LC-MS/MS Determination and Pharmacokinetic Study of Pedunculoside in Rat Plasma after Oral Administration of Pedunculoside and Ilex rotunda Extract

Preclinical metabolism and metabolic drug-drug interaction profile of pedunculoside and rotundic acid

Pedunculoside and rotundic acid, the most abundant components in plants of the genus Ilex L. (Aquifoliaceae), exhibit biological and pharmacological significance in the treatment of cardiovascular diseases. However, there have been few studies on their metabolism. This study performed a systematic metabolism study of pedunculoside and rotundic acid and evaluated their potential for herb-drug interaction. Pedunculoside or rotundic acid was incubated with human liver microsomes and recombinant human metabolic enzymes, and analyzed using LC-Q-TOF/MS and LC-MS/MS. Pedunculoside was found to be the most stable in human liver microsomes, whereas rotundic acid was easily metabolized. Eight pedunculoside metabolites and six rotundic acid metabolites were detected and tentatively identified through hydroxylation, glucuronidation, acetylation, and glucose conjugation. Hydroxylation of pedunculoside is mainly catalyzed by CYP3A4/5 and partly by CYP2C8. Hydroxylation of rotundic acid is almost exclusively catalyzed by CYP3A4/5, and its glucuronidation reaction is mediated by UGT1A4. Neither pedunculoside nor rotundic acid showed CYP inhibition (IC50 values > 50 μM) with the probe substrates of major CYP isoforms during incubation with human liver microsomes. This study is the first investigation into the in vitro metabolism of pedunculoside and rotundic acid using human liver microsomes. It also aims to assess their potential as perpetrators of drug-drug interactions involving CYP enzymes. The comprehensive metabolism and drug interaction studies of pedunculoside and rotundic acid enable us to evaluate and manage potential risks with their use in pharmacotherapy.

In Vitro Stability and Pharmacokinetic Study of Pedunculoside and Its Beta-CD Polymer Inclusion Complex

Pedunculoside, a triterpene saponin derived from various Ilex species, holds potential as a treatment for cardiovascular diseases. However, its clinical application is hindered by poor bioavailability, rapid elimination, and extensive intestinal metabolism to rotundic acid. To address these issues, a water-soluble inclusion complex of pedunculoside, namely, the beta-CD polymer inclusion complex of pedunculoside (pedunculoside-βCDP), was prepared in this study, and a comparative in vitro stability and pharmacokinetic behavior study was performed between pedunculoside and pedunculoside-βCDP. Both pedunculoside and pedunculoside-βCDP exhibited the highest stability in simulated gastric fluid and simulated intestinal fluid but were readily metabolized when co-incubated with Bifidobacterium adolescentis and Bifidobacterium breve. An LC-MS/MS analytical method for the simultaneous determination of pedunculoside and rotundic acid in rat plasma was successfully established, validated, and applied to investigate the pharmacokinetic behavior after rats were intravenously administered with pedunculoside or pedunculoside-βCDP. The results indicated that pedunculoside-βCDP could significantly improve the pharmacokinetic profile of pedunculoside by increasing plasma exposure, retarding elimination, and reducing intestinal metabolism. This study enhances our understanding of pedunculoside-βCDP's metabolic fate and pharmacokinetic properties and potentially advances its further research, development, and clinical application.

Pedunculoside inhibits epithelial-mesenchymal transition and overcomes Gefitinib-resistant non-small cell lung cancer through regulating MAPK and Nrf2 pathways

BACKGROUND

Lung cancer is the primary cause of cancer-related mortality worldwide owing to its strong metastatic ability. EGFR-TKI (Gefitinib) has demonstrated efficacy in metastatic lung cancer therapy, but most patients ultimately develop resistance to Gefitinib, leading to a poor prognosis. Pedunculoside (PE), a triterpene saponin extracted from Ilex rotunda Thunb., has shown anti-inflammatory, lipid-lowering and anti-tumor effects. Nevertheless, the therapeutic effect and potential mechanisms of PE on NSCLC treatment are unclear.

PURPOSE

To investigate the inhibitory effect and prospective mechanisms of PE on NSCLC metastases and Gefitinib-resistant NSCLC.

METHODS

In vitro, A549/GR cells were established by Gefitinib persistent induction of A549 cells with a low dose and shock with a high dose. The cell migratory ability was measured using wound healing and Transwell assays. Additionally, EMT-related Markers or ROS production were assessed by RT-qPCR, immunofluorescence, Western blotting, and flow cytometry assays in A549/GR and TGF-β1-induced A549 cells. In vivo, B16-F10 cells were intravenously injected into mice, and the effect of PE on tumor metastases were determined using hematoxylin-eosin staining, Caliper IVIS Lumina, DCFH₂-DA staining, and western blotting assays.

RESULTS

PE reversed TGF-β1-induced EMT by downregulating EMT-related protein expression through MAPK and Nrf2 pathways, decreasing ROS production, and inhibiting cell migration and invasion ability. Moreover, PE treatment enabled A549/GR cells to retrieve the sensitivity to Gefitinib and mitigate the biological characteristics of EMT. PE also significantly inhibited lung metastasis in mice by reversing EMT proteins expression, decreasing ROS production, and inhibiting MAPK and Nrf2 pathways.

CONCLUSIONS

Collectively, this research presents a novel finding that PE can reverse NSCLC metastasis and improve Gefitinib sensitivity in Gefitinib-resistant NSCLC through the MAPK and Nrf2 pathways, subsequently suppressing lung metastasis in B16-F10 lung metastatic mice model. Our findings indicate that PE is a potential agent for inhibiting metastasis and improving Gefitinib resistance in NSCLC.

A systematic review: Botany, phytochemistry, traditional uses, pharmacology, toxicology, quality control and pharmacokinetics of Ilex rotunda Thunb

ETHNOPHARMACOLOGICAL RELEVANCE

Ilex rotunda Thunb. (I. rotunda) is an Ilex species of Aquifoliaceae, widely distributed in East Asia. Its dried bark is commonly used as a medicinal part in the field of traditional Chinese medicine (TCM), named Ilicis Rotundae Cortex. This medicinal plant is commonly used for clearing heat and removing toxin, draining dampness and relieving pain in TCM to treat tonsillitis, acute gastroenteritis, gastric and duodenal ulcer, rheumatism, traumatic injury, and so on. It also has significant development value on lipid-lowering, hepatoprotection and anti-inflammation, but the potential mechanism needs to be further explored.

AIM OF THE REVIEW

More and more medicinal substances are being discovered in I. rotunda with multiple biological activities, which help to advance the ethno-pharmacological research in I. rotunda. However, to date there is a lack of a systematic summary of research progress on I. rotunda. This review aims to provide a critical summary of the current studies on I. rotunda. The progress in research on botany, phytochemistry, traditional uses, pharmacology, toxicology, quality control and pharmacokinetics of the plant is discussed. It hopes to provide useful references and guidance for the future directions of research on I. rotunda.

MATERIALS AND METHODS

Studies of I. rotunda were collected via Google Scholar and Baidu Scholar, PubMed, ScienceDirect, SciFinder, Web of Science, China National Knowledge Infrastructure (CNKI), WANFANG DATA and libraries. Some local books, official websites, PhD or MS's dissertations were also included. The literature cited in this review covered the period from 1956 to January 2022.

RESULTS

Analysis of the literature indicates that I. rotunda is a potentially valuable herbal medicine for the therapeutic of various diseases. To date, 120 compounds were found and identified in I. rotunda, mainly including triterpenoids, phenylpropanoids, etc. Modern pharmacological studies also found that the plant has the activities of protecting the cardiovascular system, lowering lipids and protecting the liver, as well as being an anti-inflammatory, anti-tumor and antibacterial.

CONCLUSIONS

This review summarizes the results from current studies of I. rotunda. However, the current explanation seems insufficient and unsatisfactory, in terms of the relationships between the traditional uses and the modern pharmacological activities, the mechanisms and the material basis. Thus, a critical and comprehensive evaluation is necessary to explore its future research prospects and development direction.

Quantification and Pharmacokinetics Study of Pedunculoside in Rats by Using UPLC-MS/MS

Background:

Pedunculoside (PE) is a triterpene saponin from the barks of Ilex rotunda, a Traditional Chinese Medicine called Jiubiying, which is used for the treatment of cold and fever, tonsillitis, sore throat, acute and chronic hepatitis, etc. Previous studies have confirmed that crude extract orally has a significant therapeutic effect on myocardial infarction.

Methods:

A simple, sensitive, and specific method by using UPLC-MS/MS to study the pharmacokinetics of PE in rats was developed and validated, with ilexsaponin A as an internal standard. Methanol was used as a protein precipitation reagent for blood sample extraction. A Waters Acquity C18 column (2.1 mm × 50 mm, 1.7 μm) was used for chromatographic separation with a gradient elution of CH3CN: 0.1% formic acid (0.3 mL·min-1). Negative ion electrospray ionization was used for detection in multiple reaction monitoring mode.

Results:

PE was linear within the concentration range of 0.14-1118.00 ng/mL. The LLOQ was 0.14 ng/mL for the plasma samples. The intra-day and inter-day precision were ranged from 1.18% to 10.48%, while the accuracy ranged from -1.32% to 1.68%, indicating satisfactory precision and accuracy of the assay. The extraction recoveries for PE and IS were ranged from 81.40% to 86.65%, with no significant variation among the three concentrations, respectively. PE remained stable at room temperature (25°C) for 3 h, in auto-sampler (4°C) for 24 h, after three freeze-thaw cycles, and in long-term storage at ‒20°C for 30 days. The PK results of PE indicated its poor oral bioavailability (3.37%).

Conclusion:

Non-compartmental pharmacokinetics parameters indicated that PE was rapidly distributed to the tissues and metabolized. The pharmacokinetic data of this paper highlighted the first-time report of PE oral bioavailability with two different administration manners, which will help to better understand how PE metabolized in rats and exert its pharmacological effect in vivo.

Comparative pharmacokinetic and bioavailability study of lobetyolin in rats after administration of lobetyolin and Codonopsis pilosula extract by ultra-performance LC-tandem mass spectrometry

Codonopsis pilosula (CP) is a traditional Chinese medicine used to invigorate spleen, replenish lung, nourish blood and engender fluid. A rapid, selective and sensitive ultra-performance LC-tandem mass spectrometry method was developed and validated to determine lobetyolin in rat plasma. The calibration curve showed good linearity over a concentration range of 0.46-1000 ng/mL for lobetyolin. The extraction recovery ranged from 72.5% to 89.1% with matrix effects of 81.6%-107.8%. The intra- and inter-batch precision and accuracy were 0.02-14.4% and -13.9% to -1.36%, respectively. The method was successfully applied for the bioavailability study of lobetyolin in rats after oral administration of pure lobetyolin and CP extract. Results showed that the elimination half-time (t_1/2 ) and the area under the concentration-time curve from zero to infinity of lobetyolin in CP extract were statistically different from those of the pure monomer (P < 0.05). However, the time to reach the maximum plasma concentration (T_max ) and the maximum concentration (C_max ) showed no significant differences between the two treatments. Furthermore, the bioavailability of lobetyolin in the experimental group was only 3.90%, significantly lower than that of the CP extract group (6.97%). The low bioavailability indicated that this component may be absorbed poorly or metabolized extensively in rats. Our results will provide useful information for further preclinical studies and formulation preparation of lobetyolin.

Assessment of a developed HPLC-MS/MS approach for determining plasma eupatorin in rats and its application in pharmacokinetics analysis

Eupatorin, a bioactive compound extracted from Java tea (Orthosiphon stamineus), possesses potent anti-cancer, anti-inflammatory and vasodilation activities. To date, no pharmacokinetics studies on eupatorin have yet been performed. Here, we established and validated a sensitive and selective LC-MS/MS (liquid chromatography-tandem mass spectrometry) approach for determining plasma eupatorin in rats. Chromatographic fractionation was conducted on a Wonda Cract ODS-2 C18 Column (4.6 mm × 150 mm, 5 μm) with a mobile phase containing aqueous 0.1% formic acid and acetonitrile using a flow rate of 0.8 ml min⁻¹. In multiple reaction monitoring mode, precursor-to-product ion transitions for quantification of eupatorin and the internal standard were set at 343.1 → 328.1 and 252.0 → 155.9, respectively. The intra- and inter-day precision and accuracy were found to be below 6.72% and within ±8.26% in rat plasma, respectively. Meanwhile, all values of the matrix effect, recovery and stability were within the accepted ranges. Furthermore, we carried out the pharmacokinetic analysis using the developed method. The pharmacokinetic study revealed that while the C_max (maximum plasma concentration) of eupatorin and time for reaching the C_max (T_max) were 974.886 ± 293.898 μg L⁻¹ and 0.25 h, respectively, the half-life was 0.353 ± 0.026 h. This study will be of great significance to the research on the pharmacology, clinical pharmacy and drug action mechanism of eupatorin.

Eupatorin, a bioactive compound extracted from Java tea (Orthosiphon stamineus), possesses potent anti-cancer, anti-inflammatory and vasodilation activities.

Rapid profiling and pharmacokinetic studies of multiple potential bioactive triterpenoids in rat plasma using UPLC/Q-TOF-MS/MS after oral administration of Ilicis Rotundae Cortex extract

Triterpenoids, the major bioactive ingredients of Ilicis Rotundae Cortex, contributes a significant cardiovascular protection activity. Although many studies about the total saponins have been reported, the absorption triterpenoids and pharmacokinetic behaviors were unclear. Thus, the present study aims to comprehensive elucidate the absorption triterpenoids and their pharmacokinetics in rats after oral administration the crude extract using UPLC/Q-TOF-MS/MS. A total of forty-two triterpenoids were successfully characterized from the rat plasma, and thirty-two of them were validated by the reference substances, while the others were tentatively identified based on the mass spectral fragmental patterns. Furthermore, the plasma concentrations of six absorption bioactive triterpenoids (rotundinoside C, ilexoside O, pedunculoside, rotundic acid, rotundanonic acid and ilexgenin A) were simultaneously quantified by selected reaction monitoring in negative ionization mode. All analytes exhibited good linearity with correlation coefficients values greater than 0.99 and the LLOQ ranged from 1.2 to 3.2 ng/mL, and method validation for selectivity, precision, accuracy, recovery, matrix effect and stability were reckoned acceptable. The results were successfully applied for the multiple-component pharmacokinetic study of the six bioactive triterpenoids.

The Applications and Features of Liquid Chromatography-Mass Spectrometry in the Analysis of Traditional Chinese Medicine

With increasingly improved separation of complex samples and detection of unknown material capabilities, liquid chromatography coupled with mass spectrometry (LC-MS) has been widely used in traditional Chinese medicine (TCM) research. This article describes the principles of liquid chromatography (LC) and mass spectrometry (MS) and their advantages and disadvantages in qualitative and quantitative analysis of TCM. We retrieved research literatures about the application of LC-MS in TCM published during the past five years at home and abroad. To better guide the analysis of TCM, this review mainly focuses on the applications category of LC-MS, how often different kinds of LC-MS are used, and the qualitative and quantitative ability of various LC-MS in the study of TCM.