The Chemical Composition Of National Drug Malabar Spinach And Hypoglycemic Effect

Herba Gynurae Cusimbuae is a herb of Gynura cusimbua (D.Don)S.Moore. G. cusimbua was applied to fracture, injuries and rheumatoid arthritis in the Yi and Lahu Nationality Traditional Medicines in China.Ethnobotanical studies of medicinal plants in genus Gynura (Family:Asteraceae), is widely used in fracture, injuries and rheumatoid arthritis,at the same time,many herbal extracts as antidiabetic agents,such as G. bicolor,G. divaricata,G. fomosana,G. japonica,G. medica,G. procumbens. In this study was firstly to evaluate the antidiabetic activity and secondly to identify the active components of G. cusimbua.1. The volatile oil and fat-soluble components were extracted by the method of hydrodistillation and Soxlet extraction,analyzed volatile oil and fat-soluble components by GC-MS.47and20kinds of volatile oil and fat-soluble components were identified of G. cusimbua. G. cusimbua volatile oil mainly composed of ylangene (7.30%)、 δ-cadinene (6.85%)、caryophyllene oxide (5.90%) and1,5,9-trimethyl-12-(1-me-thyle-thyl)-4,8,13-cyclotetradecatriene-1,3-diol (5.83%), et al.G. cusimbua fat-soluble components mainly composed of8,11-octadecadienoic acid,methyl ester (16.09%)、 hexadecanoic acid,methyl ester (12.15%)、eicosanoic acid,methyl ester (7.06%) and linolenic acid methyl ester (7.00%), et al.2. Establish and optimize a-glucosidase inhibitory activity screening model was based on PNPG as substrate.The partitioned extracts were subjected to a-glucosidase inhibition assay of G. cusimbua. The same method was used to calculate the50%inhibition of enzymatic activity (IC50),if inhibitory rates more than50%at1mg/mL. Ethyl acetate extracts as a a-glucosidase activity in vitro with an IC50of0.532mg/mL,less than0.635mg/mL of acarbose.Ethyl acetate extracts may have hypoglycemic effects viamechanisms of a-glucosidase inhibition.3. The postprandial blood glucose levels were monitored at120min when the normal mice were administered gavage with ethyl acetate extracts for4days.As in vivo results, ethyl acetate extracts (300and600mg/kg) significantly decreased fasting serumglucose (p<0.01), ethyl acetate extracts (600mg/kg) suppressed the increase of blood glucose levels after2g/kg glucose loading in normal mice at30min and60min (p<0.01).Ethyl acetate extracts may have hypoglycemic effects viamechanisms of a-glucosidase inhibition, and thus improves postprandial hyperglycemia.4. Preparation scheme of the constituents of ethyl acetate extracts by AB-8Macroporous Resin.Many constituents (Y1、Y2、Y3and Y4) were subjected to a-glucosidase inhibition assay. The same method was used to calculate the50%inhibition of enzymatic activity (IC50),if inhibitory rates more than50%at1mg/mL. Y3constituents of ethyl acetated extracts as a a-glucosidase activity in vitro with an IC50of0.125mg/mL,less than0.635mg/mL of acarbose.Y3constituents of ethyl acetated extracts may have hypoglycemic effects viamechanisms of a-glucosidase inhibition. Y3constituents were active components of ethyl acetated extracts were characterized by HPLC.HPLC chemical characterization results show that the main components have four kinds of chemical components of Y3constituents.Conclusions:Ethyl acetate extracts form G. cusimbua may have hypoglycemic effects viamechanisms of a-glucosidase inhibition, and thus improves postprandial hyperglycemia.Especially, Y3constituents of ethyl acetated extracts may have hypoglycemic effects viamechanisms of a-glucosidase inhibition.