Enhanced polarization switching characteristics of HfO2 ultrathin films via acceptor-donor co-doping.

In the realm of ferroelectric memories, HfO2-based ferroelectrics stand out because of their exceptional CMOS compatibility and scalability. Nevertheless, their switchable polarization and switching speed are not on par with those of perovskite ferroelectrics. It is widely acknowledged that defects play a crucial role in stabilizing the metastable polar phase of HfO2. Simultaneously, defects also pin the domain walls and impede the switching process, ultimately rendering the sluggish switching of HfO2. Herein, we present an effective strategy involving acceptor-donor co-doping to effectively tackle this dilemma. Remarkably enhanced ferroelectricity and the fastest switching process ever reported among HfO2 polar devices are observed in La3+-Ta5+ co-doped HfO2 ultrathin films. Moreover, robust macro-electrical characteristics of co-doped films persist even at a thickness as low as 3 nm, expanding potential applications of HfO2 in ultrathin devices. Our systematic investigations further demonstrate that synergistic effects of uniform microstructure and smaller switching barrier introduced by co-doping ensure the enhanced ferroelectricity and shortened switching time. The co-doping strategy offers an effective avenue to control the defect state and improve the ferroelectric properties of HfO2 films.

Discovery and identification of interspecies peptide biomarkers in the seahorse species using liquid chromatography tandem mass spectrometry and chemometrics.

Seahorses have important edible and medicinal values including strengthening the body, tonifying the liver and kidneys, and reducing swelling. And there are abundant seahorse species on Earth. Many seahorses have large price differences due to the scarcity of resources, and some seahorses with similar appearances appear to be confused for use. While in market trading, Hippocampus is susceptible to loss of specialized morphology characteristics, making it difficult to distinguish between specific species. Here we report an effective method based on peptide biomarkers for the identification of seahorse species. Peptide biomarkers for each species were predicted using nano-liquid chromatography-tandem mass spectrometry (Nano-LC-MS/MS) combined with chemometrics software. One unique biomarker peptide for each species was synthesized and verified, and finally developed a liquid chromatography tandem mass spectrometry (LC-MS/MS) multiple reaction monitoring method. The results indicate that the method has great potential for species-specific identification of seahorses and their preparations, among others.

A quality-comprehensive-evaluation-index-based model for evaluating traditional Chinese medicine quality.

BACKGROUND: Evaluating traditional Chinese medicine (TCM) quality is a powerful method to ensure TCM safety. TCM quality evaluation methods primarily include characterization evaluations and separate physical, chemical, and biological evaluations; however, these approaches have limitations. Nevertheless, researchers have recently integrated evaluation methods, advancing the emergence of frontier research tools, such as TCM quality markers (Q-markers). These studies are largely based on biological activity, with weak correlations between the quality indices and quality. However, these TCM quality indices focus on the individual efficacies of single bioactive components and, therefore, do not accurately represent the TCM quality. Conventionally, provenance, place of origin, preparation, and processing are the key attributes influencing TCM quality. In this study, we identified TCM-attribute-based quality indices and developed a comprehensive multiweighted multi-index-based TCM quality composite evaluation index (QCEI) for grading TCM quality. METHODS: The area of origin, number of growth years, and harvest season are considered key TCM quality attributes. In this study, licorice was the model TCM to investigate the quality indicators associated with key factors that are considered to influence TCM quality using multivariate statistical analysis, identify biological-evaluation-based pharmacological activity indicators by network pharmacology, establish real quality indicators, and develop a QCEI-based model for grading TCM quality using a machine learning model. Finally, to determine whether different licorice quality grades differently reduced the inflammatory response, TNF-α and IL-1ß levels were measured in RAW 264.7 cells using ELISA analysis. RESULTS: The 21 quality indices are suitable candidates for establishing a method for grading licorice quality. A computer model was established using SVM analysis to predict the TCM quality composite evaluation index (TCM QCEI). The tenfold cross validation accuracy was 90.26%. Licorice diameter; total flavonoid content; similarities of HPLC chromatogram fingerprints recorded at 250 and 330 nm; contents of liquiritin apioside, liquiritin, glycyrrhizic acid, and liquiritigenin; and pharmacological activity quality index were identified as the key indices for constructing the model for evaluating licorice quality and determining which model contribution rates were proportionally weighted in the model. The ELISA analysis results preliminarily suggest that the inflammatory responses were likely better reduced by premium-grade than by first-class licorice. CONCLUSIONS: In the present study, traditional sensory characterization and modern standardized processes based on production process and pharmacological efficacy evaluation were integrated for use in the assessment of TCM quality. Multidimensional quality evaluation indices were integrated with a machine learning model to identify key quality indices and their corresponding weight coefficients, to establish a multiweighted multi-index and comprehensive quality index, and to construct a QCEI-based model for grading TCM quality. Our results could facilitate and guide the development of TCM quality control research.

Discovery of species-specific peptide markers and development of quality-evaluation strategies for deer horn gelatin using liquid chromatography-tandem mass spectrometry and a label-free methodology.

Deer horn gelatin (DHG) is a valuable nutritional dietary supplement. Due to the significant variation in the price of DHG from different sources, it is important to assess its quality and to clarify the species of its raw material. However, due to the similarity in appearance and physicochemical properties, as well as the destruction of genetic material during the manufacturing process, it is difficult to distinguish DHG from gelatin derived from other sources. Furthermore, current methods are unable to evaluate the overall quality of DHG. Using Nano LC-Orbitrap MS and data analysis software, DHG samples from five deer species were analyzed to identify peptide markers specific to alpha-2-HS-glycoprotein (AHSG) and collagen. The peptide markers were validated using HPLC-Triple Quadrupole MS, and strategies for assessing the quality of DHG were developed. Eighteen peptide markers were discovered, comprising peptides with differing specificities. Three strategies for the identification, characteristic mapping, and content determination of DHG were developed. These strategies can be used to assess the quality of deer gelatin.

On-line identification of the chemical constituents of Polygoni Multiflori Radix by UHPLC-Q-ToF MS/MS.

Introduction: Polygoni Multiflori Radix (PMR) is a type of Chinese herbal medicine with rich chemical composition and pharmacological activity used widely in medicine and food. However, in recent years, there have been increasing numbers of negative reports about its hepatotoxicity. Identification of its chemical constituents for quality control and safe use is very important. Methods: Three solvents of different polarities (water, 70% ethanol, and 95% ethanol solution) were used to extract the compounds from PMR. Extracts were analyzed and characterized by ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-Q-ToF MS/MS) in the negative-ion mode. Results: 152 compounds were detected and identified: 50 anthraquinones, 33 stilbene derivatives, 21 flavonoids, seven naphthalene compounds, and 41 other compounds. Eight other compounds were reported for the first time in the PMR-related literature, and eight other compounds were potentially new compounds. Discussion: This study lays a solid foundation for the screening of toxicity and quality-control indicators of PMR.

Exploratory Quality Control Study for Polygonum multiflorum Thunb. Using Dinuclear Anthraquinones with Potential Hepatotoxicity.

In recent years, the hepatotoxicity of Polygoni Multiflora Radix (PMR) has attracted increased research interest. Some studies suggest that anthraquinone may be the main hepatotoxic component. Most of the relevant studies have focused on the mononuclear anthraquinone component rather than binuclear anthraquinones. The hepatotoxicity of dinuclear anthraquinone (dianthrone) was investigated in a cell-based model. Next, a method for the determination of six free and total dianthonones in PMR and PMR Praeparata (PMRP) was established using ultra-high-performance liquid chromatography triple quadrupole mass spectrometry (UPLC-QQQ-MS/MS), which was then used to analyze the collected samples. The data show that four binuclear anthraquinone compounds were hepatotoxic and may be potential toxicity indicators for the safety evaluation of PMR and PMRP. Herein, we provide a theoretical basis for the improvement of PMRP quality standards.

A stepwise strategy integrating metabolomics and pseudotargeted spectrum-effect relationship to elucidate the potential hepatotoxic components in Polygonum multiflorum.

Polygonum multiflorum (PM) Thunb., a typical Chinese herbal medicine with different therapeutic effect in raw and processed forms, has been used worldwide for thousands of years. However, hepatotoxicity caused by PM has raised considerable concern in recent decades. The exploration of toxic components in PM has been a great challenge for a long time. In this study, we developed a stepwise strategy integrating metabolomics and pseudotargeted spectrum-effect relationship to illuminate the potential hepatotoxic components in PM. First, 112 components were tentatively identified using ultraperformance liquid chromatography-quadrupole-time-of-flight-mass spectrometry (UPLC-Q-TOF-MS). Second, based on the theory of toxicity attenuation after processing, we combined the UPLC-Q-TOF-MS method and plant metabolomics to screen out the reduced differential components in PM between raw and processed PM. Third, the proposed pseudotargeted MS of 16 differential components was established and applied to 50 batches of PM for quantitative analysis. Fourth, the hepatocytotoxicity of 50 batches of PM was investigated on two hepatocytes, LO2 and HepG2. Last, three mathematical models, gray relational analysis, orthogonal partial least squares analysis, and back propagation artificial neural network, were established to further identify the key variables affecting hepatotoxicity in PM by combining quantitative spectral information with toxicity to hepatocytes of 50 batches of PM. The results suggested that 16 components may have different degrees of hepatotoxicity, which may lead to hepatotoxicity through synergistic effects. Three components (emodin dianthrones, emodin-8-O-ß-D-glucopyranoside, PM 14-17) were screened to have significant hepatotoxicity and could be used as toxicity markers in PM as well as for further studies on the mechanism of toxicity. Above all, the study established an effective strategy to explore the hepatotoxic material basis in PM but also provides reference information for in-depth investigations on the hepatotoxicity of PM.

Application of Multiple-Source Data Fusion for the Discrimination of Two Botanical Origins of Magnolia Officinalis Cortex Based on E-Nose Measurements, E-Tongue Measurements, and Chemical Analysis.

Magnolia officinalis Rehd. et Wils. and Magnolia officinalis Rehd. et Wils. var. biloba Rehd. et Wils, as the legal botanical origins of Magnoliae Officinalis Cortex, are almost impossible to distinguish according to their appearance traits with respect to medicinal bark. The application of AFLP molecular markers for differentiating the two origins has not yet been successful. In this study, a combination of e-nose measurements, e-tongue measurements, and chemical analyses coupled with multiple-source data fusion was used to differentiate the two origins. Linear discriminant analysis (LDA) and quadratic discriminant analysis (QDA) were applied to compare the discrimination results. It was shown that the e-nose system presented a good discriminant ability with a low classification error for both LDA and QDA compared with e-tongue measurements and chemical analyses. In addition, the discriminating capacity of LDA for low-level fusion with original data, similar to a combined system, was superior or equal to that acquired individually with the three approaches. For mid-level fusion, the combination of different principals extracted by PCA and variables obtained on the basis of PLS-VIP exhibited an analogous discrimination ability for LDA (classification error 0.0%) and was significantly superior to QDA (classification error 1.67-3.33%). As a result, the combined e-nose, e-tongue, and chemical analysis approach proved to be a powerful tool for differentiating the two origins of Magnoliae Officinalis Cortex.

Corrigendum: Systematic Characterization and Identification of Saikosaponins in Extracts From Bupleurum marginatum var. stenophyllum Using UPLC-PDA-Q/TOF-MS.

[This corrects the article DOI: 10.3389/fchem.2021.747987.].

Identification of Dominant Strains in Liu Shenqu by MALDI-TOF MS and DNA Sequencing Methods.

BACKGROUND: Liu Shenqu has been widely used to treat the illnesses of spleen and stomach, indigestion, etc. in China. As a fermented product, strains play an important role in the fermentation process, which will affect the quality of Liu Shenqu. Therefore, it is important to identify the dominant strains in the fermentation process of Liu Shenqu. OBJECTIVES: Identify dominant strains in the fermentation process of Liu Shenqu and provide a theoretical reference for the fermentation of fixed strains in industrial production. METHODS: In this study, we aim to identify the dominant strains in Liu Shenqu through matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) combined with DNA sequencing methods. This research involves two parts: MALDI-TOF MS identifies the dominant bacteria, and the Sanger sequencing method identifies the dominant fungi. RESULTS: A total of 21 bacterial species were identified by MALDI-TOF MS and 21 fungi species were identified by Sanger sequencing. We searched the types of enzymes in the identified strains based on the GB2760-2014 National Food Safety Standard and Food Additives Use Standard (China). We compared the types of enzymes reported in Liu Shenqu with the types of enzymes retrieved in GB2760-2014 National Food Safety Standard and Food Additives Use Standard: Aspergillus oryzae and Rhizopus oryzae were determined to be the dominant strains in Liu Shenqu. CONCLUSION: This study showed that MALDI-TOF MS combined with DNA sequencing methods could be used for identification of the dominant strains in Liu Shenqu. This strategy is promising for application to strain identification in other fermented products. HIGHLIGHTS: Fresh products were frozen and transported in bacteria-preserving tubes to ensure the authenticity of the number and type of strains of Liu Shenqu. MALDI-TOF MS combined with DNA sequencing methods was successfully applied to identify the dominant strains in the fermentation process of Liu Shenqu for the first time. Aspergillus oryzae and Rhizopus oryzae were determined to be the dominant strains in Liu Shenqu.

Pharmacokinetics and metabolism of trans-emodin dianthrones in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Polygonum multiflorum Thunb. (PM) is a common traditional Chinese medicine with diverse biological activities of resolving toxins, nourishing livers and promoting hairs. Nevertheless, in recent years hepatotoxic adverse reactions caused by the administration of PM have raised worldwide concerns. In our previous study, we found that emodin dianthrones showed hepatotoxicity and may be potential toxicity markers. However, the metabolic transformation and pharmacokinetic behavior of emodin dianthrones in vivo have still not been elucidated. AIM OF THE STUDY: Taking trans-emodin dianthrones (TED) as an example, the present study was conducted to investigate the pharmacokinetics and bioavailability of TED in rats and characterized its metabolic transformation in the plasma, urine and feces of rats. MATERIALS AND METHODS: A rapid and sensitive UPLC-qqq-MS/MS method was developed for accurate quantification of TED in plasma and successfully applied to the pharmacokinetic evaluation of TED in rats after intravenous and oral administration. A reliable UFLC-Q-TOF-MS high resolution mass spectrometry combined with a scientific metabolite identification strategy was used to comprehensively characterize the metabolic transformation of TED in plasma, urine and feces in rats. RESULTS: The established UPLC-qqq-MS/MS method had a linear range of 1-500 ng/mL, and the method was accurate and reliable to meet the quantitative requirements. When 20 mg/kg TED was given by gavage rats, it was rapidly absorbed into the circulatory system and had a long half-life time of 6.44 h and wide tissue distribution in vivo. While intravenous injection of 0.4 mg/kg TED in rats, it was rapidly metabolized and eliminated with a half-life time of 1.82 h. The oral absorption bioavailability of TED was only 2.83%. Furthermore with a sensitive UFLC-Q-TOF-MS technique and metabolite identification strategy, 21 metabolites were successfully identified, including 11 in plasma, 12 in urine and 18 in feces. The main Ⅰ and Ⅱ phase metabolic processes involved glucuronidation, oxidation, carbonylation, (de)methylation, sulfation and hydrogenation. CONCLUSION: TED could be rapidly absorbed into the blood circulation and widely distributed and slowly metabolized in the body and underwent extensive cleavage and metabolic transformation in vivo. The study provided a basis for in-depth elucidation of the toxicology and mechanism research of TED, but also laid the foundation for further research on the material basis of hepatotoxicity of PM.

Identification of Pulsatilla chinensis (Bge.) Regel and look-alike species by UHPLC-TOF-MS using multivariate statistical analysis.

Pulsatillae Radix, the root of Pulsatilla chinensis (Bge.) Regel, is recorded in the Pharmacopoeia of the People's Republic of China and has been widely used for its pharmacological activities, such as anti-inflammatory, antioxidant, antibacterial, antitumor, and cardiovascular benefits. However, there are several look-alike species that can be marketed as Pulsatillae Radix. To distinguish P. chinensis (Bge.) Regel from its look-alikes, viz. Pulsatilla cernua (Thunb.) Bercht et Opiz., Pulsatilla dahurica (Fisch.) Spreng., Anemone tomeutosa (Maxim.) Pei., and Rhaponticum uniflorum (L.) DC, we used ultra high performance liquid chromatography with time-of-flight mass spectrometry combined with principal component analysis to compare their chemical compositions. Four ions, a (RT 8.98 min, m/z 1381.6671), b (RT 10.64 min, m/z 1219.6143), c (RT 11.52 min, m/z 1217.5978), and d (RT 13.6 min, m/z 749.4463), from P. chinensis (Bge.) Regel were identified as potential chemical markers to distinguish it from look-alike species using an unsupervised statistical model combined with orthogonal partial least-squares discriminant analysis. The results of this study provide an effective method for identifying and distinguishing P. chinensis (Bge.) Regel from similar plants.

A general procedure for establishing composite quality evaluation indices based on key quality attributes of traditional Chinese medicine.

Licorice, a medicinal herb and food flavor ingredient, has been widely used in traditional Chinese medicine (TCM) for the past 4000 years. In this study, we propose a new quality evaluation approach for licorice quality control based on the key quality attributes commonly used in TCM. The high quality of TCM formulations is ensured by verifying the genuine origin and implementing good agricultural and collection practices for each medicinal herb. In our study, the genuine production area, the harvest season, and the number of growth years were considered the key quality attributes of TCM. To ensure the representativeness of our analysis, we obtained a total of 158 licorice sample batches that differed in the number of growth years, the location of the production areas, and the season for harvesting. Initially, the 158 sample batches were subjected to ultra-high-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UHPLC-QTOF-MS/MS). A preliminary screen identified 11 licorice compounds related to the three key quality attributes of TCM . An analysis by ultra-high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry (UHPLC-TQ-MS/MS) verified the presence of 34 compounds in all licorice samples. These 34 compounds included the 11 compounds related to the three key quality attributes of the samples, along with other bioactive components identified in previous studies. After using UHPLC-TQ-MS/MS to assess the signal peak intensities of the 34 compounds, we selected 17 licorice compounds to establish sample content evaluation indices, which were determined by high-performance liquid chromatography at four different wavelengths in all 158 licorice sample batches. Finally, the screen identified nine compounds that were closely associated with the quality attributes of licorice based on principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA). Our results suggested that liquiritin and eight other compounds could be used as quality control indicators of licorice, which provided a foundation to establish the TCM quality composite evaluation index (TCM QCEI). In summary, this research concept can serve as a reference for research on quality markers and the evaluation of TCM.

Systematic Characterization and Identification of Saikosaponins in Extracts From Bupleurum marginatum var. stenophyllum Using UPLC-PDA-Q/TOF-MS.

Saikosaponins comprise a large group of chemical components present in the Bupleurum species that have attracted attention in the field of medicine because of their significant biological activities. Due to the high polarity, structural similarity, and the presence of several isomers of this class of components, their structural identification is extremely challenging. In this study, the mass spectrometric fragmentation pathways, UV spectral features, and chromatographic behavior of different types of saikosaponins were investigated using 24 standard substances. Saikosaponins containing carbonyl groups (C=O) in the aglycone produced fragment ions by loss of 30 Da, and in addition, type IV saikosaponins could produce [aglycone-CH2OH-OH-H]- and [aglycone-H2O-H]- fragment ions through neutral losses at positions C16 and C17. The above characteristic ions can be used to identify saikosaponins. More notably, the identification process of saikosaponins was systematically summarized, and using this method, 109 saikosaponins were identified or tentatively characterized from the saikosaponins extract of Bupleurum marginatum var. stenophyllum (BMS) using UPLC-PDA-Q/TOF-MS with both data-dependent acquisition (DDA) and data-independent acquisition (DIA) modes, of which 25 were new compounds and 60 were first discovered from BMS. Further studies revealed that the saikosaponins profiles of BMS, Bupleurum chinense DC (BC), and Bupleurum marginatum Wall. ex DC (BMW) were very similar. This work is of great significance for the basic research of the Bupleurum species and provides strong technical support to solve the resource problems associated with Radix Bupleuri.

Machine learning methods to predict the cultivation age of Panacis Quinquefolii Radix.

BACKGROUND: American ginseng (AG) is a valuable medicine widely consumed as a herbal remedy throughout the world. Huge price difference among AG with different growth years leads to intentional adulteration for higher profits. Thus, developing reliable approaches to authenticate the cultivation ages of AG products is of great use in preventing age falsification. METHODS: A total of 106 batches of AG samples along with their 9 physicochemical features were collected and measured from experiments, which was then split into a training set and two test sets (test set 1 and 2) according to the cultivation regions. Principle component analysis (PCA) was carried out to examine the distribution of the three data sets. Four machine learning (ML) algorithms, namely elastic net, k-nearest neighbors, support vector machine and multi-layer perception (MLP) were employed to construct predictive models using the features as inputs and their growth years as outputs. In addition, a similarity-based applicability domain (AD) was defined for these models to ensure the reliability of the predictive results for AG samples produced in different regions. RESULTS: A positive correlation was observed between the several features and the growth years. PCA revealed diverse distributions among different cultivation regions. The most accurate model derived from MLP shows good prediction power for the fivefold cross validation and the test set 1 with mean square error (MSE) of 0.017 and 0.016 respectively, but a higher MSE value of 1.260 for the test set 2. After applying the AD, all models showed much lower prediction errors for the test samples within AD (IDs) than those outside the AD (ODs). MLP remains the best predictive model with an MSE value of 0.030 for the IDs. CONCLUSION: Cultivation years have a close relationship with bioactive components of AG. The constructed models and AD are also able to predict the cultivation years and discriminate samples that have inaccurate prediction results. The AD-equipped models used in this study provide useful tools for determining the age of AG in the market and are freely available at https://github.com/dreadlesss/Panax_age_predictor .

UHPLC-QQQ-MS/MS assay for the quantification of dianthrones as potential toxic markers of Polygonum multiflorum Thunb: applications for the standardization of traditional Chinese medicines (TCMs) with endogenous toxicity.

BACKGROUND: The raw and processed roots of Polygonum multiflorum Thunb (PM) are commonly used in clinical practice to treat diverse diseases; however, reports of hepatotoxicity induced by Polygoni Multiflori Radix (PMR) and Polygoni Multiflori Radix Praeparata (PMRP) have emerged worldwide. Thus, it is necessary for researchers to explore methods to improve quality standards to ensure their quality and treatment effects. METHODS: In the present study, an ultra-high performance liquid chromatography triple quadrupole mass spectrometry (UHPLC-QQQ-MS/MS) method was optimized and validated for the determination of dianthrones in PMR and PMRP using bianthronyl as the internal standard. Chromatographic separation with a gradient mobile phase [A: acetonitrile and B: water containing 0.1% formic acid (v/v)] at a flow rate of 0.25 mL/min was achieved on an Agilent ZORBAX SB-C18 column (2.1 mm × 50 mm, 1.8 µm). The triple quadrupole mass spectrometer (TQMS) was operated in negative ionization mode with multiple reaction monitoring for the quantitative analysis of six dianthrones. Moreover, compounds 5 and 6 were further evaluated for their cytotoxicity in HepaRG cells by CCK-8 assay. RESULTS: The UHPLC-QQQ-MS/MS method was first developed to simultaneously determine six dianthrones in PMR and PMRP, namely, polygonumnolides C1-C4 (1-4), trans-emodin dianthrones (5), and cis-emodin dianthrones (6). The contents of 1-6 in 90 batches of PMR were in the ranges of 0.027-19.04, 0.022-13.86, 0.073-15.53, 0.034-23.35, 0.38-83.67 and 0.29-67.00 µg/g, respectively. The contents of 1-6 in 86 batches of commercial PMRP were in the ranges of 0.020-13.03, 0.051-8.94, 0.022-7.23, 0.030-12.75, 0.098-28.54 and 0.14-27.79 µg/g, respectively. Compounds 1-4 were almost completely eliminated after reasonable processing for 24 h and the contents of compounds 5 and 6 significantly decreased. Additionally, compounds 5 and 6 showed inhibitory activity in HepaRG cells with IC50 values of 10.98 and 15.45 µM, respectively. Furthermore, a systematic five-step strategy to standardize TCMs with endogenous toxicity was proposed for the first time, which involved the establishment of determination methods, the identification of potentially toxic markers, the standardization of processing methods, the development of limit standards and a risk-benefit assessment. CONCLUSION: The results of the cytotoxicity evaluation of the dianthrones indicated that trans-emodin dianthrones (5) and cis-emodin dianthrones (6) could be selected as toxic markers of PMRP. Taking PMR and PMRP as examples, we hope this study provides insight into the standardization and internationalization of endogenous toxic TCMs, with the main purpose of improving public health by scientifically using TCMs to treat diverse complex diseases in the future.

Advances in Understanding the Metabolites and Metabolomics of Polygonum multiflorum Thunb: A Mini-review.

BACKGROUND: The roots of Polygonum multiflorum (PM) are a well-known traditional Chinese medicine, widely used to treat a variety of conditions in Southeast Asia, South Korea, Japan and other countries. It is known that Polygoni Multiflori Radix Praeparata (PMRP) may enhance the efficacy and reduce the toxicity of PM. However, reports of adverse reactions, such as hepatotoxicity, caused by PM or PMRP, have continuously appeared around the world, which increased the known risks of the medication and gradually gained the extensive attention of many researchers. The chemical constituents of PM that cause hepatotoxicity have not been distinctly elucidated using the traditional phytochemical screening. Recently, with the rapid development of metabolomics, there has been a growing need to explore the potential hepatotoxic components and mechanisms of PM. METHODS: The metabolites and metabolomics of PM were searched by the Web of Science, PubMed, Google scholar and some Chinese literature databases. RESULTS: A brief description of metabolites and metabolomics of PM is followed by a discussion on the metabolite- induced toxicity in this review. More than 100 metabolites were tentatively identified and this will contribute to further understanding of the potential hepatotoxic components of PM. Meanwhile, some toxic compounds were identified and could be used as potential toxic markers of PM. CONCLUSION: This review mainly outlines the metabolites and metabolomics of PM that have been identified in recent years. This study could help to clarify the potential hepatotoxic components and metabolic mechanisms of PM and provide a scientific reference for its safe clinical use in the future.

Systemic elucidation on the potential bioactive compounds and hypoglycemic mechanism of Polygonum multiflorum based on network pharmacology.

BACKGROUND: Diabetes is a complex metabolic disease characterized by hyperglycemia, plaguing the whole world. However, the action mode of multi-component and multi-target for traditional Chinese medicine (TCM) could be a promising treatment of diabetes mellitus. According to the previous research, the TCM of Polygonum multiflorum (PM) showed noteworthy hypoglycemic effect. Up to now, its hypoglycemic active ingredients and mechanism of action are not yet clear. In this study, network pharmacology was employed to elucidate the potential bioactive compounds and hypoglycemic mechanism of PM. METHODS: First, the compounds with good pharmacokinetic properties were screened from the self-established library of PM, and the targets of these compounds were predicted and collected through database. Relevant targets of diabetes were summarized by searching database. The intersection targets of compound-targets and disease-targets were obtained soon. Secondly, the interaction net between the compounds and the filtered targets was established. These key targets were enriched and analyzed by protein-protein interactions (PPI) analysis, molecular docking verification. Thirdly, the key genes were used to find the biologic pathway and explain the therapeutic mechanism by genome ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) analysis. Lastly, the part of potential bioactive compounds were under enzyme activity inhibition tests. RESULTS: In this study, 29 hypoglycemic components and 63 hypoglycemic targets of PM were filtrated based on online network database. Then the component-target interaction network was constructed and five key components resveratrol, apigenin, kaempferol, quercetin and luteolin were further obtained. Sequential studies turned out, AKT1, EGFR, ESR1, PTGS2, MMP9, MAPK14, and KDR were the common key targets. Docking studies indicated that the bioactive compounds could stably bind the pockets of target proteins. There were 38 metabolic pathways, including regulation of lipolysis in adipocytes, prolactin signaling pathway, TNF signaling pathway, VEGF signaling pathway, FoxO signaling pathway, estrogen signaling pathway, linoleic acid metabolism, Rap1 signaling pathway, arachidonic acid metabolism, and osteoclast differentiation closely connected with the hypoglycemic mechanism of PM. And the enzyme activity inhibition tests showed the bioactive ingredients have great hypoglycemic activity. CONCLUSION: In summary, the study used systems pharmacology to elucidate the main hypoglycemic components and mechanism of PM. The work provided a scientific basis for the further hypoglycemic effect research of PM and its monomer components, but also provided a reference for the secondary development of PM.

In vivo hepatotoxicity screening of different extracts, components, and constituents of Polygoni Multiflori Thunb. in zebrafish (Danio rerio) larvae.

Polygonum multiflorum Thunb. (PM) is a traditional Chinese medicine, commonly used to treat a variety of diseases. However, the hepatotoxicity associated with PM hampers its clinical application and development. In this study, we refined the zebrafish hepatotoxicity model with regard to the following endpoints: liver size, liver gray value, and the area of yolk sac. The levels of alanine aminotransferase, aspartate transaminase, albumin, and microRNAs-122 were evaluated to verify the model. Subsequently, this model was used to screen different extracts, components, and constituents of PM, including 70 % EtOH extracts of PM, four fractions from macroporous resin (components A, B, C, and D), and 19 compounds from component D. We found that emodin, chrysophanol, emodin-8-O-ß-D-glucopyranoside, (cis)-emodin-emodin dianthrones, and (trans)-emodin-emodin dianthrones showed higher hepatotoxicity compared to other components in PM, whereas polyphenols showed lower hepatotoxicity. To the best of our knowledge, this study is the first to identify that dianthrones may account for the hepatotoxicity of PM. We believe that these findings will be helpful in regulating the hepatotoxicity of PM.

Multiflorumisides HK, stilbene glucosides isolated from Polygonum multiflorum and their in vitro PTP1B inhibitory activities.

A phytochemical study on a 70% EtOH extract of dried roots of Polygonum multiflorum resulted in the isolation of four undescribed stilbene glucosides, namely multiflorumisides HK (1-4). The structures of the natural products were elucidated by 1D and 2D nuclear magnetic resonance (NMR) as well as mass spectroscopy analyses. Among them, multiflorumiside J (3) and multiflorumiside K (4) belong to rare tetramer stilbene glucosides. Moreover, the in vitro inhibitory activities against protein tyrosine phosphatase 1B (PTP1B) were evaluated and the putative biosynthetic pathway was proposed. Notably, compounds 1-4 showed the inhibitory activity against PTP1B with the IC50 values of 1.2, 1.7, 1.5 and 4.6 µm, respectively. Based on the obtained results, stilbene glucosides could be the potential PTP1B inhibitors of P. multiflorum.