Simultaneous characterisation of multiple Mahonia fortunei bioactive compounds in rat plasma by UPLC-MS/MS for application in pharmacokinetic studies and anti-inflammatory activity in vitro

The stems of Mahonia fortunei (MF) are commonly used in Chinese Traditional Medicine and contain multiple bioactive compounds, including 3,4,5-trimethoxyphenol-1-O-β-d-glucopyranoside (1), 5-hydroxypicolinic acid methyl ester (2), acortatarin A (3), syringic acid (4), 9-epi-acortatarin A (5), vomifoliol (6), corydaldine (7), noroxyhydrastinine (8), columbamine (9), jatrorrhizine (10), palmatine (11), berberine (12) and schisandrin (13). The pharmacokinetics of these 13 compounds in the rat plasma were assessed using a novel sensitive, rapid, and specific UPLC-ESI-MS/MS method after oral administration of an aqueous extract of MF stems. Carbamazepine was employed as the internal standard (IS) and all samples were precipitated with acetonitrile. Chromatographic separation was performed on a C₁₈ column using a gradient elution at 0.3 mL/min, with the mobile phase consisting of acetonitrile and 0.06 % formic acid and 5 mM ammonium acetate aqueous solution. The calibration curves showed satisfactory linearity in the examination area (r² ≥ 0.99). The accuracy, precision, extraction recovery, matrix effect, and stability were within acceptable ranges. The method successfully assessed the pharmacokinetics of these 13 compounds. In vitro, compound 12 exhibited potent inhibitory activity against production of nitric oxide (NO) in the RAW264.7 cell line when stimulated by lipopolysaccharide (LPS), while compounds 7, 12, and 13 were the most potent inhibitors of NO production in the BV2 cell line when stimulated by LPS. The IC₅₀ values of compounds 7, 12 and 13 were 42.81, 20.55 and 22.74 μM. We conclude that these compounds have promise for clinical application, although their synergistic action may be more effective than that by any single compound alone.