Bacterial neuraminidase inhibitory chalcones from flowers of Coreopsis lanceolata, their kinetic characterization and antibiofilm effect.

BACKGROUND: Bacteria within biofilms are thousand times more resistant to antibiotics. Neuraminidase is a crucial enzyme for bacterial adhesion and biofilm formation, it hydrolyzes glycosidic residue of glycoproteins, glycolipids, and oligosaccharides. Coreopsis lanceolata L. flowers may have a significant potential of bacterial neuraminidase (BNA) inhibition because of high natural abundance of chalcones. PURPOSE: The investigation of bacterial biofilm inhibitors has emerged as a novel therapeutic strategy against antibiotic resistance. Therefore, individual chalcones were isolated from C. lanceolata and their capacity to inhibit BNA and formation of Escherichia coli biofilm were evaluated. METHODS: Different chromatographic techniques were used to isolate the compounds (1-12). Enzyme inhibition and detailed kinetic behavior of compounds was determined by estimation of kinetic parameters (Michaelis-Menten constants (Km), maximum velocity (Vmax), dissociation constant for binding with the free enzyme (KI) and enzyme-substate complex (KIS)). Binding affinities (KSV) and binding modes of inhibitors were elucidated by fluorescence quenching and molecular docking, respectively. The natural abundance of chalcones was established through UPLC-Q-TOF/MS. The most potent inhibitor (1) was tested for its ability to inhibit the formation of E. coli biofilm, which was examined by crystal violet assay, scanning electron microscope (SEM) and confocal laser scanning microscope (CLSM). RESULTS: A series of eight chalcones (1-8) and four chalcone glucosides (9-12), inhibited BNA in a dose-dependent manner with IC50 of 8.3 ∼ 77.0 µM. The most potent chalcones were butein (1, IC50 = 8.3 µM) and its glucoside 9 (IC50 = 13.8 µM). The aglycones (1-8) showed non-competitive inhibition, while chalcone glucosides (9-12) displayed a mixed type I (KI < KIS). Inhibitory behaviors were doubly confirmed by KSV and matched with tendency of IC50. The functional group responsible for BNA inhibition were disclosed as 4'-hydroxyl group on B-ring by structure activity relationship (SAR) and molecular docking experiments. Butein (1) suppressed E. coli biofilm formation by > 50 % at 100 µM according to crystal violet assay, which was confirmed by SEM and CLSM imaging. CONCLUSION: The results showed that chalcones (1-8) and chalcone glucosides (9-12), metabolites isolated from the flowers of C. lanceolata, had BNA inhibitory and antibiofilm formation effect on E. coli.

UPLC-quadrupole time-of-flight-tandem mass spectrometry combined with chemometrics and network pharmacology to differentiate Coreopsis tinctoria Nutt.

Coreopsis tinctoria Nutt. (C. tinctoria) is a traditional medicinal plant, primarily found in plateau areas with altitudes exceeding 3000 m. The efficacy of C. tinctoria appears to be intricately tied to its quality. However, there is a scarcity of studies focused on evaluating the quality of C. tinctoria from diverse geographical locations. In this study, we used ultra-performance liquid chromatography-quadrupole time-of-flight-tandem mass spectrometry to analyze and identify the prevalent chemical components in 12 batches of C. tinctoria sourced from Xinjiang, Qinghai, Tibet, and Yunnan provinces in China. By using cluster analysis and discriminant analysis of partial least squares, we assessed the similarity and identified varying components in the 12 batches of C. tinctoria. Subsequently, their quality was further evaluated. Utilizing network pharmacology, we identified potential active components for the treatment of diabetes mellitus. The findings revealed the presence of 16 flavonoids, 3 phenylpropanes, 2 sugars, 2 amino acids, and 7 hydrocarbons in the analyzed samples. Through variable importance screening, 17 constituents were identified as quality difference markers. Marein and flavanomarein emerged as pivotal markers, crucial for distinguishing variations in C. tinctoria. In addition, network pharmacology predicted 187 targets for 9 common active components, including marein and flavanomarein. Simultaneously, 1747 targets related to diabetes mellitus were identified. The drug-component-disease target network comprised 91 nodes and 179 edges, encompassing 1 drug node, 9 component nodes, and 81 target nodes. In summary, marein and flavanomarein stand out as key biomarkers for assessing the quality of C. tinctoria, offering a scientific foundation for the quality evaluation of C. tinctoria Nutt.

Aromatase inhibitors isolated from a flowering tea, snow Chrysanthemum (the capitula of Coreopsis tinctoria Nutt.).

Methanol extract from the capitula of Coreopsis tinctoria Nutt. (Asteraceae), which is also known as a flowering tea or blooming tea "Snow Chrysanthemum," was found to inhibit the enzymatic activity of aromatase. A total of 24 known isolates (1-24) were identified from the extract, including three chalcones (1-3), an aurone (4), five flavanones (5-9), four flavanols (10-13), a flavonol (14), and two biflavanones (15, 16). Among them, okanin (1, Ki = 1.6 µM), (2S)-naringenin (5, 0.90 µM), isookanin (6, 0.81 µM), (2S)-7,3',5'-trihydroxyflavaone (7, 0.13 µM), and (2S)-5,7,3',5'-tetrahydroxyflavanone (8, 0.32 µM) exhibited relatively potent competitive inhibition. Specifically, the isolates 7 and 8, having a common 3',5'-resorcinol moiety at the B ring in their flavanone skeleton, exhibited potent inhibitory activities compared to those of a clinically applied aminoglutethimide (0.84 µM) and naturally occurring flavone, chrysin (0.23 µM), which is a common non-steroidal aromatase inhibitor. Importantly, the active flavonoid constituents (1 and 5-8) did not inhibit the activity of 5α-reductase enzyme, which normally reacts with the same substrate "testosterone," thus, these compounds were suggested to be specific to aromatase.

Lanceolanone A, a new biflavanone, and a chalcone glucoside from the flower heads of Coreopsis lanceolata and their aldose reductase inhibitory activity and AMPK activation.

The MeOH extract of the flower heads of Coreopsis lanceolata L. (Asteraceae) exhibited aldose reductase (AR) inhibitory activity (IC50 8.36 µg/mL). Bioassay-guided fractionation of the extract resulted in the isolation of a new biflavanone-named Lanceolanone A (1) and a chalcone glucoside (6), along with 12 known compounds (2-5 and 7-14), of which 4, 7, 9, 10, and 12 were isolated from C. lanceolata for the first time. The structures of the new compounds (1 and 6) were determined by extensive spectroscopic analysis, including two-dimensional (2D) NMR, and ECD calculation method. Compounds 2, 4, 11, 13, and 14 exhibited AR inhibitory activities with IC50 values between 2.40 and 9.99 µM. Furthermore, 8-13 at 1.0 mM activated AMPK expression in HepG2 human hepatoma cells compared to the control.

Metabolomics study of flavonoids in Coreopsis tinctoria of different origins by UPLC-MS/MS.

To analyze the flavonoids in Coreopsis tinctoria and compare the differences in flavonoids among C. tinctoria of different origins, the chemical composition of C. tinctoria capitulum was analyzed by ultra-high-performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS), and the flavonoid metabolites were analyzed and identified based on their retention time, mass-to-charge ratio and fragment ions in the UPLC-QTOF-MS matrix. Capitulum samples of C. tinctoria were collected from three locations in the Xinjiang region at different altitudes. A total of 204 flavonoid compounds were identified, and 31 different flavonoid metabolites were then identified from flowers of C. tinctoria of different origins. Further analysis of these 31 significantly accumulated metabolites identified seven flavonoid metabolites, namely, homoplantaginin, kaempferol, quercetin, isorhamnetin, avicularin, quercetin 3-O-(6'-galloyl)-ß-D-galactopyranoside and isorhamnetin 3-O-glucoside, with high accumulation only in sample collected from Tashkurgan Tajik (TX) and low expression in sample collected from Yutian County (YT) and Shaya County (SY). Moreover, 7,4'-dihydroxyflavone and 4,4'-dimethoxychalcone showed high accumulation only in SY, and afzelin was specifically highly accumulated in YT. In addition, the identified flavonoid metabolites were annotated using the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, and key pathways that might regulate the biosynthesis of these flavonoid compounds were analyzed. These findings provide key information for research on flavonoids and their biosynthesis in C. tinctoria and will provide a theoretical basis for studying the herbal quality and origin of C. tinctoria.

Antioxidant properties of polyphenols from snow chrysanthemum (Coreopsis tinctoria) and the modulation on intestinal microflora in vitro.

CONTEXT: Coreopsis tinctoria Nutt (Asteraceae), named snow chrysanthemum, is known to have a high level of polyphenols. However, the potential prebiotic effect on modulating intestinal microflora is still unclear. OBJECTIVE: The chemical composition, antioxidant properties of snow chrysanthemum polyphenols (SCPs) and their effects on human intestinal microbiota were investigated. MATERIALS AND METHODS: SCPs were extracted using ultrasonic-assisted extraction, and further determined using UPLC-QE Orbitrap/MS. Five assays were used to investigate the antioxidant activities of SCPs. Subsequently, the effects of SCPs on intestinal microbiota in vitro were determined by high throughput sequencing and bioinformatics analysis. RESULTS: Marein, isookanin and cymaroside were the major phenolic compounds, which accounted for 42.17%, 19.53% and 12.25%, respectively. Marein exhibited higher scavenging capacities in DPPH (EC50 = 8.84 µg/mL) and super anion radical assay (EC50 = 282.1 µg/mL) compared to cymaroside and isookanin. The antioxidant capacity of cymaroside was weakest among the three phenolic compounds due to the highest EC50 values, especially for superoxide anion radical assay, EC50 > 800 µg/mL. The result of in vitro fermentation showed that the three phenolic compounds increased the relative abundances of Escherichia/Shigella, Enterococcus, Klebsiella, etc., and isookanin notably increased the relative abundance of Bifidobacterium and Lactobacillus. DISCUSSION AND CONCLUSIONS: SCPs exhibited antioxidant properties and potential prebiotic effects on modulating the gut microbiota composition. The findings indicated that SCPs consumption could exert prebiotic activity that is beneficial for human health.

Study on the metabolism profile of flavanomarein in Coreopsis tinctoria Nutt.

Coreopsis tinctoria Nutt. (family Asteraceae) is a popular medicine-food plant, which improves chronic diseases such as hyperlipemia, hypertension, and diabetes. Flavanomarein is the main active component of Coreopsis tinctoria Nutt, in which the blood concentration of volunteers is low and bioavailability is poor. Thus, the understanding of flavanomarein metabolites and metabolic pathways is significant to clarify its effectiveness. This study systematically studied the metabolites of flavanomarein by oral and injection. The biological samples (feces, urine, and plasma) were analyzed by ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry in negative ion mode. The metabolic law of flavanomarein in the liver was further verified by a liver microsomal incubation experiment in vitro. A total of 12 metabolites were identified by oral administration while 15 metabolites were detected by injection. It was shown that metabolic pathways include acetylation, hydroxylation, glucuronidation, methylation, dehydrogenation, and so forth. The liver extraction rate of flavanomarein was 0.08, which means the metabolic stability of flavanomarein is well in rats' liver microsomes. It is a systematic study on the metabolism of flavanomarein and provides a metabolic rationale for further in-depth in vivo biotransformation.

Simultaneous Determination and Comparison of Phenolic Bioactives among Three Main Kinds of Edible Chrysanthemums.

In this study, we report a simple and reliable high-performance liquid chromatography coupled with diode array detection method for simultaneous and quantitative analysis and comparison of major phenolic compounds dominant phytochemicals in Chrysanthemum morifolium, Florists chrysanthemum and snow chrysanthemum (Coreopsis tinctoria or C. tinctoria). The chromatographic separation was achieved using a reversed phase C18 column with a mobile phase of water [containing 0.1% trifluoroacetic acid (TFA)] and acetonitrile. The major phenolic compounds were completely separated within 16 min at a flow rate of 1.0 mL/min. Flavonoid and phenolic acid profiles of the ethanol extracts of the three flowers were analyzed. The results revealed that C. tinctoria possessed the highest amount of flavonoids (flavanomarein, flavanokanin, marein and okanin) and relative lower content of phenolic acid (chlorogenic acid and 3,5-dicafeoylquinic acid). The total content of the four flavonoids in C. tinctoria reached 53.99 ± 1.32 mg/g. In particular, the marein content in C. tinctoria was as high as 36.50 mg/g. Flavanomarein was only detected in C. tinctoria, whereas chlorogenic acid and 3,5-dicafeoylquinic acid were abundant in Chrysanthemum morifolium and Florists chrysanthemum. The content of marein in Chrysanthemum morifolium was slightly higher than that in Florists chrysanthemum, whereas no okanin was detected in Florists chrysanthemum under these high-performance liquid chromatography conditions. The results indicated phenolic components differ significantly depending on the cultivar, especially between C. tinctoria and common commercially available chrysanthemums. The method adopted in this study is helpful for quality control of different chrysanthemum species as well as their products, which is essential for usage and functionality clarification.

Mechanisms of Coreopsis tinctoria Nutt in the treatment of diabetic nephropathy based on network pharmacyology analysis of its active ingredients / Mecanismos de Coreopsis tinctoria Nutt. En el tratamiento de la nefropatía diabética basado en el análisis farmacológico de red de sus principios activos

SUMMARY: Coreopsis tinctoria Nutt. (C. tinctoria Nutt.) can protect diabetic kidneys, but the mechanisms are unclear. This work is to investigate the potential mechanisms of C. tinctoria Nutt. in the treatment of diabetic nephropathy based on network pharmacology analysis of its active ingredients. Twelve small molecular compounds of C. tinctoria Nutt. and targets related to diabetic nephropathy were docked by Discovery Studio 3.0. DAVID database was used for GO enrichment and KEGG pathway analysis. Cytoscape 3.6.1 was used to construct active ingredient-target network. Cell viability was detected with MTT. Glucose consumption was analyzed with glucose oxidase method. Protein expression was measured with Western blot and immunofluorescence. Electron microscopy observed autophagosomes. The core active ingredients of C. tinctoria Nutt. included heriguard, flavanomarein, maritimein, and marein. Twenty-one core targets of the 43 potential targets were PYGM, TLR2, RAF1, PRKAA2, GPR119, INS, CSF2, TNF, IAPP, AKR1B1, GSK3B, SYK, NFKB2, ESR2, CDK2, FGFR1, HTRA1, AMY2A, CAMK4, GCK, and ABL2. These 21 core targets were significantly enriched in 50 signaling pathways. Thirty- four signaling pathways were closely related to diabetic nephropathy, of which the top pathways were PI3K/AKT, insulin, and mTOR, and insulin resistance. The enriched GO terms included biological processes of protein phosphorylation, and the positive regulation of PI3K signaling and cytokine secretion; cellular components of cytosol, extracellular region, and extracellular space; and molecular function of protein kinase activity, ATP binding, and non-membrane spanning protein tyrosine kinase activity. In vitro experiments found that marein increased the expression of phosphorylated AKT/AKT in human renal glomerular endothelial cells of an insulin resistance model induced by high glucose, as well as increased and decreased, respectively, the levels of the microtubule-associated proteins, LC3 and P62. C. tinctoria Nutt. has many active ingredients, with main ingredients of heriguard, flavanomarein, maritimein, and marein, and may exert anti-diabetic nephropathy effect through various signaling pathways and targets.

RESUMEN: Coreopsis tinctoria Nutt. (C. tinctoria Nutt.) puede proteger riñones diabéticos, sin embargo los mecanismos son desconocidos. Este trabajo se realizó para investigar los potenciales mecanismos de C. tinctoria Nutt. en el tratamiento de la nefropatía diabética basado en el análisis de farmacología en red de sus principios activos. Doce compuestos moleculares pequeños de C. tinctoria Nutt. y los objetivos relacionados con la nefropatía diabética fueron acoplados por Discovery Studio 3.0. La base de datos DAVID se utilizó para el enriquecimiento GO y el análisis de la vía KEGG. Se usó Cytoscape 3.6.1 para construir una red de ingrediente-objetivo activa. La viabili- dad celular se detectó mediante MTT. El consumo de glucosa se analizó con el método de glucosa oxidasa. La expresión proteica fue determinada mediante Western blot e inmunofluorescencia. En la microscopía electrónica se observó autofagosomas. Los principales ingredientes activos de C. tinctoria Nutt. incluyeron heriguard, flavanomarein, maritimin y marein. Veintiún de los 43 objetivos potenciales fueron PYGM, TLR2, RAF1, PRKAA2, GPR119, INS, CSF2, TNF, IAPP, AKR1B1, GSK3B, SYK, NFKB2, ESR2, CDK2, FGFR1, HTRA1, AMY2A, CAMK4, GCK y ABL2. Estos 21 objetivos principales se enriquecieron significativamente en 50 vías de señalización. Treinta y cuatro vías de señalización estuvieron estrechamente relacionadas con la nefropatía diabética, de las cuales las principales vías fueron PI3K/ AKT, insulina y mTOR, y resistencia a la insulina. Los términos GO enriquecidos incluyeron procesos biológicos de fosforilación proteica, la regulación positiva de la señalización de PI3K y la secreción de citoquinas; componentes celulares del citosol, región extracelular y espacio extracelular; y la función molecular de la actividad de la proteína quinasa, la unión de ATP y la actividad de la proteína tirosina quinasa que no se extiende por la membrana. Los experimentos in vitro encontraron que la mareína aumentaba la expresión de AKT/AKT fosforilada en células endoteliales glomerulares renales humanas en un modelo de resistencia a la insulina inducida por niveles elevados de glucosa, así como aumentaron y disminuyeron respectivamente, los niveles de las proteínas asociadas a los microtúbulos, LC3 y P62. C. tinctoria Nutt. tiene muchos principios activos, con ingredientes principales de heriguard, flavanomarein, maritimain y marein, y puede ejercer un efecto de nefropatía antidiabética a través de distintass vías de señalización y objetivos.

Aurones and Flavonols from Coreopsis lanceolata L. Flowers and Their Anti-Oxidant, Pro-Inflammatory Inhibition Effects, and Recovery Effects on Alloxan-Induced Pancreatic Islets in Zebrafish.

(1) Background: Many flavonoids have been reported to exhibit pharmacological activity; a preparatory study confirmed that Coreopsis lanceolata flowers (CLFs) contained high flavonoid structure content; (2) Methods: CLFs were extracted in aqueous methanol (MeOH:H2O = 4:1) and fractionated into acetic ester (EtOAc), normal butanol (n-BuOH), and H2O fractions. Repeated column chromatographies for two fractions led to the isolation of two aurones and two flavonols; (3) Results: Four flavonoids were identified based on a variety of spectroscopic data analyses to be leptosidin (1), leptosin (2), isoquercetin (3), and astragalin (4), respectively. This is the first report for isolation of 2-4 from CLFs. High-performance liquid chromatography (HPLC) analysis determined the content levels of compounds 1-4 in the MeOH extract to be 2.8 ± 0.3 mg/g (1), 17.9 ± 0.9 mg/g (2), 3.0 ± 0.2 mg/g (3), and 10.9 ± 0.9 mg/g (4), respectively. All isolated compounds showed radical scavenging activities and recovery activities in Caco-2, RAW264.7, PC-12, and HepG2 cells against reactive oxygen species. MeOH extract, EtOAc fraction, and 1-3 suppressed NO formation in LPS-stimulated RAW 264.7 cells and decreased iNOS and COX-2 expression. Furthermore, all compounds recovered the pancreatic islets damaged by alloxan treatment in zebrafish; (4) Conclusions: The outcome proposes 1-4 to serve as components of CLFs in standardizing anti-oxidant, pro-inflammatory inhibition, and potential anti-diabetic agents.

Anti-Neuroinflammatory and Anti-Inflammatory Activities of Phenylheptatriyne Isolated from the Flowers of Coreopsis lanceolata L. via NF-κB Inhibition and HO-1 Expression in BV2 and RAW264.7 Cells.

Aging is associated with immune disregulation and oxidative stress which lead to inflammation and neurodegenerative diseases. We have tried to identify the anti-neuroinflammatory and anti-inflammatory components of Coreopsis lanceolata L. The dried flowers of C. lanceolata were extracted with 70% EtOH, and the obtained extract was divided into CH2Cl2, EtOAc, n-BuOH, and H2O fractions. The CH2Cl2 fraction was separated using silica gel and C-18 column chromatography to yield phenylheptatriyne (1), 2'-hydroxy-3,4,4'-trimethoxychalcone (2), and 4',7-dimethoxyflavanone (3). Additionally, the EtOAc fraction was subjected to silica gel, C-18, and Sephadex LH-20 column chromatography to yield 8-methoxybutin (4) and leptosidin (5). All the compounds isolated from C. lanceolata inhibited the production of nitric oxide (NO) in LPS-induced BV2 and RAW264.7 cells. In addition, phenylheptatriyne and 4',7-dimethoxyflavanone reduced the secretion of inflammatory cytokines, tumor necrosis factor alpha (TNF-α), and interleukin (IL)-6. Among them, phenylheptatriyne was significantly downregulated in the expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2). Subsequently, phenylheptatriyne also effectively inhibited nuclear factor-kappa B (NF-κB) activation in LPS-stimulated BV2 and RAW264.7 cells. Based on these results, the anti-neuroinflammatory effect of phenylheptatriyne isolated from C. lanceolata was confirmed, which may exert a therapeutic effect in treatment of neuroinflammation-related diseases.

Isolation, purification and structural characterization of two pectin-type polysaccharides from Coreopsis tinctoria Nutt. and their proliferation activities on RAW264.7 cells.

Coreopsis tinctoria Nutt. (C.tinctoria) is an annual herb of the Compositae family with many health benefits, such as clearing heat, antioxidant and anticancer activity. In this paper, two polysaccharides were isolated from C.tinctoria, named CTAP-1 and CTAP-2, respectively. Structure of CTAP-1and CTAP-2 were elucidated by high-performance gel permeation chromatography, chemical derivative analyses, GC-MS and NMR techniques. Results reveal that they both CTAP-1 and CTAP-2 consisted of predominant amounts of galacturonic acid residues along with small amounts of arabinose, rhamnose and galactose.Both them contain homogalacturonan and rhammnogalcturan I regions in different ratio, suggesting their pectin-type features. The proliferation activities of CTAP-1 and CTAP-2 on RAW264.7 cells in vitro were detected. Results show both them have the significant proliferation effect on RAW264.7 cells when the concentration from 40 to 200 µg/mL. Given their structural characteristics and proliferation activities, the pectins are expected to be potential natural immune modulators, which need further study.

Effects of ethyl acetate extract from Coreopsis tinctoria on learning and memory impairment in d-galactose-induced aging mice and the underlying molecular mechanism.

The aim of this study was to investigate the effects of ethyl acetate extract from Coreopsis tinctoria (EACC) on learning and memory impairment in d-galactose-induced aging mice and the underlying molecular mechanism. The composition of EACC was analyzed by UPLC-MS, and the targets and pathways of EACC to improve learning and memory impairment were predicted and analyzed by the network pharmacology method. A mouse aging model was established by subcutaneous injection of d-galactose in mice, and EACC and piracetam were given to the model mice by gavage to observe their behavioral changes and changes in their SOD and GSH-Px activities in MDA contents in their peripheral blood serum and in the contents of Glu and GABA in their brain tissues. Then the hippocampus of the three mice selected from each of the MOD group and EACC-H group was separated for RT-qPCR assay. The results of the animal experiments showed that EACC could improve the learning and memory impairment of model mice by affecting the level of oxidative stress enzymes in serum and the content of neurotransmitters in the brain tissue. The results of network pharmacology analysis showed that the EACC components corresponded to 74 learning and memory-related targets, of which 13 were enriched in the long-term potentiation pathway. The results of RT-qPCR showed that 12 of the 13 detected targets were consistent with the predicted targets, and 9 of them were located in the NMDA receptor-related pathway of the long-term potentiation process and the pathway played an important regulatory role. It is believed that EACC could improve the learning and memory impairment of d-galactose-induced aging mice by acting on the nine targets Grin1, Grin2a, Camk2a, Camk2b, Kras, Raf1, Mapk1, Mapk3 and Creb to affect the NMDA receptor-related pathway of long-term potentiation.

Marein ameliorates Ang II/hypoxia-induced abnormal glucolipid metabolism by modulating the HIF-1α/PPARα/γ pathway in H9c2 cells.

The objectives of this study were to investigate the effects of marein, a major bioactive compound in functional food Coreopsis tinctoria, in hypertrophic H9c2 cells. Treating angiotensin II/hypoxia-stimulated H9c2 cells with marein led to decreasing cell surface area, intracellular total protein, atrial natriuretic peptide, and free fatty acids levels, but increasing glucose level. Marein treatment decreased hypoxia inducible factor-1α (HIF-1α), peroxisome proliferator activated receptor γ (PPARγ), medium chain acyl-coenzyme A dehydrogenase, glucose transporter-4, and glycerol-3-phosphate acyltransferase protein expressions, and increased PPARα, fatty acid transport protein-1, carnitine palmitoyltransferase-1, and pyruvate dehydrogenase kinase-4 protein expressions. Similar results were observed in HIF-1α-overexpressing H9c2 cells, whereas these effects were abolished in siRNA-HIF-1α-transfected H9c2 cells. It was concluded that marein could ameliorate abnormal glucolipid metabolism in hypertrophic H9c2 cells, and the effects could be attributable to reduction of HIF-1α expression and subsequent regulation PPARα/γ-mediated lipogenic gene expressions.

Constituents of Coreopsis lanceolata Flower and Their Dipeptidyl Peptidase IV Inhibitory Effects.

A new polyacetylene glycoside, (5R)-6E-tetradecene-8,10,12-triyne-1-ol-5-O-ß-glucoside (1), was isolated from the flower of Coreopsis lanceolata (Compositae), together with two known compounds, bidenoside C (10) and (3S,4S)-5E-trideca-1,5-dien-7,9,11-triyne-3,4-diol-4-O-ß-glucopyranoside (11), which were found in Coreopsis species for the first time. The other known compounds, lanceoletin (2), 3,2'-dihydroxy-4-3'-dimethoxychalcone-4'-glucoside (3), 4-methoxylanceoletin (4), lanceolin (5), leptosidin (6), (2R)-8-methoxybutin (7), luteolin (8) and quercetin (9), were isolated in this study and reported previously from this plant. The structure of 1 was elucidated by analyzing one-dimensional and two-dimensional nuclear magnetic resonance and high resolution-electrospray ionization-mass spectrometry data. All compounds were tested for their dipeptidyl peptidase IV (DPP-IV) inhibitory activity and compounds 2-4, 6 and 7 inhibited DPP-IV activity in a concentration-dependent manner, with IC50 values from 9.6 to 64.9 µM. These results suggest that C. lanceolata flower and its active constituents show potential as therapeutic agents for diseases associated with type 2 diabetes mellitus.

Okanin in Coreopsis tinctoria Nutt is a major quorum-sensing inhibitor against Chromobacterium violaceum.

ETHNOPHARMACOLOGICAL RELEVANCE: Coreopsis tinctoria Nutt has various medical and functional properties and its flower is widely used as health-care tea to decrease blood glucose and to lower blood lipids. However, the quorum sensing (QS) inhibition activity of Coreopsis tinctoria Nutt flower remains unclear. AIM OF THE STUDY: To assess inhibitory activity against quorum sensing by Chromobacterium violaceum, to identify the chemical composition of the extracts and to disclose the action mechanism of separated compound. MATERIAL AND METHODS: Violacein inhibition assays were performed in 96-wells microplates. The compounds extracted from Coreopsis tinctoria Nutt flower were separated and purified by various chromatography techniques. Respectively, thin layer chromatography (TLC, GF254), mass spectrometer (Agilent 1100 Series LC/MSD Trap SL), Medium-pressure automatic purification system (Buscisepacore C 620, Switzerland), High performance liquid chromatography (HPLC, Shimadzu LC-20AD, Japan), Liquid preparation Chromatography (Waters2545, USA). The chemical structures were identified by nuclear magnetic resonance (NMR, Bruker AV-500, Germany) technique. The inhibitory mechanism of okanin against C. violaceum quorum sensing was detected by quantitative real-time PCR (qRT-PCR). RESULTS: Quorum sensing regulates production of bacterial virulence factors, thereby making it an intriguing target for attenuating bacterial pathogenicity. In this study, anti-QS activity of Coreopsis tinctoria Nutt methanol fraction (CTM) was investigated against C. violaceum ATCC12472. CTM showed an inhibitory effect on the QS-mediated virulence factors production such as violacein in C. violaceum without effect on growth rate. Also, okanin was isolated from CTM and its potential of anti-QS was confirmed after observing a significant reduction of violacein production in C. violaceum. An attempt was made to assess the effect of okanin on vioABCDE expression in C. violaceum to disclose acting mechanisms. CONCLUSIONS: The results of this study contribute to validate an inhibitory effect of Coreopsis tinctoria Nutt flower on quorum sensing by Chromobacterium violaceum and to determine the compound responsible for inhibition. Also, the inhibitory effect was achieved in tandem with the down-regulation of vio operon.

Protective Effects of Anthocyanins from Coreopsis tinctoria against Oxidative Stress Induced by Hydrogen Peroxide in MIN6 Cells.

Anthocyanins (AC) from Coreopsis tinctoria possesses strong antioxidant properties, while the effects of AC on cells damage induced by reactive oxygen species (ROS) in diabetes mellitus diseases progression have not been reported. The present study was carried out to evaluate the protective property of AC against cellular oxidative stress with an experimental model, H2 O2 -exposed MIN6 cells. AC could reverse the decrease of cell viability induced by H2 O2 and efficiently suppressed cellular ROS production and cell apoptosis. In addition, Real-time PCR and Western blot analyses indicated that AC could protect MIN6 cells against oxidative injury through increasing the translocation of Nrf2 into nuclear, decreasing the phosphorylation level of p38 and up-regulating the protein expression of antioxidant enzyme (SOD1, SOD2 and CAT). Thus, this study provides evidence to support the beneficial effect of AC in inhibiting MIN6 cells from H2 O2 -induced oxidative injury.

The chemical components of Coreopsis tinctoria Nutt. and their antioxidant, antidiabetic and antibacterial activities.

Seventeen compounds were isolated from the capitula of Coreopsis tinctoria Nutt. with various column chromatographic methods and semi-preparative HPLC. Their structures were identified by the spectroscopic data and comparison with literatures as 2'-hydroxy-4,4'-dimethoxy-chalcone; (1), isoliquiritigenin (2), eriodictyol (3), naringenin (4), maritimetin (5), butin (6), taxifolin (7), luteolin (8), 7,3',4'-trihydroxyflavone (9), 8,3',4'-trihydroxyflavone-7-O-ß-d-glucoside (10), quercetin (11), quercetagitin-7-O-ß-d-glucoside (12), quercetin-7-O-ß-d-glucoside (13), 3,4-dihydroxybenzoic acid (14), caffeic acid (15), coreoside B (16), and myo-inositol (17). Compounds 1, 4, 9, 10 and 17 were isolated from C. tinctoria Nutt. for the first time. Compounds 7 and 12 possessed the highest antioxidant activity (IC50 = 64.37 and 32.86 µg/ml, respectively) among the tested compounds (IC50 value of positive control was 5.34 µg/ml). Compound 7 exhibited potent PTP1B enzymatic inhibition with an IC50 value of 7.73 µg/ml (IC50 value of positive control is 1.46 µg/ml). Furthermore, compound 5 showed strong antibacterial activity against the Gram-positive bacterium, S. aureus.

Anti-Lipid Peroxidation, α-Glucosidase and α-Amylase Inhibitory Effects of the Extract of Capitula of Coreopsis tinctoria Nutt. and Protection Effects on High-Fat/High-Sugar and Streptozotocin-Induced Type 2 Diabetes in Mice.

Coreopsis tinctoria capitula (CTC) of the Compositae family has been used traditionally to treat various diseases in China, particularly type 2 diabetes mellitus (T2DM). This study evaluated the anti-lipid peroxidation, α-glucosidase and α-amylase inhibitory effects of CTC extracts, and analyzed its chemical composition by HPLC. Moreover, the antioxidant activity and protection effects of CTC extracts were investigated on high-fat/high-sugar and streptozotocin-induced T2DM mice. In vitro study, the ethyl acetate extract (EAE) and butanol extract (BE) of CTC exhibited anti-lipid peroxidation (IC50 : BHA>BE or EAE>ascorbic acid, p<0.05) and α-glucosidase inhibitory activity (IC50 : BE>EAE, p<0.05). In vivo, the BE at the dose of 600 mg/kg was intragastrically given to T2DM mice, which exhibited a certain extent of repair and improvement of the levels of CAT, GSH, GSH-PX , SOD, as well as plasma biomarkers, compared with those in the model group (p<0.05). These results demonstrated that CTC extracts have a positive effect to treat T2DM and it can be used for the treatment of T2DM in the future.

[Protective Effect of a Dihydroflavonol Glycoside from Coreopsis tinctoria Nutt. in Mouse Model of Alcoholic Acute Pancreatitis].

OBJECTIVE: To investigate the protective effect of (2R, 3R)-dihydroquercetin 7-O-ß-D-glucopyranose (C1) extracted from Coreopsis tinctoria Nutt. in a mouse model of alcoholic acute pancreatitis (FAEE-AP) induced byfatty acid ethyl ester (FAEE). METHODS: The 30 healthy SPF mice were randomly divided into control group, model group, low dose group, middle dose group and high dose group, 6 in each group. Alcoholic pancreatitis was induced by ethanol and palmitoleic acid administration (1.75 g/kg ethanol, 200 mg/kg palmitoleic acid, 2 times peritoneal injections). The three treatment groups were given C1 (0 h, 4 h, 8 h) at the dose of 12.5, 25 and 50 mg/kg, respectively. After 24 h of molding, the serum amylase, lipase and IL-6 levels were detected. The trypsin level in pancreatic tissue and myeloperoxidase (MPO) level in pancreatic and lung tissue were detected. Hematoxylin-eosin (HE) staining was used to observe the pathological changes of pancreatic tissue and immunohistochemical (IHC) staining was used to detect the expression of nuclear factor-erythroid 2 related factor 2 (Nrf2) in pancreatic tissue. RESULTS: The pancreatic histopathological scores, serum amylase and lipase activity, trypsin level in pancreatic tissue, serum IL-6 level, MPO level of pancreas and lung were significantly higher in the model group than in the control group (P < 0.01). Compared with the model group, the pancreatic histopathologies of the low dose group was significantly improved (P < 0.05), as well as the serum amylase and lipase activity, trypsin level of pancreas, serum IL-6 level, the pancreas andthe lung's MPO level decreased significantly (P < 0.05), and up-regulate that expression of Nrf2 in pancreatic tissue. CONCLUSION: 12.5 mg/kg of (2R, 3R) -dihydroquercetin 7-O-ß-D-glucopyranose (C1) improved the expression of Nrf2, reduced the expression of inflammatory factor IL-6, and protected acute pancreatitis caused by FAEE.