Effect of Xin-Gui Gel Plaster on Peripheral Neuropathy in Diabetic Rats / 中药新药与临床药理

ABSTRACT

Objective To observe the effects of Xin-Gui Gel Plaster(Cinnamomi Cortex,Asari Radix et Rhizoma,Euodiae Fructus,Chuanxiong Rhizoma,Borneolum Syntheticum)on peripheral neuropathy in diabetic rats.Methods A single intraperitoneal injection of 1%streptozotonic(STZ,35 mg·kg-1)was used to replicate a type 2 diabetes mellitus(T2DM)rat model followed by the induction of diabetic peripheral neuropathy(DPN)in combination with a long-term(8 consecutive weeks)high-fat and high-sugar diet.SD rats were randomly divided into normal group,model group,Mecobalamin group and Xin-Gui Gel Plaster group,with 6 rats in each group.The rats in the Xin-Gui Gel Plaster group were given Xin-Gui Gel Plaster at acupoints once a day for 8 weeks;the rats in the Mecobalamin group were given Mecobalamin solution by gavage(0.045 mg·kg-1),and the rats in the normal group and the model group were given physiological saline by gavage.Body mass and fasting blood glucose(FBG)were measured at weeks 2,4,6 and 8;the latency of thermal withdrawal latency(TWL)was measured at weeks 4 and 8;nerve conduction velocities,including motor nerve conduction velocity(MNCV)and sensory nerve conduction velocity(SNCV),were measured at week 8;and serum total cholesterol(TC),triglyceride(TG),fasting blood glucose(FBG)were measured using a fully automated biochemical analyzer.Fasting insulin(FINS)levels were detected by ELISA,and the index of insulin resistance(HOMA-IR)was calculated;and pathological changes in the sciatic nerve tissues of rats were observed by HE staining.Results Compared with the normal group,rats in the model group had significantly lower body mass and FINS levels(P＜0.01),significantly higher levels of FBG,TC,TG and HOMA-IR(P＜0.05,P＜0.01);TWL,MNCV and SNCV were significantly decreased(P＜0.01),and sciatic nerve fibres were disorganized and loosely aligned,with demyelination,axon atrophy and vacuole-like phenomenon.Compared with the model group,there was no significant change in body mass and levels of FBG,TC and TG in the Xin-Gui Gel Plaster group(P＞0.05),FINS level was significantly increased(P＜0.05),and HOMA-IR levels was significantly decreased(P＜0.05);TWL,MNCV and SNCV in the Mecobalamin group and Xin-Gui Gel Plaster group were significantly increased(P＜0.05,P＜0.01),sciatic nerve lesions were improved to different degrees,nerve fibre arrangement was more regular,myelin deficiency and axonal atrophy were significantly improved.Conclusion Xin-Gui Gel Plaster can improve insulin resistance,relieve thermal stimulation sensitivity,improve sciatic nerve conduction velocity to a certain extent in DPN rats,and have a protective effect on peripheral nerves in diabetic rats,but the hypoglycemic and hypolipidemic effects are not obvious.