Biological analysis of constituents in Spatholobi Caulis by UFLC-MS/MS: Enhanced quantification and application to permeability properties study in Caco-2 cell monolayer model.

Major chemical constituents in medicinal materials are often used as the marker compounds of traditional Chinese medicine (TCM) for treating various diseases. For spatholobi caulis (SPC), it contains a variety of flavones, phenolic acid esters, and lignans which exert many pharmacological effects. However, the absorption and permeability properties of these constituents of SPC are still unclear and require further investigation. Different types and major compounds of SPC were chosen as representative constituents to study their absorption and transepithelial transport characteristics in the human intestinal epithelium-like Caco-2 cell monolayer model. 35 constituents of SPC were evaluated by using ultra fast liquid chromatography combined with electrospray ionization triple quadrupole tandem mass spectrometry (UFLC-MS/MS) method, acetonitrile and water containing with 0.5 mM ammonium acetate were used as mobile phase, these analytes with good linear relationships (R2 was within 0.9967-0.9998), precision (CV values were less than 10.23 %, LLOQ was less than 13.69 %), accuracy (Mean of inter- and intra-day were within 85.02 %-111.61 % and 85.50-112.97 %, respectively) and stability (The mean was within 85.07 %-113.93 %), among which 16 analytes showed good permeability, 5 analytes were considered to be poorly permeable compounds, and the other 14 analytes were assigned for the moderately absorbed compounds in Caco-2 cell monolayer model. The further results showed that the absorption mechanism of 7 well absorbed compounds, 8-O-methylretusin (1), genistein (7), spasuberol B (16), naringenin (18), isoliquiritigenin (19), 4-hydroxy-3-methoxy cinnamic acid methyl ester (23) and (+)-epipinoresinol (31) in SPC was mainly passive diffusion, their bidirectional transport rate was correlated with the concentration and transport time. The chemical structures of these compounds could affect the permeability properties on the cell monolayer. This study demonstrated the utility of Caco-2 cell monolayer model for evaluating the absorption properties and initial mechanisms of compounds in SPC in vitro, and provided important basis for predicting oral bioavailability of SPC compounds.

Integrative transcriptomic and metabolomic analyses unveil tanshinone biosynthesis in Salvia miltiorrhiza root under N starvation stress.

Salvia miltiorrhiza is a model plant for Chinese herbal medicine with significant pharmacologic effects due to its tanshinone components. Our previous study indicated that nitrogen starvation stress increased its tanshinone content. However, the molecular mechanism of this low nitrogen-induced tanshinone biosynthesis is still unclear. Thus, this study aimed to elucidate the molecular mechanism of tanshinone biosynthesis in S. miltiorrhiza under different N conditions [N-free (N0), low-N (Nl), and full-N (Nf, as control) conditions] by using transcriptome and metabolome analyses. Our results showed 3,437 and 2,274 differentially expressed unigenes between N0 and Nf as well as Nl and Nf root samples, respectively. N starvation (N0 and Nl) promoted the expression of the genes involved in the MVA and MEP pathway of tanshinone and terpenoid backbone biosynthesis. Gene ontology and KEGG analyses revealed that terpenoid backbone biosynthesis, hormone signal transduction, and phenylpropanoid biosynthesis were promoted under N starvation conditions, whereas starch and sucrose metabolisms, nitrogen and phosphorus metabolisms, as well as membrane development were inhibited. Furthermore, metabolome analysis showed that metabolite compounds and biosynthesis of secondary metabolites were upregulated. This study provided a novel insight into the molecular mechanisms of tanshinone production in S. miltiorrhiza in response to nitrogen stress.

Effective components and mechanism analysis of anti-platelet aggregation effect of Justicia procumbens L.

ETHNOPHARMACOLOGICAL RELEVANCE: Justicia procumbens L. is a traditional Chinese medicine, first recorded in "Shen Nong's Herbal Classic", for the treatment of lumbar pain and fever. As a widely distributed herb, it has also been documented in India, Nepal, and Malaysia. In "Tang Materia Medica", a famous medicinal book of Tang Dynasty in ancient China, it was first used to treat diseases associated with blood stasis. Blood stasis syndrome is closely related to thrombus formation and platelet aggregation. Although some compounds isolated from this plant have anti-platelet aggregation effects, the main chemical components and mechanism of J. procumbens in terms of these effects are little known. AIMS OF THE STUDY: Through in vivo and in vitro experiments, this studsy revealed the characteristic components and action mechanism of anti-platelet aggregation by J. procumbens from an overall perspective. MATERIALS AND METHODS: The effective crude extracts of the whole plant were screened via an in vitro anti-platelet aggregation test. After incubating these extracts with apheresis platelets, high affinity compounds were detected by HPLC-MS and regulatory genes were detected using gene chips. The effective components and potential target proteins were analyzed using computational docking technology. Furthermore, the compound with the strongest predicted activity was evaluated in vivo via an anti-thrombotic test. RESULTS: Integrin aⅡbß3, PKCα, PI3Kγ, and mitogen-activated protein kinase 14 were found to be potential targets. Justicidin B, tuberculatin, chinensinaphthol methyl ether, and neojusticin B were effective compounds that inhibited human platelet aggregation by suppressing Gq-PLC-PKC and Gi-PI3K-MAPK signaling pathways. Among the compounds that bind to platelets, justicidin B showed the strongest virtual binding force. The test of carotid artery thrombosis induced by ferric chloride in SD rats confirmed that justicidin B inhibited thrombus formation. CONCLUSION: Experimental investigation showed that arylnaphthalene lignan aglycones with one methylenedioxy group and two methoxy groups are effective components for anti-platelet aggregation by J. procumbens. These compounds inhibit Gq-PLC-PKC and Gi-PI3K-MAPK signaling pathways by suppressing the expression of genes such as ITGB3, PRKCA, PIK3CG, and MAPK14. These results reflected the characteristics of multi-component and multi-target synergistic treatment of Chinese medicine.

Prediction the Molecular Mechanism of Shengmai Injection in Acute Treatment of COVID-19 Based on Network Pharmacology.

Objective: To predict the mechanism of Shengmai Injection (SMI) in the acute treatment of COVID-19 by network pharmacology and molecular docking. Methods: Search the compounds in the Traditional Chinese Medicine Systems Pharmacology (TCMSP), and screen them by Drug-like properties (DL) and Oral bioavailability (OB); Using PharmMapper database and GeneCards database to collect compounds targets and COVID-19 targets, and using UniProt database to standardize the names of target genes; Using DAVID database for KEGG pathway annotation and GO bioinformatics analysis; Using Cytoscape 3.8.2 software and STRING 10.5 database to construct "Component-Target-Pathway" network and Protein-Protein Interaction network (PPI); Using molecular docking to predict the binding ability of key compounds and key proteins. Results: A total of 34 active components, 38 core targets and 180 signaling pathways were screened out. The results of molecular docking showed that Schisantherin A and Moupinamide have strong binding with EGFR and MAPK1. Conclusion: The key active compounds of SMI in the treatment of COVID-19 may be Schisantherin A and Moupinamide, and the molecular mechanism may be related to key targets such as EGFR and MAPK1, and may be involved in the PI3K-Akt signaling pathway and MAPK signaling pathway.

Effect of compound Sophorae decoction in the treatment of ulcerative colitis by tissue extract metabolomics approach.

OBJECTIVE: To investigate how compound Sophorae decoction (CSD) works on rats' models of ulcerative colitis (UC) induced by 2,4,6-trinitrobenzenesulfonic acid solution (TNBS) by metabolomics studies of colon, liver, and kidney tissue extracts. METHODS: Rats with UC induced by TNBS enema were used as models in this study. Metabolic profiles of the three tissues were analyzed and pathway analysis of biomarkers was performed after CSD administration and further integration of metabolic networks. RESULTS: Thirteen biomarkers were screened from colon, liver, and kidney tissue extracts, and the levels of these substances were up- or down-regulated in the model group, but their levels were reversed after CSD administration. These biomarkers were mainly related to Phenylalanine, tyrosine and tryptophan biosynthesis, Phenylalanine metabolism, Glutathione metabolism, Arachidonic acid metabolism, Nicotinate and nicotinamide metabolism, Alanine, aspartate and glutamate metabolism. CONCLUSION: CSD could significantly ameliorate the symptoms of UC by regulating multiple metabolic pathways.

Revealing the mechanism of "Huai Hua San" in the treatment of ulcerative colitis based on network pharmacology and experimental study.

ETHNOPHARMACOLOGICAL RELEVANCE: "Huai Hua San" (HHS) is one of the first hundred ancient classic prescriptions drugs, which is commonly used to treat hemorrhoids, colitis, and other symptoms of wind heat in stool. However, the potential molecular mechanism of action of this substance remains unclear. AIMS OF THE STUDY: In this study, we explored the active compounds of HHS for the treatment of ulcerative colitis (UC), predicted the potential targets of the drug, and studied its mechanism of action through network pharmacology via in vitro and in vivo experiments. MATERIALS AND METHODS: First, we identified the active compounds and key targets of HHS for treating UC via network pharmacology. The key signaling pathways associated with the anti-inflammatory effect of HHS were analyzed. The anti-inflammatory effects of HHS and its active compounds were studied using the RAW264.7 inflammatory cell model in vitro. Furthermore, we used the dextran sulfate sodium (DSS) mouse model to explore the efficacy and mechanism of HHS in UC in vivo, and the expression level of key proteins were detected by Western blotting. RESULTS: In all, 23 compounds and 97 targets were obtained from TCMSP database, PharmMapper database, and GeneCards database. After enrichment via Kyoto Encyclopedia of Genes and Genomes (KEGG), HIF-1 signaling pathway, PI3K/AKT signaling pathway, and VEGF signaling pathway were identified to be the top three signaling pathways associated with UC treatment. The results of molecular docking showed that the docking scores of the top 10 active compounds were higher than the threshold values. In vitro, different concentrations of HHS and the four main active compounds could effectively inhibit the release of inflammatory cytokines interleukin (IL)-6, tumor necrosis factor (TNF)-α, and IL-1 ß. In vivo, HHS could alleviate UC symptoms. CONCLUSION: Taken together, the treatment of UC with HHS may alleviate the inflammatory response of the colon, and HHS mainly inhibits the EGFR/PI3K/AKT/HIF-1/VEGF signaling pathways.

Compound Sophorae Decoction: treating ulcerative colitis by affecting multiple metabolic pathways.

Ulcerative colitis (UC) is a chronic refractory non-specific intestinal inflammatory disease that is difficult to be cured. The discovery of new ulcerative colitis-related metabolite biomarkers may help further understand UC and facilitate early diagnosis. It may also provide a basis for explaining the mechanism of drug action in the treatment of UC. Compound Sophorae Decoction (CSD) is an empirical formula used in the clinical treatment of UC. Although it is known to be efficacious, its mechanism of action in the treatment of UC is unclear. The purpose of this study was to investigate the changes in endogenous substances in UC rats and the effects of CSD on metabolic pathways using the metabonomics approach. Metabolomics studies in rats with UC and normal rats were performed using LC-MS/MS. Rats with UC induced using TNBS enema were used as the study models. Metabolic profiling and pathway analysis of biomarkers was performed using statistical and pathway enrichment analyses. 36 screened potential biomarkers were found to be significantly different between the UC and the normal groups; it was also found that CSD could modulate the levels of these potential biomarkers. CSD was found to be efficacious in UC by regulating multiple metabolic pathways.

Network pharmacology and molecular docking reveal the mechanism of Scopoletin against non-small cell lung cancer.

AIMS: Scopoletin is a natural anticarcinogenic and antiviral coumarin component. Many studies have proved its anti-cancer effect, and after the preliminary screening of this study, Scopoletin had the best inhibitory effect on Non-small cell lung cancer (NSCLC). But its mechanism for treating NSCLC is still unclear. Therefore, network pharmacology and molecular docking technology were used to explore the potential anti-NSCLC targets and pathways of Scopoletin. The results were verified in vitro. MAIN METHODS: First, Scopoletin was isolated from Fennel and screened to conduct cell proliferation assay on Human lung cancer cell line A549, Human colon cancer cell line HCT-116 and Human hepatoma cell line HepG2 respectively, through the MTT test. Then, the key targets and related pathways were screened through Protein-protein Interaction (PPI) network and "component-target-pathway" (C-TP) network constructed by network pharmacology. And the key targets were selected to dock with Scopoletin via molecular docking. A549 and Human normal lung epithelial cell BEAS-2B were used to verify the results, finally. KEY FINDINGS: Through MTT, A549 was chosen as the test cancer cell. From network pharmacology, 16 targets, 27 signaling pathways and 16 GO items were obtained (P < 0.05). The results of PPI network and molecular docking showed that EGFR, BRAF and AKT1 were the key targets of Scopoletin against NSCLC, which were consistent with the western-blot results. SIGNIFICANCE: Through network pharmacology, molecular docking and experiments in vitro, Scopoletin was verified to against NSCLC through RAS-RAF-MEK-ERK pathway and PI3K/AKT pathway.

Systematic analysis of the metabolites of Angelicae Pubescentis Radix by UPLC-Q-TOF-MS combined with metabonomics approaches after oral administration to rats.

Angelicae Pubescentis Radix (APR) is a typical Traditional Chinese Medicine (TCM) and has been widely used to treat rheumatism and headache diseases in China. This research aimed to illustrate the metabolites of APR in vivo to lay a foundation for the clinics application. A UPLC-Q-TOF-MS method combined with metabonomics approaches is used to address this objective. The separation was achieved on an Agilent SB-C18 column (1.8 µm, 2.1 × 50 mm) with a gradient elution system (ACN and 0.1 % formic acid-water). An electrospray ionization (ESI) was used for mass spectrometer and operated in a full-scan mode at m/z 100 - 800. The data were collected in the positive ion mode and analyzed by the Masslynx 4.1 and SIMCA 13.0 software. Furthermore, an orthogonal partial least-squares discriminant analysis (OPLS-DA) using SIMCA 13.0 software was applied to investigate the differences between the blank and drug groups in bio-samples of rats (plasma, urine, feces). Totally 213 compounds including 41 prototype ingredients, 107 phase I and 65 phase II metabolites were detected, according to the MS and MS/MS data. Among them, 134 metabolites are potential new compounds.

Active Ingredients and Mechanism of Action of Rhizoma Coptidis against Type 2 Diabetes Based on Network-Pharmacology and Bioinformatics.

A pharmacological network of "component/target/pathway" for Rhizoma coptidis against type 2 diabetes (T2D) was established by network-pharmacology, and the active components of Rhizoma coptidis and its mechanism were explored. A literature-based and database study of the components of Rhizoma coptidis was carried out and screened by ADME parameters. The targets of Rhizoma coptidis were predicted by the ligand similarity method. Related pathways were analyzed with databases, and software was used to construct a "component/target/path" network. The mechanism was further confirmed by GEO database with R software. A total of 12 active components were screened from Rhizoma coptidis, involving 57 targets including MAPK1, STAT3, INSR, and 38 signaling pathways were associated with T2D. Related signaling pathways included essential pathways for T2D such as insulin resistance, and pathways that had indirect effect on T2D. It was suggested that Rhizoma coptidis may exert its effects against T2D through multi-component, multi-target, and multi-pathway forms.

Network Pharmacology-based Research of Active Components of Albiziae Flos and Mechanisms of Its Antidepressant Effect.

Albiziae Flos (AF) has been experimentally proven to have an antidepressant effect. However, due to the complexity of botanical ingredients, the exact pharmacological mechanism of action of AF in depression has not been completely deciphered. This study used the network pharmacology method to construct a component-target-pathway network to explore the active components and potential mechanisms of action of AF. The methods included collection and screening of chemical components, prediction of depression-associated targets of the active components, gene enrichment, and network construction and analysis. Quercetin and 4 other active components were found to exert antidepressant effects mainly via monoaminergic neurotransmitters and cAMP signaling and neuroactive ligand-receptor interaction pathways. DRD2, HTR1A, and SLC6A4 were identified as important targets of the studied bioactive components of AF. This network pharmacology analysis provides guidance for further study of the antidepressant mechanism of AF.

Anti-Inflammatory Activity of Some Characteristic Constituents from the Vine Stems of Spatholobus suberectus.

The dried vine stems of Spatholobus suberectus are commonly used in traditional Chinese medicine for treating gynecological and cardiovascular diseases. In this study, five new compounds named spasuberol A (2), homovanillyl-4-oxo-nonanoate (5), spasuberol C (6), spasuberoside A (14), and spasuberoside B (15), together with ten known compounds (1, 3, 4, 7-13), were isolated from the dried vine stems of S. suberectus. Their chemical structures were analyzed using spectroscopic assays. This is the first study interpreting the detailed structural information of 4. The anti-inflammatory activity of these compounds was evaluated by reducing nitric oxide overproduction in RAW264.7 macrophages stimulated by lipopolysaccharide. Compounds 1 and 8-10 showed strong inhibitory activity with half maximal inhibitory concentration (IC50) values of 5.69, 16.34, 16.87, and 6.78 µM, respectively, exhibiting higher activity than the positive drug l-N6-(1-iminoethyl)-lysine (l-NIL) with an IC50 value of 19.08 µM. The IC50 values of inhibitory activity of compounds 2 and 4-6 were 46.26, 40.05, 45.87, and 28.29 µM respectively, which were lower than l-NIL, but better than that of positive drug indomethacin with an IC50 value of 55.44 µM. Quantitative real-time polymerase chain reaction analysis revealed that assayed compounds with good anti-inflammatory activity, such as 1, 6, 9, and 10 at different concentrations, can reduce the messenger RNA (mRNA) expression of some pro-inflammatory cytokines such as tumor necrosis factor α (TNF-α), nitric oxide synthase (iNOS), and cyclooxygenase 2 (COX-2). The anti-inflammatory activity and the possible mechanism of the compounds mentioned in this paper were studied preliminarily.

Magnetic Graphene Oxide-Fe3O4-PANI Nanoparticle Adsorbed Platinum Drugs as Drug Delivery Systems for Cancer Therapy.

Graphene-based magnetic nanoparticles (NPs) were synthesized using a simple and effective chemical precipitation method. To determine the biocompatibility of GO-Fe3O4-PANI NPs with MTT assay, cytotoxicity testing from a low concentration (1 µg/mL) to a high concentration (125 µg/mL) was conducted using various cancer and normal cell lines. Cytotoxicity testing for cancer cell lines (SMMC-7721, HepG-2, RAW264.7) and normal cell lines (HL-7702) showed almost no toxicity within the 1~125 µg/mL concentration range. Carboplatin (CBP) and oxaliplatin (OXP) were then used as drug models to study the drug release of CBP and OXP loaded on GO-Fe3O4-PANI NPs in vitro. Results indicated that the release of CBP and OXP from GO-Fe3O4-PANI NPs were affected by pH, dose, and temperature. The release of CBP was more sensitive to pH, and the amounts released in neutral and acidic environments (pH 6.0 and 7.4, respectively) were higher than those released in alkaline environments (pH 8.0). Meanwhile, at different pH levels, the release of OXP was not as large. In addition, at a low temperature (27 °C), the amount released is small when the energy level does not meet that required by C═N. At a considerably higher temperature (47 °C), the energy required for C═N fracture is met, allowing the slow release of the drug over a longer period. The results of our studies suggest that GO-Fe3O4-PANI NPs are biocompatible with MTT assay, and as drug delivery systems, these particular NPs can lead to advances in cancer treatment.

Plasma pharmacokinetics and cerebral nuclei distribution of major constituents of Psoraleae fructus in rats after oral administration.

BACKGROUND: The fruit of Psoralea corylifolia L., Psoraleae fructus (PF), is widely used in traditional Chinese medicine as a well-known herbal tonic. Previous studies have shown that PF and its major constituents may have potential values in the treatment of Parkinson and Alzheimer diseases, though their pharmacokinetics and brain distribution were largely unknown. PURPOSE: To develop a liquid chromatographic-tandem mass spectrometry (LC-MS/MS) method for simultaneous studies of the plasma pharmacokinetics and cerebral nuclei (including cerebellum, thalamus, brainstem, hippocampus, corpus striatum and cortex) distribution in rats of eleven known PF compounds following as psoralen, isopsoralen, psoralidin, bavachin, bavachinin, isobavachin, isobavachalcone, bavachalcone, neobavaisoflavone, corylifol A, and corylin. METHODS: Rats were orally administered via gavage at a single dose of PF extract at 1.2 g/kg. The eleven known PF compounds were extracted from rat plasma and cerebral nuclei at different time points, and then determined by the established LC-MS/MS method. Non-compartmental pharmacokinetic profiles were calculated, and the distribution in rat plasma and cerebral nuclei were compared. RESULTS: The results showed that all the tested compounds were quickly absorbed into rat plasma and distributed almost evenly to the cerebral nuclei. The distribution concentrations at different nuclei varied at one determined time point, but the overall trends were basically similar to the plasma concentration-time results. Psoralen and isopsoralen, the two highest coumarins contained in PF, displayed far higher plasma concentrations (AUC0→∞, plasma≈53,884∼65,578 ng·h/ml) and central nervous system penetration (AUC0→∞, brain nuclei ≈44,659∼65,823 ng·h/g) than the prenylflavonoids (other compounds except psoralidin, AUC0→∞, plasma≈69∼324 ng·h/ml; AUC0→∞, brain nuclei ≈119∼3662 ng·h/g). However, the total brain-to-plasma ratios of the prenylflavonoids were higher than the coumarins, suggesting the prenylflavonoids can more readily enter the brain than the coumarins. CONCLUSION: The established LC-MS/MS method is sensitive and specific for the simultaneous quantitation of the eleven PF compounds in rat plasma and cerebral nuclei. The results of plasma pharmacokinetics and cerebral nuclei distribution may reveal the possible substance basis for the CNS activities of PF, and highlight the application possibility of PF and its major constituents in the treatment of Parkinson and Alzheimer diseases.

Distribution Assessments of Coumarins from Angelicae Pubescentis Radix in Rat Cerebrospinal Fluid and Brain by Liquid Chromatography Tandem Mass Spectrometry Analysis.

Angelicae Pubescentis Radix (APR) is a widely-used traditional Chinese medicine. Pharmacological studies have begun to probe its biological activities on neurological disorders recently. To assess the brain penetration and distribution of APR, a validated ultra-performance liquid chromatography tandem mass spectrometry method was applied to the simultaneous determinations of the main coumarins from APR in the rat cerebrospinal fluid (CSF) and brain after oral administration of APR extract, including psoralen, xanthotoxin, bergapten, isoimperatorin, columbianetin, columbianetin acetate, columbianadin, oxypeucedanin hydrate, angelol B, osthole, meranzin hydrate and nodakenetin. Most of the tested coumarins entered the rat CSF and brain quickly, and double-peak phenomena in concentration-time curves were similar to those of their plasma pharmacokinetics. Columbianetin had the highest concentration in the CSF and brain, while psoralen and columbianetin acetate had the largest percent of CSF/plasma and brain/plasma, indicating that these three coumarins may be worthy of further research on the possible nervous effects. Correlations between the in vivo brain distributions and plasma pharmacokinetics of these coumarins were well verified. These results provided valuable information for the overall in vivo brain distribution characteristics of APR and also for its further studies on the active substances for the central nervous system.

Blood-brain barrier permeability and neuroprotective effects of three main alkaloids from the fruits of Euodia rutaecarpa with MDCK-pHaMDR cell monolayer and PC12 cell line.

The fruits of Euodia rutaecarpa (Euodiae Fructus, EF), the widely used traditional Chinese medicine, have various central nervous system effects. Alkaloids following as evodiamine (EDM), rutaecarpine (RCP) and dehydroevodiamine (DEDM) are the major substances in EF. The MDCK-pHaMDR cell monolayer model was utilized as a blood-brain barrier (BBB) surrogate model to study their BBB permeability. The transport samples were analyzed by high performance liquid chromatography and the apparent permeability coefficients (Papp) were calculated. EDM and RCP showed high permeability through BBB by passive diffusion, while DEDM showed moderate permeability with efflux mechanism related to P-glycoprotein (P-gp). EDM and RCP could also reduce the efflux of DEDM probably by inhibiting P-gp. The neuroprotective effects of the three alkaloids were then studied on the PC12 cell line injured by 1-methyl-4-phenylpyridinium ion (MPP+) or hydrogen peroxide (H2O2). EDM could significantly reduce MPP+ or H2O2-induced cell injury dose-dependently. RCP could increase the cell viability in MPP+ treated group while DEDM showed a protective effect against H2O2 injury. This study predicted the permeability of EDM, RCP and DEDM through BBB and discovered the neuroprotective substance basis of EF as a potential encephalopathy drug.

The Blood-Brain Barrier Permeability of Six Indole Alkaloids from Uncariae Ramulus Cum Uncis in the MDCK-pHaMDR Cell Monolayer Model.

Uncariae Ramulus Cum Uncis (URCU) is a widely used traditional Chinese medicine, and is reported to have various central nervous system effects. Alkaloids have been demonstrated to be the predominant pharmacological active components of URCU. In order to evaluate the blood-brain barrier (BBB) permeability and transport mechanism of six typical indole alkaloids from URCU, the MDCK-pHaMDR cell monolayer model was used as an in vitro surrogate model for BBB. The samples were analyzed by high-performance liquid chromatography, and the apparent permeability coefficients (Papp) were calculated. Among the six alkaloids, isorhynchophylline (2), isocorynoxeine (4), hirsutine (5) and hirsuteine (6) showed high permeability, with Papp values at 10-5 cm/s level in bidirectional transport. For rhynchophylline (1) and corynoxeine (3), they showed moderate permeability, with Papp values from the apical (AP) side to the basolateral (BL) side at 10-6 cm/s level and efflux ratio (Papp BL→AP/Papp AP→BL) above 2. The time- and concentration-dependency experiments indicated that the main mechanism for 2, 4, 5 and 6 through BBB was passive diffusion. The efflux mechanism involved in the transports of compounds 1 and 3 could be reduced significantly by verapamil, and molecular docking screening also showed that 1 and 3 had strong bindings to P-glycoprotein. This study provides useful information for predicting the BBB permeability for 1-6, as well as better understanding of their central nervous system pharmacological activities.

Intestinal Absorption of Triterpenoids and Flavonoids from Glycyrrhizae radix et rhizoma in the Human Caco-2 Monolayer Cell Model.

Glycyrrhizae radix et rhizoma has been used as a traditional Chinese medicine for the treatment of various diseases. Triterpenoids and flavonoids from the plant have many beneficial effects and their chemical structures are modified in the gastrointestinal tract after oral administration. However, absorption of these triterpenoids and flavonoids still needs to be defined. Here, the uptake and transepithelial transport of the selected major triterpenoids, glycyrrhizin (1), glycyrrhetic acid-3-O-mono-ß-d-glucuronide (2), and glycyrrhetinic acid (3); and the selected major flavonoids, licochalcone A (4), licochalcone B (5), licochalcone C (6), echinatin (7), isoliquiritin apioside (8), liquiritigenin (9), liquiritin apioside (10) isolated from Glycyrrhizae radix et rhizoma, were investigated in the human intestinal epithelium-like Caco-2 cell monolayer model. Compounds 3, 5-7, and 9 were designated as well-absorbed compounds, 2 and 4 were designated as moderately absorbed ones, and 1, 8, and 10 were assigned for the poorly absorbed ones. The absorption mechanism of well and moderately absorbed compound was mainly passive diffusion to pass through the human intestinal Caco-2 cell monolayer. These findings provided useful information for predicting their oral bioavailability and the clinical application.

Simultaneous assessment of absorption characteristics of coumarins from Angelicae Pubescentis Radix: In vitro transport across Caco-2 cell and in vivo pharmacokinetics in rats after oral administration.

Angelicae Pubescentis Radix (APR), a well-known traditional Chinese medicine, is widely used for the treatments of rheumatism and headache for centuries. To assess the absorption characteristics of coumarins from APR, a sensitive and reliable UPLC-MS/MS method was established for the simultaneous determination of sixteen coumarins from APR, including psoralen, xanthotoxin, bergapten, bergaptol, isoimperatorin, imperatorin, columbianetin, columbianetin acetate, columbianadin, oxypeucedanin hydrate, angelol B, umbelliferone, scopoletin, osthole, meranzin hydrate and nodakenetin. The specificity, linearity, sensitivity, precision, accuracy, recovery, matrix effect and stability of the method were all validated to be satisfactory. The method was then applied to the in vitro transport of APR extract (APRE) across human intestinal epithelial Caco-2 cell and in vivo pharmacokinetics in rats after oral administration of APRE. All of the tested coumarins were well or moderately absorbed across Caco-2 monolayers, and could be quickly absorbed into rat blood circulation after oral administration. Columbianetin was the most easily absorbed compound across Caco-2 cell, and also had extremely highest plasma concentration in vivo. Excellent correlation between in vitro absorption across Caco-2 cell monolayers and in vivo pharmacokinetics of coumarins from APRE was well verified. The results provided valuable information for the overall absorption characteristics of the coumarins from APR, as well as for its further studies of in vivo active substances in the further.

Anti-Inflammatory Phenolic Acid Esters from the Roots and Rhizomes of Notopterygium incisium and Their Permeability in the Human Caco-2 Monolayer Cell Model.

A new ferulic acid ester named 4-methyl-3-trans-hexenylferulate (1), together with eight known phenolic acid esters (2-9), was isolated from the methanolic extract of the roots and rhizomes of Notopterygium incisium. Their structures were elucidated by extensive spectroscopic techniques, including 2D NMR spectroscopy and mass spectrometry. 4-Methoxyphenethyl ferulate (8) NMR data is reported here for the first time. The uptake and transepithelial transport of the isolated compounds 1-9 were investigated in the human intestinal Caco-2 cell monolayer model. Compounds 2 and 6 were assigned for the well-absorbed compounds, compound 8 was assigned for the moderately absorbed compound, and compounds 1, 3, 4, 5, 7, and 9 were assigned for the poorly absorbed compounds. Moreover, all of the isolated compounds were assayed for the inhibitory effects against nitric oxide (NO) production in the lipopolysaccharide-activated RAW264.7 macrophages model and L-N6-(1-iminoethyl)-lysine (L-NIL) was used as a positive control. Compounds 1, 5, 8, and 9 exhibited potent inhibitory activity on NO production with the half maximal inhibitory concentration (IC50) values of 1.01, 4.63, 2.47, and 2.73 µM, respectively, which were more effective than L-NIL with IC50 values of 9.37 µM. These findings not only enriched the types of anti-inflammatory compounds in N. incisum but also provided some useful information for predicting their oral bioavailability and their suitability as drug leads or promising anti-inflammatory agents.