LC-MS/MS method for the determination of an anti-tumor compound C17 in nude mice plasma and its application to a pharmacokinetic study / 药学学报

C17 is an orally available anti-tumor compound inhibiting cancer stem cell (CSC). In this study, a stable, sensitive and simple liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was established and validated, and was further applied to a pharmacokinetic study in nude mice receiving C17 by gavage. Using propranolol as the internal standard, the plasma samples were pre-treated by precipitation with methanol and analyzed on an Intersil C8-3 column (100 mm × 2.1 mm, 3 μm), and gradient elution was performed with a mobile phase consisting of 0.1% formic acid aqueous and solution mixed up by 90% isopropanol and 10% acetonitrile. The analyte was detected by a triple quadrupole tandem mass spectrometer, and multiple reaction monitoring was employed to select C17 at m/z 439.3/247.1 and propranolol at m/z 260.2/116.2 in the positive ion mode. The calibration curves were linear (r > 0.995) over the range of 5-800 ng·mL-1. The intra- and inter-day precisions and accuracies were 7.42%-13.22% and -8.99%-8.81% respectively. The method was successfully applied to a PK study in nude mice administered with a single oral dose of 50 mg·kg-1 C17, and the PK data were analyzed with non-linear mixed effect model (NONMEM). Two separated absorption peaks were found in the PK curve of C17, and a two-compartment model with two sequential first-order absorption rate was utilized to describe the PK properties of C17, and the model could provide insights into the physiological process and exposure of C17 in nude mice. All animal experiments were in strict accordance with the regulations of the Biomedical Ethics Committee of Peking University.

[Twenty years in the 21st century: identification technologies for and multimodal research on chemical changes in exploration of processing mechanism of Chinese medicine].

Chinese medicine undergoes complex chemical changes during processing and identifying these changes is the key to the processing mechanism. In the past 20 years of the 21 st century, research on the chemical changes in Chinese medicine after processing has focused the changes in the biopharmaceutical process in addition to the variation during processing. With the surging of information technologies, various identification technologies(instrumental analysis techniques, molecular biological techniques, data mining techniques, and biotransformation techniques) have developed rapidly and been widely applied to the research on processing mechanism. Thus, based on the chemical changes in the processing and biopharmaceutical process, the author suggested a research tactic of multimodal identification as the core by reorganizing key technologies for chemical identification from studies of the processing mechanism of Chinese me-dicine, aiming at establishing an interdisciplinary multi-dimensional research model for the processing mechanism of Chinese medicine.

[Twenty years in the 21st century: research hotspots and frontier analysis on Chinese medicine processing mechanism].

The research on the processing mechanism of Chinese medicine is the key and core foundation to improve processing technologies of Chinese medicine, formulate the quality standards of Chinese medicinal pieces, enhance the clinical efficacy of Chinese medicine, enrich Chinese medicine processing theories, and promote the development of Chinese medicine processing. Many researc-hers have conducted in-depth exploration on the processing mechanism of Chinese medicine in the 20 years in the 21 st century. Significant progress has been made in the transformation of chemical components during the processing, the change of active components in the body, the law of toxicity attenuation in the processing of toxic Chinese medicine, the mechanism of efficacy enhancement and toxicity attenuation of processing with auxiliary materials, and the application of new biomedical technologies. At present, the processing mechanism of multiple Chinese medicines has been preliminarily clarified, which has greatly promoted the development of Chinese me-dicine processing. The development of the processing mechanism of Chinese medicine reveals that the in vitro transformation of chemical components is combined with the in vivo absorption, transport, and metabolism, and the macroscopic biological effects of the organism are combined with the cells, molecules, targets, and pathways in the study of the processing mechanism of Chinese medicine. More attention has been paid to exploring the processing mechanism from the overall level, and a modern systematic research system on the processing mechanism of Chinese medicine has been initially formed. To further promote the scientific development of Chinese me-dicine processing, the present study proposed that the research on the processing mechanism of Chinese medicine should take Chinese medicine properties into account, focus on the influence of disease condition on the mode of action and effect strength of the drugs, comply with the characteristics of clinical compound compatibility of Chinese medicine, use the holistic view research strategies of systems bio-logy, and deeply explore the processing mechanism of Chinese medicine from traditional Chinese medicine theories and the characteristics of clinical medication of Chinese medicine.

[Twenty years in the 21st century: research approaches and techniques in modern system biology for mechanisms of Chinese medicinal processing].

Clarifying the mechanisms of Chinese medicinal processing is pivotal to the modernization of Chinese medicine. Research on Chinese medicinal processing gives priority to the mechanisms of the processing in enhancing efficacy, reducing toxicity, and repurposing medicinals. During the past 20 years, scholars have carried out in-depth studies on the mechanisms of Chinese medicinal processing via modern system biology. They mainly focused on the changes of medicinal properties and efficacy caused by processing using techniques of modern pharmacology and molecular biology, spectrum-efficacy correlation, and biophoton emission. However, these techniques fail to reflect the holistic view of traditional Chinese medicine. With the introduction of system biology, multi-omics techno-logies(genomics, transcriptomics, proteomics, and metabolomics) have surged, which have been applied to the research on the mec-hanisms of Chinese medicinal processing. These multi-omics technologies have advantages in the research on holism. This study aims to summarize the research techniques and approaches in system biology for mechanisms of Chinese medicinal processing in the past 20 years and analyze the limitations and advantages of them. It is concluded that the multi-omics techniques of system biology can reconstruct the mechanisms of Chinese medicinal processing. This study provides a new direction for further research on the mechanisms of Chinese medicinal processing.

The Cholinesterase Inhibitory Properties of Stephaniae Tetrandrae Radix.

Stephaniae tetrandrae radix (STR) is a commonly used traditional Chinese medicine in alleviating edema by inducing diuresis. In the clinic, STR extracts or its components are widely used in the treatment of edema, dysuria, and rheumatism for the regulation of water metabolism. Furthermore, STR has been used in treating emotional problems for years by combining with other Chinese herbs. However, the material basis and mechanism of STR on the nervous system have not been revealed. Here, the main components of STR extracts with different extracting solvents were identified, including three major alkaloids, i.e., cyclanoline, fangchinoline, and tetrandrine. The cholinesterase inhibitory activity of STR extracts and its alkaloids was determined using the Ellman assay. Both cyclanoline and fangchinoline showed acetylcholinesterase (AChE) inhibitory activity, demonstrating noncompetitive enzyme inhibition. In contrast, tetrandrine did not show enzymatic inhibition. The synergism of STR alkaloids with huperzine A or donepezil was calculated by the median-effect principle. The drug combination of fangchinoline-huperzine A or donepezil synergistically inhibited AChE, having a combination index (CI) < 1 at Fa = 0.5. Furthermore, the molecular docking results showed that fangchinoline bound with AChE residues in the peripheral anionic site, and cyclanoline bound with AChE residues in the peripheral anionic site, anionic site, and catalytic site. In parallel, cyclanoline bound with butyrylcholinesterase (BChE) residues in the anionic site, catalytic site, and aromatic site. The results support that fangchinoline and cyclanoline, alkaloids derived from STR, could account for the anti-AChE function of STR. Thus, STR extract or its alkaloids may potentially be developed as a therapeutic strategy for Alzheimer's patients.

Ophiopogon Polysaccharide Promotes the In Vitro Metabolism of Ophiopogonins by Human Gut Microbiota.

Gut microbiota play an important role in metabolism of intake saponins, and parallelly, the polysaccharides deriving from herbal products possess effects on gut microbiota. Ophiopogonis Radix is a common Chinese herb that is popularly used as functional food in China. Polysaccharide and steroidal saponin, e.g., ophiopogonin, mainly ophiopogonin D (Oph-D) and ophiopogonin D' (Oph-D'), are the major constituents in this herb. In order to reveal the role of gut microbiota in metabolizing ophiopogonin, an in vitro metabolism of Oph-D and Oph-D' by human gut microbiota, in combination with or without Ophiopogon polysaccharide, was conducted. A sensitive and reliable UPLC-MS/MS method was developed to simultaneously quantify Oph-D, Oph-D' and their final metabolites, i.e., ruscogenin and diosgenin in the broth of microbiota. An elimination of Oph-D and Oph-D' was revealed in a time-dependent manner, as well as the recognition of a parallel increase of ruscogenin and diosgenin. Ophiopogon polysaccharide was shown to stimulate the gut microbiota-induced metabolism of ophiopogonins. This promoting effect was further verified by increased activities of ß-D-glucosidase, ß-D-xylosidase, α-L-rhamnosidase and ß-D-fucosidase in the broth. This study can be extended to investigate the metabolism of steroidal saponins by gut microbiota when combined with other herbal products, especially those herbs enriched with polysaccharides.

Polysaccharide deriving from Ophiopogonis Radix promotes metabolism of ginsenosides in the present of human gut microbiota based on UPLC-MS/MS assay.

The combined usage of Ginseng Radix et Rhizoma (ginseng) and Ophiopogonis Radix is common in oriental countries for thousands of years. The major active constituents of ginseng are ginsenosides, and the conversion of ginsenosides to different metabolites by gut microbiota has been reported. However, the effect of Ophiopogonis Radix, especially its polysaccharides, on the metabolism of ginsenosides by gut microbiota is not known. Here, an in vitro metabolism of ginseng extract, or ginsenosides, in combination with or without Ophiopogon polysaccharide was conducted. A sensitive and reliable UPLC-MS/MS approach using multiple reaction monitoring (MRM) in positive ion mode was developed simultaneously to quantify 22 ginsenosides in the broth of gut microbiota. After fermentation with the microbiota, 15 ginsenosides were detected and quantified, including 6 primary ginsenosides, i.e. Rb1, Rc, Rb2, Rb3, Rd and Re, and 9 metabolites, i.e. F2, Rg3, compound K, Rh2, PPD, Rg1, Rh1, Rg2 and PPT. The quantitative results therefore revealed the elimination of primary ginsenosides and the formation of their metabolites in time-dependent manners. Furthermore, Ophiopogon polysaccharide was shown to stimulate the metabolism of ginsenosides, triggered by gut microbiota. Our study can be extended to investigate the metabolism of different Panax species by gut microbiota when combining with other herbs.

Simultaneous Determination of Quercitrin, Afzelin, Amentoflavone, Hinokiflavone in Rat Plasma by UFLC-MS-MS and Its Application to the Pharmacokinetics of Platycladus orientalis Leaves Extract.

Leaves of Platycladus orientalis have been used as blood cooling and homeostatic therapy for thousands of years in traditional Chinese medicine. Emerging evidences of modern pharmacology have proved flavonoids as the key elements responsible for the efficacies. However, there has been no report on pharmacokinetic study of the flavonoids from Platycladus orientalis leaves extract. In this study, a sensitive and rapid ultra-flow liquid chromatography-tandem mass spectrometry method was established and validated for the simultaneous determination of amentoflavone, afzelin, hinokiflavone and quercitrin in rat plasma. The four flavonoids and luteolin (internal standard, IS) were recovered from rat plasma by methanol-ethyl acetate (v:v, 50:50). Chromatographic separation was performed on a C18 column with gradient elution. Our results showed that the recoveries from spiked control samples were more than 85% for all analytes and IS. The relative standard deviations of intra-day and inter-day precision were within 15% while the REs ranged from -6.6% to 8.0%. The validated method in this study was successfully applied to pharmacokinetic study in healthy rats after oral administration of P. orientalis leaves extract.

Simultaneous quantification of twelve compounds in ethyl acetate extracts of Euphorbia kansui before and after fry-baked with vinegar by UPLC-MS/MS and its toxic effect on zebrafish.

The dried roots of Euphorbia kansui T.N. Liou ex T.P. Wang have been traditionally used for edema in China. However, the severe toxicity caused by Euphorbia kansui has seriously restricted its clinical application. Therefore, in order to study the material basis of the toxicity attenuation effect of processing with vinegar, a rapid, sensitive, validated and reliable UPLC-MS/MS method was developed to determine twelve compounds in ethyl acetate extracts of Euphorbia kansui before and after fry-baked with vinegar simultaneously. Meanwhile, the study of their toxic effect on zebrafish was conducted. Chromatographic separation was accomplished on Waters BEH C18 UPLC column. 0.3% formic acid in water and acetonitrile were used as mobile phase with a flow rate of 0.40 mL/min and a temperature at 30 °C. The analysis was performed in multiple reaction monitoring (MRM) mode using positive electrospray ionization (ESI). Furthermore, the toxic research results indicated that the toxicity of Euphorbia kansui was decreased after vinegar-processed, which might because of the increase in the content of 5-O-benzoyl-20-deoxyingenol and the decrease in the contents of the remaining terpenoids in ethyl acetate extracts of Euphorbia kansui fry-baked with vinegar. This study demonstrated that the method used is a powerful approach to determine the content of twelve compounds that responsible for the toxic effect of Euphorbia kansui at the same instant. And provided the experimental evidence for the rationale behind the reduction of toxicity.

Studies on chemical constituents and anti-hepatoma effects of essential oil from Annona squamosa L. pericarps.

Annona squamosa L. fruit played great anti-neoplastic activities. Its pericarps were discarded as waste. In this study, essential oil extracted from A. squamosa L. pericarps (APEO) was obtained by hydrodistillation and analysed by GC-MS. Furthermore, the anti-hepatoma activities and the underlying mechanism of the oil were firstly described. A total of 59 compounds were identified by Gas chromatography-mass spectrometry (GC-MS). The major compound in the oil was (-)-spathulenol (32.51%). The APEO demonstrated anti-hepatoma activity against SMMC-7721 hepatoma cell line with IC50 lower than 55 µg/mL. At the same time, nucleus shrinkage or broken were found in cells incubated with APEO through fluorescent microscope. In addition, pro-apoptosis and cell cycle arrest effects were confirmed by flow cytometry analysis.

Anti-inflammatory effect of volatile oil from Schizonepeta tenuifolia on carrageenin-induced pleurisy in rats and its application to study of appropriate harvesting time coupled with multi-attribute comprehensive index method.

ETHNOPHARMACOLOGICAL RELEVANCE: Schizonepeta tenuifolia Briq. (ST) herbs have been used as a Traditional Chinese Medicine (TCM) for treating colds for thousands of years. The volatile oil is considered as the main material basis responsible for the efficacy of ST and has attracted lots of attention on its anti-inflammatory effect recently. AIM OF STUDY: This paper investigated the anti-inflammatory effects of the distilled volatile oils from Schizonepeta tenuifolia (STVO) that were collected at different harvesting times on carrageenin-induced pleurisy in rats. Based on the anti-inflammatory effects, instead of contents of marker components, we aim to evaluate the quality and determine the appropriate harvesting time of ST. MATERIALS AND METHODS: There were eleven groups with eight male rats in each randomly. They were model group, control group, positive group (dexamethasone) and eight groups treated with eight STVOs at different harvesting times. All treatments were performed by gavage and administered once a day on four consecutive days. One hour after the last treatments, except the rats in control group, those in other groups were treated with carrageenin to induce the pleurisy. Four hours later, all the rats were sacrificed and their pleurisy exudates and lung tissues were collected for further analysis. To evaluate the comprehensive anti-inflammatory effect of the eight STVOs, multi-attribute comprehensive index method (MACIM) was used to obtain the integration of various effects. RESULTS: All the eight STVOs could decrease the seven indicators relating to pleurisy, which were exudate volume, leukocytes, protein level, myeloperoxidase (MPO), malondialdehyde (MDA), tumor necrosis factor-α (TNF-α) and interleukine-1ß (IL-1ß). Majority of these decreases were significant (P<0.01, P<0.05). As far as each indicator was concerned, each STVO showed different effect from others. With MACIM, it was found that STVO in Group 6 was the most effective one with the highest Vs and appropriate harvesting time of ST was in late September. CONCLUSIONS: The study may provide scientific basis to further understanding of the mechanism of STVO in anti-inflammatory effect of carrageenin-induced pleurisy. Meanwhile, this study also provides a new access to determining the appropriate harvesting time of TCM and even evaluating the quality of TCM.