OBJECTIVETo investigate the effects of Zhenqing Capsule (ZQC), a compound traditional Chinese herbal medicine, in treating type 1 diabetic rats with peripheral neuropathy.METHODSType 1 diabetes was induced by caudal vein injection of high-dose streptozotocin in 30 male Wistar rats. The thirty diabetic rats were randomly divided into three groups: ZQC-treated group, untreated group and aminoguanidine-treated group. Another group of 10 rats was taken as normal control. After 10-week treatment, the changes of body weight and fasting plasma glucose level were measured, and the serum MDA level and the changes of neurological electrophysiology were analyzed. The samples of sciatic nerve in diabetic rats were taken for morphological observation.RESULTSThe MDA level in type 1 diabetic rats was notably reduced in ZQC-treated group as compared with the untreated group (P<0.01). Compared with the untreated group, ZQC could improve the electrophysiology of sciatic nerve including conduction velocity (P<0.05), latency (P<0.01) and wave amplitude (P<0.05). The nerve myelin staining results showed that segmental demyelination of the nerve fibers in ZQC-treated group was not as serious as that in the untreated group.CONCLUSIONZQC can obviously ameliorate the neurological electrophysiological function and the pathological changes of peripheral nerve in type 1 diabetic rats through the removal of free radical and resistance of lipid peroxidation.