Dauricine is the major bioactive component isolated from the roots of Menispermum dauricum D.C., a bisbenzylisoquinoline alkaloid derivative, and has shown multiple pharmacological properties. In this work, a sensitive and selective ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for determination of dauricine in rat plasma and its application to pharmacokinetic study of dauricine after intravenous and oral administration in rats. After addition of daurisoline as an internal standard (IS), protein precipitation by acetonitrile was used to prepare samples. Chromatographic separation was achieved on a UPLC BEH C18 column (2.1 mm × 50 mm, 1.7 μm) with 0.1% formic acid and acetonitrile as the mobile phase with gradient elution. An electrospray ionization source was applied and operated in positive ion mode; multiple reactions monitoring (MRM) mode was used for quantification. Calibration plots were linear throughout the range 2-600 ng mL −1 for dauricine in rat plasma. Relative standard deviation (RSD) of intra-day and inter-day precision was less than 13%. The accuracy of the method was between 95.8% and 105.9%. Matrix effect of dauricine in rat plasma ranged from 88.0% to 90.3%. Mean recoveries of dauricine in rat plasma ranged from 91.5% to 95.1%. The method was successfully applied to pharmacokinetic study of dauricine after intravenous and oral administration in rats. The bioavailability of dauricine was found to be 55.4% for the first time.

We developed a metabolomic method to evaluate the effect of pirfenidone on rats with acute paraquat (PQ) poisoning, through the analysis of various tissues (lung, liver, kidney, and heart), by gas chromatography-mass spectrometry (GC-MS). Thirty-eight rats were randomly divided into a control group, an acute PQ (20 mg kg) poisoning group, a pirfenidone (20 mg kg) treatment group, and a pirfenidone (40 mg kg) treatment group. Partial least squares-discriminate analysis (PLS-DA) revealed metabolic alterations in rat tissue samples from the two pirfenidone treatment groups after acute PQ poisoning. The PLS-DA 3D score chart showed that the rats in the acute PQ poisoning group were clearly distinguished from the rats in the control group. Also, the two pirfenidone treatment groups were distinguished from the acute PQ poisoning group and control group. Additionally, the pirfenidone (40 mg kg) treatment group was separated farther than the pirfenidone (20 mg kg) treatment group from the acute PQ poisoning group. Evaluation of the pathological changes in the rat tissues revealed that treatment with pirfenidone appeared to decrease pulmonary fibrosis in the acute PQ poisoning rats. The results indicate that pirfenidone induced beneficial metabolic alterations in the tissues of rats with acute PQ poisoning. Rats with acute PQ poisoning exhibited a certain reduction in biochemical indicators after treatment with pirfenidone, indicating that pirfenidone could protect liver and kidney function. Accordingly, the developed metabolomic approach proved to be useful to elucidate the effect of pirfenidone in rats of acute PQ poisoning.

In this work, a sensitive and selective UPLC-MS/MS method for determination of ardisiacrispin A in rat plasma was developed. Cyasterone used as an internal standard (IS) and protein precipitation by acetonitrile-methanol (9:1, v/v) was used to prepare samples. Chromatographic separation was achieved on a UPLC BEH C column (2.1 × 100 mm, 1.7 μm) with 0.1% formic acid and acetonitrile as the mobile phase with gradient elution. An electrospray ionization source was applied and operated in positive ion mode; multiple reaction monitoring mode was used for quantification using target fragment ions m/z 1083.5 → 407.1 for ardisiacrispin A and m/z 521.3 → 485.2 for IS. Calibration plots were linear throughout the range 5-2000 ng/mL for ardisiacrispin A in rat plasma. Mean recoveries of ardisiacrispin A in rat plasma ranged from 80.4 to 92.6%. The values of RSD of intra- and inter-day precision were both <11%. The accuracy of the method was between 97.3 and 105.6%. The method was successfully applied to pharmacokinetic study of ardisiacrispin A after intravenous administration in rats.

We developed a serum metabolomic method by gas chromatography-mass spectrometry (GC-MS) to evaluate the effect of alprazolam in rats. The GC-MS with HP-5MS (0.25 μm × 30 m × 0.25 mm) mass was conducted in electron impact ionization (EI) mode with electron energy of 70 eV, and full-scan mode with m/z 50-550. The rats were randomly divided to four groups, three alprazolam-treated groups and a control group. The alprazolam-treated rats were given 5, 10 or 20 mg/kg (low, medium, high) of alprazolam by intragastric administration each day for 14 days. The serum samples were corrected on the seventh and fourteenth days for metabolomic study. The blood was collected for biochemical tests. Then liver and brain were rapidly isolated and immersed for pathological study. Compared with the control group, on the seventh and fourteen days, the levels of d-glucose, 9,12-octadecadienoic acid, butanoic acid, l-proline, d-mannose and malic acid had changed, indicating that alprazolam induced energy metabolism, fatty acid metabolism and amino acid metabolism perturbations in rats. There was no significant difference for alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, urea and uric acid between controls and alprazolam groups. According to the pathological results, alprazolam is not hepatotoxic. Metabolomics could distinguish different alprazolam doses in rats.

In this work, a sensitive and selective ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and fully validated for determination of jaceosidin in rat plasma. Avicularin was used as the internal standard (IS), and protein precipitation by acetonitrile was used to prepare samples. Chromatographic separation was achieved on a UPLC BEH C18 column (2.1 mm × 100 mm, 1.7 μm) with 0.1% formic acid and acetonitrile as the mobile phase with gradient elution. An electrospray ionization (ESI) source was applied and operated in positive ion mode; multiple reaction monitoring (MRM) mode was used for quantification. Calibration plots were linear throughout the range 2-500 ng mL −1 for jaceosidin in rat plasma. Relative standard deviation (RSD) of intra-day and inter-day precision was less than 12%. The accuracy of the method was between 88.7% and 109.7%. Mean recoveries of jaceosidin in rat plasma ranged from 65.4% to 77.9%. The developed UPLC-MS/MS method was successfully applied to pharmacokinetic study of jaceosidin after intravenous administration of 2 mg kg −1 in rats. We could find that the jaceosidin rapidly eliminated, the t 1/2 was 0.7 ± 0.3 h, and clearance (CL) was 22.4 ± 3.0 L h −1 kg −1 .