Screening allergic components of Yejuhua injection using LAD2 cell membrane chromatography model online with high performance liquid chromatography-ion trap-time of flight-mass spectrum system

MrgX2-SNAP-tag/cell membrane chromatography model coupled with liquid chromatography-mass spectrometry for anti-pseudo-allergic compound screening in Arnebiae Radix

Pseudo-allergic reactions (PARs) are IgE-independent hypersensitivity reactions. Mas-related G protein-coupled receptor-X2 (MrgX2) was proved the key receptor of PAR. The anti-pseudo-allergic compound discovery based on MrgX2 was of great value. Cell membrane chromatography (CMC) based on MrgX2 provides a convenient and effective tool in anti-pseudo-allergic compound screening and discovery, and further improvements of this method are still needed. In this work, SNAP-tag was introduced at C-terminal of Mas-related G protein-coupled receptor (MrgX2-SNAP-tag), and an MrgX2-SNAP-tag/CMC model was then conducted using CMC technique. Comparative experiments showed that the new model not only satisfied the good selectivity and specificity of screening but also exhibited more stable and longer life span than traditional MrgX2/CMC model. By coupling with HPLC-MS, two compounds were screened out from Arnebiae Radix and identified as shikonin and acetylshikonin. Nonlinear chromatography was performed to study the interactions between two screened compounds and MrgX2, and binding constant (K_A) of shikonin and acetylshikonin with MrgX2 were 2075.67 ± 0.34 M^-1 and 32201.36 ± 0.35 M^-1, respectively. Furthermore, β-hexosaminidase and histamine release assay in vitro demonstrated that shikonin (1-5 μM) and acetylshikonin (2.5-10 μM) could both antagonize C48/80-induced allergic reaction. In conclusion, the MrgX2-SNAP-tag/CMC could be a reliable model for screening pseudo-allergy-related components from complex systems.

Enhanced stability designs of cell membrane chromatography for screening drug leads

Cell membrane chromatography is an effective method for screening bioactive components acting on specific receptors in complex systems, which maintains the biological activity of the membrane receptors and improves screening efficiency. However, traditional cell membrane chromatography suffers from poor stability, resulting in a limited life span and low reproducibility, greatly limiting the application of this method. To address this problem, cyanuric chloride-decorated silica gel was used for the covalent immobilization of the cell membranes. Cyanuric chloride reacts with amino groups on the cell membranes and membrane receptors to form covalent bonds. In this way, the cell membranes are not easy to fall off. The column life of the cyanuric chloride-decorated epidermal growth factor receptor/cell membrane chromatography column was extended to more than 8 days, whereas the column life of the normal cell membrane chromatography column dropped sharply in the first 3 days. A cyanuric chloride-decorated epidermal growth factor receptor/cell membrane chromatography online HPLC-IT-TOF-MSn system was applied for screening drug leads from Trifolium pratense L.. One potential drug lead, formononetin, which acts on the epidermal growth factor receptor, was screened. Our strategy of covalently immobilizing cell membrane receptors also improved the stability of cell membrane chromatography. This article is protected by copyright. All rights reserved.

Advances in analytical techniques and quality control of traditional Chinese medicine injections

Traditional Chinese medicine injections (TCMIs) are a new pharmaceutical form in the modernization of traditional Chinese medicines (TCMs). Its efficacy is rapid, the curative effect is improved, and is widely used in critical and acute diseases, complicated and severe diseases, and other treatment. However, with the broad applications of TCMIs, clinical adverse reactions frequently occur, and safety problems become more prominent. Therefore, the quality control of TCMIs is essential. Chemical analysis methods and biological analysis methods are widely used in the quality control of TCMIs. This article describes the current status of TCMIs, the analytical techniques, and methods currently used, and the quality control of TCMIs. A summary of the advantages and disadvantages of the current analysis methods is presented. An overview of the quality control of TCMIs is introduced. In addition, emerging techniques of the quality control of TCMIs are introduced.

Oroxylin A is a severe acute respiratory syndrome coronavirus 2-spiked pseudotyped virus blocker obtained from Radix Scutellariae using angiotensin-converting enzyme II/cell membrane chromatography

The current worldwide outbreak of the coronavirus disease 2019 (COVID‐19) has been declared a public health emergency. The angiotensin‐converting enzyme II (ACE2) has been reported as the primary host‐cell receptor for severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), the causative virus of COVID‐19. In this study, we screened ACE2 ligands from Radix Scutellariae and investigated its suppressive effect on SARS‐CoV‐2 spiked pseudotyped virus in vitro. HEK293T cells stably expressing ACE2 receptors (ACE2 cells) were used to provide the receptor for the ACE2/cell membrane chromatography (CMC) method used for analysis. The SARS‐CoV‐2‐spiked pseudotyped virus was used to examine the anti‐viropexis effect of the screened compounds in ACE2 cells. Molecular docking and the surface plasmon resonance (SPR) assay were used to determine the binding properties. Oroxylin A exhibited an appreciable suppressive effect against the entrance of the SARS‐CoV‐2‐spiked pseudotyped virus into ACE2 cells, which showed good binding to ACE2 as determined using SPR and CMC. Oroxylin A was shown to be a potential candidate in the treatment for COVID‐19 by virtue of its blocking the entrance of SARS‐CoV‐2 into ACE2 cells by specifically binding to the ACE2 receptor.

Pseudo-allergic compounds screened from Shengmai injection by using high-expression Mas-related G protein-coupled receptor X2 cell membrane chromatography online coupled with liquid chromatography and mass spectrometry

Adverse drug reactions of traditional Chinese medicine injection mainly manifested as pseudo-allergic reactions. In the present study, ginsenoside Rd, Ro, and Rg₃ were identified as pseudo-allergic components in Shengmai injection by a high-expression Mas-related G protein-coupled receptor X2 cell membrane chromatography coupled online with high-performance liquid chromatography and mass spectrometry. Their pseudo-allergic activities were evaluated by in vitro and in vivo assay. The three compounds were further found to induce pseudo-allergic reaction through Mas-related G protein-coupled receptor X2. Therefore, we concluded that ginsenoside Rd, Ro and Rg₃ may be potential allergens that cause pseudo-allergic reactions. This study might be helpful for the safe use of Shengmai injection.

Advances in cell membrane chromatography

Cell membrane chromatography (CMC) is a biomimetic chromatographic method based on the ability of membrane receptors to selectively interact with their ligands in vivo. Using membrane receptors as a stationary phase, the CMC method helps in determining the binding characteristics between ligands and membrane receptors and in efficiently identifying specific target components in a complex sample that produce the cellular biological effects of ligands (drugs, antibodies, enzymes, cytokines, etc.). CMC is an analytical tool for revealing characteristics of ligand-receptor interactions, screening and discovering target substances, and accurately controlling the quality of drugs. Since establishment of CMC in the early 1990s, with the rapid development of cell biology, significant progress has been made in the development of high-expression receptors, engineered cell cultures, and standardized preparations, which allowed in vitro immobilization of cell membrane receptors and miniaturization of binding assays. A variety of CMC models have been established using different membrane receptors as a stationary phase, and many new methods have been developed by combining CMC with high-performance liquid chromatography (HPLC)/mass spectrometry or HPLC-IT-TOF technologies. CMC methods have been widely used to study drug-receptor interactions and to screen complex samples for effective or harmful components.

LABEL-FREE BIO-AFFINITY MASS SPECTROMETRY FOR SCREENING AND LOCATING BIOACTIVE MOLECULES

Despite the recent increase in the development of bioactive molecules in the drug industry, the enormous chemical space and lack of productivity are still important issues. Additional alternative approaches to screen and locate bioactive molecules are urgently needed. Label-free bio-affinity mass spectrometry (BA-MS) provides opportunities for the discovery and development of innovative drugs. This review provides a comprehensive portrayal of BA-MS techniques and of their applications in screening and locating bioactive molecules. After introducing the basic principles, alongside some application notes, the current state-of-the-art of BA-MS-assisted drug discovery is discussed, including native MS, size-exclusion chromatography-MS, ultrafiltration-MS, solid-phase micro-extraction-MS, and cell membrane chromatography-MS. Finally, several challenges and limitations of the current methods are summarized, with a view to potential future directions for BA-MS-assisted drug discovery. © 2019 John Wiley & Sons Ltd. Mass Spec Rev.

Liquid Chromatography Tandem Mass Spectrometry Based Label-Free Quantification Method for Assessment of Allergen-Induced Anaphylactoid Reactions

Mast cells are essential in mediating inflammatory processes. When activated, mast cells can rapidly release characteristic granules and various mediators into the interstitium. Tryptase (TPS) and β-hexosaminidase (HEXB) are typical protease mediators stored in granules and released upon activation. They have been recognized as important biomarkers of anaphylaxis, and the released level is associated with the severity of allergic reactions. In this study, a sensitive, accurate, and selective liquid chromatography tandem mass spectrometry (LC-MS/MS) method for simultaneously quantifying the two biomarkers was developed and validated in LAD2 cell culture supernatant, and P₁₄R was used as internal standard. Good linearity was observed in the range of 50-2500 ng/mL for TPS and 10-2000 ng/mL for HEXB both with R² > 0.99. The matrix effect and recovery were both within acceptable limits. We quantified TPS and HEXB released from Laboratory of Allergic Disease 2 (LAD2) mast cells treated with several potential allergens, and the results demonstrate that the method can be used to investigate TPS and HEXB levels in LAD2 mast cell model during allergy research. We anticipate our approach to be a robust and sensitive assessment method for more biomarkers with similar kinetics characteristics and to be a major tool of allergic drug assessment or antiallergic drug development in research.

Screening of bioactive components from traditional Chinese medicines using cell membrane chromatography coupled with mass spectrometry

INTRODUCTION

Cell membrane chromatography (CMC), as a highly selective type of affinity chromatography, has been demonstrated as an effective method to screen bioactive components acting on specific receptor from a complicated biological system.

OBJECTIVE

To review the recent research progress and the technical applications of these analytical methods using CMC combined with gas chromatography-mass spectrometry, (GC/MS) and liquid chromatography-mass spectrometry (LC/MS).

METHODOLOGY

In this review, we briefly introduce the CMC offline GC/MS, CMC online GC/MS, CMC offline LC/MS, and CMC online LC/MS system. And the practical application of these technologies is also enumerated. Then the future of these technologies and research methods were discussed.

RESULTS

Many bioactive components interacting with specific receptors have been screened and identified in traditional Chinese medicines.

CONCLUSION

CMC technique has been combined with GC/MS and HPLC/MS and these combined systems have been successfully used to screen bioactive components acting on specific receptors from a complicated biological system.