Study on the Analgesic Effect and Mechanism of Buyang Huanwu Decoction on Diabetic Peripheral Neuropathy Rats / 广州中医药大学学报

ABSTRACT

Objective To investigate the analgesic effect and mechanism of Buyang Huanwu Decoction on diabetic peripheral neuropathy(DPN)rats.Methods Sixty rats were divided into normal group,model group,low-,medium-and high-dose groups of Chinese medicine,and high-dose + H-89[protein kinase A(PKA)inhibitor]group,with 10 rats in each group.Except for the normal group,rats in all other groups were fed with high-fat and high-sugar chow combined with intraperitoneal injection of streptozotocin(STZ)method to construct DPN model.At the end of drug administration,the foot thermal pain threshold of rats was detected,the motor nerve conduction velocity(MNCV)and sensory nerve conduction velocity(SNCV)of rats was measured,the intraepidermal nerve fiber(IENF)in the epidermis was observed by immunohistochemistry,and serum fasting insulin(FINS),total cholesterol(TC),triglyceride(TG),low-density lipoprotein cholesterol(LDL-C),high-density lipoprotein cholesterol(HDL-C),insulin resistance index(HOMA-IR),and the interleukin(IL)-1β,IL-6,tumor necrosis factor α(TNF-α),vascular endothelial growth factor(VEGF),angiopoietin 1(Ang-1),CD34 levels,cyclic adenosine monophosphate(cAMP)concentration in the sciatic nerve tissues were detected by enzyme-linked immunosorbent assay(ELISA),and Western Blot assay to detect the PKA and the carbohydrate responsive element binding(CREB)in the sciatic nerve tissues.Results Compared with the normal group,foot thermal pain threshold,TC,TG,LDL-C,HOMA-IR,IL-1β,IL-6 and TNF-α levels were significantly increased in the model group(P＜0.05),HDL-C,FINS,VEGF,Ang-1,CD34,IENF,MNCV and SNCV values,cAMP concentration levels,PKA and CREB phosphorylation levels were significantly reduced(P＜0.05).Compared with the model group,the above indexes were significantly improved in the low-,medium-and high-dose groups of Chinese medicine(P＜0.05)in a dose-dependent manner.Compared with the Chinese medicine high-dose + H-89 group,all the indexes were reversed in the Chinese medicine high-dose group.Conclusion Buyang Huanwu Decoction can improve insulin resistance and lipid metabolism,reduce limb pain,improve local microcirculation disorder,and protect nerve function in DPN rats,which reflects the therapeutic characteristics of"activating blood circulation and relieving pain".The pain-relieving effect of Buyang Huanwu Decoction may be related to the improvement of local microcirculation,inhibition of inflammatory factor release and regulation of cAMP/PKA/CREB signaling pathway protein expression.