Abstract: The aim of this study was to clarify whether Toona sinensis seed (TS) extracts were therapeutic agents against diabetic peripheral neuropathy (DPN). Four polar fractions were separated from TS ethanol extracts,after that their antioxidant activities were investigated in vitro. Male Wistar rats were used to induce DPN model and DPN related indicators were detected. The results showed that the extracts exhibited favorable antioxidant activity against DPPH radical and lipid peroxidation. After treating with TS extracts,general features of DPN rats were improved,the blood glucose levels and MDA contents in sciatic nerve were decreased,the serum NGF-β contents,SOD and GSH-PX activities were increased and the sciatic nerve conduction velocity was recovered significantly (P<0.05). This study indicated that TS extracts can alleviate DPN through inhibiting oxidative stress and up-regulating NGF-β and among the four extracts,the n-butyl alcohol extract showed the best effect.

Key words: Toona sinensis, diabetes mellitus, DPN, oxidative stress, nerve growth factor