Characterisation and critical processes identification for production of herbal preparations using 1H-NMR and chemometrics: A case study of Trichosanthis Pericarpium injection.

INTRODUCTION: Herbal preparations are extensively utilised for the treatment of diseases in Asian countries. However, the variations in origin, climate, and production processes can lead to inconsistencies in the quality of herbal preparations. Existing quality control methods only target a few components in the finished product but ignore the control in the pharmaceutical process. Therefore, this study intends to develop a comprehensive component analysis method for intermediates in the pharmaceutical process to reveal the change patterns of substances and deepen the process understanding. OBJECTIVE: This study aims to develop a rapid and comprehensive process characterisation and critical process identification method for herbal preparations. METHODS: Six batches of Trichosanthis Pericarpium injection (TPI) intermediates were collected from the production process. Proton nuclear magnetic resonance (1H-NMR) spectra were acquired for qualitative and quantitative analysis of the se intermediates. Subsequently, chemometrics were used to identify critical processes and potential chemical markers. RESULTS: A total of 39 components in intermediates were identified, and the transfer of 25 components during the production process was investigated. Column chromatography was determined as the critical process. Nine components were identified as chemical markers. CONCLUSION: The application of 1H-NMR facilitated a comprehensive reflection of the chemical composition information of process intermediates, enabling investigations into the transfer of multi-component substances and accurate identification of critical processes and chemical markers.

A multivariate curve resolution-alternating least squares (MCR-ALS) technology assisted 1 H-NMR methodology for multi-component quantitation of Trichosanthis Pericarpium injection.

INTRODUCTION: Trichosanthis Pericarpium injection (TPI) is a traditional Chinese medicine preparation obtained from Trichosanthis Pericarpium by extraction, purification and sterilisation. It contains amino acids, alkaloids, nucleotides and other components. Existing quantitative methods only analyse a few components in injections, so this study intends to develop a method for comprehensive analysis of TPI components. OBJECTIVE: To develop a method for quantification of components in TPI by multivariate curve resolution-alternating least squares (MCR-ALS) assisted proton nuclear magnetic resonance (1 H-NMR). METHODS: A 1 H-NMR method was developed for the quantification of components in TPI. For components with independent signals, 3-(trimethylsilyl) propionic-2,2,3,3-d4 acid sodium salt (TSP) was used as an internal standard to calculate the component contents. For components with overlapping signals, the method of MCR-ALS was used. RESULTS: A total of 36 components were identified in TPI, of which 33 were quantified. Methodological validation results showed that the developed 1 H-NMR method has good linearity, accuracy, precision, robustness and specificity. CONCLUSION: The use of 1 H-NMR provides a reliable and universal method for the TPI components identification and quantification. Also, it can be used as a powerful tool for analysing the contents in a complex mixture as a quality control measure.

Establishing a chromatographic fingerprint using tandem UV/charged aerosol detection and similarity analysis for Shengmai capsule: A novel method for natural product quality control.

INTRODUCTION: Shengmai San, a well-known traditional Chinese medicine formula, is used to treat coronary heart diseases and myocardial infarction. The complex composition and complicated mechanism of the Shengmai preparations bring a significant challenge in the development of a suitable quality control method. OBJECTIVES: This work aims to establish a chromatographic fingerprinting method and propose a weighting algorithm for application in fingerprint similarity analysis to ensure consistent quality of the Shengmai capsule. METHODOLOGY: A chromatographic fingerprint method was established using tandem UV/charged aerosol detection (CAD) for Shengmai capsule quality control. After method verification, the developed method was applied to analyze 15 batches of the samples. Then a weighting algorithm of the fingerprint peak was proposed and used for the fingerprint similarity analysis. RESULTS: An HPLC-UV/CAD fingerprint method was successfully developed for the Shengmai capsules. Chromatographic conditions of the HPLC-UV/CAD method were optimized with a definitive screening design, and the optimized ranges of operating parameters were obtained with a Monte Carlo simulation method. The combined use of the proposed weighting algorithm and similarity analysis on fingerprint data improves the sensitivity of distinguishing batch-to-batch quality differences. CONCLUSION: The developed HPLC-UV/CAD fingerprint method is robust, reliable, and efficient. The proposed weighting algorithm combined with similarity analysis is promising and meaningful for the quality consistency assessment of HPLC-UV/CAD fingerprints.

Quantitative profiling of comprehensive composition in compound herbal injections: An NMR approach applied on Shenmai injection.

INTRODUCTION: Compound herbal injections (CHIs) can be regarded as a significant innovation in the modernisation of herbal medicine. Therefore, improving the quality control level of CHIs has always been an active research topic in traditional herbal medicine. OBJECTIVES: In this study, Shenmai injection was used as a representative sample for investigating the ability of proton nuclear magnetic resonance (1 H NMR) in the quality evaluation of CHIs. METHODS: A quantitative 1 H NMR method was developed to simultaneously determine the contents of total ginsenosides, polysorbate 80, and 20 primary metabolites in Shenmai injection. Multivariate statistical analysis was combined to compare differences between samples from different manufacturers. RESULTS: It was found that the combined measurement uncertainty of each component is less than 1.61%, which demonstrates the reliability of the method. Furthermore, the components determined by this method account for up to 92.64% of the total solids, which is an unprecedented success in the analysis of Shenmai injection. In the end, the method was applied to the quality comparison of Shenmai injection from six manufacturers. The results showed that the differences among the samples from the six manufacturers were reflected in multiple types of components. CONCLUSION: This study fully demonstrates the superiority of the quantitative 1 H NMR method in comprehensive composition profiling of CHIs, which is conducive to improving the quality control level of Shenmai injection. Further, the present study can be used as a reference study for the research on the quality and safety of CHIs.

[Quantitative NMR spectroscopy and its application in quality control of Chinese medicinal injection].

Chinese medicinal injection, made of active components extracted from Chinese medicine or Chinese medicinal compound, is a novel dosage form of Chinese patent medicine in China and is pivotal in the traditional Chinese medicine(TCM) industry. The quality control standard of Chinese medicinal injection determines its safety and efficacy. The quantitative nuclear magnetic resonance(qNMR) spectroscopy is a non-targeted, non-invasive, and non-destructive technique with high reproducibility, short measurement time, convenient sample preparation, a broad range of linearity, and no requirement on the reference substance of tested components, which is advantageous as compared with traditional chromatographic methods, and it can provide information about the molecular composition of the tested samples. Therefore, in light of multiple challenges in the quality control of Chinese medicinal injection, such as complex composition, difficulties in quantitative analysis, and the shortage of reference substances, the application of qNMR spectroscopy combined with chemometrics techniques was proposed for the quality evaluation of Chinese medicine reference substances, Chinese medicinal injection, and intermediates in the production process, as well as for the stability analysis of Chinese medicinal injection. This study is expected to provide references for the application of qNMR spectroscopy in the quality control of Chinese medicinal injection.

[Quality evaluation of ginsenoside reference substances based on qNMR spectroscopy].

The present study established a quality evaluation method for ginsenoside reference substances based on quantitative nuclear magnetic resonance(qNMR) spectroscopy. ~1H-NMR spectra were collected on Bruker Avance Ⅲ 500 MHz NMR spectrometer equipped with a 5 mm BBO probe. The acquire parameters were set up as follows: pulse sequence of 30°, D_1=20 s, probe temperature= 303 K, and the scan number = 32. Dimethyl terephthalate, a high-quality ~1H-qNMR standard, was used as the internal standard and measured by the absolute quantitative method. Methyl peaks of comparatively good sensitivity were selected for quantification, and linear fitting deconvolution was adopted to improve the accuracy of integration results. The qNMR spectroscopy-based method was established and validated, which was then used for the quality evaluation of ginsenoside Rg_1, ginsenoside Re, ginsenoside Rb_1, ginsenoside Rd, and notoginsenoside R_1. The results suggested that the content of these ginsenoside reference standards obtained from the qNMR spectroscopy-based method was lower than that detected by the normalization method in HPLC provided by the manufacturers. In conclusion, the qNMR spectroscopy-based method can ensure the quality of ginsenoside reference substances and provide powerful support for the accurate quality evaluation of Chinese medicine and its preparations. The qNMR spectroscopy-based method is simple, rapid, and accurate, which can be developed for the quantitative assay of Chinese medicine standard references.

[Fingerprint of Shenmai Injection based on ~1H-NMR technique].

Shenmai Injection is a Chinese medicinal injection prepared from Ginseng Radix et Rhizoma Rubra and Ophiopogonis Radix, which is widely used in clinical practice for the treatment and adjuvant therapy of cardiovascular diseases with significant pharmacological effects. Proton nuclear magnetic resonance spectroscopy(~1H-NMR) has the advantages of simple and nondestructive sample pretreatment, fast analysis, abundant chemical information, quantification and no need to follow the standard curve. It is widely used in the analysis and research of complex mixtures of traditional Chinese medicine, clinical blood and urine samples. In this study, the ~1H-NMR fingerprint of Shenmai Injection was established. Thirty-two chemical components were identified, including seven amino acids, eight small molecular organic acids, one alkaloid, four sugars, two nucleosides, seven saponins, and three other components. Pearson's correlation coefficient and multivariate analysis of variance(principal component analysis combined with hierarchical cluster analysis) were applied based on the ~1H-NMR fingerprint to evaluate the quality consistency. The results showed high-quality consistency of 82 batches of Shenmai Injection. This study confirms that the ~1H-NMR fingerprint has great potential in the application of quality control of Chinese medicinal injection.

[~1H-qNMR quantification of total ginsenosides in Shenmai Injection].

A content determination method based on ~1H-qNMR was developed for the determination of total ginsenosides in Shenmai Injection. The parameters were optimized with CD_3OD as the solvent, dimethyl terephthalate as the internal standard, the peak at δ 8.11 as the internal standard peak, and the peaks at δ 1.68 and δ 0.79 as quantitative peaks of total ginsenosides. The developed ~1H-qNMR-based method was validated methodologically. The results showed that the method could achieve accurate measurement of total ginsenosides in Shenmai Injection in the range of 0.167 6-3.091 1 mmol·L~(-1). The developed ~1H-qNMR-based method for total ginsenosides is simple in operation, short in analysis time, strong in specificity, independent of accompanying standard curve, and small in sample volume, which can serve as a reliable mean for the quality control of Shenmai Injection. This study is expected to provide new ideas for the development of quantification methods of total ginsenosides.

[NMR method for simultaneous determination of 21 chemical components in Danhong Injection].

Danhong Injection, a compound Chinese medicine injection prepared from Salviae Miltiorrhizae Radix et Rhizoma and Carthami Flos, is used in the clinical treatment of coronary heart disease, cerebral thrombosis, myocardial infarction, angina pectoris and other cardiovascular and cerebrovascular diseases. In this study, a quantitative method for simultaneous determination of multiple components in Danhong Injection was developed based on ~1H-qNMR technology and then methodological verification was carried out. The results showed that the established method had good methodological indexes. This method can simultaneously determine the content of 21 chemical components including 6 amino acids, 4 small molecular organic acids, 5 sugars and their derivatives, 1 nucleoside, and 5 aromatic compounds in Danhong Injection. The total content accounted for about 85% of the total solid mass, which reflected the great advantage of ~1H-qNMR method in the analysis of Chinese medicine injections. The ~1H-qNMR method for simultaneous determination of multiple components in Danhong Injection developed in this study has simple operation, short analysis time, and wide application range, which has practical significance for the quality evaluation of Danhong Injection and provides reference for the development of quality control methods for Chinese medicine injections.

Establishment and validation of the quantitative analysis of multi-components by single marker for the quality control of Qishen Yiqi dripping pills by high-performance liquid chromatography with charged aerosol detection.

INTRODUCTION: Charged aerosol detection (CAD) has the merits of high sensitivity, high universality and response uniformity. The strategy that combines the quantitative analysis of multi-components by single marker (QAMS) with CAD has certain advantages for the quantification of multi-components. However, relevant research was limited. OBJECTIVES: To comprehensively investigate the crucial factors that affect the performance of the HPLC-CAD-QAMS approach and validate the credibility and feasibility of the method. METHODOLOGY: Multiple components of Qishen Yiqi dripping pills (QSYQ) were assayed using the high-performance liquid chromatography (HPLC)-CAD-QAMS approach. Some factors that affect the sensitivity and accuracy of the approach were sufficiently studied. After the method verification, principal component analysis (PCA) was applied to evaluate the quality consistency of three types of samples: normal samples, expired samples and negative samples. RESULTS: A HPLC-CAD-QAMS method was successfully developed for the multi-component determination of QSYQ. First, chromatographic conditions were optimised by a definitive screening design, and the optimised ranges of operating parameters were obtained with a Monte Carlo simulation method. Next, a new method to select the internal reference standards was successfully introduced based on the heatmap of Pearson correlation coefficients of the response factors. Then, the multi-point method was selected to calculate the relative correction factors, and a robustness test was conducted with Plackett-Burman design. Finally, the PCA was proved to be effective for the quality consistency evaluation of different samples. CONCLUSION: The developed HPLC-CAD-QAMS method can be a reliable and superior means for the multi-component quantitative analysis of QSYQ.

[Study on rapid quality analysis method of Shengxuebao Mixture].

A rapid analysis method based on ultraviolet-visual(UV-Vis) spectroscopy, near infrared(NIR) spectroscopy and multivariable data analysis was established for quality evaluation of Shengxuebao Mixture. The contents of eight active ingredients of Shengxuebao Mixture including albiflorin, paeoniflorin, 2, 3, 5, 4'-tetra-hydroxy-stilbene-2-O-ß-D-glucopyranoside, specnuezhenide,ecliptasaponin D, emodin, calycosin-7-glucoside and astragaloside Ⅳ were simultaneously detected by using this method. HPLC-UV-MS was used as a reference method for determining the contents of these ingredients. Partial least squares(PLS) analysis was implemented as a linear method for multivariate models calibrated between UV spectrum/NIR spectrum and contents of 8 ingredients. Finally, the performance of the model was evaluated by 24 batches of test samples. The results showed that both UV-Vis and NIR models gave a good calibration ability with an R~2 value above 0.9, and the prediction ability was also satisfactory, with an R~2 value higher than 0.83 for UV-Vis model and higher than 0.79 for NIR model. The overall results demonstrate that the established method is accurate, robust and fast, therefore, it can be used for rapid quality evaluation of Shengxuebao Mixture.

[Quantitative analysis method of Shengxuebao Mixture by HPLC-UV-MS based on quality by design concept].

In this study, the HPLC-UV-MS method for the simultaneous determination of eight active ingredients of Shengxuebao Mixture were developed based on the concept of quality by design（QbD）with a stepwise optimization approach. After the analytical target profile（ATP）had been defined, albiflorin, paeoniflorin, 2, 3, 5, 4'-tetra-hydroxy-stilbene-2-O-ß-D-glucopyranoside, specnuezhenide, ecliptasaponin D, emodin, calycosin-7-glucoside, and astragaloside Ⅳ were identified as the indicator components. The resolution and the signal-to-noise ratio of indicator components were then selected as critical method attributes (CMA) for the first step optimization. According to the results collected from fractional factorial design, critical method parameters (CMP) were determined with a multiple linear regression method, which included the amount of acid addition in the mobile phase, temperature, gradient, and wavelength. After that, the amount of acid addition and the wavelength were optimized to improve the resolution and the signal-to-noise ratio of the indicator components. The peak symmetry factors of specnuezhenide and emodin were then set as CMA for the second step optimization. The Box-Behnken designed experiments were conducted. The temperature and gradient were optimized after modelling. The design space were calculated and verified. The optimized analytical method was validated, and the results showed a good precision, accuracy and stability, which means that it can be used for the quantification of the indicator components in Shengxuebao Mixture.

[Optimization of lime milk precipitation process of Lonicera Japonica aqueous extract based on quality by design concept].

Design space approach was applied in this study to optimize the lime milk precipitation process of Lonicera Japonica (Jinyinhua) aqueous extract. The evaluation indices for this process were total organic acid purity and amounts of 6 organic acids obtained from per unit mass of medicinal materials. Four critical process parameters (CPPs) including drop speed of lime milk, pH value after adding lime milk, settling time and settling temperature were identified by using the weighted standardized partial regression coefficient method. Quantitative models between process evaluation indices and CPPs were established by a stepwise regression analysis. A design space was calculated by a Monte-Carlo simulation method, and then verified. The verification test results showed that the operation within the design space can guarantee the stability of the lime milk precipitation process. The recommended normal operation space is as follows： drop speed of lime milk of 1.00-1.25 mL•min⁻¹, pH value of 11.5-11.7, settling time of 1.0-1.2 h, and settling temperature of 10-20 ℃..

Exploring metabolic responses and pathway changes in CHO-K1 cells under varied aeration conditions and copper supplementations using 1 H NMR-based metabolomics.

The optimization of bioprocess for CHO cell culture involves careful consideration of factors such as nutrient consumption, metabolic byproduct accumulation, cell growth, and monoclonal antibody (mAb) production. Valuable insights can be obtained by understanding cellular physiology to ensure robust and efficient bioprocess. This study aims to improve our understanding of the CHO-K1 cell metabolism using 1 H NMR-based metabolomics. Initially, the variations in culture performance and metabolic profiles under varied aeration conditions and copper supplementations were thoroughly examined. Furthermore, a comprehensive metabolic pathway analysis was performed to assess the impact of these conditions on the implicated pathways. The results revealed substantial alterations in the pyruvate metabolism, histidine metabolism, as well as phenylalanine, tyrosine and tryptophan biosynthesis, which were especially evident in cultures subjected to copper deficiency conditions. Conclusively, significant metabolites governing cell growth and mAb titer were identified through orthogonal partial least square-discriminant analysis (OPLS-DA). Metabolites, including glycerol, alanine, formate, glutamate, phenylalanine, and valine, exhibited strong associations with distinct cell growth phases. Additionally, glycerol, acetate, lactate, formate, glycine, histidine, and aspartate emerged as metabolites influencing cell productivity. This study demonstrates the potential of employing 1 H NMR-based metabolomics technology in bioprocess research. It provides valuable guidance for feed medium development, feeding strategy design, bioprocess parameter adjustments, and ultimately the enhancement of cell proliferation and mAb yield.

Application of the Analytical Procedure Lifecycle Concept to a Quantitative 1H NMR Method for Total Dammarane-Type Saponins.

Dammarane-type saponins (DTSs) exist in various medicinal plants, which are a class of active ingredients with effects on improving myocardial ischemia and immunomodulation. In this study, a quantitative 1H NMR method of total DTSs in herbal medicines was developed based on the analytical procedure lifecycle. In the first stage (analytical procedure design), the Ishikawa diagram and failure mode effects and criticality analysis were used to conduct risk identification and risk ranking. Plackett-Burman design and central composite design were used to screen and optimize critical analytical procedure parameter. Then, the method operable design region was obtained through modeling. In the second stage (analytical procedure performance qualification), the performance of methodological indexes was investigated based on analytical quality by design. As examples of continued procedure performance verification, the method was successfully applied to determine the total DTSs in herbal pharmaceutical preparations and botanical extracts. As a general analytical method to quantify total DTSs in medicinal plants or pharmaceutical preparations, the developed method provides a new quality control strategy for various products containing dammarane-type saponin.

1 H NMR-based process understanding and biochemical marker identification methodology for monitoring CHO cell culture process during commercial-scale manufacturing.

Controlling the process of CHO cell fed-batch culture is critical for biologics quality control. However, the biological complexity of cells has hampered the reliable process understanding for industrial manufacturing. In this study, a workflow was developed for the consistency monitoring and biochemical marker identification of the commercial-scale CHO cell culture process through 1 H NMR assisted with multivariate data analysis (MVDA). Firstly, a total of 63 metabolites were identified in this study object in 1 H NMR spectra of the CHO cell-free supernatants. Secondly, multivariate statistical process control (MSPC) charts were used to evaluate process consistency. According to MSPC charts, the batch-to-batch quality consistency was high, indicating the CHO cell culture process at the commercial scale was well-controlled and stable. Then, the biochemical marker identification was provided through orthogonal partial least square discriminant analysis (OPLS-DA) based S-line plots during the cell logarithmic expansion, stable growth, and decline phases. Identified biochemical markers of the three cell growth phases were as follows: L-glutamine, pyroglutamic acid, 4-hydroxyproline, choline, glucose, lactate, alanine, and proline were of the logarithmic growth phase; isoleucine, leucine, valine, acetate, and alanine were of the stable growth phase; acetate, glycine, glycerin, and gluconic acid were of the cell decline phase. Additional potential metabolic pathways that might influence the cell culture phase transitions were demonstrated. The workflow proposed in this study demonstrates that the combination of MVDA tools and 1 H NMR technology is highly appealing to the research of the biomanufacturing process, and applies well to provide guidance in future work on consistency evaluation and biochemical marker monitoring of the production of other biologics.

A novel aquaphotomics based approach for understanding salvianolic acid A conversion reaction with near infrared spectroscopy.

As a fast and non-destructive detection method, near infrared spectroscopy, mainly containing overtones and combinations, can be used to quantify the components with a concentration of ≥ 1% in the analytical sample. Aquaphotomics uses the characteristic that the water structure changes with the addition of solute, which is reflected in the region of the water spectrum. Thus, it provides the possibility to unlock the information hidden in the spectrum. In our work, near infrared spectroscopy combined with aquaphotomics was used to quantify aqueous solution containing salvianolic acid B. It has shown that the aquaphotomics approach accurately quantifies the aqueous solution's salvianolic acid from 0.51 mg/mL to 25.86 mg/mL. The obtained RMSEP, R2, RPD, and MRE of prediction were 0.52 mg/mL, 0.995, 14.88 and 4.74%, respectively. For the salvianolic acid A reaction solution, the predicted R2 was 0.93, RMSEC was 0.85 mg/mL, and RMSEP was 0.82. The results of this study supported the concept of aquaphotomics, and the aquaphotomics approach was successfully applied in the reaction system of salvianolic acid A at 120 °C. This method was conducive to understanding the reaction and improving the accuracy of the quantitative model. It is a rapid and accurate alternative for analysis and measurement of transformation reactions at high temperature and high pressure, even for the substance with a concentration of less than 5 mg/mL.

Development of a comprehensive method based on quantitative 1H NMR for quality evaluation of Traditional Chinese Medicine injection: a case study of Danshen Injection.

OBJECTIVES: This study aimed to establish a rapid and comprehensive method for quantitative determination of complex ingredients in Traditional Chinese Medicine injections. METHODS: A 1H quantitative nuclear magnetic resonance method was developed to simultaneously quantify comprehensive chemical components in Danshen Injection. Multivariate statistical analysis technique was applied to quality evaluation of multiple batches of Danshen injection. KEY FINDINGS: A complete signal attribution to the 1H nuclear magnetic resonance spectrum of Danshen injection was developed and performed for the first time. A total of 32 chemical components were identified from Danshen Injection. Among them, 20 were quantified simultaneously, accounting for up to 80% (w/w) of the total solids and 95% (w/w) of total organic matter, representing success compared to the previous studies. The developed method was further applied to analyze 13 batches of Danshen Injection from three manufacturers to make a realistic analysis. CONCLUSION: It was found that the comprehensive chemical information provides an adequate characterization for quality profiles among different commercial batches of Danshen Injection. The developed method further offered a guarantee for improving the consistency and safety of Traditional Chinese Medicine injections.

A HPLC-DAD-MS/MS Method for Simultaneous Determination of Six Active Ingredients of Salviae Miltiorrhizae and Ligustrazine Hydrochloride Injection in Rat Plasma and its Application to Pharmacokinetic Studies.

AIMS: This is a pharmacokinetic study of Salviae miltiorrhizae and ligustrazine hydrochloride injection. The study aimed to evaluate the mechanism of action, safety and rational clinical use of Salviae miltiorrhizae and ligustrazine hydrochloride injection. BACKGROUND: Salviae miltiorrhizae and ligustrazine hydrochloride injection is a compound preparation consisted of Salvia miltiorrhiza extract and ligustrazine hydrochloride for the treatment of cardiovascular and cerebrovascular diseases in China. OBJECTIVE: The study aimed to develop a rapid and sensitive high-performance liquid chromatography-diode array detector-tandem mass spectrometry (HPLC-DAD-MS/MS) method for simultaneous determination of six major active ingredients of Salviae miltiorrhizae and ligustrazine hydrochloride injection, namely danshensu, protocatechuic aldehyde, rosmarinic acid, lithospermic acid, salvianolic acid A, and ligustrazine hydrochloride, in rat plasma. METHODS: Plasma samples were precipitated with methanol, which was spiked with ascorbic acid and the supernatant was separated on a Waters Cortecs C18 column, by using a gradient mobile phase system of acetonitrile-water containing 0.05% formic acid (v/v). For internal standards, puerarin was selected for the five salvianolic acids, while isofraxidin was used for ligustrazine hydrochloride. Besides, electrospray ionization in negative mode and multiplereaction monitoring were used to identify and quantify the five salvianolic acids, whereas ligustrazine hydrochloride was quantified at 310 nm using the diode array detector. RESULTS: Noticeably, all calibration curves showed good linearity (R2>0.99) over the concentration range, with a lower limit of quantification between 0.00411 and 0.0369 µg/mL for salvianolic acids, and 1.74 µg/mL for ligustrazine hydrochloride. Next, the precision of the developed method was evaluated by intra- and inter-day assays, and the percentage of relative standard deviation was within 10%. Although the extraction efficiency of some salvianolic acids was not very satisfactory, the sensitivity of the analytical method met the analysis requirements of rat plasma samples. Moreover, the validated method was successfully applied to a pharmacokinetic study of Salviae miltiorrhizae and ligustrazine hydrochloride injection in the rat model. CONCLUSION: Linear pharmacokinetic characteristics were observed for the six active ingredients after intravenous infusion administration in rats within the dose range examined here. In summary, our study proposed a HPLC-DADMS/ MS method with the simultaneous determination of multiple ingredients, and demonstrated its applicability in pharmacokinetic studies.

Combination of Danshen and ligustrazine has dual anti-inflammatory effect on macrophages and endothelial cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Salvia Miltiorrhiza Radix et Rhizoma (Danshen) and Chuanxiong Rhizoma (Chuanxiong) are both traditional Chinese medicines with vascular protective effects, and their combination is widely used in China to treat occlusive or ischemic diseases of the cerebrovascular or cardiovascular system. Although it is widely accepted that these diseases have high relevance to inflammation, little is known about the anti-inflammatory effect of Danshen, Chuanxiong, and their combination. AIM OF STUDY: We aimed to investigate the complex mode of action of Danshen, Chuanxiong, and their combination and the molecular mechanisms underlying their anti-inflammatory activity. Specifically, toll-like receptor (TLR1/2, 3, and 4)-triggered macrophages and endothelial cells, the two major cell players in atherosclerosis as well as in related cardiovascular and cerebrovascular injuries, were emphasized. METHODS: TLR1/2-, TLR3-, and TLR4-induced bone marrow macrophages (BMMs) and human umbilical vein endothelial cells (HUVECs) were treated with Danshen extract (S. miltiorrhiza extract, SME), ligustrazine (2, 3, 5, 6-tetramethylpyrazine, TMP), and their combination (S. miltiorrhiza and TMP injection, SLI), respectively. The proinflammatory cytokines interleukin 6 (IL-6), IL-12, and tumor necrosis factor alpha (TNF-α) were detected as the preliminary indicators of inflammation. In addition, RNA sequencing (RNA-seq)-based transcriptional profiling analyses were conducted for TLR2-activated BMMs to determine the molecular mode of action of SLI as well as the contribution of SME to SLI activity. RESULTS: SLI mitigated inflammation in both BMMs and HUVECs. Refer to the combination, SME had pronounced anti-inflammatory effect on BMMs but had only a slight effect on HUVECs. In contrast, TMP had considerable anti-inflammatory effect on HUVECs but not on BMMs. Bioinformatic analysis identified a broad spectrum of regulatory genes, in addition to IL-6 gene, and C-X-C motif chemokine ligand 10 (CXCL10) appeared to be another key molecule involved in the mechanism underlying SLI and SME effects. At the molecular level, SME was a major contributor of the anti-inflammatory activity of SLI. CONCLUSIONS: In TLR-activated inflammation, SLI exhibits a "multiple ingredient-multiple target" effect, with SME primarily affecting macrophages and TMP affecting HUVECs. Our study provides evidence for the clinical application of SLI in treating complex diseases involving inflammation-induced injury of both macrophages and epithelial cells. Further bioinformatics studies are required to reveal the entire molecular network involved in TMP, SME, and SLI activity.