Jiao-Tai-Wan (JTW), a classical Chinese prescription, has been clinically employed to treat diabetes mellitus in recent years. To investigate the comparative evaluations on anti-diabetic effects and pharmacokinetics of the active ingredient berberine in mice treated with JTW in various combinations of its constituent herbs. In our study, the anti-diabetic study was carried out in diabetic mice induced by intraperitoneal injection of streptozotocin. The diabetic mice were randomly assigned to three therapy groups and orally administered with different prescription proportions of Rhizoma Coptidis and Cinnamomum cassia respectively. The level of plasma glucose, lipid profile and parameters related to oxidative stress were determined. The concentrations of berberine in non-diabetic mice plasma were determined using HPLC, and main pharmacokinetic parameters were investigated. The results indicated that the compatibility effects of ingredients present in Cinnamomum cassia could affect the anti-diabetic ability and pharmacokinetics of berberine in JTW. (C) 2013 Elsevier GmbH. All rights reserved.