UPLC-Q-TOF/MS-based screening and identification of the main flavonoids and their metabolites in rat bile, urine and feces after oral administration of Scutellaria baicalensis extract

Identification and pre-clinical investigation of 3-O-cyclohexanecarbonyl-11-keto-β-boswellic acid as a drug for external use to treat psoriasis

BACKGROUND AND PURPOSE

Psoriasis vulgaris is a refractory skin inflammatory disorder with 80% of the cases belonging to the mild-to-moderate type, which can be controlled by topical treatment. Nevertheless, the drugs for external use have not been upgraded for decades. We modified acetyl-11-keto-beta-boswellic acid (ABKA), a natural compound shown to treat psoriasis animal models, to improve efficacy and solubility for topical use.

EXPERIMENTAL APPROACH

Eleven compounds were synthesized using AKBA as a lead compound, and their effects on Th17 cell differentiation were screened. 3-O-cyclohexanecarbonyl-11-keto-β-boswellic acid (CKBA) potently inhibited Th17 cell differentiation. Its efficacy in a mouse model of psoriasis was assessed along with its pharmacology and safety profile when topically or systemically delivered to several animal species.

KEY RESULTS

CKBA inhibited mouse and human Th17 cell differentiation with an IC50 of 3.28 and 3.61 μM, respectively, and directly targeted acetyl-CoA carboxylase 1 (ACC1). Safety evaluation and toxicity tests suggested that systemically delivered high-dose CKBA for 14 days had no dose-associated adverse effects on the CNS, haematopoietic, cardiovascular, respiratory and digestive systems of cynomolgus monkeys. CKBA ointment permeated the skin and did not irritate or sensitize intact skin. CKBA ointment mediated dose-dependent suppression of imiquimod-induced psoriasis-like skin inflammation with slow absorption and limited bioavailability (<10% in rats and <1% in minipigs).

CONCLUSIONS AND IMPLICATIONS

CKBA is safe when topically or systemically delivered to animals. The beneficial effects of CKBA ointment in a mouse model of psoriasis indicate that this is a promising drug candidate for further development as a treatment for psoriasis.

UPLC-Q-Exactive/MS based analysis explore the correlation between components variations and anti-influenza virus effect of four quantified extracts of Chaihu Guizhi decoction

ETHNOPHARMACOLOGICAL RELEVANCE

Chaihu Guizhi decoction (CGD) is a classic Traditional Chinese Medicine (TCM) prescription for the treatment of influenza and fever, composes of Bupleuri Radix (Chaihu), Cinnamomi Ramulus (Guizhi), Scutellariae Radix (Huangqin), Codonopsis Radix (Dangshen), Glycyrrhizae Radix Et Rhizoma Praeparata Cum Melle (Zhigancao), Pinelliae Rhizoma Praeparatum (Fabanxia), Zingiberis Rhizoma Recens (Shengjiang), Paeoniae Radix Alba (Baishao) and Jujubae Fructus (Dazao) in the ratio of 12:4.5:4.5:4.5:3:6:4.5:4.5:4. The efficacy of TCM, if there are differences, depends on the different extraction methods and extracted components.

AIM OF THE STUDY

This study was to evaluate the anti-influenza virus effect of CGD extracts with different extraction methods, analyze the components and explore their correlation.

MATERIALS AND METHODS

CGD were prepared with four extraction methods respectively, the traditional decoction (TD), two steps alcohol-water extraction (AWE), alcohol reflux extraction (AE) and water reflux extraction (WE). Based on the influenza mouse model, the efficacy of anti-influenza virus in vivo of the four CGD extracts were evaluated with the therapeutic index of body weight, rectal temperature, lung index, thymus index and lung viral load of mice. The chemical components in four CGD extracts, and compounds absorbed in rats blood with prototypes or metabolites were identified by UPLC-Q-Exactive/MS. The partial least squares (PLS) method was used to explore the correlation between the components variation in CGD extracts and the comprehensive efficacy index. The potential effective components were further accessed by molecular docking.

RESULTS

Comparing with the other three extracts, AWE has the best anti-influenza effect. It could ameliorate the symptoms caused by influenza virus infection in mice, increase body weight and rectal temperature, reduce the lung index and virus load in lung tissue. 129, 144, 140 and 129 components were identified from TD, AWE, AE, and WE respectively. The identified components were mainly including flavonoids, terpenoids, organic acids, phenylpropanoids, amino acids, nucleosides, phenols, alkaloids, etc. 43 prototypes and 49 metabolites of CGD were detected in rat plasma after oral administration. Seven components, cinnamaldehyde, wogonoside, baicalin, baicalein, gallic acid, oroxylinA-7-O-glucuronide and coumarin, showed significant correlation with anti-influenza effects, all of which had good binding activity with NA, IL-6, STAT3, AKT1, EGFR and TNF.

CONCLUSION

Two steps alcohol-water extraction was optimal for CGD preparation. Cinnamaldehyde, wogonoside, oroxylinA-7-O-glucuronide, coumarin, gallic acid, baicalein and baicalin play a certain essential role in anti-influenza effects and may be taken as a potential maker compounds for quality evaluation of CGD.

Dietary flavonoids: a novel strategy for the amelioration of cognitive impairment through intestinal microbiota

The chances of people suffering from cognitive impairments increase gradually with age. Diet and lifestyle are closely related to the occurrence and development of cognitive function. Dietary flavonoid supplementation has been shown to be one of the protective factors against cognitive decline. Flavonoids belong to a class of polyphenols that have been proposed for the treatment of cognitive decline. Recent evidence has shown that intestinal flora in the human body can interact with flavonoids. Intestinal microbiota can modify the chemical structure of flavonoids, producing new metabolites, the pharmacological activities of which may be different from those of the parent; meanwhile, flavonoids and their metabolites can, in turn, regulate the composition and structure of intestinal flora. Notably, intestinal flora affect host nervous system activity through the gut-brain axis, ultimately causing changes in cognitive function. This review therefore summarizes the interaction of dietary flavonoids and intestinal flora, and their protective effect against cognitive decline through the gut-brain axis, indicating that dietary flavonoids may ameliorate cognitive impairment through their interaction with intestinal microbiota. © 2022 Society of Chemical Industry.

The Application of UHPLC-HRMS for Quality Control of Traditional Chinese Medicine

UHPLC-HRMS (ultra-high-performance liquid chromatography-high resolution mass spectrometry) is a new technique that unifies the application of UHPLC with HRMS. Because of the high sensitivity and good separation ability of UHPLC and the sensitivity of HRMS, this technique has been widely used for structure identification, quantitative determination, fingerprint analysis, and elucidation of the mechanisms of action of traditional Chinese medicines (TCMs) in recent years. This review mainly outlines the advantages of using UHPLC-HRMS and provides a survey of the research advances on UHPLC-HRMS for the quality control of TCMs.

Regulation mechanisms of flavonoids biosynthesis of Hancheng Dahongpao peels (Zanthoxylum bungeanum Maxim) at different development stages by integrated metabolomics and transcriptomics analysis

BACKGROUND

Flavonoids have strong free radical scavenging and antioxidant capacity. The high abundance of flavonoids in Chinese prickly ash peels have many benefits to human health. In this study, 'Hancheng Dahongpao', a main cultivar, was taken as materials to investigate the flavonoids biosynthesis mechanism of Zanthoxylum bungeanum Maxim at three key development stages by integration of metabolomics and transcriptomics analysis.

RESULTS

A total of 19 differentially accumulated metabolites were identified, the key flavonoids compounds were kaempferol, quercetin and their glycoside derivatives, and two major anthocyanins (peonidin O-hexoside and peonidin 3-O-glucoside). 5 gene networks/modules including 15 important candidate genes were identified, which was highly correlated with flavonoids. Among these genes, ZM-163828 and ZM-184209 were strongly correlated with kaempferol and quercetin, and ZM-125833 and ZM-97481 were controlled the anthocyanins biosynthesis. Moreover, it was shown that MYB-ZM1, MYB-ZM3, MYB-ZM5, MYB-ZM6 and MYB-ZM7 coordinately controlled flavonoids accumulation through regulating the structural genes.

CONCLUSIONS

Generally, this study systematically revealed the flavonoids metabolic pathways and candidate genes involved in flavonoids biosynthesis and laid a foundation for the potential targets for the breeding of new valuable Chinese prickly ash cultivars.

Absorption, distribution, metabolism and excretion of apigenin and its glycosides in healthy male adults

The bioavailability of apigenin and its O-glycosides in humans was investigated with apigenin-4'-glucuronide (Ap-4'-GlcUA), apigenin-7-glucuronide and apigenin-7-sulfate being identified as in vivo metabolites. Apigenin per se was poorly absorbed with metabolites equivalent to 0.5% of intake excreted in urine 0-24 h post-intake. Consumption of a parsley drink containing apigenin-7-O-(2″-O-apiosyl)glucoside resulted in the peak plasma concentration (C_max) of Ap-4'-GlcUA occurring after 4 h, indicative of absorption in the lower gastrointestinal tract (GIT). Urinary excretion of the three metabolites corresponded to 11.2% of intake. Ingestion of dried powdered parsley leaves with yogurt extended the C_max of Ap-4'-GlcUA to 6 h. Consumption of chamomile tea containing apigenin-7'-O-glucoside resulted in a 2 h C_max of Ap-4'-GlcUA, in keeping with absorption in the upper GIT. Urinary excretion was equivalent to 34% of intake. Intake of the parsley drink provided information on intra- and inter-individual variations in the level of excretion of the apigenin metabolites. CLINICAL TRAIL REGISTRATION NUMBER: This trail was registered at clinicaltrials.gov as NCT03526081.

A comprehensive study of the metabolism of flavonoid oroxin B in vivo and in vitro by UHPLC-Q-TOF-MS/MS

Oroxin B, a flavonoid, is a major bioactive component form Oroxylum indicum (L.) Vent. with enormous anti-hepatoma effects. To data, the oroxin B metabolism studies remain underexplored. This study was designed to characterize oroxin B metabolism in vivo and in vitro by ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS/MS). Consequently, 30 metabolites in rats, 8 metabolites in liver microsomes and 18 metabolites in intestinal bacteria were identified, and 9 metabolites were recognized by comparison with standards. The biotransformation processes involved ketone, acetylation, loss of C₁₂H₂₀O₁₀, and loss of C₆H₁₀O₅. And baicalein and oroxin A were generated after loss of C₁₂H₂₀O₁₀, and loss of C₆H₁₀O₅, respectively, and further went through some other reactions, such as oxidation, methylation, internal hydrolysis, hydrogenation, loss of O, ketone, glycine conjugation, glucuronide conjugation and their composite reactions. The results provide valuable evidence for elucidation the potential mechanism of oroxin B pharmacological action, and offer reasonable guidelines for further investigations of oroxin B safety and efficacy.

An integrated strategy for profiling the chemical components of Scutellariae Radix and their exogenous substances in rats by ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry

RATIONALE

Traditional Chinese medicines (TCMs) attract worldwide attention because of their effects in clinical application recorded in China historical ancient codes and in records, such as 'Treatise on Febrile Diseases'. With the developments of drug analysis and research, evaluating the in vivo substances in TCMs has become of great importance. Scutellariae Radix (SR, named as huang-qing in China), the root of Scutellaria baicalensis Georgi, has shown favorable clinical effects and safety in the treatment of infection diseases; however, its in vivo compounds are unclear and need detailed investigation.

METHODS

An ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC/QTOF MS) method coupled to an integrated strategy involving diagnostic ions, neutral losses and a prediction platform was used to explore the constituents of SR, and their exogenous substances in rats.

RESULTS

A total of 118 chemical constituents mainly featuring five chemical structure types (flavone C-glycosides, flavone O-glycosides, free flavones, flavanones and phenylethanoid glycosides) were identified or tentatively characterized in SR, and 175 xenobiotics (68 prototypes and 107 metabolites) were profiled in rat plasma, urine, bile and feces after ingestion of SR. The metabolites were classified into four related chemical groups: flavone C-glycosides, flavone O-glycosides, flavanones and phenylethanoid glycosides. Phase II metabolism reactions, such as glucuronidation and sulfation, were the major metabolic reactions in addition to phase I reactions of hydrolysis and hydrogenation. The corresponding main metabolic features of SR in rats were also elucidated.

CONCLUSIONS

The metabolism of SR, as a whole, was systemically revealed for the first time, and our work also provided meaningful information for pharmacokinetics studies and pharmacological analysis of SR in future work.

Different absorption and metabolism of ginsenosides after the administration of total ginsenosides and decoction of Panax ginseng

RATIONALE

Panax ginseng C.A. Meyer (PG), which contains polysaccharides and ginsenosides as the major bioactive components, has been used to promote health and treat diseases for thousands of years in China. Total ginsenosides were extracted from a decoction of Panax ginseng (GD), which included both ginsenosides and polysaccharides, and dissolved in water to obtain a total ginsenosides aqueous solution (TGAS). To study their absorption and metabolism, the pharmacokinetics (PK) and metabolites of ginsenosides in vivo were investigated after the administration of GD and TGAS.

METHODS

Rat and mice plasma samples were collected after the administration of GD and TGAS. Ultra-performance liquid chromatography coupled with time-of-flight mass spectrometry was used with the UNIFI platform to identify metabolites in the plasma sample. The pharmacokinetic parameters were calculated using a noncompartmental method in the Drug and Statistics software package.

RESULTS

Thirty ginsenoside metabolites were identified in mice plasma, of which only seven were found in the rat plasma after the administration of GD. The PK of ginsenosides Rb₁ , Rc, and Rd were also determined after the oral administration of GD and TGAS and showed significant differences in the pharmacokinetic parameters.

CONCLUSIONS

There was no difference in the biotransformation pathways after the oral administration of GD and TGAS, indicating that there was no influence of polysaccharides on the biotransformation of ginsenosides in vivo. However, the pharmacokinetic parameters were different after the administration of GD and TGAS, possibly because of the polysaccharides in GD. This study should be of significance in exploring the basis of PG bioactivities and lays the foundation for the further development of new drugs using PG.

Baicalein suppresses the proliferation and invasiveness of colorectal cancer cells by inhibiting Snail‑induced epithelial‑mesenchymal transition

Scutellaria baicalensis (S. baicalensis) is a plant that is widely used for medicinal purposes. Baicalein, one of the primary bioactive compounds found in S. baicalensis, is thought to possess antitumor activity, although the specific mechanisms remain unclear. Therefore, the present study aimed to evaluate the ability of baicalein to disrupt the proliferation and metastatic potential of colorectal cancer (CRC) cells; a rapid and sensitive ultra-high performance liquid chromatography-tandem mass spectrometric method was employed for the identification of baicalein in an S. baicalensis aqueous extract and in rat plasma. To investigate the effects of baicalein, Cell Counting Kit-8 (CCK-8), western blotting, wound-healing and Transwell assays were performed. The data indicated that baicalein was absorbed into the blood and was able to effectively disrupt the proliferation, migration and invasion abilities of CRC cells in a dose- and time-dependent manner. Baicalein treatment was also revealed to decrease the expression of epithelial-mesenchymal transition (EMT)-promoting factors including vimentin, Twist1, and Snail, but to upregulate the expression of E-cadherin in CRC cells. The expression levels of cell cycle inhibitory proteins p53 and p21 also increased following baicalein treatment. In addition, Snail-induced vimentin and Twist1 upregulation, as well as E-cadherin downregulation, were reversed following treatment with baicalein. In conclusion, the results of the present study indicate that baicalein may suppress EMT, at least in part, by decreasing Snail activity.

Using the UPLC-ESI-Q-TOF-MSE method and intestinal bacteria for metabolite identification in the nonpolysaccharide fraction from Bletilla striata

Bletilla striata (Thunb.) Reichb. f. (Orchidaceae), also known as Bai-ji, is a traditional Chinese herb that is widely used in Asia to treat hematemesis, hemoptysis, traumatic bleeding and other similar disorders. Most studies have focused on the pharmacological activities of polysaccharide extracts from B. striata. Our previous studies found that the nonpolysaccharide fraction from B. striata extract also has a hemostatic effect; however, the active constituents responsible for this pharmacological action are unclear. Thus, the metabolic profiles of the nonpolysaccharide fraction were investigated in Sprague-Dawley rats and intestinal bacteria models using ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry. Mass data were acquired by the MS^E method. Eight components including five prototypes and three metabolites were identified in rat biofluids after oral administration of the nonpolysaccharide fraction. The parent compounds underwent various metabolic processes, including hydrolysis, deglucosylation, glycosylation and sulfate conjugation. The results not only reveal the possible metabolic pathway, but also indicate the potential pharmacological components. Further mechanistic studies using nonpolysaccharide compounds of the B. striata extract are required to obtain potential candidate compounds.

Chemical fingerprint analysis and metabolic profiling of 50% ethanol fraction of Lomatogonium rotatum by ultra-performance liquid chromatography/quadrupole-time of flight mass spectrometry

Lomatogonium rotatum (L.) Fries ex Nym (L. rotatum), a member of Gentianaceae, is an important mongolian medicine in China used to treat febrile diseases in liver and gallbladder. The aim of present study was to investigate the chemical constituents and metabolites of the 50% ethanol fraction of L. rotatum (50EtLR). Firstly, the extract of L. rotatum was partitioned by macroporous resin to obtain the target fraction (50EtLR), then several compounds were isolated from 50EtLR to obtained the standards for further analysis of chemical constituents of 50EtLR. Secondly, the chemical constituents of 50EtLR were characterized using the ultra-high performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UHPLC-Q-TOF-MS/MS). Finally, prototype constituents and related metabolites were analyzed after orally administerng 50EtLR to rats. As a result, a new compound, 6-O-[β-d-xylopyranosyl-(1 → 6)-O-β-d-glucopyranosyl]-1,4,8-trimethoxyxanthone (6) along with seven known compounds (1-5, 7 and 8) were isolated from the 50EtLR, 92 components were either unambiguously or tentatively identified. Additionally, 34 prototype constituents and 112 metabolites in rat plasma along with 32 prototype constituents and 53 metabolites in rat liver were tentatively identified. Therefore, xanthones and flavonoids were the main chemical constituents of 50EtLR and sulfation and glucuronidation are the main enzyme-induced metabolic pathways involved post-administration.

Metabolite profiling and quantification of phytochemicals of Tianma-Gouteng granule in human and rat urine using ultra high performance liquid chromatography coupled with tandem mass spectrometry

Tianma-Gouteng granule has been used for the treatment of hypertension, headache, and stroke in China. However, the metabolism of Tianma-Gouteng granule has not been clear. In the present study, an ultra high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry method has been developed for rapid identification of 35 prototypes and 43 metabolites in human and rat urine after single oral administration of Tianma-Gouteng granule. The results showed that glucuronidation and sulfation were the main metabolic pathways for flavonoids, alkaloids, iridoidic glycosides, anthraquinones, phenols, and stilbenes that were found in Tianma-Gouteng granule. Moreover, a validated ultra high performance liquid chromatography coupled with tandem mass spectrometry method was applied for the quantification of 14 compounds in rat urine after an oral administration of Tianma-Gouteng granule (2.5 g/kg). During 0-48 h after dosing, the cumulative excretion rates of nine prototype components were 53% for gastrodin, 0.07∼1.6% for geniposide, baicalin and baicalein, wogonoside, rhynchophylline and isorhynchophylline, leonurine, and emodin, indicating that urinary excretion is the major way for gastrodin to eliminate from the body. This study provides a comprehensive understanding of metabolism and excretive kinetics of Tianma-Gouteng granule in human and/or rat, and helpful information for screening of its active components in vivo and clinical application.

A High Throughput Three-step Ultra-performance Liquid Chromatography Tandem Mass Spectrometry Method to Study Metabolites of Atractylenolide-III

Atractylodes macrocephala Koidz (AMK) is a traditional Chinese medicine widely used in the treatment of various diseases, especially spleen deficiency. As the principle active constituents of AMK, however, the metabolites of Atractylenolide-III (A-lactone-III) have not been identified in rats yet. In this study, a three-step high throughput method based on UHPLC-Q-TOF-MS-MS was developed to profile and characterize the metabolites of A-lactone-III in rat feces, urine and plasma. The initial step was a full-scan that utilized a multiple mass defect filter (MMDF) combined with dynamic background subtraction (DBS). PeakView®1.2 and Metabolitepilot™1.5 software was then used to obtain data and seek possible metabolites. Finally, MS-MS spectra of the parent drug and possible metabolites were compared by the fragment ion peaks and retention times, which enabled metabolites to be identified. As a result, 53 metabolites were characterized in rats in vivo. The metabolic pathways of A-lactone-III were identified as including methylation, oxidation, hydroxylation, dihydroxylation, hydrogenation, glycosylation, sulfonation, and glucuronide, cysteine and N-acetylcysteine conjugation.

Identification of the absorbed components and their metabolites of Tianma-Gouteng granule in rat plasma and bile using ultra-high-performance liquid chromatography combined with quadrupole time-of-flight mass spectrometry

Tianma-Gouteng granule (TGG), a Chinese herbal formula preparation, is clinically used for the treatment of cardio-cerebrovascular diseases such as hypertension, cerebral ischaemia, acute ischaemic stroke and Parkinson's disease. Although few reports have been published concerning the absorbed prototype components of TGG, the possible metabolic pathways of TGG in vivo remain largely unclear. In this study, a method using UPLC-Q/TOF MS was established for the detection and identification of the absorbed prototype components and related metabolites in rat plasma and bile after oral administration of TGG at high and normal clinical dosages. A total of 68 components were identified or tentatively identified in plasma and bile samples, including absorbed prototypes and their metabolites. The major absorbed components were gastrodin, isorhynchophylline, rhynchophylline, isocorynoxeine, corynoxeine, geissoschizine methyl ether baicalin, baicalein, wogonoside, wogonin, geniposidic acid, leonurine, 2,3,5,4'-tetrahydroxystilbene-2-O-β-d-glucoside and emodin. The main metabolic pathways of these components involved phase I (isomerization, hydrolysis and reduction) and phase II (glucuronidation and sulfation) reaction, and the phase II biotransformation pathway was predominant. The present study provides rich information on the in vivo absorption and metabolism of TGG, and the results will be helpful for further studies on the pharmacokinetics and pharmacodynamics of TGG.

Study on the metabolites of betulinic acid in vivo and in vitro by ultra high performance liquid chromatography with time-of-flight mass spectrometry

Betulinic acid is a triterpenoid organic acid with remarkable antitumor properties and is naturally present in many fruits, condiments and traditional Chinese medicines. Currently, a strategy was developed for the identification of metabolites following the in vivo and in vitro biotransformation of Betulinic acid with rat intestinal bacteria utilizing ultra high performance liquid chromatography with time-of-flight mass spectrometry with polymeric solid-phase extraction. As a result, 46 metabolites were structurally characterized. The results demonstrated that Betulinic acid is universally metabolized in vivo and in vitro, and Betulinic acid could undergo general metabolic reactions, including oxidation, methylation, desaturation, loss of O and loss of CH₂ . Additionally, the main metabolic pathways in vivo and in vitro were determined by calculating the relative content of each metabolite. This is the first study of Betulinic acid metabolism in vivo, whose results provide novel and useful data for better understanding of the safety and efficacy of Betulinic acid.

Biotransformation and Metabolic Profile of Limonin in Rat Liver Microsomes, Bile, and Urine by High-Performance Liquid Chromatography Coupled with Quadrupole Time-of-Flight Mass Spectrometry

Limonin is a triterpenoid in citrus seeds, which has significant biological activities. However, the metabolic profile of limonin has not been fully understood. To expound its metabolism in vivo and in vitro, the metabolites of limonin was studied by rat liver microsomes, urine, and bile. High-performance liquid chromatography/quadrupole time-of-flight mass spectrometry was used for identification. Among the metabolites, the structures of M1 and M3 were confirmed by chemical synthesis and nuclear magnetic resonance spectra analysis. Our results indicated that reduction and hydrolysis were the two major pathways during limonin metabolism in vivo and in vitro. The results from this work are valuable and important for understanding the metabolic process of limonin.

Screening inhibitors of xanthine oxidase from natural products using enzyme immobilized magnetic beads by high-performance liquid chromatography coupled with tandem mass spectrometry

In this study, high-performance liquid chromatography coupled with tandem mass spectrometry was used to assess the results of bioactive compound screening from natural products using immobilized enzyme magnetic beads. We compared three commercial magnetic beads with modified amino, carboxy, and N-hydroxysuccinimide groups, respectively. Amino magnetic beads performed best for immobilization and were selected for further experiments. Xanthine oxidase was immobilized on amino magnetic beads and applied to screen potential inhibitors in fresh Zingiber officinale Roscoe, extracts of Scutellaria baicalensis Georgi, and Pueraria lobata Ohwi. In total, 12 potential xanthine oxidase ligands were identified from fresh Zingiber root and Scutellaria root extracts, of which eight were characterized and the concentration required for 50% inhibition was determined. Preliminary structure-function relationships were discussed based on these results. A convenient and effective method was therefore developed for the identification of active compounds from complex natural product mixtures.

A two-step ultra-high-performance liquid chromatography-quadrupole/time of flight mass spectrometry with mass defect filtering method for rapid identification of analogues from known components of different chemical structure types in Fructus Gardeniae-Fructus Forsythiae herb pair extract and in rat's blood

Fructus Gardeniae-Fructus Forsythiae herb pair is an herbal formula used extensively to treat inflammation and fever, but few systematic identification studies of the bioactive components have been reported. Herein, the unknown analogues in the first-step screening were rapidly identified from representative compounds in different structure types (geniposide as iridoid type, crocetin as crocetin type, jasminoside B as monocyclic monoterpene type, oleanolic acid as saponin type, 3-caffeoylquinic acid as organic acid type, forsythoside A as phenylethanoid type, phillyrin as lignan type and quercetin 3-rutinoside as flavonoid type) by UPLC-Q-Tof/MS combined with mass defect filtering (MDF), and further confirmed with reference standards and published literatures. Similarly, in the second step, other unknown components were rapidly discovered from the compounds identified in the first step by MDF. Using the two-step screening method, a total of 58 components were characterized in Fructus Gardeniae-Fructus Forsythiae (FG-FF) decoction. In rat's blood, 36 compounds in extract and 16 metabolites were unambiguously or tentatively identified. Besides, we found the principal metabolites were glucuronide conjugates, with the glucuronide conjugates of caffeic acid, quercetin and kaempferol confirmed as caffeic acid 3-glucuronide, quercetin 3-glucuronide and kaempferol 3-glucuronide by reference standards, respectively. Additionally, most of them bound more strongly to human serum albumin than their respective prototypes, predicted by Molecular Docking and Simulation, indicating that they had lower blood clearance in vivo and possibly more contribution to pharmacological effects. This study developed a novel two-step screening method in addressing how to comprehensively screen components in herbal medicine by UPLC-Q-Tof/MS with MDF.

UFLC-Q-TOF-MS/MS-Based Screening and Identification of Flavonoids and Derived Metabolites in Human Urine after Oral Administration of Exocarpium Citri Grandis Extract

Exocarpium Citri grandis (ECG) is an important Traditional Chinese Medicine (TCM) for the treatment of cough and phlegm, and the flavonoids contained were considered the main effective components. To date, the systematic chemical profiling of these flavonoids and derived in vivo metabolites in human have not been well investigated. ECG was extracted using boiling water and then provided to volunteers for oral administration. Following the ingestion, urine samples were collected from volunteers over 48 h. The extract and urine samples were analyzed using ultra-fast liquid chromatography/quadrupole-time-of-flight tandem mass spectrometry (UFLC-Q-TOF-MS/MS) system to screen and identify flavonoids and derived in vivo metabolites. A total of 18 flavonoids were identified in the ECG extract, and 20 metabolites, mainly glucuronide and sulfate conjugates, were screened in urine samples collected post consumption. The overall excretion of naringenin metabolites corresponded to 5.45% of intake and occurred mainly within 4–12 h after the ingestion. Meanwhile, another 29 phenolic catabolites were detected in urine. Obtained data revealed that flavonoids were abundant in the ECG extract, and these components underwent extensive phase II metabolism in humans. These results provided valuable information for further study of the pharmacology and mechanism of action of ECG.

Metabolism profiling of nevadensin in vitro and in vivo by UHPLC-Q-TOF-MS/MS

Nevadensin is major constituents of Lysionotus pauciflorus Maxim. (Chinese name: Shidiaolan), which has a variety of pharmacological effects such as anti-mycobacterium tuberculosis activities, antitussive, anti-inflammatory and anti-hypertensive. In this paper, we investigated the metabolism of nevadensin in vitro and in vivo. A strategy was firstly developed to identify the metabolites of nevadensin by using ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS/MS). An on-line data acquisition method a multiple mass defect filter (MMDF) combined with dynamic background subtraction (DBS) was developed to trace all probable metabolites. Furthermore, some assistant tools, such as key fragment ions (KFI), were employed for compound hunting and identification. Based on the proposed method, 23 metabolites were structurally characterized in vivo including 16 phase I and 7 phase II metabolites, and 12 metabolites were detected in vitro containing 10 phase I and 2 phase II metabolites. The results indicated that oxidation, hydrolysis, demethylation, methylation, sulfate conjugation and glucuronide conjugation were main metabolic pathways of nevadensin. In a word, this study maybe can provide reference and valuable evidence for further investigation of the metabolic mechanism of nevadensin.

An Improved Drugs Screening System Reveals that Baicalein Ameliorates the Aβ/AMPA/NMDA-Induced Depolarization of Neurons

The presence of amyloid-β (Aβ) plaque and tau protein hyperphosphorylation in brain tissue is the pathological hallmark of Alzheimer's disease (AD). At least some Aβ neurotoxicity is caused by the presence of excess glutamate that has been induced by Aβ accumulation. Memantine is currently the only NMDA receptor inhibitor approved for treating moderate-to-severe AD patients. We utilized primary cortical neurons and DiBAC4(3), a slow-response voltage sensitive fluorescence dye, to create a novel system for screening herbal medicines that allows the identification of pure compounds able to ameliorate Aβ-induced abnormal depolarization. The intensity of DiBAC4(3) fluorescence was increased when primary neurons were stimulated by Aβ; furthermore, pre-treatment with memantine abolished this change. Using this system, we identified six crude extracts made from herbal medicines that effectively alleviated this Aβ-induced abnormal depolarization. Among these herbal medicines, one pure compound, baicalein, which was known to be present in Scutellaria baricalensis and is known to improve memory using an AD mouse model, was identified by our assay. However, the compound's molecular mechanism remained unknown. We found that baicalein, in addition to inhibiting Aβ-induced depolarization, possibly functions as an antagonist of AMPA and NMDA receptors. Taken together, we have established a system/platform to identify herbal medicines that ameliorate Aβ-induced depolarization of neurons. Equally important, baicalein is a candidate drug with great potential for the treatment of AD patients.

Systematic study on metabolism and activity evaluation of Radix Scutellaria extract in rat plasma using UHPLC with quadrupole time-of-flight mass spectrometry and microdialysis intensity-fading mass spectrometry

Radix Scutellaria is a widely used traditional Chinese medicine in the treatment of various diseases. However, the activities of the absorbed components and metabolites of its main flavones in rat plasma need further investigation. In this study, a systematic method based on ultra-high performance liquid chromatography with quadruple time-of-flight mass spectrometry was developed to speculate the absorbed components and metabolites of the main flavonoids in Radix Scutellaria extract in rat plasma sample after oral administration of the extract. Twelve compounds, including four prototype components and eight metabolites, were confirmed in drug-containing plasma. In these metabolites, five were originally detected in rat plasma. The possible metabolic pathways of these polyhydroxy flavones in vivo were described and clarified. Microdialysis with intensity-fading mass spectrometry was originally employed to investigate the binding affinities of the absorbed components and metabolites with α-glucosidase. The order of their binding affinities was P4 > P3 > P2 > P1≥M5 > M3 > M1. The research result is helpful to deepen the understanding of the absorbed components and metabolic pathways of main flavones from Radix Scutellaria, and provide a new approach to screen potential inhibitors from in vivo components originated from Chinese herb.

UHPLC-Q-TOF-MS/MS Method Based on Four-Step Strategy for Metabolism Study of Fisetin in Vitro and in Vivo

Fisetin has been identified as an anticancer agent with antiangiogenic properties in mice. However, its metabolism in vitro (rat liver microsomes) and in vivo (rats) is presently not characterized. In this study, ultra-high-performance liquid chromatography coupled with hybrid triple quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS) was employed for data acquiring, and a four-step analytical strategy was developed to screen and identify metabolites. First, full-scan was applied, which was dependent on a multiple mass defect filter (MMDF) combined with dynamic background subtraction (DBS). Then PeakView 1.2 and Metabolitepilot 1.5 software were used to load data to seek possible metabolites. Finally, metabolites were identified according to mass measurement and retention time. Moreover, isomers were distinguished based on Clog P parameter. Based on the proposed method, 53 metabolites in vivo and 14 metabolites in vitro were characterized. Moreover, metabolic pathways mainly included oxidation, reduction, hydrogenation, methylation, sulfation, and glucuronidation.

Metabolism studies on hydroxygenkwanin and genkwanin in human liver microsomes by UHPLC-Q-TOF-MS

Hydroxygenkwanin (HYGN) and genkwanin (GN) are major constituents of Genkwa Flos for the treatment of edema, ascites, cough, asthma and cancer. This is a report about the investigation of the metabolic fate of HYGN and GN in human liver microsomes and the recombinant UDP-glucuronosyltransferase (UGT) enzymes by using ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS). An on-line data acquisition method multiple mass defect filter (MMDF) combined with dynamic background subtraction (DBS) was developed to trace all probable metabolites. Based on this analytical strategy, three phase I metabolites and seven glucuronide conjugation metabolites of HYGN, seven phase I metabolites and 12 glucuronide conjugation metabolites of GN were identified in the incubation samples of human liver microsomes. The results indicated that demethylation, hydroxylation and o-glucuronidation were main metabolic pathways of HYGN and GN. The specific UGT enzymes responsible for HYGN and GN glucuronidation metabolites were identified using recombinant UGT enzymes. The results indicated that UGT1A1, UGT1A3, UGT1A9, UGT1A10 and UGT2B7 might play major roles in the glucuronidation reactions. Overall, this study may be useful for the investigation of metabolic mechanism of HYGN and GN, and it can provide reference and evidence for further experiments.

Effects of Intestinal Microecology on Metabolism and Pharmacokinetics of Oral Wogonoside and Baicalin

Baicalin and wogonoside are two of the most abundant flavonoid glycosides in the root of Scutellaria baicalensis Georgi, which is a widely used peroral herbal medicine with anticancer, antiviral, antibacterial and anti-inflammatory properties. In the present study, the effects of intestinal microecology on the metabolism and pharmacokinetics of orally administered baicalin and wogonoside were investigated by UPLC-QTOF/MS measurement of the difference in metabolites between normal and antibiotic-pretreated rats. In the antibiotic-pretreated rats, the plasma concentration-time profile and pharmacokinetic parameters of the two flavonoid glycosides and their relevant aglycone forms were significantly changed compared with those in normal rats. Further, hydrolysis and glucuronidated metabolites were not detected in the cecum contents and urine samples from antibiotic-pretreated rats. These results suggested that intestinal microbiota may play a key role in the pharmacokinetics and metabolism of peroral baicalin and wogonoside. According to our findings, it is recommended that the root of S. baicalensis should not be co-administered with antibiotics in clinical use.

An untargeted metabolomics approach to determine component differences and variation in their in vivo distribution between Kuqin and Ziqin, two commercial specifications of Scutellaria Radix

Kuqin (KQ) and Ziqin (ZQ), derived from the roots of Scutellaria baicalensis Georgi, are two important commercial specifications of Scutellariae Radix (SR, termed Huang qin in Chinese).

He-Wei granules (HWKL) combat cisplatin-induced nephrotoxicity and myelosuppression in rats by inhibiting oxidative stress, inflammatory cytokines and apoptosis

He-Wei granules (HWKL) combat cisplatin-induced nephrotoxicity and myelosuppression in rats by inhibiting oxidative stress, inflammatory cytokines and apoptosis

He-Wei granules inhibit chemotherapy-induced vomiting (CINV) in rats by reducing oxidative stress and regulating 5-HT, substance P, ghrelin and obestatin

As a common side effect of a variety of chemotherapy drugs, CINV severely limits the clinical use of chemotherapy drugs.

An Integrated Approach for Studying Exposure, Metabolism, and Disposition of Multiple Component Herbal Medicines Using High-Resolution Mass Spectrometry and Multiple Data Processing Tools

A typical prescription of traditional Chinese medicine (TCM) contains up to a few hundred prototype components. Studying their absorption, metabolism, distribution, and elimination (ADME) presents great challenges. The objective of this study was to develop a practical approach for investigating ADME of individual prototypes in TCM. An active fraction of Xiao-Xu-Ming decoction (AF-XXMD) as a model TCM prescription was orally administered to rats. AF-XXMD-related components in plasma, urine, bile, and feces were detected using high-resolution mass spectrometry and background subtraction, an untargeted data-mining tool. Components were then structurally characterized on the basis of MS(n) spectral data. Connection of detected AF-XXMD metabolites to their precursor species, either prototypes or upstream metabolites, were determined on the basis of mass spectral similarity and the matching of biotransformation reactions. As a result, 247 AF-XXMD-related components were detected and structurally characterized in rats, 134 of which were metabolites. Among 198 AF-XXMD prototypes dosed, 65 were fully or partially absorbed and 13 prototypes and 34 metabolites were found in the circulation. Glucuronidation, isomerization, and deglycosylation followed by biliary and urinary excretions and direct elimination of prototypes via kidney and liver were the major clearance pathways of AF-XXMD prototypes. As an example, the ADME profile of H56, the single major AF-XXMD component in rat plasma, was elucidated on the basis of profiles of H56-related components in plasma and excreta. The results demonstrate that the new analytical approach is a useful tool for rapid and comprehensive detection and characterization of TCM components in biologic matrix in a TCM ADME study.

Metabolite identification and pharmacokinetic study of Lamiophlomis rotata in rats

An ultra-high performance liquid chromatography coupled with time-of-flight mass spectrometry technique and a subsequent LC-MS/MS method were developed for metabolite profile study of Lamiophlomis rotata extract after its oral administration.