Comparative study of the flavonoids of some Verbena species cultivated in Egypt by using high-performance liquid chromatography coupled with ultraviolet spectroscopy and atmospheric pressure chemical ionization mass spectrometry

Metabolic profiling of Verbena bonariensis L. extract by LC/MS and evaluation of the hepatoprotective potential with isoniazid- and rifampicin-induced hepatotoxicity in rats

The study explored the hepatoprotective activity and metabolic profile of Verbena bonariensis L. methanol extract (VBM) and fractions using isoniazid as well as rifampicin-triggered liver toxicity in Wistar albino rats. Metabolite profiling of VBM using HPLC-PDA-ESI-MS identified 12 compounds, mainly iridoids, phenylpropanoids, and flavonoids, where verbascoside represents the major compound. Different biochemical parameters such as aspartate transaminase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALP), bilirubin, and total protein levels were used to assess liver functions. All the evaluated samples exhibited hepatoprotective potential, but VBM exhibited maximum activity and a notable decline in ALP (p < 0.05, significant), even better than the standard drug (silymarin). VBM significantly reduced the elevated ALT, AST, ALP, and total bilirubin. It also triggered a significant elevation in total proteins compared with diseased animals. This was further consolidated by histopathological studies. Verbena bonariensis L. could serve as a potent hepatoprotective agent and may alleviate liver ailments.

Extract identification and evaluation of the cytotoxic activity of Polygala fallax Hemsl in Heilongjiang ethnic medicine against tumors

BACKGROUND

Heilongjiang Province is a frontier province with distinctive characteristics, fertile land and rich products.

OBJECTIVE

This study provides a new method for qualitatively studying flavonoids in traditional Chinese medicine and a new auxiliary means for identifying flavonoid isomers.

METHODS

The flavonoids in Polygala fallax Hemsl were identified by ultra-performance liquid chromatography-photo-diode array (PDA)-quadrupole-electro- static field orbitrap mass spectrometry tandem by UV Spectrum, primary and secondary high-resolution mass spectrometry (MS1/MS2) cleavage of fragments combined with databases, mass spectrometry cleavage patterns and literature.

RESULTS

The established QSRR model was used to verify the flavonoids identified from the Polygala fallax Hemsl.

CONCLUSION

The structure of multiple Polygala fallax Hemsl has been identified using various spectral methods. The tumor cytotoxic activity of the isolated compounds was evaluated. This paper is of great significance for further elucidating the pharmacodynamic substance basis and further developing and utilizing Polygala fallax Hemsl.

Key ingredients in Verbena officinalis and determination of their anti-atherosclerotic effect using a computer-aided drug design approach

Lipid metabolism disorders may considerably contribute to the formation and development of atherosclerosis (AS). Traditional Chinese medicine has received considerable attention in recent years owing to its ability to treat lipid metabolism disorders using multiple components and targets. Verbena officinalis (VO), a Chinese herbal medicine, exhibits anti-inflammatory, analgesic, immunomodulatory, and neuroprotective effects. Evidence suggests that VO regulates lipid metabolism; however, its role in AS remains unclear. In the present study, an integrated network pharmacology approach, molecular docking, and molecular dynamics simulation (MDS) were applied to examine the mechanism of VO against AS. Analysis revealed 209 potential targets for the 11 main ingredients in VO. Further, 2698 mechanistic targets for AS were identified, including 147 intersection targets between VO and AS. Quercetin, luteolin, and kaempferol were considered key ingredients for the treatment of AS based on a potential ingredient target-AS target network. GO analysis revealed that biological processes were primarily associated with responses to xenobiotic stimuli, cellular responses to lipids, and responses to hormones. Cell components were predominantly focused on the membrane microdomain, membrane raft, and caveola nucleus. Molecular functions were mainly focused on DNA-binding transcription factor binding, RNA polymerase II-specific DNA-binding transcription factor binding, and transcription factor binding. KEGG pathway enrichment analysis identified pathways in cancer, fluid shear stress, and atherosclerosis, with lipid and atherosclerosis being the most significantly enriched pathways. Molecular docking revealed that three key ingredients in VO (i.e., quercetin, luteolin, and kaempferol) strongly interacted with three potential targets (i.e., AKT1, IL-6, and TNF-α). Further, MDS revealed that quercetin had a stronger binding affinity for AKT1. These findings suggest that VO has beneficial effects on AS via these potential targets that are closely related to the lipid and atherosclerosis pathways. Our study utilized a new computer-aided drug design to identify key ingredients, potential targets, various biological processes, and multiple pathways associated with the clinical roles of VO in AS, which provides a comprehensive and systemic pharmacological explanation for the anti-atherosclerotic activity of VO.

Integrating transcriptome and chemical analyses to reveal the anti-Alzheimer's disease components in Verbena officinalis Linn

Verbena officinalis Linn. is a kind of traditional Chinese medicine, which has a long history of application and shows good effects on neuroprotection. Therefore, we consider that V. officinalis may be a potential drug for treating Alzheimer's disease (AD). First, ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) pointed out that the main chemical components in V. officinalis were iridoid glycosides, phenylethanoid glycosides, and flavonoids. These compounds were used for molecular docking and the results showed that these compounds had good anti-AD activity. To explore the biosynthetic pathway of anti-AD components in V. officinalis, UPLC and ultraviolet (UV) spectrophotometry were used for contents determination and the result was leaf > stem > root. At the same time, 92,867 unigenes were annotated in V. officinalis transcriptome; 206, 229, 115 related unigenes were, respectively, annotated in iridoid glycoside, phenylethanoid glycoside, and flavonoid pathway, of which 61, 73, and 35 were differential expression genes. The components had relatively high expression in leaves, which was consistent with the quantitative results. In addition, the tissue distribution particularity of verbenalin may be related to the branching of pathways. Meanwhile transcription factors VoWRKY6 and VoWRKY7 may be involved in the regulation of iridoid glycoside biosynthesis. Further, VoWRKY3, VoWRKY9, and VoWRKY12 may be related to flavonoid biosynthesis. The above research is helpful to explore the biosynthetic pathway of anti-AD components and the regulation mechanism of active components and to further explore the anti-AD effect of V. officinalis.

Levels of phenylpropanoids and iridoids in extracts and infusions of Verbena minutiflora

Herein we report for the first time the levels of phenylpropanoids and iridoids in extracts and infusions of V. minutiflora consumed in Brazil to treat urinary and infectious disorders. An in house validation study demonstrated good accuracy and precision to determine the bioactive compounds in V. minutiflora by HPLC-DAD. Phenylpropanoids varied in the extracts (leaves 139.70 to 221.20 mg g-1, flowers 106.43 to 227.22 mg g-1, stems 42.18 to 56.48 mg g-1). Verbascoside occurred in higher concentration in extracts of leaves (87.66 - 136.16) mg g-1 and flowers (58.12 - 148.96) mg g-1 than in stems (19.24 - 24.62) mg g-1. Iridoids in extracts were as follows: leaves (46.60 - 54.79) mg g-1, flowers (55.88 - 93.87) mg g-1 and stems (40.05 to 61.74) mg g-1. High levels of iridoids (314.70 - 415.10) μg mL-1, phenylpropanoids (1996.39 - 2674.13) μg mL-1 and verbascoside (1029.38 - 1456.42 μg mL-1) in infusions support the popular consume of V. minutiflora.

Identification of absorbed components and their metabolites in rat plasma after oral administration of Shufeng Jiedu capsule using ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry

RATIONALE

Shufeng Jiedu capsule (SFJDC), a prescription of traditional Chinese medicine, is mainly used for the treatment of acute upper respiratory tract infections. However, the bioactive components remain unclear, which partly limits its quality control and further development. This work aimed to carry out a study of plasma pharmacochemistry to identify the potential bioactive components of SFJDC.

METHODS

An effective approach based on a combination of ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC/QTOF-MS) and multivariate statistical analysis was applied to comprehensively analyze the absorbed components and their metabolites in rat plasma after oral administration of SFJDC. After UPLC/QTOF-MS detection, the differences between control and dosed plasma samples were distinguished by multivariate statistical analysis, and chromatographic signals of xenobiotic compounds were further extracted to identify structures.

RESULTS

A total of 46 SFJDC-related xenobiotic compounds were identified as potential bioactive components in rat plasma. Among these, 27 absorbed prototype constituents were mainly flavonoids, anthraquinones, stilbenes, iridoids, lignans, naphthalenes, phenylethanoid glycosides and triterpenoid saponins. Especially for hastatoside, verbenalin, forsythoside A, phillyrin and emodin, they were closely related to the anti-inflammatory effect of SFJDC.

CONCLUSIONS

The absorbed components and metabolites of SFJDC in rat plasma were analyzed for the first time. This study will be conducive for ascertaining the quality markers of SFJDC for quality control and pharmacological mechanism research at the molecular level.

Qualitative and Quantitative Analysis for the Chemical Constituents of Tetrastigma hemsleyanum Diels et Gilg Using Ultra-High Performance Liquid Chromatography/Hybrid Quadrupole-Orbitrap Mass Spectrometry and Preliminary Screening for Anti-Influenza Virus Components

Tetrastigma hemsleyanum Diels et Gilg (T. hemsleyanums) is a kind of traditional folk medicinal plant which has been used widely in China for its antivirus, antitumor, and other clinical effects. In this study, ultra-high performance liquid chromatography coupled with hybrid quadrupole-orbitrap mass spectrometry (UPLC-Q-Exactive/MS) was utilized to analyze the chemical constituents of T. hemsleyanums. Fifty-one constituents were clarified, including flavonoids, anthraquinones, esters, fatty acids, phenols, and catechins. In the subsequent quantitative analysis, the contents of ten compounds of rutin, kaempferol, astragalin, quercitrin, quercetin, vitexin-rhamnoside, isorhamnetin, vitexin, emodin-8-O-β-D-glucoside, and isoquercetin in 18 batches of T. hemsleyanums collected from different places of cultivation were determined. Meanwhile, anti-influenza virus bioactivity in vitro of the above samples was detected with Gaussia Luciferase viral titer assay. It was found that the antiviral bioactivity varied from batches to batches in accordance with content difference of the chemical constituents in T. hemsleyanums. Correlation analysis was performed with SPSS software for the association between LC-MS chemometrics and bioactivity of influenza virus inhibition, and 8 constituents of flavonoids showed positive correlation coefficient, which may provide a valuable clue for searching potential antiviral components in T. hemsleyanums.

In depth investigation of the metabolism of Nectandra megapotamica chemotypes

Plants produce a wide range of secondary metabolites. Within a single species, chemotypes can be distinguished by the differences in the composition of the secondary metabolites. Herein, we evaluated Nectandra megapotamica (Spreng.) chemotypes and the balance of different classes of metabolites to verify how significant differences in plant metabolism are regarding chemotypes. We collected N. megapotamica leaves from eight adult plants in two Brazilian states. The essential oils and ethanol/water extracts were analyzed by GC-MS and LC-DAD-MS, respectively. Histochemical tests were performed, as well as chemical analyses of leaves from adaxial and abaxial foliar surfaces of N. megapotamica, and the stereochemistry of α-bisabolol was determined. Two different chemotypes, based on volatile compounds, were identified, distinguished by the presence of isospathulenol, α-bisabolol, β-bisabolene, and (E)-nerolidol for chemotype A, and bicyclogermacrene and elemicin for chemotype B. A stereochemical analysis of chemotype A extract revealed (+)-α-bisabolol enantiomer. Histochemical tests of chemotypes showed similar results and suggested the presence of essential oil in idioblasts stained with the dye NADI. The analyses of chemotype A leaves by GC-MS revealed similar compositions for abaxial and adaxial surfaces, such pattern was also observed for chemotype B. Medium and high polarity metabolites showed high chemical similarities between the chemotypes, highlighting the presence of proanthocyanidins and glycosylated flavonoids (O- and C-glycosides). Thus, N. megapotamica produced distinct volatile chemotypes with highly conserved medium to high polarity compounds. Such results suggest that phenolic derivatives have a basal physiological function, while genetic or environmental differences lead to differentiation in volatile profiles of N. megapotamica.

Recent development of ionic liquid stationary phases for liquid chromatography

Based on their particular physicochemical characteristics, ionic liquids have been widely applied in many fields of analytical chemistry. Many types of ionic liquids were immobilized on a support like silica or monolith as stationary phases for liquid chromatography. Moreover, different approaches were developed to bond covalently ionic liquids onto the supporting materials. The obtained ionic liquid stationary phases show multi-mode mechanism including hydrophobic, hydrophilic, hydrogen bond, anion exchange, π-π, and dipole-dipole interactions. Therefore, they could be used in different chromatographic modes including ion-exchange, RPLC, NPLC and HILIC to separate various classes of compounds. This review mainly summarizes the immobilized patterns and types of ionic liquid stationary phases, their retention mechanisms and applications in the recent five years.

Chromatographic and mass spectrometric characterization of essential oils and extracts from Lippia (Verbenaceae) aromatic plants

Analytical methodologies based on GC and HPLC were developed for the separation and quantification of carnosic acid, ursolic acid, caffeic acid, p-coumaric acid, rosmarinic acid, apigenin, luteolin, quercetin, kaempferol, naringenin, and pinocembrin. These methods were used to characterize essential oils and extracts obtained by solvent (methanol) and by supercritical fluid (CO(2)) extraction from stems and leaves of Lippia (Verbenaceae family) aromatic plants (Lippia alba, Lippia origanoides, Lippia micromera, Lippia americana, Lippia graveolens, and Lippia citriodora). Supercritical CO(2) extraction isolated solely pinocembrin and narigenin from three L. origanoides chemotypes. Solvent extracts possessed a more varied composition that additionally included apigenin, quercetin, and luteolin. Solvent extraction afforded higher overall flavonoid yields from all species in comparison with supercritical CO(2) extraction. Pinocembrin was determined in L. origanoides extract at a concentration of 30 mg/g of plant material, which is more than ten times higher than the amount at which polyphenols are regularly found in aromatic plant extracts.

HPLC-ESI-MS/MS analysis and pharmacokinetics of luteoloside, a potential anticarcinogenic component isolated from Lonicera japonica, in beagle dogs

Luteoloside is a potential anticarcinogenic component isolated from Lonicera japonica, a traditional Chinese medicine (TCM). This study details the development and validation of a sensitive and accurate HPLC-ESI-MS/MS method for the quantification of luteoloside in dog plasma. Sample pretreatment includes simple protein precipitation using methanol-acetonitrile (1:1, v/v). A Phenomenex Gemini C(18) column (2.0 × 50 mm, i.d., 3.5 µm) was used to separate luteoloside and internal standard by gradient mode with mobile phase consisting of water containing 0.1% formic acid and methanol containing 0.1% formic acid at a flow rate of 0.40 mL/min with a column temperature of 25°C. The detection was performed by positive ion electrospray ionization (ESI) in multiple reaction monitoring mode. The calibration curves were linear (R > 0.995) over the concentration range 1.0-2000 ng/mL and the lower limit of quantification was 1.0 ng/mL. The intra-day and inter-day precisions (RSD) were all <15%, accuracies (RE) were within the range of ±15%, and recoveries were between 85.0 and 115%. The validated HPLC-ESI-MS/MS method was successfully applied to determine plasma concentrations of luteoloside after intravenous administration of luteoloside at a dose level of 20 mg/kg.