UPLC-MS method for quantification of pterostilbene and its application to comparative study of bioavailability and tissue distribution in normal and Lewis lung carcinoma bearing mice

A UPLC-MS method was developed for determination of pterostilbene (PTS) in plasma and tissues of mice. PTS was separated on Agilent Zorbax XDB-C₁₈ column (50×2.1mm, 1.8μm) with gradient mobile phase at the flow rate of 0.2ml/min. The detection was performed by negative ion electrospray ionization in multiple reaction monitoring mode. The linear calibration curve of PTS in mouse plasma and tissues ranged from 1.0 to 5000 and 0.50 to 500ng/ml (r²0.9979), respectively, with lowest limits of quantification (LLOQ) were between 0.5 and 2.0ng/ml, respectively. The accuracy and precision of the assay were satisfactory. The validated method was applied to the study of bioavailability and tissue distribution of PTS in normal and Lewis lung carcinoma (LLC) bearing mice. The bioavailability of PTS (dose 14, 28 and 56mg/kg) in normal mice were 11.9%, 13.9% and 26.4%, respectively; and the maximum level (82.1±14.2μg/g) was found in stomach (dose 28mg/kg). The bioavailability, peak concentration (C_max), time to peak concentration (T_max) of PTS in LLC mice was increased compared with normal mice. The results indicated the UPLC-MS method is reliable and bioavailability and tissue distribution of PTS in normal and LLC mice were dramatically different.