Pharmacokinetics Study and Simultaneous Quantification of Eight Schisandra Lignans in Normal Rats by LC-MS/MS after Oral Administration of Schisandra Lignan Extract

Background: Schisandra chinensis has been widely used. It has many pharmacological activities. Lignans, including schizandrol A, schizandrin A, schisandrin B, schisanhenol, gomisin E, gomisin H, gomisin J, gomisin N, etc., are the major active ingredients of Schisandra chinensis. Objective: In the present study, the liquid chromatography-tandem mass spectrometric (LCMS/ MS) method was developed for the simultaneous quantification of Schisandra lignans in normal rats. Methods: Nifedipine was used as an internal standard, and chromatographic separation was achieved on Agela Venusil C18 Plus (4.6*100 mm, 3μm). Aqueous solution containing 0.1% (v/v) formic acid was used as the mobile phase A, and methanol solution containing 0.1% (v/v) formic acid was used as the mobile phase B for gradient elution. The flow rate was 0.8 mL/min. Multiple reaction monitoring (MRM) mode with positive electrospray ionization was used to detect the analytes. Results: The calibration curves provided reliable responses at concentrations of 0.5-200 ng/ml for schizandrin A, schisandrin B, schisanhenol, gomisin E, gomisin H, gomisin N, concentrations of 10-200 ng/ml for schizandrol A, and concentrations of 5-200 ng/ml for gomisin J. The inter- and intra-day coefficients of variations (CVs) for the precision ranged from 6.70% (3.44%) to 11.66% (10.38%). The inter- and intra-day accuracies of eight lignans ranged from 95.70% (93.89%) to 104.59% (106.13%). No significant variation of any of the lignans occurred in the stability tests. Conclusion: The established method can be successfully applied to the pharmacokinetic study of the Schisandra lignan extract in normal rats.