Establishment of LC-MS/MS method for determination of aloperine in rat plasma and its application in preclinical pharmacokinetics

Aloperine, a novel natural active alkaloid derived from Sophora alopecuroides L., has attracted much attention for its anti-inflammatory, antiviral, anti-tumor, anti-allergy and other pharmacological activities. In this study, we first established and validated an efficient and sensitive high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of aloperine in rat plasma. Cytisine was used as the internal standard (IS). The separation of aloperine and IS was conducted on a Phenomenex Luna Omega Polar C18 column (2.1 x 50 mm, 1.6 mu m) with 0.3% (v/v) formic acid aqueous (containing 5 mM ammonium acetate) and 0.3% (v/v) formic acid acetonitrile using isocratic elution condition at a flow rate of 0.20 mL/min. Aloperine and IS were determined under the transitions of m/z 233.2 -* 98.1 and m/z 191.2 -* 148.2 (positive ionization mode), respectively. The calibration curve of aloperine was established in the range of 5 (LLOQ) to 2000 ng/mL (r2 = 0.994). The well validated method was full compliance with the bioanalytical method validation of FDA, and was applied to the pharmacokinetic study of aloperine in Sprague-Dawley rats after 50 mg/kg oral administration and 5 mg/kg intravenous injection. This study provides valuable references for the further study of Sophora alopecuroides L., especially for the drug development and clinical application of aloperine.

Automated summary

This study established an efficient and sensitive method for quantifying aloperine in rat plasma, and conducted pharmacokinetic studies in Sprague-Dawley rats. The method was validated in compliance with FDA bioanalytical method validation guidelines.