Study on the interaction between active components from traditional Chinese medicine and plasma proteins

A comprehensive review on pharmacokinetic mechanism of herb-herb/drug interactions in Chinese herbal formula

Oral administration of Chinese Herbal Medicine (CHM) faces various challenges in reaching the target organs including absorption and conversion in the gastrointestinal tract, hepatic metabolism via the portal vein, and eventual systemic circulation. During this process, factors such as gut microbes, physical or chemical barriers, metabolic enzymes, and transporters play crucial roles. Particularly, interactions between different herbs in CHM have been observed both in vitro and in vivo. In vitro, interactions typically manifest as detectable physical or chemical changes, such as facilitating solubilization or producing precipitates when decoctions of multiple herbs are administered. In vivo, such interactions cause alterations in the ADME (absorption, distribution, metabolism, and excretion) profile on metabolic enzymes or transporters in the body, leading to competition, antagonism, inhibition, or activation. These interactions ultimately contribute to differences in the therapeutic and pharmacological effects of multi-herb formulas in CHM. Over the past two thousand years, China has cultivated profound expertise and solid theoretical frameworks over the scientific use of herbs. The combination of multiple herbs in one decoction has been frequently employed to synergistically enhance therapeutic efficacy or mitigate toxic and side effects in clinical settings. Additionally combining herbs with increased toxicity or decreased effect is also regarded as a remedy, a practice that should be approached with caution according to Traditional Chinese Medicine (TCM) physicians. Such historical records and practices serve as a foundation for predicting favorable multi-herb combinations and their potential risks. However, systematic data that are available to support the clinical practice and the exploration of novel herbal formulas remain limited. Therefore, this review aims to summarize the pharmacokinetic interactions and mechanisms of herb-herb or herb-drug combinations from existing works, and to offer guidance as well as evidence for optimizing CHM and developing new medicines with CHM characteristics.

Linking soil nutrients, microbial community composition, and enzyme activities to saponin content of Paris polyphylla after addition of biochar and organic fertiliser

The application of organic fertilisers and biochar has become widespread in agroforestry ecosystems to enhance the yield and quality of crops and medicinal plants. However, their specific impact on both the yield and quality of Paris polyphylla (P. polyphylla), along with the underlying mechanisms, remains unclear. In this study, we investigated the distinct effects of organic fertiliser (at concentrations of 5% and 10%) and biochar application (at levels of 2% and 4%) on P. polyphylla saponin content. This content is intricately regulated by available soil nutrients, enzyme activities, and microbial community compositions and activities. Our results clearly demonstrated a significant increase in the saponin content, including total saponin, polyphyllin I (PPI), polyphyllin II (PPII), polyphyllin VI (PPVI), and polyphyllin VII (PPVII), in P. polyphylla following the application of both biochar and organic fertiliser. Moreover, in comparison to the control group, the addition of biochar and organic fertiliser led to a considerable rise in the activity of glycosyltransferase enzyme (GTS) and cycloartenol synthase (CAS) in P. polyphylla. Additionally, it increased soil available potassium (AK) and soil organic matter (SOM) concentration, along with the activity of urease, acid phosphatase, and catalase, although biochar amendment resulted in a decrease in nitrate nitrogen (NO3--N) concentration. Crucially, our findings revealed a positive correlation between total saponin content and the activity of CAS in P. polyphylla, soil AK, SOM concentration, and the activities of urease, acid phosphatase, and catalase. Conversely, there was a negative correlation with NO3--N content. Furthermore, the application of organic fertiliser and biochar significantly influenced microbial community structures and specific microbial taxa. Notably, total saponin content exhibited a positive relationship with the relative abundances of Dehalococcoidia, Saccharomycetes, and Agaricomycetes taxa while showing a negative correlation with the abundance of Verrucomicrobiae. In conclusion, the observed increase in saponin content can be attributed to the modulation of specific microbial taxa in soils, as well as alterations in soil nutrients and enzyme activities resulting from the application of biochar and organic fertiliser. This study identifies a potential mechanism for enhancing saponin content in the artificial cultivation of P. polyphylla.

Benzohydroxamate and nitrobenzohydroxamate affect membrane order: Correlations between spectroscopic and molecular dynamics to approach tuberculosis

This work correlates the effects of benzohydroxamate (BH) and nitrobenzohydroxamate (NBH) anions in two membrane models which may be used for anti-tuberculosis (anti-TB) spectroscopic studies and/or computational studies. Firstly, the BH and NBH influence in the physico-chemical properties of soy asolectin (ASO)-based large multilamellar vesicles (MLVs) were evaluated by spectroscopic and calorimetric studies. In parallel, the BH and NBH interaction with a Mycobacterium tuberculosis (Mtb) inner membrane model, composed of phosphatidyl-myo-inositol-dimannoside (PIM2), was investigated by molecular dynamics (MD) simulations. Spectroscopic data showed a localization of BH close to the lipid phosphate group, while NBH was found close to the choline region. The BH ordered the ASO choline, phosphate and carbonyl regions and disrupted the acyl methylenes, reducing the membrane packing of the lipid hydrophobic region. On the other hand, NBH showed an ordering effect in all the lipid groups (polar, interface and hydrophobic ones). By MD studies, it was found that NBH enhanced the stability of the PIM2 membrane more than BH, while also being positioned closer to its mannosyl oxygens. As in ASO MLVs, BH was localized close to the PIM2 phosphate group and disrupted its acyl chains. However, higher values of lateral diffusion were observed for NBH than BH. Despite this, BH and NBH increased the membrane thickness by 35 %, which suggests a global ordering effect of both drugs. Findings of this work reinforce the accordance and complementarity between MLVs based on ASO and the PIM2 MD model results to study the drug effects in Mtb membrane properties.

Exploring the binding behavior mechanism of vitamin B12 to α-Casein and β-Casein: multi-spectroscopy and molecular dynamic approaches

The aim of this study was to investigate the behavior interaction of α-Casein-B12 and β-Casein-B12 complexes as binary systems through the methods of multiple spectroscopic, zeta potential, calorimetric, and molecular dynamics (MD) simulation. Fluorescence spectroscopy denoted the role ofB12as a quencher in both cases of α-Casein and β-Casein fluorescence intensities, which also verifies the existence of interactions. The quenching constants of α-Casein-B12 and β-Casein-B12 complexes at 298 K in the first set of binding sites were 2.89 × 104 and 4.41 × 104 M-1, while the constants of second set of binding sites were 8.56 × 104 and 1.58 × 105 M-1, respectively. The data of synchronized fluorescence spectroscopy at Δλ = 60 nm were indicative of the closer location of β-Casein-B12 complex to the Tyr residues. Additionally, the binding distance between B12 and the Trp residues of α-Casein and β-Casein were obtained in accordance to the Förster's theory of nonradioactive energy transfer to be 1.95 nm and 1.85 nm, respectively. Relatively, the RLS results demonstrated the production of larger particles in both systems, while the outcomes of zeta potential confirmed the formation of α-Casein-B12 and β-Casein-B12 complexes and approved the existence of electrostatic interactions. We also evaluated the thermodynamic parameters by considering the fluorescence data at three varying temperatures. According to the nonlinear Stern-Volmer plots of α-Casein and β-Casein in the presence of B12 in binary systems, the two sets of binding sites indicated the detection of two types of interaction behaviors. Time-resolved fluorescence results revealed that the fluorescence quenching of complexes are static mechanism. Furthermore, the outcomes of circular dichroism (CD) represented the occurrence of conformational changes in α-Casein and β-Casein upon their binding to B12 as the binary system. The experimental results that were obtained throughout the binding of α-Casein-B12 and β-Casein-B12 complexes were confirmed by molecular modeling.Communicated by Ramaswamy H. Sarma.

Self-Assembled Aggregated Structures of Natural Products for Oral Drug Delivery

The self-assembling aggregated structures of natural products have gained significant interest due to their simple synthesis, lack of carrier-related toxicity, and excellent biological efficacy. However, the mechanisms of their assembly and their ability to traverse the gastrointestinal (GI) barrier remain unclear. This review summarizes various intermolecular non-covalent interactions and aggregated structures, drawing on research indexed in Web of Science from 2010 to 2024. Cheminformatics analysis of the self-assembly behaviors of natural small molecules and their supramolecular aggregates reveals assembly-favorable conditions, aiding drug formulation. Additionally, the review explores the self-assembly properties of macromolecules like polysaccharides, proteins, and exosomes, highlighting their role in drug delivery. Strategies to overcome gastrointestinal barriers and enhance drug bioavailability are also discussed. This work underscores the potential of natural products in oral drug delivery and offers insights for designing more effective drug delivery systems.

New strategies for evaluating imidacloprid-induced biological consequences targeted to Eisenia fetida species and the corresponding mechanisms of its toxicity

Imidacloprid (IMI), a neonicotinoid insecticide, has a wide variety of applications in both agriculture and horticulture. As a result of it massive and repeated use, its traces remained in soil pose severe damage to soil invertebrates, particularly earthworms. Limited information is available regarding the underlying mechanisms of IMI toxicity toward earthworms at the molecular, transcriptional, and cellular levels. Here, Eisenia fetida coelomocytes and key defensive proteins were selected as targeted receptors to explore the toxic mechanisms of oxidative stress-mediated cytotoxicity, genotoxicity, and antioxidant responses induced by IMI stress and the molecular mechanisms underlying the binding of IMI and superoxide dismutase (SOD)/catalase (CAT). Results showed that IMI exposure destroyed the cell membrane integrity of earthworm cells, causing cell damage and cytotoxicity. The intracellular levels of ROS, including ·O2- and H2O2 were induced by IMI exposure, thereby triggering oxidative stress and damage. Moreover, IMI exposure attenuated the antioxidative stress responses (reduced antioxidant capacity and CAT/SOD activities) and caused deleterious effects (enhanced DNA damage, lipid peroxidation (LPO), and protein carbonylation (PCO)) through ROS-mediated oxidative stress pathway. Aberrant gene expression associated with oxidative stress and defense regulation, including CAT, CRT, MT, SOD, GST, and Hsp70 were induced after IMI exposure. Concentration-dependent conformational and structural alterations of CAT/SOD were observed when IMI binding. Also, direct binding of IMI resulted in significant inhibition of CAT/SOD activities in vitro. Molecular simulation showed that IMI preferred to bind to CAT active center through its direct binding with the key residue Tyr 357, while IMI bound more easily to the connecting cavity of two subunits away from SOD active center. In addition, hydrogen bonds and hydrophobic force are the main driving force of IMI binding with CAT/SOD. These findings have implications for comprehensive evaluation of IMI toxicity to soil eco-safety and offer novel strategies to elucidate the toxic mechanisms and pathways of IMI stress.

The Research Progress of Bioactive Peptides Derived from Traditional Natural Products in China

Traditional natural products in China have a long history and a vast pharmacological repertoire that has garnered significant attention due to their safety and efficacy in disease prevention and treatment. Among the bioactive components of traditional natural products in China, bioactive peptides (BPs) are specific protein fragments that have beneficial effects on human health. Despite many of the traditional natural products in China ingredients being rich in protein, BPs have not received sufficient attention as a critical factor influencing overall therapeutic efficacy. Therefore, the purpose of this review is to provide a comprehensive summary of the current methodologies for the preparation, isolation, and identification of BPs from traditional natural products in China and to classify the functions of discovered BPs. Insights from this review are expected to facilitate the development of targeted drugs and functional foods derived from traditional natural products in China in the future.

High resolution micro-confocal Raman spectrometer-based photo-affinity microarray technology for the investigation of active ingredients - Target protein recognition strategy

Natural products has been used for the prevention and treatment of diseases for a long history. Research on the bioactive components from natural products and their interaction with target proteins are essential for drug discovery. However, studying the binding ability of natural products' active ingredients to target proteins is usually time-consuming and laborious due to their complex and diverse chemical structures. In this study, we have developed a high resolution micro-confocal Raman spectrometer-based photo-affinity microarray (HRMR-PM) technology for the investigation of active ingredients-target protein recognition strategy. The novel photo-affinity microarray was constructed by photo-cross-linking the small molecule with the photo-affinity group (4-[3-(Trifluoromethyl)-3H-diazirin-3-yl]benzoic acid, TAD) on the photo-affinity linker coated (PALC) slides under 365 nm ultraviolet irradiation. The small molecules on the microarrays with specific binding ability might immobilize target protein, which were characterized by high resolution micro-confocal Raman spectrometer. Using this method, more than a dozen components of Shenqi Jiangtang granules (SJG) were made into small molecule probe (SMP) microarrays. As a result, 8 of them had been identified to have α-glucosidase binding ability according to characteristic Raman shift at about 3060 cm^-1. These compounds were further verified by different small molecule-protein interaction analysis methods, including contact angle D-value, surface plasmon resonance (SPR) and molecular docking. The results showed that Ginsenosides Mb, Formononetin and Gomisin D exhibited the strongest binding ability. In conclusion, the HRMR-PM strategy for investigating the interaction between target proteins and small molecules has the advantages such as high throughput, low sample consumption and fast qualitative characterization. This strategy is universal which can be applied in the study of in vitro binding activity of various types of small molecules to target proteins.

Interaction of Positively Charged Oligopeptides with Blood Plasma Proteins

In this project, we combine two areas of research, experimental characterization and molecular docking studies of the interaction of positively charged oligopeptides with crucial blood plasma proteins. The investigated peptides are rich in NH₂ groups of amino acid side chains from Dap, Orn, Lys, and Arg residues, which are relevant in protein interaction. The peptides are 9- and 11-mer with the following sequences: (Lys-Dab-Dab-Gly-Orn-Pro-His-Lys-Arg-Lys-Dbt), (Lys-Dab-Ala-Gly-Orn-Pro-His-Lys-Arg), and (Lys-Dab-Dab-Gly-Orn-Pro-Phe(2-F)-Lys-Arg). The net charge of the compound strongly depends on the pH environment and it is an important aspect of protein binding. The studied oligopeptides exhibit therapeutic properties: anti-inflammatory activity and the capacity to diminish reactive oxygen species (ROS). Therefore, the mechanism of potential binding with blood plasma components is the next challenge. The binding interaction has been investigated under pseudo-physiological conditions with the main blood plasma proteins: albumin (BSA), α1-acid glycoprotein (AAG), and γ-globulin fraction (GGF). The biomolecular quenching constant (k_q) and binding constant (K_b) were obtained by fluorescence spectroscopy at various temperatures. Simultaneously, the changes in the secondary structure of proteins were monitored by circular dichroism (CD) and infrared spectroscopy (IR) by quantity analysis. Moreover, molecular docking studies were conducted to estimate the binding affinity, the binding domain, and the chemical nature of these interactions. The results show that the investigated oligopeptides could be mainly transported by albumin, and the binding domain I is the most favored cavity. The BSA and GGF are able to form stable complexes with the studied compounds as opposed to AAG. The binding reactions are spontaneous processes. The highest binding constants were determined for Lys-Dab-Dab-Gly-Orn-Pro-His-Lys-Arg-Lys-Dbt peptide, in which the values of the binding constants K_b to BSA and GGF were 10.1 × 10⁴ dm³mol^-1 and 3.39 × 10³ dm³mol^-1, respectively. The positively charged surface of peptides participated in salt bridge interaction with proteins; however, hydrogen bonds were also formed. The secondary structure of BSA and GGF after contact with peptides was changed. A reduction in the α-helix structure was observed with an increase in the β-sheet and β-turn and random coil structures.

Monitoring the interactions between bovine serum albumin and ZnO/Ag nanoparticles by spectroscopic techniques

Inducing the bio-functionalization in noble metal nanoparticles like gold, silver, zinc is very important to accomplish their biocompatibility in biological activities. These metal nanoparticles are being rigorously used in bio-sensing tools keeping their remarkable properties in mind. Amongst the serum albumins, the most ample proteins in plasma are bovine serum albumin and human serum albumin. A broad variety of physiological functions of bovine serum albumin has made it a model protein for bio-functionalization. In the present study, ZnO/Ag nanoparticles were synthesized and characterized by SEM and XRD techniques and the interaction between bovine serum albumin and ZnO/Ag nanoparticles was evaluated by employing ultra-violet, steady state fluorescence, circular dichroism and FTIR spectroscopic techniques. Upon the excitation of bovine serum albumin, ZnO/Ag nanoparticles appreciably reduced the intrinsic fluorescence intensity of bovine serum albumin. The number of binding locations and apparent binding constants at different temperatures were calculated by the fluorescence quenching method. Static mechanism of quenching and conformational modifications in bovine serum albumin were also found.Communicated by Ramaswamy H. Sarma.

Elucidation of the binding mechanism of astragaloside IV derivative with human serum albumin and its cardiotoxicity in zebrafish embryos

LS-102 is a new derivative of astragaloside IV (AGS IV) that has been shown to possess potentially significant cardioprotective effects. However, there are no reports concerning its interaction with human serum albumin (HSA) and toxicology in vertebrates. The present investigation was undertaken to characterize the interaction of AGS IV and LS-102 with HSA using equilibrium dialysis and UHPLC-MS/MS methods, along with computational methods. Notably, the effects of AGS IV and LS-102 were studied in vivo using the zebrafish embryo model. Markers related to embryonic cardiotoxicity and thrombosis were evaluated. We showed that the plasma protein binding rate of AGS IV (94.04%–97.42%) was significantly higher than that of LS-102 (66.90%–69.35%). Through site marker competitive experiments and molecular docking, we found that AGS IV and LS-102 were located at the interface of subdomains IIA and IIIA, but the site I might be the primary binding site. Molecular dynamics revealed that AGS IV showed a higher binding free energy mainly due to the stronger hydrophobic and hydrogen bonding interactions. Moreover, the secondary structure implied no obvious effect on the protein structure and conformation during the binding of LS-102. LS-102 significantly ameliorated the astramizole-induced heart rate slowing, increased SV-BA spacing, and prevented arachidonic acid-induced thrombosis in zebrafish. To our knowledge, we are the first to reveal that LS-102 binds to HSA with reversible and moderate affinity, indicating its easy diffusion from the circulatory system to the target tissue, thereby providing significant insights into its pharmacokinetic and pharmacodynamic properties when spread in the human body. Our results also provide a reference for the rational clinical application of LS-102 in the cardiovascular field.

Dialdehyde Starch Nanocrystals as a Novel Cross-Linker for Biomaterials Able to Interact with Human Serum Proteins

In recent years, new cross-linkers from renewable resources have been sought to replace toxic synthetic compounds of this type. One of the most popular synthetic cross-linking agents used for biomedical applications is glutaraldehyde. However, the unreacted cross-linker can be released from the materials and cause cytotoxic effects. In the present work, dialdehyde starch nanocrystals (NDASs) were obtained from this polysaccharide nanocrystal form as an alternative to commonly used cross-linking agents. Then, 5-15% NDASs were used for chemical cross-linking of native chitosan (CS), gelatin (Gel), and a mixture of these two biopolymers (CS-Gel) via Schiff base reaction. The obtained materials, forming thin films, were characterized by ATR-FTIR, SEM, and XRD analysis. Thermal and mechanical properties were determined by TGA analysis and tensile testing. Moreover, all cross-linked biopolymers were also characterized by hydrophilic character, swelling ability, and protein absorption. The toxicity of obtained materials was tested using the Microtox test. Dialdehyde starch nanocrystals appear as a beneficial plant-derived cross-linking agent that allows obtaining cross-linked biopolymer materials with properties desirable for biomedical applications.

A novel strategy for screening angiotensin-converting enzyme inhibitors from natural products based on enzyme-immobilized ligand fishing combined with active-site blocking and directional enrichment

Some natural products are important sources of treatments for hypertension based on their potential inhibitory effects on angiotensin-converting enzyme (ACE); however, it is difficult to identify natural ACE inhibitors (ACEIs) due to the complex secondary metabolite environment of natural products. Enzyme immobilization is an important method for screening active constituents in natural products, but this method can sometimes return false-positive and false-negative results. To improve the accuracy and reliability of ligand-fishing methods, we established a novel strategy based on enzyme-immobilized ligand fishing combined with active-site blocking and directional enrichment technologies. We first synthesized ACE-immobilized mesoporous magnetic beads and then verified the screened compounds by molecular docking and in vitro activity detection. We then used active-site blocking to exclude non-specific binding constituents and applied directional enrichment to enrich the low-content constituents for ligand fishing. The screening identified six potential ACEIs from Scutellariae Radix and eight potential ACEIs from Lonicerae japonicae flos, and their inhibitory activity was confirmed by molecular docking simulations and in vitro activity detection. This process screened six additional compounds and excluded two false-positive results as compared with results exclusively using enzyme immobilization. This strategy provides a feasible method for screening active compounds in natural products.

In silico and multi-spectroscopic analyses on the interaction of 5-amino-8-hydroxyquinoline and bovine serum albumin as a potential anticancer agent

5-Amino-8-hydroxyquinoline (5A8HQ), an amino derivative of 8-hydroxyquinoline, has become a potential anticancer candidate because of its promising proteasome inhibitory activity to overcome and yet synergize bortezomib for fighting cancers. Therefore, in this study, its physicochemical properties and interaction activities with serum protein have extensively been elucidated by both in vitro and in silico approaches to fulfill the pharmacokinetic and pharmacodynamic gaps. 5A8HQ exhibited the drug-likeness properties, where oral administration seems to be a route of choice owing to its high-water solubility and intestinal absorptivity. Multi-spectroscopic investigations suggested that 5A8HQ tended to associate with bovine serum albumin (BSA), a representative of serum protein, via the ground-state complexation. It apparently bound in a protein cleft between subdomains IIA and IIIA of BSA as suggested by the molecular docking and molecular dynamics simulations. The binding was mainly driven by hydrogen bonding and electrostatic interactions with a moderate binding constant at 10⁴ M⁻¹, conforming with the predicted free fraction in serum at 0.484. Therefore, 5A8HQ seems to display a good bioavailability in plasma to reach target sites and exerts its potent pharmacological activity. Likewise, serum albumin is a good candidate to be reservoir and transporter of 5A8HQ in the circulatory system.

Potential and applications of capillary electrophoresis for analyzing traditional Chinese medicine: a critical review

Capillary electrophoresis (CE) presents a promising possibility for analyzing traditional Chinese medicine (TCM) due to its low reagent consumption, high analysis speed, and enhanced efficiency. Herein we review the employment of CE for analyzing the effective components in TCM and identifying TCM via a fingerprint. Furthermore, we discuss the application of state-of-the-art capillary electrophoresis modes for screening enzyme inhibitors and investigating the interactions between TCM and plasma proteins. The review concludes with recommendations for future studies and improvements in this field of research. The general development trend identified in this review indicates that the application of CE has significantly improved TCM assay performance.

A comprehensive review of integrative pharmacology-based investigation: A paradigm shift in traditional Chinese medicine

Over the past decade, traditional Chinese medicine (TCM) has widely embraced systems biology and its various data integration approaches to promote its modernization. Thus, integrative pharmacology-based traditional Chinese medicine (TCMIP) was proposed as a paradigm shift in TCM. This review focuses on the presentation of this novel concept and the main research contents, methodologies and applications of TCMIP. First, TCMIP is an interdisciplinary science that can establish qualitative and quantitative pharmacokinetics-pharmacodynamics (PK-PD) correlations through the integration of knowledge from multiple disciplines and techniques and from different PK-PD processes in vivo. Then, the main research contents of TCMIP are introduced as follows: chemical and ADME/PK profiles of TCM formulas; confirming the three forms of active substances and the three action modes; establishing the qualitative PK-PD correlation; and building the quantitative PK-PD correlations, etc. After that, we summarize the existing data resources, computational models and experimental methods of TCMIP and highlight the urgent establishment of mathematical modeling and experimental methods. Finally, we further discuss the applications of TCMIP for the improvement of TCM quality control, clarification of the molecular mechanisms underlying the actions of TCMs and discovery of potential new drugs, especially TCM-related combination drug discovery.

Evaluation of the antiglycating potential of thymoquinone and its interaction with BSA

Thymoquinone (TQ) is a bioactive component of medicinal plant, Nigella sativa. It has been identified as promising anti-inflammatory and anti-analgesic properties. In the present study, the TQ has been investigated for physiological interaction as well as binding properties with serum albumin and their thermodynamic parameters at different temperatures. Glycation process was checked with the measurement of fructosamine content, carbonyl content and total advanced glycated end products. The aggregation of amyloid β-structure was measured with Thioflavin-T and the secondary structure of BSA was observed by circular dichroism (CD) in glycated and thermal treated samples. The results indicate that the TQ showed binding interaction (both static and dynamic) with BSA (K_b= 18.31 × 10⁷ M^-1 at 293 K) and suppression of glycated products. The glycation-induced and thermal aggregation were prevented and the secondary structure of BSA was maintained. Therefore, these findings suggest that TQ may be used for a therapeutic drug for antiglycation as well as anti-aggregation.Communicated by Ramaswamy H. Sarma.

Molecular evidence of herbal formula: a network-based analysis of Si-Wu decoction

INTRODUCTION

Emerging network pharmacology (NP) combines phytochemical information with bioinformatics tools allowing herbal formulae to be illustrated holistically in the context of phytochemical basis and therapeutic mechanisms.

OBJECTIVE

This study attempted to explore the holistic molecular evidence of herbal formula Si-Wu decoction (SWD) by using the method of NP.

MATERIAL AND METHOD

Databases of traditional medicines combined with PubChem, SciFinder, SEA, STRING, and KEGG were employed to gather information for establishing the "compound similarity" (CS) network and the "target-(pathway)-target" (TPT) network. Gephi software was applied to visualise the networks, with further module-based and node-based network topological analysis. Moreover, the approved drugs and shortest path analysis were used to validate the TPT network.

RESULTS

The CS network presented the phytochemical profile of SWD, including the major compound groups of iridoid glycosides, glycosides, phthalide lactones, phenylpropanoids, and monoterpenoids. Furthermore, the topological analysis of TPT network depicted the holistic property of SWD in interpretable neuroendocrine immunomodulation (NIM) perspective, and the node degree analysis indicated a closer connection of SWD with endocrine or metabolism system. Moreover, by combing the analysis of the CS network and TPT network, potential active ingredients could be primarily identified.

CONCLUSION

The phytochemical profile and molecular target profile, which might pave the way for an understanding of SWD in modern science and provide a reference for relevant quality research and evaluation, were demonstrated by network analysis. Moreover, the methods could be further applied to discover the phytochemical or biomolecular evidence with distinct advantages in dealing with the tremendous separated information.

Integrated UPLC-MS/MS and UHPLC-Q-orbitrap HRMS Analysis to Reveal Pharmacokinetics and Metabolism of Five Terpenoids from Alpiniae oxyphyllae Fructus in Rats

BACKGROUND

Alpiniae oxyphyllae Fructus (AOF), a traditional Chinese medicine (TCM), is widely used in the treatment of urinary, gastrointestinal and neurologic diseases in China. Although terpenoids are the main active ingredients of AOF, there are few researches on their pharmacokinetics and metabolism.

METHODS

In this study, a sensitive, rapid, accurate and novel ultra high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was established to evaluate the pharmacokinetic behavior of five terpenoids (oxyphyllenodiol B, (4S*,5E,10R*)-7-oxo-tri-nor-eudesm-5-en-4β-ol, 7-epi-teucrenone, (+)- (4R,5S,7R)-13-hydroxynootkatone, (E)-labda-12,14-dien-15(16)-olide-17-oic acid) in rats after oral administration of AOF extracts. 27 metabolic metabolites of the five terpenoids were identified by ultra high performance liquid chromatography -Q Exactive hybrid quadrupole-orbitrap high-resolution accurate mass spectrometry (UHPLC-Q-Orbitrap HRMS) based on precise mass and fragment ions.

RESULTS

The established pharmacokinetic analysis method showed good linearity over a wide concentration range, and the lower quantitative limit (LLOQ) ranged from 0.97 to 4.25 ng/mL. Other validation parameters were within the acceptable range. In addition, 27 metabolites were identified in plasma, urine and feces samples, and the metabolic pathways of five terpenoids were mainly focused on glucoside conjugation, dehydration, desaturation and glycine conjugation.

CONCLUSION

This is the first study on the pharmacokinetics and metabolism of five terpenoids in AOF, illuminating the disposal process of terpenoids in vivo. It was expected that the results of this study would provide some references for the apprehension of the action mechanism and the further pharmacological study of five terpenoids in AOF.

Physico-chemical interactions of a new rod-coil-rod polymer with liposomal system: Approaches to applications in tryptophan-related therapies

This work describes the synthesis of the new supramolecular rod-coil-rod polymer, designated as cholesterol-PEO₁₀₀₀-tryptophan (Chl-PEO-Trp), as well as its effects on the physico-chemical properties of phosphatidylcholine (PC)-based liposomes. The molecular interactions between the Chl-PEO-Trp and PC were characterized by HATR-FTIR, DSC, NMR, DLS and zeta (ζ) potential techniques. The Chl-PEO-Trp polymer yield was 75 %. FTIR and DSC data showed that the motion of almost all PC groups was restricted by the polymer, and it promoted a decrease of the trans-gauche isomerization of the PC methylene, restricting the mobility of the hydrophobic region of the liposomes. NMR analyses indicated a Chl-PEO-Trp-induced restriction in the rotation of the PC phosphorus and a discreet increase of the hydrogen mobility of the choline. Despite this increase in the rotation of the choline, DLS and ζ-potential analyses suggested a reorientation of the choline group toward the system surface, which contributed, along with the other physico-chemical effects, to a globally packed membrane arrangement and reduced liposome size. Data described in this work were correlated to possible applications of the Chl-PEO-Trp in its free or PC liposome-loaded forms in the diagnosis and therapy of cancer, SARS caused by coronaviruses, and central nervous system-related diseases.

Synthesis and biological properties of a series of aryl alkyl disulfide derivatives

Disulfide containing compounds are recognized for their wide range of biological properties and are known for their important applications in the pharmaceutical field. In this study, a series of diaryl disulfides with varying alkyl chain length (C8-C16) was synthesized and assessed for their physicochemical and biological properties. The interactions of compounds with bovine serum albumin (BSA) was investigated in order to study their ability to bind with blood serum protein. An increase in the binding constants (Ka) was observed with increasing chain length C8-C12, while a decrease in value was obtained with compounds of chain length C14 and C16 showing a cut off effect at C12. The thermodynamic parameters of binding indicated that the compounds bound to BSA mostly by van der Waals forces and hydrogen bonding. Molecular docking studies showed that the diaryl disulfides displayed greater binding affinity to Trp 213 rather than the Trp 134 residue on the BSA molecule. The trend observed in molecular docking is in line with the fluorescence binding studies whereby the C12 derivative was found to show optimum affinity with BSA. The disulfide with chain length C10 showed moderate antibacterial activity the highest inhibitory activity against Bacillus cereus. The cytotoxicity of the disulfides towards HaCaT cells decreased from C8 to C14. The overall results obtained show that these disulfides have potent antibacterial properties against Gram-positive bacteria Bacillus cereus at concentrations which are relatively non-toxic to normal cells.

Investigation of interactions between cytochrome c and ginsenosides by native mass spectrometry and molecular docking simulations

RATIONALE

Ginsenosides are considered to be the main functional components in ginseng and possess various important pharmacological activities. The study of the interactions between ginsenosides and proteins is indispensable for understanding the pharmacological activities of ginsenosides. In this work, the interactions of ginsenosides with cytochrome c (cyt c) were investigated by native mass spectrometry and molecular docking simulations.

METHODS

The interactions of four ginsenosides (Rb₁ , Rb₃ , Rf, Rg₁ ) and cyt c in NH₄ OAc solution were investigated by electrospray ionization linear ion trap mass spectrometry (ESI-LTQ-MS). Molecular docking simulations of cyt c complexes were carried out by AutoDock.

RESULTS

The native mass spectrometry results showed that the four ginsenosides were directly bound to cyt c, with stoichiometric ratios of 1:1 and 2:1 in NH₄ OAc. The order of relative binding abilities of ginsenosides to cyt c obtained by ESI-MS was Rb₁  > Rb₃  > Rf > Rg₁ , which was consistent with the docking results. Moreover, molecular docking simulations also indicated potential binding sites of cyt c and ginsenosides. Hydrogen-bond interaction played a very important role in cyt c binding with ginsenosides.

CONCLUSIONS

It has been demonstrated that native MS is a useful tool to investigate the interactions of ginsenosides with cyt c. Molecular docking is a good complement to ESI analysis, and can provide information on potential binding sites of cyt c-ginsenoside complexess. This strategy will be helpful to further understand the interactions of proteins and small molecules.

Study on the Plasma Protein Binding Rate and Compatibility Regularity of the Constituents Migrating to Blood of Simiao Yong'an Decoction

OBJECTIVE

To study the compatibility regularity of Simiao Yong'an decoction by determining the plasma protein binding rate with the constituents in Simiao Yong'an decoction and to preliminarily clarify the effects of the compatibility on the plasma protein binding rate of different components.

METHODS

Based on the equilibrium dialysis method, high-performance liquid chromatography was used to determine the contents of six constituents, which were divided into a single group and combination groups, in Simiao Yong'an decoction in the internal and external dialysis solutions. The obtained plasma protein binding rate through calculations was an index to evaluate the binding of the above components to plasma protein in different conditions.

RESULTS

Harpagide, harpagoside, sweroside and loganin showed low plasma protein binding rates, ferulic acid exhibited a moderate plasma protein binding rate, and glycyrrhizic acid showed a high plasma protein binding rate. The compatibility study showed that glycyrrhizic acid promoted the binding of ferulic acid to plasma protein. Glycyrrhizic acid and ferulic acid were the key compounds to promote the binding of harpagide to plasma protein. Glycyrrhizic acid, harpagide, harpagoside and loganin had a significant inhibitory effects on the binding of sweroside to plasma protein. The plasma protein binding capacities of harpagoside and loganin were reduced by the other five constituents. Glycyrrhizic acid had the strongest plasma protein binding effect, and the binding effect was not affected by other components.

CONCLUSION

This study explores the effects of compound compatibility on effective components from the perspective of plasma protein binding by high-performance liquid chromatography combined with the equilibrium dialysis method, and lays a foundation for clarifying the compatibility rule of Simiao Yong'an decoction and also provides a new idea for the study of the compatibility of traditional Chinese medicine formulas.

Impact of Drug Metabolism/Pharmacokinetics and their Relevance Upon Traditional Medicine-based Cardiovascular Drug Research

BACKGROUND

The representative cardiovascular herbs, i.e. Panax, Ligusticum, Carthamus, and Pueraria plants, are traditionally and globally used in the prevention and treatment of various cardiovascular diseases. Modern phytochemical studies have found many medicinal compounds from these plants, and their unique pharmacological activities are being revealed. However, there are few reviews that systematically summarize the current trends of Drug Metabolism/Pharmacokinetic (DMPK) investigations of cardiovascular herbs.

METHODS

Here, the latest understanding, as well as the knowledge gaps of the DMPK issues in drug development and clinical usage of cardiovascular herbal compounds, was highlighted.

RESULTS

The complicated herb-herb interactions of cardiovascular Traditional Chinese Medicine (TCM) herb pair/formula significantly impact the PK/pharmacodynamic performance of compounds thereof, which may inspire researchers to develop a novel herbal formula for the optimized outcome of different cardiovascular diseases. While the Absorption, Distribution, Metabolism, Excretion and Toxicity (ADME/T) of some compounds has been deciphered, DMPK studies should be extended to more cardiovascular compounds of different medicinal parts, species (including animals), and formulations, and could be streamlined by versatile omics platforms and computational analyses.

CONCLUSION

In the context of systems pharmacology, the DMPK knowledge base is expected to translate bench findings to clinical applications, as well as foster cardiovascular drug discovery and development.

Study on the Interactions Between Caffeoylquinic Acids With Bovine Serum Albumin: Spectroscopy, Antioxidant Activity, LC-MSn, and Molecular Docking Approach

Clarified the binding mechanism of drugs with plasma proteins could provide fresh insights into the drug development. Caffeoylquinic acids (CQAs) are a kind of phenolic acid compounds which has extensive biological effects. This study investigated the binding mechanism of three CQAs, including chlorogenic acid, neochlorogenic acid, and cryptochlorogenic acid, with bovine serum albumin (BSA) by using multi-spectroscopic techniques, including fluorescence, UV-Vis, Fourier transform infrared (FT-IR) and circular dichroism (CD) spectroscopy, LC-MSⁿ, molecular docking and antioxidant activity assessment. In addition, the influences of PBS buffer, Tris-HCl buffer and water as solvents on the characteristics of CQAs and BSA interaction were also investigated. The results showed that intrinsic fluorescence of BSA was quenched by CQAs and the interaction was static quenching with the formation of a non-fluorescent complex. The binding of CQAs and BSA was spontaneous, and Van der Waals forces and hydrogen-bond interaction occupied crucial roles in the binding. All the three CQAs could bind to Site I in Domain IIA. The weakest interaction between neochlorogenic acid and BSA may due to its larger polarity. The results also indicated that the binding affinity of CQAs had a descending order of Tris-HCl > H₂O > PBS. This study firstly clarified the binding mechanism of CQAs with BSA and changes of the binding in different solvents, and provided fresh insights into this drug transportation and metabolism.

The dipeptidyl peptidase-4 inhibitory effect of flavonoids is hindered in protein rich environments

Dipeptidyl peptidase-4 (DPP-4) inhibitors present a unique approach for the management of type 2 diabetes (T2D). In the present study, the inhibition of DPP-4 was evaluated for a large panel of flavonoids, important components of the human diet, using in vitro and ex vivo models. The activity of the isolated enzyme was assayed in vitro. Subsequently, the most active flavonoids were tested ex vivo in human whole blood and plasma. In this study, contrary to the in vitro fluorometric tests, flavonoids did not show inhibitory activity against DPP-4. Due to the discrepancy in the results between the in vitro and ex vivo approaches, plasma protein binding values were determined, presenting values from 43.9 to 100.0%. This work provides a new insight into the inhibitory activity for DPP-4, based on the flavonoid scaffold. Additionally, the obtained results showed that the inhibitory effect of flavonoids against DPP-4 was hindered in protein rich environments, like that occurring in blood, and indicated the need for experimental refinement in drug discovery for blood targets.