Hypoglycemic effects and mechanisms of action of Cortex Lycii Radicis on alloxan-induced diabetic mice

Abstract

Cortex Lycii Radicis (CLR) has been used as a traditional Oriental medicine as an antipyretic and to treat pneumonia, night-sweats, cough, hematemesis, inflammation, and diabetes mellitus for centuries. This study aimed to determine the effects of CLR on alloxan-induced diabetic mice and its mechanisms. Based on thin-layer chromatography (TLC) assay, the main compounds of CLR include an organic acid, flavone, alkaloid, polysaccharide, anthraquinone, and saponin. The mice were divided into four groups: normal control (NC), diabetes control (DC), diabetes + high-dose CLR (200 mg kg-1), and diabetes?+ low-dose CLR (100 mg kg-1). The diabetic mice were administered CLR daily for 28 days. The CLR treatment resulted in significant decreases in fasting blood glucose, total cholesterol, and triglycerides. CLR also showed a tendency to improve body weight gain in diabetic mice. Furthermore, the serum insulin level of each group was assayed, and the DC group had a lower serum insulin level than the NC group. Insulin levels were dose dependently raised in the CLR-treated groups compared with the DC group. According to single-cell gel electrophoresis and LD50 analysis, CLR was nontoxic to the animals. The results indicate that CLR alleviates the blood glucose and lipid increases associated with diabetes and improves the abnormal glucose metabolism and increases insulin secretion by restoring impaired pancrease βcells in alloxan-induced diabetic mice. The results suggest that CLR has hypoglycemic potential and could be useful in diabetes therapy. © 2007 The Pharmaceutical Society of Japan.