Protective Effects Of GSPE On Diabetic Peripheral Neuropathy Of Diabetic Rats

Objective To study the protective effects of GSPE on the function and structure of the sciatic nerve of the STZ induced diabetic rats.Method 75 male Wistar rats were randomly divided into normal control group(n=15),modle group(n=20),GSPEL-treated group(50mg/100g/d,n=20) and GSPES-group(25mg/100g/d,n=20).After 12 hours of fasting, 1%STZ was injected peritoneally or from the tail vain into the model,GSPEL and GSPES groups to establish the experimental diabetes.Those whose glucose level of the tail vein blood were above 16.7mmol/L 72 hours after STZ injected were considered valid diabetes.The rats were given standard feeding 24 weeks.Mechanical algesia threshold of each rat was measured using Voy Frey filaments. All the rats were killed at the end of 24 weeks and various parameters were measured as follows:the conductive speed and action potential of the sciatic nerve using BL-310 system ;the morphorlogy study under light microscope and transmission electron microscope;and the serum malondialdehyde (MDA) level by chromatometry. Results (1)Compared with the modle group,GSPE has no significant amelioration in body weight and blood glucose level (P>0.05).(2)Compared with the normal control group,the rat's sciatic nerve conductive velocity significantly decrease in all the other three groups (P＜0.01), while the difference among modle groupe,GSPEL-group and GSPES-group is significant,too (P<0.01).There is no apparent difference between GSPEL and GSPES-group.It is the same with the action potential of the sciatic nerve. (3)The diabetic rats appear hyperalgia compared with the normal contral group (P<0.01), GSPE treatment both 50mg/100g and 25mg/100g could alleviate this abnormality. (P<0.01,P<0.05)(4)All the diabetic rats' sciatic nerves had obvious injury when observed under light microscope and transmission electron microscope,but those in GSPEL and GSPES were much better.(5)The average serum MDA level of the model group is much higher than that of the normal control group (P<0.01),although above the normal level, the MDA levels of GSPEL-group and GSPES group are better compaired with that of the model group ( P<0.01 ) ,no significant difference between those two treated groups(P>0.05).Conclusion Grape seed proanthocyanidin extract has no effect on blood glucose level of STZ induced diabetic rats,but can significantly inhibit their oxidative stress level and can alleviates the diabetic peripheral neuropathy apparently.