Zhibin Wang

Determination and pharmacokinetic study of two triterpenoid saponins in rat plasma after oral administration of the extract of Aralia elata leaves by UHPLC–ESI–MS/MS

Aralia elata (Miq.) Seems (A. elata) grow in Northeast China and the total saponins of A. elata is used to auxiliary treatment for the acute hepatitis, chronic hepatitis and the transaminase on the high side. Aralia-saponinV and Aralia-saponinVI are the major bioactive saponins in A. elata leaves. A selective and sensitive UHPLC-MS/MS method was developed and validated for the determination and pharmacokinetic study of Aralia-saponinV and Aralia-saponinVI indwelling the extract in rat plasma in this article. The sample pretreatment involved a one-step extraction of 0.2mL plasma with methanol. Shengmaxinside C was used as internal standard (I.S.). The separation was carried out on an Agilent SB-C18 column (1.8μm, 50mm×2.1mm) at 30°C with a mobile phase of acetonitrile-5mM ammonium acetate (90:10, v/v) at a flow rate of 0.2mL/min. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) mode via electrospray ionization (ESI) source operating in the negative ionization mode. The optimized mass transition ion-pairs (m/z) monitored for Aralia-saponinV, Aralia-saponinVI and I.S. were 1103.2/941.2, 1119.2/957.0 and 707.0/647.1, respectively. The current UHPLC-MS/MS assay method was validated for linearity, intra-day and inter-day precisions, accuracy, extraction recovery and stability, and it was suitable for the pharmacokinetic studies of the two saponins after oral administration of extract of A. elata leaves. The lower limits of quantification were 5.70ng/mL for Aralia-saponinV and 6.15ng/mL for Aralia-saponinVI. Intra-day and inter-day precisions were less than 7.4% and the accuracy range was from 1.19% to 8.60%. The mean extraction recoveries of analytes and I.S. from rat plasma were all more than 89.5%. This paper described a simple, sensitive and validated UHPLC-MS/MS method for simultaneous determination of Aralia-saponinV and Aralia-saponinVI in rat plasma after oral administration of the extract of A. elata leaves, and investigated on their pharmacokinetic studies as well.

Corynoline Isolated from Corydalis bungeana Turcz. Exhibits Anti-Inflammatory Effects via Modulation of Nfr2 and MAPKs

Corydalis bungeana Turcz. is an anti-inflammatory medicinal herb used widely in traditional Chinese medicine for upper respiratory tract infections. It is demonstrated that corynoline is its active anti-inflammatory component. The nuclear factor-erythroid-2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway and the mitogen-activated protein kinase (MAPK) pathway play important roles in the regulation of inflammation. In this study, we investigated the potential anti-inflammatory mechanism of corynoline through modulation of Nfr2 and MAPKs. Lipopolysaccharide (LPS)-activated RAW264.7 cells were used to explore modulatory role of NO production and the activation of signaling proteins and transcription factors using nitrite assay, Western bloting and qPCR. Treatment with corynoline reduced production of nitric oxide (NO) and the protein and mRNA levels of inducible nitric oxide (iNOS) and cyclooxygenase-2 (COX-2) Treatment also significantly increased the expression of Nrf2, quinone oxidoreductase 1 (NQO1) and hemeoxygenase-1 (HO-1) at the mRNA and protein levels, which demonstrated that corynoline may protect cells from inflammation through the Nrf2/ARE pathway In addition, corynoline suppressed the expression of inflammatory cytokines, such as tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), at the mRNA and protein levels. Furthermore, molecular data revealed that corynoline inhibited lipopolysaccharide-stimulated phosphorylation of c-jun NH2-terminal kinase (JNK) and p38. Taken together, these results suggest that corynoline reduces the levels of pro-inflammatory mediators, such as iNOS, COX-2, TNF-α and IL-1β, by suppressing extracellular signal-regulated kinase 1/2 (ERK) and p38 phosphorylation in RAW264.7 cells, which is regulated by the Nrf2/ARE pathway. These findings reveal part of the molecular basis for the anti-inflammatory properties of corynoline.

Simultaneous Determination of Purpurin, Munjistin and Mollugin in Rat Plasma by Ultra High Performance Liquid Chromatography-Tandem Mass Spectrometry: Application to a Pharmacokinetic Study after Oral Administration of Rubia cordifolia L. Extract.

A specific, simple, sensitive Ultra High Performance Liquid Chromatography-tandem Mass Spectrometry (UHPLC-MS/MS) method has been developed and validated for the simultaneous determination and pharmacokinetic study of purpurin, munjistin, and mollugin in rat plasma. Chromatographic separation was carried out using a C18 column (ACQUITY UPLC® HSS T3, 1.8 μm, 2.1 × 100 mm) with gradient elution. The compounds were detected on a 6430 triple-quadrupole tandem MS with an electrospray ionization (ESI) interface using multiple reaction monitoring (MRM) in positive ionization mode. The samples were prepared by a liquid-liquid extraction (LLE) method with ethyl acetate after being spiked with an internal standard (bifendate). The current UHPLC-MS/MS assay was validated for its linearity, intra-day and inter-day precisions, accuracy, extraction recovery, matrix effect and stability in different conditions. The method was linear for all analytes over the investigated range with all determined correlation coefficients exceeding 0.9900. The intra-day and inter-day precisions were in the range of 4.21% to 14.84%, and the relative errors of accuracies were in the range of −14.05% to 14.75%. The mean recoveries and matrix effects of purpurin, munjistin, and mollugin were higher than 78.87% and 92.56%, repectively. After oral administration of 0.82 g/kg of Rubia cordifolia extract, the maximum plasma concentrations (Cmax) were 70.10 ± 11.78 ng/mL for purpurin, 26.09 ± 6.6 ng/mL for munjistin, and 52.10 ± 6.71 ng/mL for mollugin. The time for maximal concentration (Tmax) was 1.61 ± 0.24 h for purpurin, 2.58 ± 0.19 h for munjistin, and 1.99 ± 0.21 h for mollugin. The established method was further applied to a pharmacokinetic study of purpurin, munjistin, and mollugin in rat plasma. It was concluded from the pharmacokinetic parameters that the three analytes showed a process of slow absorption and metabolism after oral administration of R. cordifolia extract to rats.

Determination and pharmacokinetic study of four xanthones in rat plasma after oral administration of Gentianella acuta extract by UHPLC-ESI-MS/MS.

ETHNOPHARMACOLOGICAL RELEVANCEnGentianella acuta (Michx.) Hulten belonging to the family of Gentianaceae is an annual plant mainly distributed in north of China, Mongolia plateau, Siberia and Far East areas of Russia. The whole herb was used as folk medicine to treat hepatitis, jaundice, headache and fever in Mongolia native medicine. Xanthones are the main active compounds of G. acuta and possess a lot of pharmacological and biological activitiesnnnAIM OF THE STUDYnA selective and sensitive UHPLC-MS/MS method was developed and validated for the determination and pharmacokinetic study of swertianolin, norswertianolin, bellidifolin and demethylbellidifolin (DMB) in rat plasma after oral administration of G. acuta extract.nnnMATERIALS AND METHODSnSample preparation involved a liquid-liquid extraction of the analytes with ethyl acetate. Butylparaben was employed as an internal standard. LC separation was achieved on an Agilent SB-C18 RRHD column (1.8 μm, 150 mm × 2.1 mm) at 30°C with an isocratic mobile phase consisting of acetonitrile-water (0.1% formic acid) (90:10, v/v). The detection was accomplished by multiple-reaction monitoring (MRM) scanning with electrospray ionization (ESI) source operating in the negative ionization mode. The optimized mass transition ion-pairs (m/z) monitored for swertianolin, norswertianolin, bellidifolin, DMB and I.S. were 435.1/272.0, 420.8/258.9, 273.0/258.0, 258.9/214.9 and 193.0/92.0, respectively.nnnRESULTSnThe current UHPLC-MS/MS assay was validated for linearity, intra-day and inter-day precisions, accuracy, extraction recovery and stability and was suitable for pharmacokinetic studies of the four xanthones after oral administration of G. acuta extract. The time to reach the maximum plasma concentration (Tmax) was 0.40 ± 0.12 h for swertianolin, 0.27 ± 0.07 h for norswertianolin, 1.00 ± 0.18 h for bellidifolin and 0.94 ± 0.15 h for demethylbellidifolin. The elimination half-time (t1/2) of swertianolin, norswertianolin, bellidifolin and DMB, was 19.7 ± 9.64 h, 11.3 ± 4.51 h, 19.9 ± 8.11 h and 24.9 ± 8.19 h, respectively.nnnCONCLUSIONnThis study described a simple, sensitive and validated UHPLC-MS/MS method for simultaneous determination of four xanthones in rat plasma after oral administration of G. acuta extract, and investigated on their pharmacokinetic studies as well.

Triterpenoids and Flavonoids from the Leaves of Astragalus membranaceus and Their Inhibitory Effects on Nitric Oxide Production

Four new cycloartane triterpenes, named huangqiyegenins V and VI and huangqiyenins K and L (1–4, resp.), together with nine known triterpenoids, 5–13, and eight flavonoids, 14–21, were isolated from a 70%‐EtOH extract of Astragalus membranaceus leaves. The structures of the new compounds were elucidated by detailed spectroscopic analyses, and the compounds were identified as (9β,11α,16β,20R,24S)‐11,16,25‐trihydroxy‐20,24‐epoxy‐9,19‐cyclolanostane‐3,6‐dione (1), (9β,16β,24S)‐16,24,25‐trihydroxy‐9,19‐cyclolanostane‐3,6‐dione (2), (3β,6α,9β,16β,20R,24R)‐16,25‐dihydroxy‐3‐(β‐D‐xylopyranosyloxy)‐20,24‐epoxy‐9,19‐cyclolanostan‐6‐yl acetate (3), and (3β,6α,9β,16β,24E)‐26‐(β‐D‐glucopyranosyloxy)‐16‐hydroxy‐3‐(β‐D‐xylopyranosyloxy)‐9,19‐cyclolanost‐24‐en‐6‐yl acetate (4). All isolated compounds were evaluated for their inhibitory activities against LPS‐induced NO production in RAW264.7 macrophage cells. Compounds 1–3, 14, 15, and 18 exhibited strong inhibition on LPS‐induced NO release by macrophages with IC50 values of 14.4–27.1u2005μM.

Determination and Pharmacokinetic Study of Three Diterpenes in Rat Plasma by UHPLC-ESI-MS/MS after Oral Administration of Rosmarinus officinalis L. Extract

Rosmarinus officinalis L. is commonly used as a spice and flavoring agent. Diterpenes are the main active compounds of R. officinalis. An Ultra High Performance Liquid Chromatography-Tandem Mass Spectrometry (UHPLC-ESI-MS/MS) method was developed for the determination of carnosol, rosmanol, and carnosic acid isolated from R. officinalis in rat plasma, and applied to a pharmacokinetic study after oral administration of R. officinalis extract. Sample preparation involved a liquid-liquid extraction of the analytes with ethyl acetate. Butylparaben was employed as an internal standard (I.S.). Chromatographic separation was carried out on a C18 column (ACQUITY UPLC® HSS T3, 1.8 μm, 2.1 mm × 100 mm) with a gradient system consisting of the mobile phase solution A (0.1% formic acid in water) and solution B (acetonitrile) at the flow rate of 0.3 mL/min. The quantification was obtained using multiple reaction monitoring (MRM) mode with electrospray ionization (ESI). The UHPLC-MS/MS assay was validated for linearity, accuracy, precision, extraction recovery, matrix effect and stability. This study described a simple, sensitive and validated UHPLC-MS/MS method for the simultaneous determination of three diterpene compounds in rat plasma after oral administration of R. officinalis extract, and investigated on their pharmacokinetic studies as well.

Taxifolin Activates the Nrf2 Anti-Oxidative Stress Pathway in Mouse Skin Epidermal JB6 P+ Cells through Epigenetic Modifications

Nuclear factor erythroid-2 related factor 2 (Nrf2) is a vital transcription factor that regulates the anti-oxidative defense system. Previous reports suggested that the expression of the Nrf2 gene can be regulated by epigenetic modifications. The potential epigenetic effect of taxifolin (TAX), a potent cancer chemopreventive agent, in skin cancer chemoprotection is unknown. In this study, we investigated how Nrf2 is epigenetically regulated by TAX in JB6 P+ cells. TAX was found to inhibit the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced colony formation of JB6 P+ cells. TAX induced antioxidant response element (ARE)-luciferase activity in HepG2-C8 cells and up-regulated mRNA and protein levels of Nrf2 and its downstream genes heme oxygenase-1 (HO-1) and NAD(P)H quinone oxidoreductase 1 (NQO1), in JB6 P+ cells. Furthermore, bisulfite genomic sequencing revealed that TAX treatment reduces the methylation level of the first 15 CpGs sites in the Nrf2 promoter. Western blotting showed that TAX inhibits the expression levels of DNA methyltransferase (DNMT) and histone deacetylase (HDAC) proteins. In summary, our results revealed that TAX can induce expression of Nrf2 and its downstream target genes in JB6 P+ cells by CpG demethylation. These finding suggest that TAX may exhibit a skin cancer preventive effect by activating Nrf2 via an epigenetic pathway.

Simultaneous Determination of Eight Alkaloids in Rat Plasma by UHPLC-MS/MS after Oral Administration of Coptis deltoidea C. Y. Cheng et Hsiao and Coptis chinensis Franch

A ultra-high performance liquid chromatography-electrospray ionization tandem mass spectrometry (UHPLC-ESI-MS/MS) method was successfully developed and validated for the identification and determination of eight alkaloids: tetrahydropalmatine (A); palmatine (B); magnoflorine (C); columbamine (D); berberine (E); worenine (F); berberrubine (G) and coptisine (H) in rat plasma, which are the active components in Coptis deltoidea C. Y. cheng et Hsiao (CCY) and Coptis chinensis Franch (CF). The chromatographic separation of analytes was successfully achieved on an Agilent SB-C18 column (1.8 µm, 150 mm × 2.1 mm) using a programme with a mobile phase consisting of acetonitrile and water containing 0.3% acetic acid at a flow rate of 0.25 mL/min. The analytes were detected with a triple quadrupole tandem MS in multiple reaction monitoring (MRM) mode and an electrospray ionization (ESI) source in positive mode. The validated method showed good linearity over a wide concentration range (r2 > 0.991), and lower limits of quantification (LLOQ) less than 1.1 ng/mL for all analytes, and matrix effects ranged from 85.2% to 106.8%. The mean extraction recoveries were no less than 86.4%, and the precision and accuracy were within the acceptable limits. All analytes were proven to be stable during sample storage and analysis procedures. The method validation results demonstrated that the proposed method was sensitive, specific, and reliable, which could lay a foundation for the pharmacokinetic study of eight analytes after oral administration of CCY and CF in subsequent studies.

GC–MS method for determination and pharmacokinetic study of four phenylpropanoids in rat plasma after oral administration of the essential oil of Acorus tatarinowii Schott rhizomes

ETHNOPHARMACOLOGICAL RELEVANCEnAcorus tatarinowii Schott (AT), belong to the family Araceae, is perennial herbaceous plant mainly present in China, Japan and India. The rhizomes of AT have been used as a famous traditional Chinese medicine for the treatment of central nervous system related diseases.nnnAIM OF THE STUDYnA selective, accurate and sensitive method using gas chromatography-mass spectroscopy (GC-MS) for the simultaneous determination and pharmacokinetic study of β-asarone, α-asarone, elemicin and cis-methyl isoeugenol in rat plasma was developed and validated.nnnMATERIALS AND METHODSnThe GC-MS system was operated under selected ion monitoring (SIM) mode. The samples were prepared by protein precipitation with acetonitrile after being spiked with an internal standard (1-naphthol). The GC separation was achieved on a DB-1701 column (60 m × 0.25 mm ID, and 0.25 µm film thickness).nnnRESULTSnThe current GC/MS assay was validated for linearity, intra-day and inter-day precisions, accuracy, extraction recovery and stability. The analyte calibration curves were linear over a wide concentration range and the lowest limit of quantifications (LLOQ) were 5.53 ng/mL (β-asarone), 6.50 ng/mL (α-asarone), 3.10 ng/mL (elemicin) and 7.60 ng/mL (cis-methyl isoeugenol). After oral administration 0.9 g /Kg of AT rhizomes, the maximum plasma concentration (Cmax) was 2508.6±498.7 ng/mL for β-asarone, 257.5±37.1 ng/mL for α -asarone, 345.5±33.4 ng/mL for elemicin and 452.7±59.1 ng/mL for cis-methyl isoeugenol, respectively. The time to reach the maximum plasma concentration (Tmax) was 1.42±0.18 h for β-asarone, 1.58±0.19 h for α -asarone, 1.67±0.24 h for elemicin and 1.75±0.38 h for cis-methyl isoeugenol, respectively.nnnCONCLUSIONnThis paper described a simple, sensitive and validated GC-MS method for simultaneous determination of four phenylpropanoids in rat plasma after oral administration of the essential oil of AT rhizomes and investigated on their pharmacokinetics studies as well.

Simultaneous Determination of Seven Phenolic Acids in Rat Plasma Using UHPLC-ESI-MS/MS after Oral Administration of Echinacea purpurea Extract

A rapid and sensitive Ultra High Performance Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometry (UHPLC-ESI-MS/MS) method was developed and validated to simultaneously determine the concentration of seven phenolic acids (syringic acid, ferulic acid, caffeic acid, vanillic acid, p-coumaric acid, 3,4-dihydroxybenzoic acid and 4-hydroxybenzoic acid) in rat plasma after oral administration of Echinacea purpurea extract. After mixing with the internal standard (IS), butylparaben, plasma samples were prepared by liquid–liquid extraction with ethyl acetate. The separation was performed using the Agilent Eclipse Plus C18 column (1.8 μm, 2.1 mm × 50 mm) with a gradient system consisting of solution A (0.1% acetic acid in water) and solution B (methanol) at a flow rate of 0.3 mL/min. The detection was accomplished by a multiple reaction monitoring (MRM) mode with electrospray ionization (ESI). The method was validated in terms of linearity, precision, accuracy, extraction recovery, matrix effect and stability. This method was successfully applied to study the pharmacokinetic properties of the seven compounds after oral administration of Echinacea purpurea extract in rats.