Study Of The Protective Effects Of LIP On Diabetic Peripheral Neuropathy And Its Mechanisms

Objective:T2DM rats model was induced by high-fat diet and intraperitoneal injection of STZ.And then establish DPN rats model,carrying out LIP to investigate the protective effects of LIP on peripheral nerve function and its mechanisms in DPN rats.Further,apply LIP to DPN patients in clinical,observing the effect of LIP on peripheral nerve function in DPN patients.Method:Fifty male SD rats were randomly divided into normal control group（8rats feed with normal diet）and experimental group which were fed by high-fat-diet for 4 weeks and then peritoneal injection of streptozotocin(STZ,35mg?kg^-1)to induce T2DM rats.After the success of the modeling,wait for 4weeks,and using Electric Von Frey to measure pain threshold of rats.If the pain threshold value decreased,which indicated that the DPN model was successfully established.Then,the model rats were randomly subdivided into DPN model group,positive control group(mecobalamin,175ug?kg^-1),LIP group and LIP+mecobalamin group,8 rats in each group.Rats were intramuscular injection administered once daily for 4 weeks.After trreatment for 4 weeks:（1）Weigh the weight;measure mechanical pain threshold、hot plate pain reaction time、sciatic nerve conduction velocity;detect FBG with glucose oxidase method;detect of sciatic nerve tissue with Nissl staining method;（2）detect SOD with hydroxylamine method;detect MDA with thiobarbituric acid method;detect Bcl-2、Caspase-3mRNA of sciatic nerve tissue with Real-Time PCR method;detect Bcl-2、Caspase-3 protein of sciatic nerve tissue with immunohistochemical method.There are 60 patients with DPN were selected from the department of endocrinology in the second people’s hospital of guangdong province from October 2017 to March 2018.They were randomly divided into two groups:the experimental group（methycobal+LIP）and the control group（methycobal）,and there are 30 cases in each group.Two groups of DPN patients were treated with conventional treatment and the relevant health education,and on this basis,the experimental group（methycobal+LIP）give 20 ml 0.9%sodium chloride solution,methycobal（trade name:mecobalamin,be made in Eisai Co Ltd）500 ug,1 time/day,intravenous injection,while giving LIP:carrying out noninvasive limb ischemic preconditioning on the patient’s upper arm through using sphygmomanometer cuff,untial the radial artery pulse is disappearing（pulse sensors）5 min,then deflated 5 min reperfusion,thinking the reproduce of radial artery pulse as a symbol of reperfusion,keep the cycle going 5 times,7 days as a period of treatment.Control group（use methycobal）give 20 ml0.9%sodium chloride solution,methycobal 500 ug,1 time/day,intravenous injection,7 days as a period of treatment.Results:1.Compared with the model group,the levels of mechanical pain threshold,nerve conduction velocity increased significantly（P<0.05,P<0.05）,the hot plate pain reaction time decreased significantly（P<0.05）in the LIP and experimental group（methycobal+LIP）,there are statistically difference significantly.The body weight and FBG changed slightly（P>0.05）.There are no statistically difference.2.Compared with the model group,the levels of SOD and Bcl-2 mRNA increased significantly（P<0.05,P<0.05）in the LIP and experimental group（methycobal+LIP）.The levels of MDA and Caspase-3 mRNA decreased significantly（P<0.05）in the LIP and experimental group（methycobal+LIP）,there are statistically difference significantly.3.Compared with the control group（use methycobal）,DPN patients’clinical symptoms and VPT threshold significantly improved（P<0.05）in experimental group（methycobal+LIP）,there are statistically difference significantly.Conclusion:1.LIP could improve symptoms of diabetic peripherial neuropathy（DPN）rats.2.LIP could improve DPN patients’symptoms and vibration perception threshold in clinical.3.The effect of LIP on improving peripherial neuropathy function is associated with the inhibition of oxidative stress.