Inhibition Effects And Separation Of SCP50 On Carbohydrase Enzymes In The Rat Small Intestine

The polysaccharides were extracted from sweet corncobs and purified by DEAE-52 cellulose and Sephadex G-100.The purified polysaccharides were identified by purity,molecular weight and monosaccharide composition.The inhibitory of ?-glucosidase and ?-amylase from sweet corncobs polysaccharides,and inhibition of sucrase and ?-amylase in the rat small intestine of SCP50.Diabetic rat model was established and rats were fasted for 12h after 7?14?21 and 28 days by gavage.The body weight and blood glucose of rats were measured,and the rat pancreatic tail sections were observed by light microscopy islet tissue with HE staining.At the same time,the activities of disaccharidase in duodenum,intestinum jejunum and ileum in each group diabetic rats were measured.The following conclusions were obtained:Extraction of sweet corncob polysaccharides by hot water extraction,Sevage deproteinization,macroporous resin decolorization.According to the different components of polysaccharides and the difference of molecular weight,a component was obtained by gradient elution on DEAE-52 cellulose column,distilled water and NaCl solution.The recovery rate was 35.01%.This fraction was chromatographed on a Sephadex G-100 column to give a homogeneous fraction designated as SCP50 with a recovery of 55.31%.UV absorption spectroscopy,indicating SCP50 does not or contain a small amount of nucleic acids,proteins and other impurity components.Infrared absorption spectroscopy showed that there was ?-glycosidic bond in SCP50.The gas chromatogram and high performance liquid chromatography analysis showed that the molecular weight of SCP50 was 9280.325Da,which was a heteropolysaccharide composed of mannose and glucose.Enzyme inhibition kinetics studies showed that SCP50 showed a strong inhibitory activity on ?-glucosidase and ?-amylase with IC50 of 4.866mg/mL and 5.129mg/mL,respectively,and the inhibition rate of enzyme with the concentration of polysaccharide.SCP50 is a typical rice enzyme,the type of inhibition of ?-glucosidase and ?-amylase reversibly inhibited the competition for high activity competition,Km values were 1.297 × 10-3 and 0.669,respectively,Vmax 0.0759 and 0.1437mol/L·min-1.In vivo experiments showed that SCP50 had certain inhibitory effects on sucrase and?-amylase in the intestine of rats,with IC50 of 5.413 and 27.263 mg/mL,respectively.Animal experiments showed that SCP50(50,100,200mg/kg·d-1)could improve the weight loss and blood sugar level of STZ-induced diabetic rats and effectively alleviate the symptoms of diabetes.HE staining,according to STZ-induced pancreas histopathological analysis speculated that SCP50 on rat ? cells were significantly repaired.The results showed that SCP50 had inhibitory effect on maltase,sucrase and lactase in the duodenum,jejunum and ileum of diabetic rats.