E)-2-[(2′R)-2′-hydroxyldocosanoyl -amino]-10-octadecene-1,3,4-trio(l2),kaempfero(l3),astragulin(4),nicotiflorin (5),kaempferol 3,7-O-di-β-D-glucopyranside(6),kaempferol 5-O-(6′′-O-acetyl)-β-D- glucoside (7),5-hydroxyl-4-hydroxymethyl-γ-butyrolactone (8),2-(1′, 2′, 3′, 4′-tetrahydroxybutyl)-6-(2′′, 3′′, 4′′-trihydroxybutyl)-pyrazine (9),2-(1′, 2′, 3′, 4′-tetrahydroxybutyl)-5-(2′′, 3′′, 4′′-trihydroxybutyl)-pyrazine (10),nicotinic acid (11),5-hydroxy-picolinic acid (12),methyl-5-hydroxy-2- pyridinecarboxylate (13),adenosine (14),uridine(15),β-sitosteryl glucoside- 6′-O-heptadecoicate(16),β-sitostero(l17),stigmastero(l18),daucostero(l19),stigmasterol-5-O-β-D-glucoside(20),dibutyl terephthalat(e21),methyl chlorogenat(e22),n-eicosan(e23). Among them, compound 1,2 was new compound. and 6,7,8,9,10,13,16,21,22 was obtained for the first time from Gynura genus,3, 4,11,12 was obtained for the first time from Gynura divaricata.RE-HPLC was used to determine the contents of kaempferol,astragulin and nicotiflorin in Gynura divaricata (L.) DC, the results show that the contents of three flavones in Gynura divaricata (L.) DC. Collected in september is highest. The extracting process was studied by single factor method and orthogonal method, The optimal extracting techniques: 60% ethanol by ultrasonic extracting at 60℃with material and solvent ratio 1:40 for 2 times. Total flavones of Gynura divaricata(FGD) were obtained using polyamide, with content of kaempferol,astragulin and nicotiflorin more than 70%.Male Sprague Dawley(SD) rats were fed with high fatty and high sugar diet for 4 weeks,then Streptozotocin(STZ) was injected intraperitioneally to m-ake rat model of T2DM.. The diabetic rats were randomly divided into six gr-oups:normal control group,diabetic model group,Glibenclamide group,Met-formin group,high dose of FGD and low dose of FGD. Blood glucose,TC,TG,blood serum insulin,SOD,MDA,NO and ET were detected after the rats given drugs for 4 weeks. The islands of Langerhans were dying with HE and immunohistochemistry to observate the beta cells of islands of Langerhans.The results showed that FGD has obvious glucose-lowering effect on T2DM rats. It can improve T2DM lipid peroxidation and hyperinsulinism ,and it can increase the level of SOD and reduce production of MDA in serum which were related to protecting the blood vessel endothelium injury and repairing the beta cells of T2DM islands of Langerhans. FGD has good effect for preventi-on and curing of T2DM. it also can protect the blood vessel endothelium inj-ury,The mechnism of hypoglycemic effect may relate to improve serum SOD,lipidperoxidation and hyperinsulinism that can repair the beta cells of T2DM islands of Langerhans.
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