Synthesis and Biological Evaluation of Gentiopicroside Derivatives as Novel Cyclooxygenase-2 Inhibitors with Anti-Inflammatory Activity.

Purpose: Nonsteroidal anti-inflammatory drugs cause a series of adverse reactions. Thus, the search for new cyclooxygenase-2 selective inhibitors have become the main direction of research on anti-inflammatory drugs. Gentiopicroside is a novel selective inhibitor of cyclooxygenase-2 from Chinese herbal medicine. However, it is highly hydrophilic owing to the presence of the sugar fragment in its structure that reduces its oral bioavailability and limits efficacy. This study aimed to design and synthesize novel cyclooxygenase-2 inhibitors by modifying gentiopicroside structure and reducing its polarity. Materials and Methods: We introduced hydrophobic acyl chloride into the gentiopicroside structure to reduce its hydrophilicity and obtained some new derivatives. Their in vitro anti-inflammatory activities were evaluated against NO, TNF-α, PGE2, and IL-6 production in the mouse macrophage cell line RAW264.7 stimulated by lipopolysaccharide. The in vivo inhibitory activities were further tested against xylene-induced mouse ear swelling. Molecular docking predicted that whether new compounds could effectively bind to target protein cyclooxygenase-2. The inhibitory activity of new compounds to cyclooxygenase-2 enzyme were verified by the in vitro experiment. Results: A total of 21 novel derivatives were synthesized, and exhibit lower polarities than the gentiopicroside. Most compounds have good in vitro anti-inflammatory activity. The in vivo activity results demonstrated that 8 compounds were more active than gentiopicroside. The inhibition rate of some compounds was higher than celecoxib. Molecular docking predicted that 6 compounds could bind to cyclooxygenase-2 and had high docking scores in accordance with their potency of the anti-inflammatory activity. The confirmatory experiment proved that these 6 compounds had significant inhibitory effect against cyclooxygenase-2 enzyme. Structure-activity relationship analysis presumed that the para-substitution with the electron-withdrawing groups may benefit the anti-inflammatory activity. Conclusion: These gentiopicroside derivatives especially PL-2, PL-7 and PL-8 may represent a novel class of cyclooxygenase-2 inhibitors and could thus be developed as new anti-inflammatory agents.

Quantitative Analysis of the Multicomponent and Spectrum-Effect Correlation of the Antispasmodic Activity of Shaoyao-Gancao Decoction.

Shaoyao-Gancao Decoction (SGD) is a well-known classic traditional Chinese medicine (TCM) with antispasmodic, anti-inflammatory, and analgesic effects. This preparation has been widely used to treat spasticity diseases in the clinic. To date, the material basis of SGD remains unclear, and the spectrum-effect correlation of its antispasmodic activity has not been reported yet. In this study, high-performance liquid chromatography (HPLC) was used to establish the fingerprint and determine the multiple components of SGD. The common peaks of fingerprints were evaluated by the similarity with the chromatographic fingerprints of the TCM. Meanwhile, the multiple components were quantified and analysed using the heatmap and box size analysis. Furthermore, data on the antispasmodic effect were extracted through in vitro smooth muscle contraction assay. Grey relational analysis combined with partial least square regression was used to study the spectrum-effect correlation of SGD. Finally, the potential antispasmolytic components were validated using an isolated tissue experiment. The HPLC fingerprint was established, and 20 common peaks were identified. The similarities of 15 batches of SGD were all above 0.965. The HPLC method for simultaneous determination of the multiple components was accurate and reliable. The contents of albiflorin, paeoniflorin, liquiritin, and glycyrrhizic acid were higher than the other components in SGD. The heatmap and box size also showed that X3 (albiflorin), X4 (paeoniflorin), X5 (liquiritin), X11 (liquirtigenin), and X16 (glycyrrhizic acid) could be used as quality indicators in the further establishment of quality standards. The spectrum-effect correlation results indicated that X4, X11, and X16 were highly correlated with antispasmolytic activity. Verification tests showed that paeoniflorin (11.7-29.25 µg/mL) and liquirtigenin (17.19-28.65 µg/mL) could significantly reduce the maximum contractile (P < 0.01). These compounds exerted concentration-dependent spasmolytic effects with the inhibitory response for acetylcholine (Ach)-evoked contraction. Thus, SGD had a significant antispasmodic effect, which resulted from the synergistic activity of its multiple components. These findings can be used for the pharmacodynamics study of SGD and are of great significance for the determination of quality markers and quality control.

Synthesis, and anti-inflammatory activities of gentiopicroside derivatives.

A series of 26 novel derivatives have been synthesized through structural modification of gentiopicroside, a lead COX-2 inhibitor. And their in vivo and in vitro anti-inflammatory activities have been investigated. The in vitro anti-inflammatory activities were evaluated against NO, PGE2, and IL-6 production in the mouse macrophage cell line RAW264.7 stimulated by LPS. Results showed that most compounds had good inhibitory activity. The in vivo inhibitory activities were further tested against xylene-induced mouse ear swelling. Results demonstrated that several compounds were more active than the parent compound gentiopicroside. The inhibition rate of the most active compound P23 (57.26%) was higher than positive control drug celecoxib (46.05%) at dose 0.28 mmol·kg-1. Molecular docking suggested that these compounds might bind to COX-2 and iNOS. Some of them, e.g P7, P14, P16, P21, P23, and P24, had high docking scores in accordance with their potency of the anti-inflammatory activitiy, that downregulation of the inflammatory factors, NO, PGE2, and IL-6, was possibly associated with the suppression of iNOS and COX-2. Therefore, these gentiopicroside derivatives may represent a novel class of COX-2 and iNOS inhibitors.

Recent advances in research on vine tea, a potential and functional herbal tea with dihydromyricetin and myricetin as major bioactive compounds.

Vine tea has been used as an herbal tea by several ethnic minorities for hundreds of years in China. Flavonoids, a kind of indispensable component in a variety of nutraceutical, pharmaceutical and cosmetic applications, are identified to be the major metabolites and bioactive ingredients in vine tea. Interestingly, vine tea exhibits a wide range of significant bioactivities including anti-oxidant, anti-inflammatory, anti-tumor, antidiabetic, neuroprotective and other activities, but no toxicity. These bioactivities, to some extent, enrich the understanding about the role of vine tea in disease prevention and therapy. The health benefits of vine tea, particularly dihydromyricetin and myricetin, are widely investigated. However, there is currently no comprehensive review available on vine tea. Therefore, this report summarizes the most recent studies investigating bioactive constituents, pharmacological effects and possible mechanisms of vine tea, which will provide a better understanding about the health benefits and preclinical assessment of novel application of vine tea.

Recent advances in research on vine tea,a potential and functional herbal tea with dihydromyricetin and myricetin as major bioactive compounds / 药物分析学报

Vine tea has been used as an herbal tea by several ethnic minorities for hundreds of years in China.Flavonoids,a kind of indispensable component in a variety of nutraceutical,pharmaceutical and cosmetic applications,are identified to be the major metabolites and bioactive ingredients in vine tea.Interest-ingly,vine tea exhibits a wide range of significant bioactivities including anti-oxidant,anti-inflammatory,anti-tumor,antidiabetic,neuroprotective and other activities,but no toxicity.These bioactivities,to some extent,enrich the understanding about the role of vine tea in disease prevention and therapy.The health benefits of vine tea,particularly dihydromyricetin and myricetin,are widely investigated.However,there is currently no comprehensive review available on vine tea.Therefore,this report summarizes the most recent studies investigating bioactive constituents,pharmacological effects and possible mechanisms of vine tea,which will provide a better understanding about the health benefits and preclinical assessment of novel application of vine tea.

Simultaneous determination of five bioactive components of Gancao in rat plasma by UHPLC-MS/MS and its application to comparative pharmacokinetic study of incompatible herb pair Gansui-Gancao and Gansuibanxia Decoction.

Incompatible herb pair Gansui-Gancao is recorded in "eighteen incompatible" medicaments in many monographs of TCM (Traditional Chinese Medicine) which means the two herbs can not be co-used in most cases. However, Gansuibanxia decoction composed of Gansui(Kansui), Banxia(Pinellia), Shaoyao(Peony) and Gancao(Liquorice) is a traditional Chinese formula which has been clinically employed for the treatment of cancerous ascites, pleural effusion, peritoneal effusion, etc. The purpose of the study was to investigate the pharmacokinetics of main bioactive components in Gancao to explore the reasons why Gansui-Gancao can be used in Gansuibanxia decoction. A simple, rapid and sensitive UHPLC-MS/MS method for simultaneous determination of liquiritigenin, isoliquiritigenin, liquiritin, glycyrrhetinic acid and glycyrrhizic acid of liquorice in rat plasma was developed and validated. After extraction from plasma, the analytes and internal standard were separated on a C18 column with the mobile phase consisting of 0.1% acetic acid containing 0.2 mM ammonium acetate in water and acetonitrile via gradient elution. The electrospary ionization source was adopted under the multiple reaction monitoring mode. The method was succesfully applied to a comparative pharmacokinetic study of main bioactive components of Gancao in rat plasma after oral administration of the extracts of Gancao (GC), Gansui-Gancao (GS-GC), Shaoyao-Gancao (SY-GC), Gansui-Shaoyao-Gancao (GS-SY-GC) and Gansuibanxia decoction (GSBXD), respectively. The pharmacokinetic parameters had significant differences (P < 0.05) in different groups which showed that Gansui decreased the bioavailability of Gancao, while Shaoyao increased the bioavailability of Gancao. Hence, these may be the pharmacokinetic mechanism of incompatible herb pair Gansui-Gancao and the reasons why the herb pair can be used in Gansuibanxia decoction.

Simultaneous identification and quantification of the common compounds of Viscum coloratum and its corresponding host plants by ultra-high performance liquid chromatography with quadrupole time-of-flight tandem mass spectrometry and triple quadrupole mass spectrometry.

Viscum coloratum is a perennial evergreen, semi-parasitic plant. It is generally used for treating cardiovascular diseases, cancer, hepatitis and hemorrhage. In this study, reliable methods were developed for the qualitative and quantitative analysis of the common constituents in Viscum coloratum and its corresponding host. In the rapid qualitative analysis, a method of ultra-high performance liquid chromatography and quadrupole time-of-flight tandem mass spectrometry was established for identification of the same compounds. Based on the retention times, accurate mass measurement and previous literatures, 23 components were clearly identified by comparison with reference substances. In the quantitative analysis, a method for Viscum coloratum and its corresponding host was developed by ultra-high performance liquid chromatography with triple quadrupole mass spectrometry. 13 common compounds of viscum coloratum and host plants from 19 batches were analyzed with a good linearity (r2≥0.9991), intra-day precision (RSD≤3.24%), inter-day precision (RSD≤3.31%), repeatability (RSD≤2.43%), stability (RSD≤2.63%), and recovery (98.2-102.4%). The overall limits of quantification were less than 5.0ng/mL. The results indicated that these effective and comprehensive methods can be applicable to simultaneous qualitative and quantitative analysis of these common compounds presented in Viscum coloratum and corresponding host plants.

Plasma Pharmacokinetics, Bioavailability, and Tissue Distribution of Four C-Glycosyl Flavones from Mung Bean (Vigna radiata L.) Seed Extracts in Rat by Ultrahigh-Performance Liquid Chromatography-Tandem Mass Spectrometry.

The main polyphenols in mung bean (Vigna radiata L.) seed (MBS), an edible legume with various biological activities, are C-glycosyl flavones (vitexin, isovitexin, isovitexin-6″-O-α-l-glucoside, and dulcinoside). In our study, a validated ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed to quantitate the concentrations of four C-glycosyl flavones from MBS extracts in the plasma and various tissues of rats and successfully applied to study their pharmacological profile and tissue distribution in vivo. Four C-glycosyl flavones were rapidly absorbed after oral administration, achieving a Cmax at around 1.5 h, and they could be distributed widely and rapidly in tested tissues. The concentrations of four C-glycosyl flavones in all of the tested tissues decreased obviously in 4 h, which indicated that there was not a trend of long-term accumulation of them. This is the first time to report on pharmacokinetic and tissue distribution studies of four C-glycosyl flavones in rat. The results provided a significative basis for the application of MBS.

Anesthetic constituents of Zanthoxylum bungeanum Maxim.: A pharmacokinetic study.

A sensitive and selective ultra high performance liquid chromatography with tandem mass spectrometry method was established and validated for the simultaneous determination of hydroxy-α-sanshool, hydroxy-ß-sanshool, and hydroxy-γ-sanshool in rat plasma after the subcutaneous and intravenous administration of an extract of the pericarp of Zanthoxylum bungeanum Maxim. Piperine was used as the internal standard. The analytes were extracted from rat plasma by liquid-liquid extraction with ethyl acetate and separated on a Thermo Hypersil GOLD C18 column (2.1 mm × 50 mm, 1.9 µm) with a gradient elution system at a flow rate of 0.4 mL/min. The mobile phase consisted of acetonitrile/0.05% formic acid in water and the total analysis time was 4 min. Positive electrospray ionization was performed using multiple reaction monitoring mode for the analytes. The calibration curves of the three analytes were linear over the tested concentration range. The intra- and interday precision was no more than 13.6%. Extraction recovery, matrix effect, and stability were satisfactory in rat plasma. The developed and validated method was suitable for the quantification of hydroxy-α-sanshool, hydroxy-ß-sanshool, and hydroxy-γ-sanshool and successfully applied to a pharmacokinetic study of these analytes after subcutaneous and intravenous administration to rats.

Simultaneous determination of cinnamaldehyde, cinnamic acid, and 2-methoxy cinnamic acid in rat whole blood after oral administration of volatile oil of Cinnamoni Ramulus by UHPLC-MS/MS: An application for a pharmacokinetic study.

A simple and rapid ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed for the simultaneous determination of cinnamaldehyde, cinnamic acid, and 2-methoxy cinnamic acid in rat whole blood. It was the first time to study the pharmacokinetics of 2-methoxy cinnamic acid in rat whole blood. Samples were processed by a one-step protein precipitation with acetonitrile-37% formaldehyde (90:10, v:v). Chromatographic separation was performed on a Thermo Scientific C18 column (2.1mm×50mm, 1.9µm) at room temperature. The total run time was 4min. The detection was accomplished by using positive and negative ion electrospray ionization in multiple reaction monitoring mode. The method was linear for all of the analytes over 1000 times concentration range with correlation coefficients greater than 0.99. The lower limits of quantification (LLOQ) were 0.1ng/mL for cinnamaldehyde, 5.8ng/mL for cinnamic acid, and 10ng/mL for 2-methoxy cinnamic acid, respectively. To our knowledge, this was the first time that the LLOQ for cinnamaldehyde in validated methods for biological samples was as low as 0.1ng/mL. Intra- and inter-day precision and accuracy were within ±9% for all of the analytes during the assay validation. Assay recoveries were higher than 80% and the matrix effects were minimal. The half-life were 8.7±0.7h for cinnamaldehyde, 1.0±0.5h for cinnamic acid, and 1.4±0.4h for 2-methoxy cinnamic acid, respectively. The validated assay was firstly applied to the simultaneous quantification of cinnamaldehyde, cinnamic acid, and 2-methoxy cinnamic acid, especially for 2-methoxy cinnamic acid in rat whole blood after oral administration of 15mg/kg essential oil of Cinnamoni Ramulus. It was observed that the Cmax and AUC of 2-methoxy cinnamic acid (0.01% in essential oil of Cinnamoni Ramulus) were greater than those of cinnamaldehyde (83.49% in essential oil of Cinnamoni Ramulus), which implied that 2-methoxy cinnamic acid might be the major bioactive constitutes in essential oil of Cinnamoni Ramulus.

Simultaneous determination and pharmacokinetic study of Atractylenolide I, II and III in rat plasma after intragastric administration of Baizhufuling extract and Atractylodis extract by UPLC-MS/MS.

A simple and rapid ultra high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the simultaneous determination of Atractylenolide I, II and III in rat plasma. Plasma samples were processed by liquid-liquid extraction with ethyl acetate, using schisandrin as internal standard (IS). Chromatographic separation was accomplished on a Thermo Hypersil GOLD C18 column (2.1mm×50mm, 1.9µm) with mobile phase consisting of acetonitrile and 0.1% formic acid-water (50:50, v/v). The detection was carried out by ESI-MS (positive ionization mode) and low-energy collision dissociation tandem mass spectrometric analyses using the multiple-reaction monitoring (MRM) scan mode. The quantification was performed using the transitions of the protonated molecule→product ion at m/z 231.0→185.1 for Atractylenolide I, at m/z 233.1→187.1 for Atractylenolide II and at m/z 249.1→231.1 for Atractylenolide III, respectively. Method validation revealed excellent linearity over investigated range together with satisfactory intra- and inter-day precision, accuracy, matrix effects and extraction recoveries. This method was successfully applied to the comparative pharmacokinetic study of Atractylenolide I, II and III in rat plasma after intragastric administration of Baizhufuling extract and Atractylodis extract.