ABSTRACT
Objective To explore the pharmacodynamic action of the extract from raw materials of Rhizoma Anemarrhenae and Cortex Phellode ndri, a classic herb pair in traditional Chinese medicine, on mice with diabetic peripheral neuropathy(DNP). Methods The mice were administrated with intraperitoneal injection of streptozotocin (STZ, 30 mg/kg) and fed with high-fat diet to establish the DNP mouse model. One hundred and sixty male C57BL/6j mice were divided into normal group, model group, metfomin group(130 mg/kg), Xuezhikang group(200 mg/kg), high- and low-dose Rhizoma Anemarrhenae extract group(360, 90 mg/kg) , high-and low-dose Cortex Phellodendri extract group(135, 45 mg/kg), 20 mice in each group. The medication lasted for 24 weeks. On medication week 8, 16 and 24, the plasma levels of glucose (GLU), total cholesterol (TC), triglyceride(TG), low density lipoprotein-cholesterol(LDL-C) and insulin(INS) were determined respectively. On medication week 10, oral glucose tolerance test(OGTT)was carried out. On medication week 24, the plasma nuclear factor kappa B(NF-κB) activity and the plasma levels of transforming growth factor-beta 1(TGF-β1), superoxide dismutase(SOD) and reduced glutathione(GSH) were detected. Results Five weeks after injection of STZ, the body mass of the model group was firstly increased and then decreased, and FBG was increased(P<0.05 compared with the normal group). Compared with the normal group, FBG, TC, TG, LDL-C and INS levels were increased(P<0.01 or P<0.001), plasma NF-κB activity, TGF-β1 and SOD levels were enhanced, and GSH level was decreased in the model group, the difference being statistically significant (P<0.01 or P<0.001). Contrasted with the model group, FBG, TC, TG, LDL-C and INS levels in high-and low-dose Rhizoma Anemarrhenae extract group and in high-and low-dose Cortex Phellodendri extract group were decreased to various degrees. After continuous medication, plasma NF-κB activity and TGF-β1 and SOD levels in high-dose Rhizoma Anemarrhenae extract group and in high-dose Cortex Phellodendri extract group were reduced(P<0.05 or P<0.001), and plasma GSH level was increased(P<0.01). Conclusion Extract from raw materials of Rhizoma Anemarrhenae and Cortex Phellodendri has obvious hypoglycemic effect and protective effect on experimental mice with DPN.