Determination of extracellular hesperidin in blood and bile of anaesthetized rats by microdialysis with high-performance liquid chromatography: a pharmacokinetic application.

A method coupled with microdialysis technique and liquid chromatography was applied in the continuous and concurrent in vivo monitoring of extracellular hesperidin in the blood and bile of anaesthetized rats. Hesperidin was intravenously administered via the femoral vein. Sampling was achieved using two microdialysis probes, which were implanted into the jugular vein and into the bile duct. Dialysates of blood and bile were both directly injected onto the liquid chromatographic system, so no further clean-up procedures were required. Separation was performed using a reversed phase ODS-2 microbore column 150 mm x 1 mm i.d., particle size 5 microm with mobile phase of acetonitrile-0.1M ammonium acetate (30:70, v/v) at flow-rate of 0.05 ml/min. The UV detection for hesperidin was set at a wavelength of 283 nm. This method was used to determine the pharmacokinetics of hesperidin and its interaction in the presence of cyclosporin A, which is a P-glycoprotein modulator. The results indicate that the curve of area under the concentration versus time (AUC) for hesperidin in bile was significantly greater than that for hesperidin in blood at the dose of 30 mg/kg. The blood-to-bile distribution ratio (k = AUC(bile)/AUC(blood)) was 8.9 +/- 2.5 for hesperidin at 30 mg/kg. Following cyclosporin A treatment, the distribution ratio was reduced to 3.2 +/- 0.6. In conclusion, hesperidin goes through hepatobiliary elimination against the concentration gradient from blood to bile, and this hepatobiliary excretion of hesperidin may be regulated by the P-glycoprotein.