Hypoglycemic Effects And Its Mechanism Of Cactus Pear In Diabetic Mice

Objective To investigate the hypoglycemic effects of cactus pear and it's polysaccharides in diabetic mice induced by streptozotocin(STZ),and investigate its action mechanism.Methods Cut off the thorn of cactus pear and squeezed by juice squeezer were cactus pear juice(CPJ).It's juice were extracted with water were water-extracted.It's juice were extracted with 99.9% ethanol were ethanol-extracted.It's juice were water-extracted and alcohol-Precipitated and then concentracted respectively were cactus pear polysaccharide(CPP).Their main components were analyzied by chemical method.The hypoglycemic effects of CPJ,water-extracted,ethanol-extracted and CPP were evaluated in diabetic mice induced by STZ.The experimental mice were randomly divided into 7 groups:control group,model group,gli group(75mg.kg^-1·d^-1),CPJ(1.40g·kg^-1·d^-1),water-extracted(1.44g·kg^-1·d^-1), ethanol- extracted(1.44g·kg^-1·d^-1),cactus juice(1.20g·kg^-1·d^-1).The drug were administrated to mice in every morning for 15 days.The experimental rats were. randomly divided into 6 groups:control group,model group,insulin group(10U·kg(-1)·d^-1),CPJ(1.40g·kg^-1·d^-1),middle dosage group of CPP(1.58 g·kg^-1·d^-1),high dosage group of CPP(2.37g.kg^-1.d^-1).The drug were administrated to rats in every morning for 8 weeks.During the experiment, comsumptions of food and water,body weight,feces and urine,death were observed and recorded.In the corresponding time,the contents of FBG and GHB of rats were determined.The insulin receptor(ISR)in liver and skeletal muscle of experimental rats and the glucose transporter 4(Glu T4)mRNA in skeletal muscle of experimental rats were analyzied by RT-PCR half quantitative analysis.The pathology ofβcell and a cell in pancreas of experimental rats were observed by immunochistochemistry.The cardiac muscle of rats were obtained and MDA,SOD activity were determined,and ultra-structure of cardiac muscle were observed by transmission electron microscope.Results After 15 days of the treatments with drugs,CPJ,water-extracted,ethanolextracted and cactus juice could markedly decrease blood glucose in STZ-induced diabetic mice.The hypoglycemic rate of CPJ,water-extracted and cactus juice were higher than ethanol- extracted.After 8 weeks of the treatments with drugs,CPJ,middle dosage group of CPP and high dosage group of CPP could markedly decrease blood glucose in STZ - induced diabetic rats,meanwhile markedly decreased GHB,protected and increasedβcells in pancreas,increased insulin receptor in liver and skeletal muscle,increased glucose transporter 4 in muscle,improved insulin resist,reduced the content of MDA and increased the activity of SOD in cardiac muscle,protected the damaged cells of cardiac muscle and improved diabetic cardiopathy.Conclusion cactus pear and water-extracted can markedly decrease blood glucose in STZ-induced diabetic mice.cactus pear and CPP can markedly decrease blood glucose in STZ-induced diabetic rats,increaseβcells,increase insulin receptor and GLU T4,protect damaged cells of cardiac muscle,markedly improve the condition of STZ-induced diabetic rats.After all,cactus pear and it's polysaccharide have a very potential value in the treatment of diabetes and preventment of diabetic cardiopathy.The action mechanism are related to the increasement ofβcells,IRand GLU T4.