M10, a novel myricetin derivative, is an anti-inflammatory agent designed for treatment of colitis. Here, we aim to investigate its pharmacokinetic behavior and tissue distribution in a mouse model with colitis. Pharmacokinetics and tissue distribution of M10 and its metabolite myricetin were compared in normal mice and in dextran-sodium-sulfate (DSS)-induced colitis mice. The role of fecal microbiota was also analyzed during metabolism of M10 in vitro. After oral administration, M10 was very low in the plasma of both normal and diseased mice. However, both M10 and myricetin were mainly distributed in the gastrointestinal tract, including the stomach, colon and small intestine, in physiological and pathological conditions. Significantly, M10 and myricetin were found in higher levels in gastrointestinal tracts with inflamed tissues than in normal tissues of mice. An in vitro assay revealed that 80% of M10 was metabolized to myricetin via fecal microbiota. After oral administration, M10 was not absorbed into circulation but mainly distributed in the inflamed submucosal tissues of colitic mice, where it was metabolized into myricetin to prevent colitis development.Keywords:M10;myricetin;pharmacokinetics;tissue distribution;ulcerative colitis
Hengyi Yu,Dongyan Li,Dong Xiang,Xiping Li,Lu Liu,Dong Liu,Xuepeng Gong
A rapid, specific and accurate high-performance liquid chromatography with tunable ultraviolet detection method was developed to simultaneously determine azathioprine metabolites, 6-thioguanine nucleotides (6-TGN) and 6-methyl mercaptopurine riboside (6-MMPr) in human red blood cells. Erythrocyte lysate sample was precipitated by perchloric acid under the protection of dithiothreitol, with 6-TGN and 6-MMPr being acid hydrolyzed to produce 6-thioguanine (6-TG) and 6-methymercaptopurine (6-MMP). A Waters Cortecs C 18 column (2.1 × 150 mm, 2.7 μm) was used for chromatographic separation with a water (containing 0.01 mol/L ammonium acetate and 0.2% acetic acid)/methanol linear gradient at a flow rate of 0.45 mL/min in a 5.5 min. UV detection wavelengths were 340 nm for 6-TG, 303 nm for 6-MMP and the IS (5-bromouracil). The calibration curves fitted a least squares model (weighed 1/ x 2 ) from 0.15 to 15 μmol/L for 6-TG ( r 2 = 0.9999) and from 1 to 100 μmol/L for 6-MMP ( r 2 = 0.9998). This method was validated according to the FDA bioanalytical method validation guidance and ICH M10 bioanalytical method validation and study sample analysis guidance for industry, and successfully utilized in ten IBD patients receiving azathioprine therapy.
The use of conventional opioids that act on μ-receptors is a recognized care agent for moderate-to-severe acute treatment. However, recent attention has shifted to a new class of μ-receptor agonists which can selectively activate the G-protein pathway and thus have better efficacy and fewer side effects. Recently, YZJ-4729 was developed as a new G protein selective μ-opioid receptor agonist. And for its clinical trial investigation usage, a rapid LC-MS/MS method was established for the concurrent measurement of YZJ-4729 and its major metabolite M10 in human plasma. A step involving the precipitation of proteins was used for plasma sample preparation. The chromatography separation was done on a Poroshell 120 EC-C18 analytical column (2.1 × 50 mm, 2.7-μm, Agilent). Gradient elution was performed with 5.0 mM ammonium acetate (NH 4 Ac) and 0.1 % formic acid (FA) water solution as the mobile phase A and pure acetonitrile (ACN) as the mobile phase B. Detection occurred in the mode of positive ion electrospray ionization through multiple reaction monitoring using deuterium YZJ-4729 (d6-YZJ-4729) as the internal standard. The ionic transitions used were YZJ-4729: m/z 409.3 → 244.2; d6-YZJ-4729: m/z 415.3 → 244.2; M10: m/z 425.3 → 260.2;). The method showed excellent linearity across the ranges of 0.500 to 500 ng/mL for YZJ-4729 and 0.0500 to 50.0 ng/mL for M10. The method was utilized to assess the plasma concentrations of YZJ-4729 and M10 in healthy volunteers after a 30-min intravenous infusion in the phase I clinical study, and the clinical pharmacokinetic profiles of YZJ-4729 and M10 were described.