Effects of HuangKui capsules on glibenclamide pharmacokinetics in rats

Ethnopharmacology: The main components of HuangKui capsules' are the total flavonoids extracted from the flowers of Abelmoschus manihot L medic. They have been widely used to treat chronic glomerulonephritis, diabetic nephropathy and nephrotic syndrome. The combination of HuangKui capsules and glibenclamide is a possible therapy for patients with diabetes mellitus and diabetic nephropathy. However, there is no report about effects of HuangKui capsules on the glibenclamide pharmacokinetics till now. Aim of the study: This study was aimed investigating the effect of HuangKui capsules on pharmacokinetics of glibenclamide in rats. Material and methods: Eight rats were administered with an oral dose of HuangKui capsules (0.75 g kg(-1)) once daily for 10 consecutive days. All the rats were administered orally with the glibenclamide (1 mg kg(-1)) before the first time and after the last time given HuangKui capsules. LC-MS/MS was utilized to determine the concentration of glibenclamide in rat plasma and to calculate the corresponding pharmacokinetic parameters. The statistical differences of the two cycles were evaluated by paired-samples t-test. Results: In the rats treated with HuangKui capsules and glibenclamide, the t(1/2), the time point of maximum plasma concentration (T-max) of glibenclamide increased obviously (p < 0.05) compared with the glibenclamide alone, while maximum plasma concentrations (C-max), area under the plasma concentration-time curve (AUC((0-t)) decreased significantly (p < 0.05). There was no significant difference between other parameters. Conclusion: HuangKui capsules can reduce the absorption of glibenclamide and accelerate the metabolism of glibenclamide. (C) 2011 Elsevier Ireland Ltd. All rights reserved.