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Screening and deciphering active natural products of herbal medicines are of great importance for modern drug discovery. In this study, a novel strategy was proposed to rapidly filter ineffective compounds and target the most potential leads. The aim is to answer the key question of what components are responsible for the holistic bioactivity of an herbal product. To support the strategy, the pharmacophore-guided knockout/knockin chromatography was established for the first time. The greatest advantage of this method is that any interesting components could be automatically fished or knocked out. The method validation shows that the herbal extract was accurately reconstructed according to the experimental design. By combining with bioactivity assays, we demonstrated that "functional compound combination (FCC)", which is the core and indispensable effective part, could be discovered from an herbal medicine and suitable as marker compounds for quality control. The applicable objects of the strategy include single herbs, herbal formulas and commercially herbal preparations. As an illustrative case study, the strategy was successfully applied to simultaneously determine active leads and the FCC in Dan-Qi formula which shows excellent free radical scavenging activity. The potential mechanisms of compounds in Dan-Qi formula reacting with three different free radicals were systematically reported for the first time. This strategy was expected to unveil the mystery of herbal medicines and inspire a natural product-based drug discovery., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Sample extraction is the first challenge in analysis of herbal medicines (HMs). Numerous methods have been developed to improve extraction efficiency, use less solvent and short time. In this work, a tissue-smashing based ultra-rapid extraction (TSURE) method has been proposed through the designed particle crushing, drastic stir, and dynamic molecular permeation at normal temperature. Factors in TSURE like extraction time, volts, and solvents were optimized for extraction efficiency of salvianolic acid B, cryptotanshinone, and tanshinone IIA from Salvia miltiorrhiza. The TSURE method was validated in terms of repeatability (RSD<2.2%) and extraction recoveries (93-106% with RSD<5.0%). TSURE showed a comparable extraction efficiency to conventional heat reflux extraction (HRE) and better than ultrasonic assisted extraction (UAE). The extraction time was about 2.0-3.0 min for TSURE, 60 times faster than the performance of HRE and 20 times faster than UAE. Microscopic analysis showed that the Krummbein diameter of plant particles after extraction were about 600-1200 μm for HRE and UAE, and decreased to 50-80 μm for TSURE. Subsequently, the developed TSURE was applied to high-throughput extraction of 19 S. miltiorrhiza samples collected in different regions of China. Besides, application of TSURE to other herbal medicines was also investigated, including Panax quinquefolius and Lonicera japonica. TSURE method provided an ultra-rapid and promising alternation for extraction of ingredients in herbal medicines, and can be extended to pharmaceutics, foods and cosmetics., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Quality standardization of herbal medicines (HMs) is an important task with great challenges. Selection of abundant compounds as markers is currently a major approach for the quality control of HMs; however, such marker compounds are irrelevant to the bioactivities in many cases. Taking Lycoridis Radiatae Bulbus (LRB) as an example, we proposed a universal strategy to identify the effective combinatorial markers (ECMs) that are representative of the bioactivities of HMs, and took them as chemical markers for quality standardization. Fingerprinting and quantification were employed to find out the common components in various batches of medicines. The contribution of each common compound to the overall bioactivity was determined through fingerprint-bioactivity modeling, which based on the absolute quantification of each compound and the acetylcholinesterase (AChE) inhibitory activity of LRB. Two most effective compounds, ungerimine and galanthamine, were therefore proposed as ECMs. Interestingly, these two compounds could synergistically inhibit AChE. This approach demonstrated its strong advantage of the bioactivity relevant quality assessment when compared with conventional methods. And the success of applying this ECMs-based method to the quality assessment of unknown LRB samples proved that our approach was reliable and reproducible. In conclusion, this approach is not only useful for the bioactivity relevant quality control of HMs but also helpful for the discovery of ECMs as new drug candidates., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Neuraminidase, also known as sialidase, is ubiquitous in animals and microorganisms. It is predominantly distributed in the cell membrane, cytoplasmic vesicles, and lysosomes. Neuraminidase generally recognizes the sialic acid glycosidic bonds at the ends of glycoproteins or glycolipids and enzymatically removes sialic acid. There are four types of neuraminidases, named as Neu1, Neu2, Neu3, and Neu4. Among them, Neu1 is the most abundant in mammals. Recent studies have revealed the involvement of Neu1 in several diseases, including cardiovascular diseases, diabetes, cancers, and neurological disorders. In this review, we center the attention to the role of Neu1 in cardiovascular diseases, including atherosclerosis, ischemic myocardial injury, cerebrovascular disease, congenital heart disease, and pulmonary embolism. We also summarize inhibitors from Chinese herbal medicines (CHMs) in inhibiting virus neuraminidase or human Neu1. Many Chinese herbs and Chinese herb preparations, such as Lonicerae Japonicae Flos, Scutellariae Radix, Yupingfeng San, and Huanglian Jiedu Decoction, have neuraminidase inhibitory activity. We hope to highlight the emerging role of Neu1 in humans and potentially titillate interest for further studies in this area. [ABSTRACT FROM AUTHOR]

Purpose: To identify bioactive equivalent combinatorial components (BECCs) in herbal medicines. The exact composition of effective components in herbal medicines is often elusive due to the lack of adequate screening methodology. Herein, we propose a hypothesis that BECCs accounting for the whole efficacy of original herbal medicines could be discovered from a complex mixture of constituents. Methods: We developed a bioactive equivalence oriented feedback screening method and applied it to discover the BECCs from an herbal preparation Cardiotonic Pill (CP). The operations include chemical profiling of CP, followed by an iterative loop of determining, collecting and evaluating candidate BECCs. Results: A combination of 18 compounds was identified as BECCs from CP, which accounts for 15.0% (w/w) of original CP. We have demonstrated that the BECCs were as effective as CP in cell models and in a rat model of myocardial infarction. Conclusions: This work answers the key question of which are real bioactive components for CP that have been used in clinic for many years, and provides a promising approach for discovering BECCs from herbal medicines. More importantly, the BECCs could be extended to improve quality control of herbal products and inspire an herbal medicines based discovery of combinatorial therapeutics. [ABSTRACT FROM AUTHOR]

In this work, a rapid and simple method based on matrix solid-phase dispersion (MSPD) and ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed. Guge Fengtong preparation (GGFT), a traditional Chinese herbal medicine, was investigated for validation, and eight major constituents were determined including four saponins (protodioscin, protogracillin, pseudoprotodioscin and dioscin) and four gingerols (6-gingerol, 8-gingerol, 10-gingerol and 6-shogaol). Response surface methodology and desirability function were employed to optimize the extraction conditions, such as dispersant, dispersant/sample ratio, solvent concentration, and elution volume, of MSPD. Results showed that MSPD using C18 (1.75 g) as the dispersant material and methanol (89%, v/v) as the eluting solvent (12.00 mL) resulted in a high extraction efficiency. MSPD extraction had the advantages of combining extraction and clean-up in a single step, was less time consuming and required lower solvent volumes compared with conventional methods. Quantification of chemical compounds from GGFT preparations were performed using UPLC-MS/MS in multiple-reaction monitoring mode. The proposed method afforded a low limit of detection ranging from 0.02 to 0.40 ng for saponins and gingerols. For all the analytes, recoveries ranged from 80.9% to 103% and repeatabilities were acceptable with relative standard deviations of less than 6.81%. The proposed MSPD-UPLC-MS/MS method was successfully utilized to analyze five batches of GGFTs, and the results demonstrated that this method is simple, efficient and has potential to be applied for the quality control of herbal preparations. [ABSTRACT FROM AUTHOR]

Abstract: Radix Polygoni Multiflori, Rhizoma et Radix Polygoni Cuspidati, and Radix et Rhizoma Rhei are the most frequently used traditional Chinese medicines in the family Polygonaceae. The three herbal medicines (HMs) contain similar types of compounds. In Chinese Pharmacopoeia, five high-performance liquid chromatography (HPLC) coupled with ultraviolet (UV) detection methods have been employed for their quality control. The aim of this study was to develop a simple and conventional strategy, segmental monitoring based on variable wavelength detection (VWD), for simultaneous quantification of phenolic acids, flavonoids, stilbenes and anthraquinones in the three chemically analogous HMs. Compared with the commonly used HPLC-diode array detection (DAD), the proposed method afforded desirable performance on linearity, precision and sensitivity. Additionally, a quadrupole time-of-flight mass spectrometry (QTOF-MS) was applied to the structural confirmation of analytes from complex matrices. Based on the chemical profiles and contents of the analyses, 27 samples from three HMs were well classified using the principal component analysis. The results of this study demonstrated the potential and applicability of segmental monitoring strategy based on VWD for comprehensive quality control of HMs. [Copyright &y& Elsevier]

Abstract: The fact that the effects of herbal medicines (HMs) are brought about by their chemical constituents has created a critical demand for powerful analytical tools performing the chemical analysis to assure their efficacy, safety and quality. Liquid chromatography coupled to mass spectrometry (LC–MS) is an excellent technique to analyze multi-components in complex herbal matrices. Due to its inherent characteristics of accurate mass measurements and high resolution, time-of-flight (TOF) MS is well-suited to this field, especially for qualitative applications. The purpose of this article is to provide an overview on the potential of TOF, including the hybrid quadrupole- and ion trap-TOF (QTOF and IT-TOF), hyphenated to LC for chemical analysis in HMs or HM-treated biological samples. The peculiarities of LC–(Q/IT)TOF-MS for the analysis of HMs are discussed first, including applied stationary phase, mobile-phase selection, accurate mass measurements, fragmentation and selectivity. The final section is devoted to describing the applicability of LC–(Q/IT)TOF-MS to routine analysis of multi-components, including target and non-target (unknown) compounds, in herbal samples, emphasizing both the advantages and limitations of this approach for qualitative and quantitative purposes. The potential and future trends of fast high-performance liquid chromatography (HPLC) (e.g. rapid resolution LC and ultra-performance LC) coupled to (Q)TOF-MS for chemical analysis of HMs are highlighted. [Copyright &y& Elsevier]

Abstract: Plant-based medicines become increasingly popular over the world. Authentication of herbal raw materials is important to ensure their safety and efficacy. Some herbs belonging to closely related species but differing in medicinal properties are difficult to be identified because of similar morphological and microscopic characteristics. Chromatographic fingerprinting is an alternative method to distinguish them. Existing approaches do not allow a comprehensive analysis for herbal authentication. We have now developed a strategy consisting of (1) full metabolic profiling of herbal medicines by rapid resolution liquid chromatography (RRLC) combined with quadrupole time-of-flight mass spectrometry (QTOF MS), (2) global analysis of non-targeted compounds by molecular feature extraction algorithm, (3) multivariate statistical analysis for classification and prediction, and (4) marker compounds characterization. This approach has provided a fast and unbiased comparative multivariate analysis of the metabolite composition of 33-batch samples covering seven Lonicera species. Individual metabolic profiles are performed at the level of molecular fragments without prior structural assignment. In the entire set, the obtained classifier for seven Lonicera species flower buds showed good prediction performance and a total of 82 statistically different components were rapidly obtained by the strategy. The elemental compositions of discriminative metabolites were characterized by the accurate mass measurement of the pseudomolecular ions and their chemical types were assigned by the MS/MS spectra. The high-resolution, comprehensive and unbiased strategy for metabolite data analysis presented here is powerful and opens the new direction of authentication in herbal analysis. [Copyright &y& Elsevier]

Abstract: Spinosin, a major bioactive herbal ingredient isolated from Semen Ziziphi Spinosae, plays an important role in sedation and hypnosis. However, the pharmacokinetic behavior of spinosin in special sites has not been reported. Microdialysis (MD) technique, as a continuous, realtime monitoring sampling technique, is very suitable for the evaluation of the disposition of diverse drugs. To obtain more useful information on spinosin, an in vivo microdialysis sampling technique with High Performance Liquid Chromatography–mass spectrograph (HPLC–MS) method was developed to investigate the pharmacokinetics of spinosin and its interaction with cyclosporin A (CsA) in the brain, blood and bile of rats. The method was validated in terms of selectivity, linearity and sensitivity, and showed advantages in monitoring the pharmacokinetic behavior of drugs. The results revealed that CsA has obvious effects on the pharmacokinetic process of spinosin. When co-administered, the area under the curve (AUC) of spinosin in blood, bile and brain increased from 205.70 to 673.51mgmin/L, 7.77×104 to 1.25×105 mgmin/L, and 2.09 to 5.58mgmin/L, respectively. The t 1/2 values of spinosin in blood, bile and brain also changed from 48.07 to 95.04min, from 97.20 to 152.21 and from 42.18 to 73.83min, respectively. These results demonstrated that the CsA decreased the efflux of spinosin through the inhibition of P-glycoprotein (P-gp) efflux transporter and it might be used as a group of P-gp substrate. Other transporters or pathways may also be involved in the metabolism of spinosin. [Copyright &y& Elsevier]

Graphical abstract Abstract The development of simple, easy-to-operate and real-time detection methods for the active ingredients in herbal medicines has aroused growing interest owing to their pivotal health benefits. In this study, a qualitative and quantitative detection method for the flavonoids was developed based on the specific interaction between flavonoids and bovine serum albumin (BSA). A fluorescent gold nanocluster was imbedded into the cavity enclosed in the tertiary structure of BSA, the fluorescence of which can be quenched by the flavonoids with fast response (<5 s). This decrease in fluorescence intensity of BSA-AuNCs as output signal enables the real-time visual inspection of flavonoids. We demonstrated that the present approach was capable of detecting quercetin in serum, plasma, and monitoring the content of flavonoids in proprietary Chinese medicine Rutin Tablets. BSA-AuNCs was the first fluorescent probe for the specific determination of active ingredients in herbal medicines. Hence the reported protein-AuNCs sensing platform can serve as a convenient detection strategy in pharmaceutical analysis. [ABSTRACT FROM AUTHOR]

American ginseng is a commonly consumed herbal medicine in the United States and other countries. Ginseng saponins are considered to be its active constituents. We have previously demonstrated in an in vitro experiment that human enteric microbiota metabolize ginseng parent compounds into their metabolites. In this study, we analyzed American ginseng saponins and their metabolites in human plasma, urine and feces samples by liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS). Six healthy male volunteers ingested 1 g of American ginseng twice a day for 7 days. On day 7, biological samples were obtained and pretreated with solid phase extraction. The ginseng constituents and their metabolites were characterized, including 5 ginseng metabolites in plasma, 10 in urine, and 26 in feces. For the plasma, urine and feces samples, the levels of ginsenoside Rb 1 (a major parent compound) were 8.6, 56.8 and 57.7 ng/mL, respectively, and the levels of compound K (a major metabolite) were 58.4 ng/mL, 109.8 ng/mL and 10.06 μg/mL, respectively. It suggested that compound K had a remarkably high level in all three samples. Moreover, in human feces, ginsenoside Rk 1 and Rg 5 , Rk 3 and Rh 4 , Rg 6 and F 4 were detected as the products of dehydration. Further studies are needed to evaluate the pharmacological activities of the identified ginseng metabolites. [ABSTRACT FROM AUTHOR]

Single standard to determine multi-components (SSDMC) is a practical pattern for quality evaluation of herbal medicines (HMs). However, it remains challenging because of potential inconsistency of relative response factors (RRF) on different instruments. In this work, the effects of two key roles, i.e., ultraviolet (UV) wavelength and standard solution concentrations, on reproducibility of RRF were investigated. The effect of UV wavelength on reproducibility of RRF was studied by plotting the relationship of the peak area ratios (internal standard vs analyte) to wavelengths. The preferable wavelength should be set at the flat parts of the curve. Optimized 300 nm produced a 0.38% RSD for emodin/emodin-8- O -β- D -glucopyranoside on five instruments, much lower than 2.80% obtained from the maximum wavelength at 290 nm. Next, the effects of standard solution concentrations of emodin on its response factor (RF) were investigated. For one single point method, low concentration less than 49b/k resulted in significant variations in RF. For emodin, when the concentration is higher than 7.00 μg mL −1 , a low standard deviation (SD) value at 0.13 was obtained, while lower than 7.00 μg mL −1 , a high SD at 3.71 was obtained. The developed SSDMC method was then applied to determination of target components in 10 Polygonum cuspidatum samples and showed comparable accuracy to conventional calibration methods with deviation less than 1%. [ABSTRACT FROM AUTHOR]

Abstract: In this study, an efficient strategy based on bioassay-guided fractionation, high-performance liquid chromatography/electrospray ionization quadrupole time-of-flight mass spectrometry (HPLC-ESI-Q/TOF-MS) and high-speed counter-current chromatography (HSCCC) was established to screen and purify bioactive compounds from Chinese herbal medicines (CHMs). This screening system was efficient and successfully applied to reveal anti-prostate cancer candidates from Puerariae thomsonii Flos. As a result, an active fraction with strong in vitro anti-prostate cancer activity was obtained, and the main compounds in the fraction were purified by HSCCC, giving 82mg of tectoridin, 36mg of tectorigenin-7-O-[β-d-xylopyranosyl-(1→6)-β-d-glucopyranoside and 64mg of tectorigenin. Among them, tectorigenin, possessing the highest anti-prostate cancer activity with IC50 value of 0.08μM, has priority to be lead compound. The results of this work demonstrated that the developed method was efficient and could be employed for the rapid screening, identification and purification of active components from CHMs. [Copyright &y& Elsevier]

Abstract: Various analytical technologies have been developed for quantitative determination of marker compounds in herbal medicines (HMs). One important issue is matrix effects that must be addressed in method validation for different detections. Unlike biological fluids, blank matrix samples for calibration are usually unavailable for HMs. In this work, practical approaches for minimizing matrix effects in HMs analysis were proposed. The matrix effects in quantitative analysis of five saponins from Panax notoginseng were assessed using high-performance liquid chromatography (HPLC). Matrix components were found to interfere with the ionization of target analytes when mass spectrometry (MS) detection were employed. To compensate the matrix signal suppression/enhancement, two matrix-matched methods, standard addition method with the target-knockout extract and standard superposition method with a HM extract were developed and tested in this work. The results showed that the standard superposition method is simple and practical for overcoming matrix effects for quantitative analysis of HMs. Moreover, the interference components were observed to interfere with light scattering of target analytes when evaporative light scattering detection (ELSD) was utilized for quantitative analysis of HMs but was not indicated when Ultraviolet detection (UV) were employed. Thus, the issue of interference effects should be addressed and minimized for quantitative HPLC–ELSD and HPLC–MS methodologies for quality control of HMs. [Copyright &y& Elsevier]

Abstract: Flos Lonicerae, referred to the flower buds of several medicinal Lonicera species, is a commonly used traditional Chinese herbal medicine. A multi-component-assay quality control method, using high performance liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry (HPLC-ESI/TOF MS), has been developed for the simultaneous identification and quantification of 32 bioactive compounds in Flos Lonicerae. The limits of detection (LOD) and quantification (LOQ) were in the range of 0.002–0.089 and 0.006–0.355μg/ml, respectively. All calibration curves showed good linear regression (r 2 ≥0.99) within the test ranges. The overall intra- and inter-day precisions of analytes were less than 3.47% for peak area and 0.38% for retention time. The recoveries were from 85.4% to 101.6%. The validated method was applied to assay of 32 compounds in 8 medicinal Lonicera species. Furthermore, six unknown chromatographic peaks were tentatively characterized. It was demonstrated that the HPLC-ESI/TOF MS method was suitable for quality control of Lonicera species, owing to the advantages of accurate mass analysis, resolving power, enhanced selectivity and high sensitivity. [Copyright &y& Elsevier]