Comprehensive characterization of the in vitro and in vivo metabolites of ziyuglycoside I in rat microsome, intestinal flora, excretion specimen and fresh tissues based on LC–Q-TOF/MS

Terpenoids with α-glucosidase inhibitory activity from Rhododendron minutiflorum Hu

Five undescribed triterpenoids, two unusual omphalane-type sesquiterpenoids together with twenty-five known compounds were isolated from the leaves and stems of Rhododendron minutiflorum Hu. The absolute configurations of 1-3 and 6 were established by single-crystal X-ray diffraction analysis and electronic circular dichroism (ECD). Compounds 6-7 feature the rare omphalane-type sesquiterpene skeleton and are verified by single-crystal X-ray diffraction analysis for the first time. In the biological activity assay, most of the triterpenoids have different degrees of inhibitory effects on α-glucosidase, with IC₅₀ values ranging from 6.97 to 229.3 μM (the positive control drug acarbose has an IC₅₀ value of 3.07 × 10^-3 μM). Structure and activity relationship (SAR) study reveals that the oxidation degrees of C-3, C-8, or C-11 to C-13 of the ursane-type triterpenoid influence the inhibitory activity dramatically.

The systematic characterization of multiple components and metabolic profiling of bioactive constituents in Yaobitong capsule by UHPLC/Q-TOF-MS/MS

Yaobitong capsule is a valuable traditional Chinese medicine prescription (TCMP), which can effectively treat lumbar disc herniation clinically. However, the effective substances in Yaobitong capsule are still unclear due to a lack of metabolic studies. This poses a huge obstacle preventing the clinical safety assessment and quality control of Yaobitong capsule. In order to explore the metabolic landscape of the multiple components of Yaobitong capsule, this paper proposed a rapid and high-throughput UHPLC/Q-TOF-MS/MS method for carrying out a systematic study, including analyzing the chemical ingredients in vitro and studying the metabolic processes in rat urine, feces, and bile after the oral administration of Yaobitong capsule. A total of 90 Yaobitong-capsule-related chemical components were characterized or tentatively identified in extract solution based on the retention behaviors, measured mass values, and fragmentation patterns. Furthermore, 49 related metabolites were detected in urine, feces, and bile samples. All metabolites were also identified with the help of the Sciex OS tool from these biological samples. The results revealed that triterpenoid saponins, alkaloids, monoterpene glycosides, and phthalides were the main chemical components of Yaobitong capsule. In addition, glucuronidation, hydroxylation, sulfation, and N-acetylcysteine conjugation were the main metabolic reactions in rats after the oral administration of Yaobitong capsule. The results indicated that the established method for multicomponent metabolism identification was appropriate, and the metabolic profiling of Yaobitong capsule provides abundant material for a wide range of further research; this is of significance for carrying out studies of pharmacodynamic mechanisms.

Chemical profile of Xian-He-Cao-Chang-Yan formula and its effects on ulcerative colitis

ETHNOPHARMACOLOGICAL RELEVANCE

Xian-He-Cao-Chang-Yan formula (XHCF) is consisting of six crude drugs including Agrimoniae Herba, Coptidis Rhizoma, Aucklandiae Radix, Cicadae Periostracum, Acori Tatarinowii Rhizoma, and Platycodonis Radix at the ratio of 5:1.5:1.5:1.5:1.5:1. It has been used to improve syndromes of ulcerative colitis (UC) for many years.

AIM OF THE STUDY

This study was designed to study the bioactive ingredients and therapeutic mechanisms of XHCF.

MATERIALS AND METHODS

The chemical profile of XHCF was characterized by UHPLC-QTOF-MS/MS. The effects and mechanisms of XHCF on UC were investigated in colitis mice induced by dextran sulfate sodium (DSS) and LPS-stimulated RAW 264.7 cells.

RESULTS

A total of 103 compounds were characterized in XHCF. XHCF could effectively improve acute colitis induced by DSS. More importantly, XHCF significantly decreased M1 macrophage markers (CD11c, IL-6 and IL-1β) whereas increased M2 macrophage markers (CD206) in colitis mice, suggesting it could regulate macrophage polarization. Furthermore, the levels of HK2 and lactic acid in colon tissues were significantly reduced by XHCF, indicating that XHCF could inhibit glycolysis. It also down-regulated HK2 expression in macrophages challenged by LPS. In addition, XHCF enhanced the phosphorylation of AMPK both in vivo and in vitro, suggesting the involvement of AMPK in XHCF function.

CONCLUSIONS

XHCF ameliorated DSS-induced colitis in mice via inhibition of M1 macrophage polarization, probably by the modulation of macrophage metabolic reprogramming via AMPK, contributing to its anti-inflammatory activity. The synergistic actions of multiple ingredients might be responsible for the therapeutic benefits of XHCF on UC.

Metabolites profiling and pharmacokinetics of troxipide and its pharmacodynamics in rats with gastric ulcer

Troxipide is widely used to treat gastric ulcer (GU) in the clinic. However, a lack of systematic metabolic, pharmacokinetic and pharmacological studies limits its clinical use. This study aimed to firstly explore the metabolic, pharmacokinetic and pharmacological mechanisms of troxipide in rats with GU compared to normal control (NC) rats. First, metabolic study was perormed by a highly selective, high-resolution mass spectrometry method. A total of 45 metabolites, including 9 phase I metabolites and 36 phase II metabolites, were identified based on MS/MS spectra. Subsequently, the pharmacokinetics results suggested that the Cmax, Ka, t1/2, AUC(0-t) and AUC(0-∞) of troxipide were significantly increased in rats with GU compared with NC rats. The Vz, K10 and absolute bioavailability of troxipide were obviously decreased in rats with GU compared with NC rats, and its tissue distribution (in the liver, lung and kidney) was significantly different between the two groups of rats. Additionally, the pharmacodynamic results suggested that the levels of biochemical factors (IL-17, IL-6, TNF-α, IFN-γ, AP-1, MTL, GAS, and PG-II) were significantly increased, the PG-Ӏ level was obviously decreased, and the protein expression levels of HSP-90, C-Cas-3 and C-PARP-1 were markedly increased in rats with GU compared with NC rats. The above results suggested that the therapeutic mechanisms underlying the metabolic, pharmacokinetic and pharmacological properties of troxipide in vivo in rats deserve further attention based on the importance of troxipide in the treatment of GU in this study, and these mechanisms could be targets for future studies.

Analysis of Flavonoids in Dalbergia odorifera by Ultra-Performance Liquid Chromatography with Tandem Mass Spectrometry

Dalbergia odorifera, a traditional Chinese medicine, has been used to treat cardio- and cerebrovascular diseases in China for thousands of years. Flavonoids are major active compounds in D. odorifera. In this paper, a rapid and sensitive ultra-high performance liquid chromatography-triple quadrupole mass spectrometry method was developed and validated for simultaneous determination of 17 flavonoids in D. odorifera. Quantification was performed by multiple reaction monitoring using electrospray ionization in negative ion mode. Under the optimum conditions, calibration curves for the 17 analytes displayed good linearity (r² > 0.9980). The intra- and inter-day precisions (relative standard deviations) were lower than 5.0%. The limit of quantitation ranged from 0.256 to 18.840 ng/mL. The mean recovery range at three spiked concentrations was 94.18-101.97%. The validated approach was successfully applied to 18 samples of D. odorifera. Large variation was observed for the contents of the 17 analytes. Sativanone and 3'-O-methylviolanone were the dominant compounds. The fragmentation behaviors of six flavonoids were investigated using UPLC with quadrupole time-of-flight tandem mass spectrometry. In negative ion electrospray ionization mass spectrometry, all the flavonoids yielded prominent [M - H]^- ions. Fragments for losses of CH₃, CO, and CO₂ were observed in the mass spectra. Formononetin, liquiritigenin, isoliquiritigenin, sativanone, and alpinetin underwent retro-Diels-Alder fragmentations. The proposed method will be helpful for quality control of D. odorifera.

Comparative analysis of constitutes and metabolites for traditional Chinese medicine using IDA and SWATH data acquisition modes on LC-Q-TOF MS

Identification of components and metabolites of traditional Chinese medicines (TCMs) employing liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-Q-TOF MS) techniques with information-dependent acquisition (IDA) approaches is increasingly frequent. A current drawback of IDA-MS is that the complexity of a sample might prevent important compounds from being triggered in IDA settings. Sequential window acquisition of all theoretical fragment-ion spectra (SWATH) is a data-independent acquisition (DIA) method where the instrument deterministically fragments all precursor ions within the predefined m/z range in a systematic and unbiased fashion. Herein, the superiority of SWATH on the detection of TCMs’ components was firstly investigated by comparing the detection efficiency of SWATH-MS and IDA-MS data acquisition modes, and sanguisorbin extract was used as a mode TCM. After optimizing the setting parameters of SWATH, rolling collision energy (CE) and variable Q1 isolation windows were found to be more efficient for sanguisorbin identification than the fixed CE and fixed Q1 isolation window. More importantly, the qualitative efficiency of SWATH-MS on sanguisorbins was found significantly higher than that of IDA-MS data acquisition. In IDA mode, 18 kinds of sanguisorbins were detected in sanguisorbin extract. A total of 47 sanguisorbins were detected when SWATH-MS was used under rolling CE and flexible Q1 isolation window modes. Besides, 26 metabolites of sanguisorbins were identified in rat plasma, and their metabolic pathways could be deduced as decarbonylation, oxidization, reduction, methylation, and glucuronidation according to their fragmental ions acquired in SWATH-MS mode. Thus, SWATH-MS data acquisition could provide more comprehensive information for the component and metabolite identification for TCMs than IDA-MS.

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SWATH was first used to identify components and metabolites of TCMs.

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Superiority of SWATH on the detection of TCM was firstly investigated.

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The number of components detected by SWATH was greatly higher than IDA.

Efficacy of MaZiRenWan, a Chinese Herbal Medicine, in Patients With Functional Constipation in a Randomized Controlled Trial

BACKGROUND & AIMS

The Chinese herbal medicine, MaZiRenWan (MZRW), has been used for more than 2000 years to treat constipation, but it has not been tested in a randomized controlled trial. We performed a trial to evaluate the efficacy and safety of MZRW, compared with the stimulant laxative senna or placebo, for patients with functional constipation (FC).

METHODS

We performed a double-blind, double-dummy, trial of 291 patients with FC based on Rome III criteria, seen at 8 clinics in Hong Kong from June 2013 through August 2015. Patients were observed for 2 weeks and then assigned randomly (1:1:1) to groups given MZRW (7.5 g, twice daily), senna (15 mg daily), or placebo for 8 weeks. Patients were then followed for 8 weeks and evaluated at baseline and weeks 4, 8 (end of treatment), and 16 (end of follow up). Participants recorded information on stool form and frequency, feeling of complete evacuation, and research medication taken. Data on individual bowel symptoms, global symptom improvement, and adverse events were collected. A complete response was defined as an increase ≥1 complete spontaneous bowel movement (CSBM)/week from baseline (the primary outcome). Secondary outcomes included response during the follow-up period, colonic transit, individual and global symptom assessments, quality of life measured with 36-item short form Chinese version, and adverse events.

RESULTS

Although there was no statistically significant difference in proportions of patients with a complete response to MZRW (68%) vs. senna (57.7%) (P = .14) at week 8, there was a statistically significant difference vs. placebo (33.0%) (P < .005). At the 16-week timepoint (after the 8-week follow-up period), 47.4% of patients had a complete response to MZRW, 20.6% had a complete response to senna, and 17.5% had a complete response to placebo (P < .005 for MZRW vs. placebo). The group that received MZRW group also had significant increases in colonic transit and reduced severity of constipation, straining, incomplete evacuation, and global constipation symptoms compared with the groups that received placebo or senna in (P < .05 for all comparisons).

CONCLUSIONS

In a randomized controlled trial of 291 patients with FC, we found MZRW to be well-tolerated and effective in increasing CSBM/week. MZRW did not appear to be more effective than senna and might be considered as an alternative to this drug. ClincialTrials.gov no: NCT01695850.

Metabolites study on 5-O-methylvisammioside in vivo and in vitro by ultra high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry

5-O-Methylvisammioside is one of major chromones of Radix Saposhnikoviae possessing definite pharmacological activities, but there are few reports with respect to the metabolism of 5-O-methylvisammioside. In this work, metabolites in vivo were explored in male Sprague-Dawley rats and in vitro investigated on rat intestinal bacteria incubation model and were identified by using ultra high performance liquid chromatography/quadrupole time-of-flight mass spectrometry. An online data acquisition method based on a multiple mass defect filter and dynamic background subtraction was developed to trace all probable metabolites. As a result, 26 metabolites in vivo (including 18, 15, 10, and 10 in rat urine, faece, bile, and blood) and 7 metabolites in vitro were characterized, respectively. Additionally, the main metabolic pathways in vivo and in vitro, including deglycosylation, deglycosylation + demethylation, deglycosylation + oxidation, N-acetylation, and sulfate conjugation, were summarized by calculating the relative content of each metabolite. The obtained results significantly enriched our knowledge about 5-O-methylvisammioside metabolism and will lead to a better understanding of its safety and efficacy.

Gut microbiota: a new angle for traditional herbal medicine research

Traditional Herbal Medicine (THM) has been used for thousands of years, and is popular worldwide due to its effectiveness in a variety of diseases.

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.

Simultaneous Determination and Pharmacokinetics Study of Six Triterpenes in Rat Plasma by UHPLC-MS/MS after Oral Administration of Sanguisorba officinalis L. Extract

A selective and sensitive ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for the determination of ziyuglycoside I (I), 3β,19α-dihydroxyurs-12-en-28-oic-acid 28-β-d-glucopyranosyl ester (II), 3β-[(α-l-arabinopyranosyl) oxy]-urs-12,18(19)-dien-28-oic acid β-d-glucopyranosyl ester (III), rosamultin (IV), 1β-hydroxyeuscaphic acid (V) and alpinoside (VI) in rats after oral administration of Sanguisorba officinalis L. (S. officinalis) extract. The 3β,19α-dihydroxyurs-12-en-28-oic-acid 28-β-d-glucopyranosyl ester, 3β-[(α-l-arabinopyranosyl) oxy]-urs-12,18(19)-dien-28-oic acid β-d-glucopyranosyl ester, rosamultin, 1β-hydroxyeuscaphic acid and alpinoside in rat plasma were the first report in the pharmacokinetics study in the present study. The analytes were quantified using the multiple reaction monitoring (MRM) mode with the electrospray ion source in positive electrospray ionization. Plasma was extracted with ethyl acetate via liquid–liquid extraction. Bifendate was used as internal standard (IS). The current method was validated for linearity, intra-day and inter-day precisions, accuracy, extraction recovery, matrix effect and stability. The lower limits of quantification of ziyuglycoside I, 3β,19α-dihydroxyurs-12-en-28-oic-acid 28-β-d-glucopyranosyl ester, 3β-[(α-l-arabinopyranosyl) oxy]-urs-12,18(19)-dien-28-oic acid β-d-glucopyranosyl ester, rosamultin, 1β-hydroxyeuscaphic acid and alpinoside were 6.1, 4.9, 1.3, 3.8, 1.5 and 5.7 ng/mL, respectively. Intra-day and inter-day precision and the accuracy of the assay were in range from −9.48 to 12.74%. The extraction recoveries of analytes and bifendate (IS) from rat plasma ranged from 77.17% to 92.48%. Six compounds could be rapidly absorbed into blood (T_max, 0.58–1.58 h), and then eliminated relatively slowly (t_1/2, 6.86–11.63 h). The pharmacokinetic results might contribute to further guide the clinical application of S. officinalis.

Studies on the metabolism and degradation of vancomycin in simulated in vitro and aquatic environment by UHPLC-Triple-TOF-MS/MS

Vancomycin is one of the most commonly used glycopeptide antiobiotics, and as such is an important emerging environmental contaminant. Pharmaceuticals and personal care products (PPCPs), such as antibiotics, are problematic since wastewater treatment processes are not completely effective at removing these chemical compounds. Since wastewater treatment processes are not completely effective, vancomycin occurs in surface water. Vancomycin and its metabolites in vivo and degradation products in aquatic environment may lead to undesirable ecological effects that threaten the environment or cause undesirable reactions that affect human health. We aimed to study vancomycin metabolism in vitro and its natural degradation in aquatic environment, as well as explore for related metabolites and degradation products. Accordingly, we established four systems, using a constant temperature oscillator at 37 °C for 10 days for vancomycin in activated rat liver microsomes (experimental system), inactivated rat liver microsomes (control system), phosphate buffer saline (PBS system) and pure water (pure water system), as well as an additional system of activated rat liver microsomes without vancomycin (blank system). The metabolism and degradation of vancomycin were studied using a high resolution and high sensitivity ultra-high performance liquid chromatography (UHPLC)-Triple-time of flight (TOF)-mass spectrometry (MS) method in positive ion mode. The compared result of activated rat liver microsomes system and inactivated rat liver microsomes system confirms that vancomycin is not metabolized in the liver. Vancomycin was degraded in the four non-blank incubation systems. The MetabolitePilot 2.0 software was used for screening the probable degradation products, as well as for establishing its associated degradation pathways. Eventually, four degradation products were identified and their chemical structures were deduced. The results of this study provide a foundation for evaluation of the effects of vancomycin and its degradation products on environmental safety and human health in the future.

Characterization of the In Vivo and In Vitro Metabolites of Linarin in Rat Biosamples and Intestinal Flora Using Ultra-High Performance Liquid Chromatography Coupled with Quadrupole Time-of-Flight Tandem Mass Spectrometry

Linarin, a flavone glycoside, is considered to be a promising natural product due to its diverse pharmacological activities, including analgesic, antipyretic, anti-inflammatory and hepatoprotective activities. In this research, the metabolites of linarin in rat intestinal flora and biosamples were characterized using ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS/MS). Three ring cleavage metabolites (4-hydroxybenzoic acid, 4-hydroxy benzaldehyde and phloroglucinol) were detected after linarin was incubated with rat intestinal flora. A total of 17 metabolites, including one ring cleavage metabolite (phloroglucinol), were identified in rat biosamples after oral administration of linarin. These results indicate that linarin was able to undergo ring fission metabolism in intestinal flora and that hydrolysis, demethylation, glucuronidation, sulfation, glycosylation, methylation and ring cleavage were the major metabolic pathways. This study provides scientific support for the understanding of the metabolism of linarin and contributes to the further development of linarin as a drug candidate.

In vitro and in vivo metabolic investigation of the Palbociclib by UHPLC-Q-TOF/MS/MS and in silico toxicity studies of its metabolites

Palbociclib (PAB) is a CDK4/6 inhibitor and U. S Food and Drug Administration (FDA) granted regular approval for the treatment of hormone receptor (HR) positive, metastatic breast cancer in combination with an aromatase inhibitor in postmenopausal women. Metabolite identification is a crucial aspect during drug discovery and development as the drug metabolites may be pharmacologically active or possess toxicological activity. As there are no reports on the metabolism studies of the PAB, the present study focused on investigation of the in vitro and in vivo metabolic fate of the drug. The in vitro metabolism studies were carried out by using microsomes (HLM and RLM) and S9 fractions (Human and rat). The in vivo metabolism of the drug was studied by administration of the PAB orally to the Sprague-Dawley rats followed by analysis of urine, faeces and plasma samples. The sample preparation includes simple protein precipitation (PP) followed by solid phase extraction (SPE). The extracted samples were analyzed by ultrahigh-performance liquid chromatography-quadruple time-of-flight tandem mass spectrometry (UHPLC/Q-TOF/MS/MS). A total of 14 metabolites were detected in in vivo matrices. The PAB was metabolized via hydroxylation, oxidation, sulphation, N-dealkylation, acetylation and carbonylation pathways. A few of the metabolites were also detected in in vitro samples. Metabolite identification and characterization were performed by using UHPLC/Q-TOF/MS/MS in combination with HRMS data. To identify the toxicity potential of these metabolites, in silico toxicity assessment was carried out using TOPKAT and DEREK softwares.

A facile and selective approach to the qualitative and quantitative analysis of triterpenoids and phenylpropanoids by UPLC/Q-TOF-MS/MS for the quality control of Ilex rotunda

Ilex rotunda, in which triterpenoids and phenylpropanoids are major bioactive constituents, has been widely used in traditional Chinese medicines. In this study, a validated UPLC/Q-TOF-MS/MS method was developed to simultaneously identify and quantify the triterpenoids and phenylpropanoids in the stem bark, fruit, leaves, roots and stem xylem of this herbal medicine. A total of seventy triterpenoids and twelve phenylpropanoids were identified with the assistance of the modified mass defect filter and key product ion filter data processing strategies, and forty-eight of them were confirmed by reference substances. Meanwhile, the contents of twelve triterpenoids and three phenylpropanoids in the five plant parts were determined with good linearity (R² ≥ 0.9993), precision (RSD ≤ 2.04%), repeatability (RSD ≤ 1.99%), stability (RSD ≤ 1.88%) and recovery (96.65-103.17% and RSD ≤ 3.54%). Furthermore, PCA and OPLS-DA methods were employed to visualize the relationships and discrimination of the forty-two stem bark samples from two origins based on the contents of fifteen analytes. Our findings may provide early scientific evidence for quality control and for elucidating the therapeutic principle of Ilex rotunda.

A Sample and Sensitive HPLC-MS/MS Method for Simultaneous Determination of Ziyuglycoside I and Its Metabolite Ziyuglycoside II in Rat Pharmacokinetics

Ziyuglycoside I (ZGS1) is a promising drug candidate for the treatment of leucopenia. Currently, information on ZGS1 and its in vivo metabolite ziyuglycoside II (ZGS2) is limited. The objective of this study was to investigate the pharmacokinetics, tissue distribution, and excretion of ziyuglycoside I (ZGS1) and its metabolite ziyuglycoside II (ZGS2) in rats. In our study, a simple and sensitive high-performance liquid chromatography-mass spectrometry (HPLC-MS/MS) method was established for simultaneous determination of ZGS1 and its metabolite for Sprague-Dawley rat pharmacokinetics studies. The method was validated following internationally-approved guidelines. The results presented in this study indicated that subcutaneous administration of ZGS1 prolonged its extension time and increased the area under the curve (AUC_0-t) of ZGS2 during 0 to t minutes. In summary, in this study, the pharmacokinetic characteristics of ZGS1 and its metabolite ZGS2 were defined and its tissue distribution, and excretion in rats were described. Our finding may be beneficial for leucopenia drug that focus on ZGS1.

Identification of rotundic acid metabolites after oral administration to rats and comparison with the biotransformation by Syncephalastrum racemosum AS 3.264

The objective of this study was to identify the metabolites of rotundic acid after oral administration to rats and compare the similarities with its biotransformation by Syncephalastrum racemosum AS 3.264 using ultra-high performance liquid chromatography coupled with quadrupole time of flight mass spectrometry. A total of fourteen metabolites were determined based on the mass spectrometry and chromatographic behaviors, among which eleven (M1-M3, M7-M14) and six (M2, M4-M8) metabolites were identified in rats and S. racemosum, respectively. Three identical metabolites (M2, M7 and M8) were found in rats and S. racemosum, indicating that there were metabolic similarities. Moreover, to confirm the results of mass spectrometry, three (M2, M4 and M7) metabolites were obtained by the means of amplifying incubation and their structures were determined by various spectroscopic analyses, and M4 was proved to be a previously undescribed compound. This results showed that in vitro assisted preparation by microbial transformation is a feasible and effective method of obtaining metabolites which are in low amounts and difficult to be prepared in vivo.

Metabolomics revealed the toxicity of cationic liposomes in HepG2 cells using UHPLC-Q-TOF/MS and multivariate data analysis

Cationic liposomes (CLs) are novel nonviral vectors widely used for delivering drugs or genes. However, applications of CLs are largely hampered by their cytotoxicity, partly because the potential mechanism underlying the cytotoxicity of CLs remains unclear. The aim of the present study was to explore the underlying mechanism of cytotoxicity induced by CLs on HepG2 cells. Differential metabolites were identified and quantified using ultra-liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF/MS). The toxicity of CLs on HepG2 cells was evaluated by multivariate data analysis and statistics. Additionally, CCK-8 assay, heatmap, pathway and co-expression network were carried out to explore the relations between the metabolites and the pathways. The results showed a dose-dependent toxic effect of CLs on HepG2 cells, with an IC₅₀ value of 119.9 μg/mL. Multivariate statistical analysis identified 42 potential metabolites between CLs exposure and control groups. Pathway analysis showed significant changes in pathways involving amino acid metabolism, energy metabolism, lipid metabolism and oxidative stress in the CLs exposure group vs the control group. Metabolites related to the above-mentioned pathways included phenylalanine, methionine, creatine, oxalacetic acid, glutathione, oxidized glutathione, choline phosphate and several unsaturated fatty acids, indicating that cells were disturbed in amino acid metabolism, energy and lipid supply when CLs exposure-induced injury occurred. It is concluded that CLs may induce cytotoxicity by enhancing reactive oxygen species in vitro, affect the normal process of energy metabolism, disturb several vital signaling pathways and finally induce cell death.

Understanding the Molecular Mechanisms of the Interplay Between Herbal Medicines and Gut Microbiota

Herbal medicines (HMs) are much appreciated for their significant contribution to human survival and reproduction by remedial and prophylactic management of diseases. Defining the scientific basis of HMs will substantiate their value and promote their modernization. Ever-increasing evidence suggests that gut microbiota plays a crucial role in HM therapy by complicated interplay with HM components. This interplay includes such activities as: gut microbiota biotransforming HM chemicals into metabolites that harbor different bioavailability and bioactivity/toxicity from their precursors; HM chemicals improving the composition of gut microbiota, consequently ameliorating its dysfunction as well as associated pathological conditions; and gut microbiota mediating the interactions (synergistic and antagonistic) between the multiple chemicals in HMs. More advanced experimental designs are recommended for future study, such as overall chemical characterization of gut microbiota-metabolized HMs, direct microbial analysis of HM-targeted gut microbiota, and precise gut microbiota research model development. The outcomes of such research can further elucidate the interactions between HMs and gut microbiota, thereby opening a new window for defining the scientific basis of HMs and for guiding HM-based drug discovery.

Development of a novel sectional multiple filtering scheme for rapid screening and classifying metabolites of ziyuglycoside II in rat liver and excreta specimen based on high-resolution mass spectrometry

Ziyuglycoside II, one of the major effective ingredients of Sanguisorba officinalis L., had various pharmacological activities including anticancer, anti-inflammation and anti-oxidation, etc. Better understanding of the pharmacology and toxicology of ziyuglycoside II requires the detailed elucidation of its biologic fates in vivo. Herein, the metabolic fate of ziyuglycoside II in rats was investigated based on liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (LC-Q-TOF/MS). To accelerate and simplify the process of metabolite identification from complicated biological matrix, the sectional multiple filtering (SMF) scheme was designed according to the relationship among the molecular weight (MW), mass defect (MD) and retention time (tR) of the metabolites. SMF-I (MW: 700-850Da, MD: 0.40-0.45Da, tR: 4.0-10.0min), SMF-II (MW: 550-700Da, MD: 0.30-0.40Da, tR: 6.0-14.0min) and SMF-III (MW: 400-550Da, MD at 0.25-0.35Da, tR at 9.5-16.0min) were built and utilized to screen phase II conjugations and phase I redox metabolites and deglycosylated derivatives, respectively. As a result, dozens of metabolites, including glucuronic conjugates, hydroxylation, oxidization, dehydration and deglycosylation products, were rapidly discovered, classified and structural identified in rat urine and feces based on SMF scheme and accurate MS(1)/MS(2) information. Obviously, the SMF technique showed superior efficiency and selectivity in ziyuglycoside II metabolite identification. More importantly, SMF would find its extensive application in, but not limited to, the metabolic study for single drug or homologous compounds in traditional Chinese medicine.