Screening and identification of neuraminidase inhibitors from Baphicacanthus cusia by a combination of affinity ultrafiltration, HPLC-MS/MS, molecular docking, and fluorescent techniques.

Natural products provide a new opportunity for the discovery of neuraminidase (NA)inhibitors. In this study, an affinity ultrafiltration (AUF) coupled with HPLC-MS/MS method was firstly developed and optimized for screening of NA inhibitors from natural products. The critical factors influencing the interaction of enzyme-ligand (including sample concentration, enzyme concentration, incubation time and temperature, pH of the buffer, and dissociation solvents and time) were investigated and optimized by a one-factor-at-a-time design. The method was then applied to discover NA inhibitory compounds in stems and leaves of Baphicacanthus cusia. As a result, five active alkaloids were screened out and identifiedas 2,4(1H,3H)-quinazolinedione (1), 4(3H)-quinazolinone (2), 2(3H)-benzoxazolone (3), tryptanthrin (4), and indirubin (5) through analysis of their DAD profiles, MS/MS fragments, and comparison with reference substances. These active compounds were further evaluated for their NA inhibitory activity using a fluorescence-based NA inhibition assay. The result from the fluorescent assay revealed that all the five compounds(1-5) showed pronounced NA inhibitory activities with IC50values of 98.98, 64.69, 40.16, 69.44, and 144.73 µM, respectively. Finally, molecular docking of these five alkaloids with NA showed that hydrogen bond and π-cation interactions dominated within the binding sites with binding energies ranging between -5.7 to -7.9 kcal/mol, which was supported by the results of the AUF and the fluorescence-based enzyme assay. The developed AUF method is simple and efficient for screening potential NA inhibitors from stems and leaves of B. cusia.

The screening of lipase inhibitors based on the metal-organic framework Zeolitic Imidazolate Framework-8-immobilized enzyme microreactor.

An online capillary electrophoresis method based-lipase immobilized enzyme microreactor was developed for lipase kinetic study and inhibitor screening from compounds from natural products. Zeolitic Imidazolate Framework-8 (ZIF-8) has the advantages of large pore size, mild synthesis conditions and good biocompatibility. Lipase was immobilized on the inner wall of capillary with the help of the metal-organic framework ZIF-8. The results of electron microscopy showed that lipase could be aggregated and fixed on the inner wall of capillary by ZIF-8. After the experimental conditions including electrophoretic separation and enzymatic reaction were optimized, the baseline separation of substrate p-nitrophenyl acetate (pNPA) and product p-nitrophenol (pNP) was achieved within 3 min. The immobilized enzyme microreactor showed good repeatability and stability, and the determined Michaelis-Menten constant (Km) of lipase was 2.75 mM, which was lower than the kinetic constant determined in off-line reaction, indicating that the immobilized enzyme had a high affinity with the substrate. In addition, the IC50 value of the positive control compound orlistat on lipase inhibition was 7.26 nM, which was consistent with the literature. Then the inhibitory activity of 10 compounds from natural products on lipase was evaluated by the ZIF-8-IMER. Among them, 7 compounds including baicalein, luteolin, epicatechin gallic acid, and chlorogenic acid, had a certain inhibitory effect on lipase. The molecular docking technology proved the interaction between the enzyme and the screened inhibitor, which provides a new method for the screening of lipase inhibitors.

A Study of the Chemical Composition and Biological Activity of Michelia macclurei Dandy Heartwood: New Sources of Natural Antioxidants, Enzyme Inhibitors and Bacterial Inhibitors.

The wood of Michelia macclurei Dandy (MD) is an excellent material that is widely used in the furniture, handicraft, and construction industries. However, less research has been conducted on the chemical composition and biological activity of heartwood, which is the main valuable part of the wood. This study aimed to investigate the chemical composition and biological activities of the heartwood of Michelia macclurei Dandy (MDHW) and to confirm the active ingredients. Triple quadrupole gas chromatography-mass spectrometry (GC-MS) was used to characterize the volatile components of MDHW, while ultra-performance liquid chromatography-mass spectrometry was used to analyze the non-volatile components (UPLC-MS). The total reducing power, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging assays, acetylcholinesterase and α-glucosidase inhibition assays, and an antimicrobial test of 4 gram bacteria were used to describe the in vitro bioactivities. The GC-MS analysis showed that the volatile components of MDHW were mainly fatty compounds and terpenoids, with sesquiterpenes and their derivatives dominating the terpene composition. ß-elemene was the main terpene component in the steam distillation (11.88%) and ultrasonic extraction (8.2%) methods. A total of 67 compounds, comprising 45 alkaloids, 9 flavonoids, 6 lignans, and others, were found by UPLC-MS analysis. The primary structural kinds of the non-volatile components were 35 isoquinoline alkaloids. Alkaloids were the predominant active constituent in all MDHW extracts, including crude extracts, alkaloid fractions, and non-alkaloid fractions. These extracts all demonstrate some biological effects in terms of antioxidant, enzyme inhibition, and bacterial inhibition. The findings of this study show that MDHW is abundant in chemical structure types, has great bioactivity assessment, and has the potential to be used to create natural antioxidants, products that postpone Alzheimer's disease and lower blood sugar levels and antibacterial agents.

Asociación entre el diagnóstico de carcinoma mamario y la actividad de la enzima lactoperoxidasa sérica / Association between the diagnosis of mammary carcinoma and serum lactoperoxidase enzyme activity

Fundamento: La enzima lactoperoxidasa tiocianato es una proteína producida por células epiteliales en los acinos mamarios. Los carcinomas de la mama constituyen un tipo de cáncer que se origina por la transformación maligna de las células acinares de la mama y se caracterizan por el crecimiento y multiplicación descontrolado. Por tanto, podría existir una correlación entre el cáncer de mama y el aumento de la actividad sérica de la lactoperoxidasa. Objetivo: Determinar la asociación entre el diagnóstico de carcinoma mamario y la actividad aumentada de la enzima lactoperoxidasa sérica en muestras de pacientes que han sido atendidos en el Hospital Oncológico María Curie de Camagüey en el periodo de abril a agosto del 2022. Métodos: Se desarrolló un estudio correlacional en el Centro de Inmunología y Productos Biológicos de Camagüey, en el período de abril a agosto del 2022. Se empleó la citología por aspiración con aguja fina para el diagnóstico histopatológico del carcinoma mamario y se determinó la actividad de la enzima lactoperoxidasa sérica mediante el método del pirogalol salicilato. Se emplearon las pruebas t de student y chi-cuadrado para el análisis estadístico de los datos. Resultados: El carcinoma ductal infiltrante fue el subtipo de cáncer más frecuente con un 94,1 por ciento del total de las muestras. Se encontraron diferencias significativas entre los grupos de muestras analizadas p ( 0.000. De un total de 34 muestras positivas, 32 presentaron aumento de la actividad enzimática. Conclusiones: Hubo asociación entre el diagnóstico de carcinoma mamario y niveles aumentados de la enzima lactoperoxidasa sérica(AU)

Background: The enzyme lactoperoxidase thiocyanate is a protein produced by epithelial cells in the mammary acini. Breast carcinomas are a type of cancer that originates from the malignant transformation of the acinar cells of the breast and are characterized by uncontrolled growth and multiplication. Therefore, there could be a correlation between breast cancer and increased serum lactoperoxidase activity. Objective: To determine the association between the diagnosis of mammary carcinoma and the increased activity of the serum lactoperoxidase enzyme in samples of patients who have been treated at the Maria Curie Oncology Hospital in Camagüey from April to August 2022. Methods: A correlational study was developed at the Center for Immunology and Biological Products of Camagüey, from April to August 2022. Fine-needle aspiration cytology was used for the histopathological diagnosis of mammary carcinoma and the activity of serum lactoperoxidase enzyme by the pyrogallol salicylate method. Student's t and chi-square tests were used in the statistical analysis of the data. Results: Infiltrating ductal carcinoma was the most frequent subtype of cancer with 94,1 percent of the total samples. Significant differences were found between the groups of samples analyzed p ( 0,000. Of a total of 34 positive samples, 32 showed increased enzyme activity. Conclusions: There was an association between the diagnosis of mammary carcinoma and increased levels of the serum lactoperoxidase enzyme(AU)

An affinity interaction guided two-dimensional separation system for the screening of neuraminidase inhibitors from Reynoutria japonica Houtt. roots.

Discovering bioactive compounds from medicinal herbs is crucial for drug discovery. Ultrafiltration is often used in the screening of bioactive compounds from natural herbs because of its simple and rapid operations. However, the ultrafiltration results are often disturbed by the undissolved compounds and the non-target compounds, which reduces the accuracy of the results. Herein, an affinity interaction guided two-dimensional (2D) separation system was developed. Discovery of the potential neuraminidase (NA) inhibitors from the dried roots of Reynoutria japonica Houtt. (RRJ) was used as an example. Only the small molecules showing affinity interaction with NA could be screened by the affinity interaction guided 2D separation system. Firstly, the NA and crude extract were incubated to form a sample solution (containing NA-inhibitor complexes, NA, and three types of small molecules with different polarities) by affinity interaction. Then the sample solution was separated and detected by the 2D separation system. This aimed to reduce the interference of the undissolved compounds and non-target compounds, and pick out the NA-inhibitor complexes (NA-Is). The collected NA-Is were denatured to release small molecular inhibitors (Is) for LC-MS/MS analysis. Compared with the ultrafiltration, more obvious peak area differences were observed in the results, and four potential NA inhibitors were successfully identified. In all, we provided a simple strategy with better performance in the screening of natural bioactive compounds.

LC-ESI-MS/MS Characterization of Concentrated Polyphenolic Fractions from Rhododendron luteum and Their Anti-Inflammatory and Antioxidant Activities.

The high biological potential of polyphenols encourages the search for new natural sources of and biomedical applications for these compounds. Rhododendron luteum Sweet was previously reported to contain pharmaceutically active polyphenols. The present research investigates the polyphenolic fractions in R. luteum leaves, including a determination of the free and bound phenolic acid and flavonoid contents and their anti-inflammatory and antioxidant activities. LC-ESI-MS/MS (liquid chromatography/electrospray ionization triple quadrupole mass spectrometry) analysis revealed a great abundance of free (e.g., 5-O-caffeoylquinic acid, ferulic acid, protocatechuic acid, catechin, and dihydromyricetin) and bound (e.g., caffeic acid, p-coumaric, protocatechuic acid, myricetin, quercetin) phenolics. The R. luteum samples exhibited high anti-inflammatory potential in lipoxygenase (IC50: 0.33 ± 0.01-2.96 ± 0.06 mg dry extract (DE)/mL) and hyaluronidase (IC50: 78.76 ± 2.09 - 429.07 ± 31.08 µg DE/mL) inhibition capacity assays. Some samples also had the ability to inhibit cyclooxygenase 1 (IC50: 311.8 ± 10.95 µg DE/mL) and cyclooxygenase 2 (IC50: 53.40 ± 5.07; 608.09 ± 14.78 µg DE/mL). All fractions showed excellent antioxidant activity in the Oxygen Radical Absorbance Capacity (ORAC) assay (5.76-221.81 g Trolox/g DE), ABTS•+ radical scavenging ability (0.62 ± 0.03 - 5.09 ± 0.23 g Trolox/g DE), and moderate ion (Fe2+) chelating power. This paper expands our knowledge of the phytochemistry and pharmacological activity of R. luteum polyphenols. It reveals, for the first time, the presence of dihydromyricetin, afzelin, and laricitrin in the plant material. It indicates biologically active polyphenolic fractions that should be further investigated or which could be efficiently used in pharmaceutical, cosmetic, or nutraceutical applications.

Polarity Directed Appraisal of Pharmacological Potential and HPLC-DAD Based Phytochemical Profiling of Polygonum glabrum Willd.

The present study was designed to evaluate polarity-dependent extraction efficiency and pharmacological profiling of Polygonum glabrum Willd. Crude extracts of leaves, roots, stems, and seeds, prepared from solvents of varying polarities, were subjected to phytochemical, antioxidant, antibacterial, antifungal, antidiabetic, and cytotoxicity assays. Maximum extraction yield (20.0% w/w) was observed in the case of an acetone:methanol (AC:M) root extract. Distilled water:methanol (W:M) leaves extract showed maximum phenolic contents. Maximum flavonoid content and free radical scavenging potential were found in methanolic (M) seed extract. HPLC-DAD quantification displayed the manifestation of substantial quantities of quercetin, rutin, gallic acid, quercetin, catechin, and kaempferol in various extracts. The highest ascorbic acid equivalent total antioxidant capacity and reducing power potential was found in distilled water roots and W:M leaf extracts, respectively. Chloroform (C) seeds extract produced a maximum zone of inhibition against Salmonella typhimurium. Promising protein kinase inhibition and antifungal activity against Mucor sp. were demonstrated by C leaf extract. AC:M leaves extract exhibited significant cytotoxic capability against brine shrimp larvae and α-amylase inhibition. Present results suggest that the nature of pharmacological responses depends upon the polarity of extraction solvents and parts of the plant used. P. glabrum can be considered as a potential candidate for the isolation of bioactive compounds with profound therapeutic importance.

Based on Multi-Activity Integrated Strategy to Screening, Characterization and Quantification of Bioactive Compounds from Red Wine.

According to French Paradox, red wine was famous for the potential effects on coronary heart disease (CHD), but the specific compounds against CHD were unclear. Therefore, screening and characterization of bioactive compounds from red wine was extremely necessary. In this paper, the multi-activity integrated strategy was developed and validated to screen, identify and quantify active compounds from red wine by using ultra high performance liquid chromatography-fraction collector (UHPLC-FC), ultra fast liquid chromatography-quadrupole-time-of-flight/mass spectrometry (UFLC-Q-TOF/MS) and bioactive analysis. UHPLC-FC was employed to separate and collect the components from red wine, which was further identified by UFLC-Q-TOF/MS to acquire their structural information. Furthermore, the active fractions were tested for antioxidant activity, inhibitory activity against thrombin and lipase activities in vitro by the activity screening kit. As the results, there were 37 fractions had antioxidant activity, 22 fractions had thrombin inhibitory activity and 28 fractions had lipase inhibitory activity. Finally, 77 active components from red wine were screened and 12 ingredients out of them were selected for quantification based on the integration of multi-activity. Collectively, the multi-activity integrated strategy was helpful for the rapid and effective discovery of bioactive components, which provided reference for exploring the health care function of food.

Identification of Small Molecule Inhibitors against Staphylococcus aureus Dihydroorotase via HTS.

Drug-resistant Staphylococcus aureus is an imminent threat to public health, increasing the importance of drug discovery utilizing unexplored bacterial pathways and enzyme targets. De novo pyrimidine biosynthesis is a specialized, highly conserved pathway implicated in both the survival and virulence of several clinically relevant pathogens. Class I dihydroorotase (DHOase) is a separate and distinct enzyme present in gram positive bacteria (i.e., S. aureus, B. anthracis) that converts carbamoyl-aspartate (Ca-asp) to dihydroorotate (DHO)-an integral step in the de novo pyrimidine biosynthesis pathway. This study sets forth a high-throughput screening (HTS) of 3000 fragment compounds by a colorimetry-based enzymatic assay as a primary screen, identifying small molecule inhibitors of S. aureus DHOase (SaDHOase), followed by hit validation with a direct binding analysis using surface plasmon resonance (SPR). Competition SPR studies of six hit compounds and eight additional analogs with the substrate Ca-asp determined the best compound to be a competitive inhibitor with a KD value of 11 µM, which is 10-fold tighter than Ca-asp. Preliminary structure-activity relationship (SAR) provides the foundation for further structure-based antimicrobial inhibitor design against S. aureus.

The Kinetic and Analytical Aspects of Enzyme Competitive Inhibition: Sensing of Tyrosinase Inhibitors.

An amperometric biosensor based on tyrosinase, immobilized onto a carbon black paste electrode using glutaraldehyde and BSA was constructed to detect competitive inhibitors. Three inhibitors were used in this study: benzoic acid, sodium azide, and kojic acid, and the obtained values for fifty percent of inhibition (IC50) were 119 µM, 1480 µM, and 30 µM, respectively. The type of inhibition can also be determined from the curve of the degree of inhibition by considering the shift of the inhibition curves. Amperometric experiments were performed with a biosensor polarized at the potential -0.15 V vs. Ag/AgCl and using 0.1 M phosphate buffer (pH 6.8) as an electrolyte. Under optimized conditions, the proposed biosensor showed a linear amperometric response toward catechol detection from 0.5 µM to 38 µM with a detection limit of 0.35 µM (S/N = 3), and its sensitivity was 66.5 mA M-1 cm-2. Moreover, the biosensor exhibited a good storage stability. Conversely, a novel graphical plot for the determination of reversible competitive inhibition was represented for free tyrosinase. The graph consisted of plotting the half-time reaction (t1/2) as a function of the inhibitor concentration at various substrate concentrations. This innovative method relevance was demonstrated in the case of kojic acid using a colorimetric bioassay relying on tyrosinase inhibition. The results showed that the t1/2 provides an extended linear range of tyrosinase inhibitors.

High-intensity ultrasound processing of baobab fruit pulp: Effect on quality, bioactive compounds, and inhibitory potential on the activity of α-amylase and α-glucosidase.

Effect of high-intensity ultrasound (HIU) compared with thermal treatments on baobab fruit pulp (BFP) quality and bioactive properties were investigated. HIU treatments, particularly at intensities of 687.5 W/cm2 for 5 min, and 344 W/cm2 for 15 min significantly (p < 0.05) increased the cloudiness index, ascorbic acid (AA) retention, total phenolic and flavonoid contents, and antioxidant capacity besides a more potent α-amylase and α-glucosidase inhibition relative to thermally treated samples. Moreover, the physicochemical parameters, colour index, and browning index were maintained with HIU besides lower 5-hydroxymethylfurfural values than thermal processing. HPLC analysis revealed that the content of most phenolic compounds was the highest in HIU treatments besides a 235-256% increase in procyanidin C1 compared with control samples. The AA retention following HIU treatments was 87.62-102.86% compared to 30.47-61.90% in thermally treated samples. Our analyses portrayed ultrasound as a feasible alternative to conventional thermal processing of BFP.

Comprehensive evaluation of two Astragalus species (A. campylosema and A. hirsutus) based on biological, toxicological properties and chemical profiling.

Astragalus L. (Fabaceae) is an important genus with numerous species having various traditional medicinal uses making them of interest for scientific investigations to ascertain their therapeutic benefits. In the present study, the quantitative polyphenolic profiles of methanolic extracts from different parts (leaves, flowers, and roots) of two endemic Astragalus species growing in Turkey, i.e. A. campylosema Boiss. and A. hirsutus Vahl were determined, along with their antioxidant and enzyme inhibitory properties. A. campylosema and A. hirsutus extracts showed varying total phenolic (25.80-40.60 and18.59-29.46 mg GAE/g, respectively) and total flavonoid (11.21-105.91 and 16.06-131.91 mg RE/g, respectively) contents. HPLC-MS/MS revealed rutin to be the predominant phenolic compound in all the extracts of A. campylosema and leaf extract of A. hirsutus (133.53-752.42 µg g-1), while hyperoside was the major one in the flower and root extracts of A. hirsutus (2014.07 and 123.13 µg g-1, respectively). In DPPH and ABTS assays, radical scavenging capacity was demonstrated by all extracts of A. campylosema (47.13-48.10 and 87.03-115.36 mg TE/g, respectively) and A. hirsutus (17.82-38.67 and 47.84-57.29 mg TE/g, respectively). Reducing activity was also displayed by the extracts in CUPRAC and FRAP assays (A. campylosema: 83.06-135.20 and 59.15-90.19 mg TE/g, respectively; A. hirsutus: 53.02-83.42 and 31.25-43.25 mg TE/g, respectively). All extracts were also found to act as metal chelators (12.32-21.45 mg EDTAE/g) and exhibited total antioxidant capacity ranging from 1.16 to 1.60 mmol TE/g, in phosphomolybdenum assay. Acetyl- and butyryl-cholinesterase inhibitory effects were observed by all the extracts of the two species (1.56-4.99 mg GALAE/g). Anti-hyperpigmentation potential by inhibiting tyrosinase (54.55-67.35 mg KAE/g) was reported as well. Carbohydrate hydrolyzing enzymes, amylase and glucosidase were also inhibited (0.22-1.03 mmol ACAE/g). Overall, A. campylosema extracts showed relatively better antioxidant and enzyme inhibitory potentials compared to A. hirsutus extracts. Strikingly, A. hirsutus extracts was found to have higher AGE inhibition activity than A. campylosema. Although the cytotoxic effect of three different organs obtained from A. campylosema and A. hirsutus increased depending on the dose (from 10 to 200 µg/mL), it was found that both plant extracts did not show a genotoxic effect at the highest concentration of 200 µg/mL. Indeed, data amassed from this current scientific work showed the two selected Astragalus species to be rich in bioactive polyphenols that could be responsible for the various pharmacological activities and hence demands to be further explored for their possible applications as natural health promoting agents.

Design of Neuraminidase-Targeted Imaging and Therapeutic Agents for the Diagnosis and Treatment of Influenza Virus Infections.

The last step in influenza virus replication involves the assembly of viral components on the infected cell's plasma membrane followed by budding of intact virus from the host cell surface. Because viral neuraminidase and hemagglutinin are both inserted into the host cell's membrane during this process, influenza virus-infected cells are distinguished from uninfected cells by the presence of viral neuraminidase and hemagglutinin on their cell surfaces. In an effort to exploit this difference in cell surface markers for development of diagnostic and therapeutic agents, we have modified an influenza neuraminidase inhibitor, zanamivir, for targeting of attached imaging and therapeutic agents selectively to influenza viruses and virus-infected cells. We have designed here a zanamivir-conjugated rhodamine dye that allows visual monitoring of binding, internalization, and intracellular trafficking of the fluorescence-labeled neuraminidase in virus-infected cells. We also synthesize a zanamivir-99mTc radioimaging conjugate that permits whole body imaging of the virus's biodistribution and abundance in infected mice. Finally, we create both a zanamivir-targeted cytotoxic drug (i.e., zanamivir-tubulysin B) and a viral neuraminidase-targeted CAR T cell and demonstrate that they are both able to kill viral neuraminidase-expressing cells without damaging healthy cells. Taken together, these data suggest that the influenza virus neuraminidase inhibitor, zanamivir, can be exploited to improve the diagnosis, imaging, and treatment of influenza virus infections.

Development of a new nano arginase HPLC capillary column for the fast screening of arginase inhibitors and evaluation of their binding affinity.

A simple and rapid Nano LC method has been developed for the screening of arginase inhibitors. The method is based on the immobilization of biotinylated arginase on a neutravidin functionalized nano HPLC capillary column. The arginase immobilization step performed by frontal analysis is very fast and only takes a few minutes. The miniaturized capillary column of 170 nL (length 5 cm, internal diameter 75 µm) significantly decreased the required amount of used enzyme (25 pmol). This was of significance importance when working with less available or expensive purified enzyme. Non-selective adsorption of the organic monolith matrix was reduced (<6%) and the arginase efficient yield was high (92%). The resultant affinity capillary columns showed excellent repeatability and long lifetime. The arginase reaction product was achieved within 60 s and the immobilized arginase retained 97% of the initial activity beyond 90 days. This novel approach can thus be used for the fast evaluation of recognition assay induced bya series of inhibitor molecules (caffeic acid phenylamide, chlorogenic acid, piceatannol, nor-NOHA acetate) and plant extracts.

Tanacetum vulgare L. (Tansy) as an effective bioresource with promising pharmacological effects from natural arsenal.

The Tanacetum genus is a big treasure with the presence of biologically-active compounds and members of this genus are widely used for the treatment of several diseases in traditional medicine system. Considering this fact, we aimed to analyze the extracts from Tanacetum vulgare L. in case of chemical profiles and biological effects. Chemical characterization was performed by using UHPLC-HRMS technique and showed the presence of several phytochemical groups (107 compounds were identified, including phenolic acids, flavonoids, terpenoids and fatty acids. Biological abilities were examined by using antioxidant (DPPH, ABTS, FRAP, CUPRAC, metal chelating and phosphomolybdenum assays) and enzyme inhibition (tyrosinase, amylase, glucosidase and cholinesterase) properties. Pharmaco-toxicological investigations were also performed with the aim to identify limits of biocompatibility, anti-oxidant and neuromodulatory effects, in hypothalamic HypoE22 cells. A bioinformatic analysis was also carried to unravel the putative protein-targets for the observed biological effects. Generally, the tested hexane and hydroalcoholic extracts displayed stronger activities in antioxidant and enzyme inhibitory assays, when compared with water. In addition, multivariate analysis was performed to understand the differences in both solvents and plant parts and we clearly observed the separation of these parameters. The extracts (10 µg/mL) also stimulated DAT and inhibited TNFα and BDNF gene expression, in HypoE22 cells. In parallel, the extracts were also able to stimulate norepinephrine release from this cell line. By contrast, in the concentration range 50-100 µg/mL, the extracts reduced the HypoE22 viability, thus demonstrating cytotoxicity at concentrations 5-10 fold higher compared to those effective as neuromodulatory. Our observations manifested that T. vulgare has several beneficial effects and it can be used as a potential natural raw material for designing further health-promoting applications in nutraceutical, cosmeceutical, and pharmaceutical areas.

Metabolomic profiling and biological properties of six Limonium species: novel perspectives for nutraceutical purposes.

The genus Limonium includes important halophyte plants containing a variety of bioactive compounds of therapeutic interest. In the present work, the untargeted phytochemical profiles of both aerial part and root extracts from six Limonium species namely, L. bellidifolium, L. globuliferum, L. gmelinii, L. lilacinum, L. sinuatum and L. iconicum from Turkey were determined. Furthermore, several biological activities (in vitro antioxidant and enzyme inhibitory effects) were investigated. Overall, significant amounts of total phenolics (43.64-238.18 mg g-1) and flavonoids (1.61-129.69 mg g-1) were recorded. Particularly, the root extracts of L. gmelinii, L. iconicum and L. globuliferum showed the highest total phenolic content (204.13-238.18 mg g-1), whilst the highest total flavonoid content was recorded in the root extracts of L. gmelinii (129.69 mg g-1). Overall, the tested extracts demonstrated potent radical scavenging activities in both DPPH (2,2- diphenyl-1-picrylhydrazyl) and ABTS (3-ethylbenzothiazoline-6-sulphonic acid) (90.10-507.94 mg g-1 and 163.39-1175.34 mg g-1, respectively). However, the highest scavenging potential (p < 0.05) was displayed by the root extracts of L. iconicum. Conversely, the metal chelating ability assay revealed that L. lilacinum root extract showed the highest activity (21.03 mg g-1). Interestingly, all the extracts were found to be active inhibitors of cholinesterases (AChE (acetylcholinesterase): 4.20-5.11 mg GALAE (galantamine equivalent) per g; BChE (butyrylcholinesterase): 3.89-10.75 mg GALAE per g), amylase (0.52-1.09 mmol ACAE (acarbose equivalent) per g) and tyrosinase (119.41-155.67 mg KAE (kojic acid equivalent) per g), unlike for glucosidase (2.31-2.41 mmol ACAE per g). Taken together, these findings demonstrated a diverse chemical profiles and biological of the extracts, to be potentially considered as phytotherapeutic or functional ingredients due to their antioxidant properties and inhibition of key enzymes involved in several diseases.

Xanthine Oxidase Inhibitors from Filipendula ulmaria (L.) Maxim. and Their Efficient Detections by HPTLC and HPLC Analyses.

Filipendula ulmaria is a plant commonly used for the treatment of several pathologies, such as diarrhoea, ulcers, pain, stomach aches, fevers, and gout. Our study focused on the use of F. ulmaria for the treatment of gout disease. We first studied the chemical composition of a methanolic extract of the aerial parts and demonstrated its xanthine oxidase (XO) inhibitory activity. Then, we performed a fractionation and evaluated the most XO inhibitory active fractions by UV measurement. Purification of some fractions allowed the determination of the inhibitory activity of pure compounds. We demonstrated that spiraeoside, a glycosylated flavonoid, possesses an activity around 25 times higher than allopurinol, used as a reference in the treatment of gout disease. In order to easily and quickly identify potent inhibitors in complex matrix, we developed a complementary strategy based on an HPLC method and an Effect Directed Assay (EDA) method combining HPTLC and biochemical assays. The HPLC method, capable of determining compounds exhibiting interactions with the enzyme, could be an efficient strategy for evaluating potent enzyme inhibitors in a complex mixture. This strategy could be applied for quantitative assays using LC/MS experiments.

A self-correcting fluorescent assay of tyrosinase based on Fe-MIL-88B-NH2 nanozyme.

A self-correcting fluorescent assay of tyrosinase (TYR) was developed by utilization of Fe-MIL-88B-NH2 as a peroxidase-like nanozyme and a capture probe. Fe-MIL-88B-NH2 nanozyme was selected as an electron donor, and the oxidization product (dopamine-o-quinone) acts as an energy acceptor. First, TYR catalyzes the oxidation of tyramine hydrochloride to dopamine and then to dopamine-o-quinone. Second, Fe-MIL-88B-NH2 with intrinsic peroxidase-like activity decomposes H2O2 to produce ·OH radicals, which further accelerate the oxidation of dopamine to dopamine-o-quinone. Excessive H2O2 and ·OH radicals reduce the interferences from ascorbic acid at the same time providing a self-correcting ability. Dopamine-o-quinone reacts with -NH2 groups on the ligand of Fe-MIL-88B-NH2 through Michael reaction which results in fluorescence quenching. Under 365-nm excitation, the fluorescence emission intensity at 452 nm gradually decreased with increasing TYR concentration varying from 0 to 10 U mL-1. The linear range is from 1 to 5 U mL-1 and the detection limit is 0.05679 U mL-1. This self-correcting fluorescent assay of tyrosinase exhibits good sensitivity and selectivity which is also successfully applied for tyrosinase inhibitor detection. Schematic representation of fluorescent assay for tyrosinase determination based on Fe-MIL-88B-NH2 nanozyme. A self-correcting fluorescent assay for tyrosinase was developed based on the Fe-MIL-88B-NH2 nanozyme.

Development of a Novel Label-Free and High-Throughput Arginase-1 Assay Using Self-Assembled Monolayer Desorption Ionization Mass Spectrometry.

Arginase-1, an enzyme that catalyzes the reaction of L-arginine to L-ornithine, is implicated in the tumor immune response and represents an interesting therapeutic target in immuno-oncology. Initiating arginase drug discovery efforts remains a challenge due to a lack of suitable high-throughput assay methodologies. This report describes the combination of self-assembled monolayers and matrix-assisted laser desorption ionization mass spectrometry to enable the first label-free and high-throughput assay for arginase activity. The assay was optimized for kinetically balanced conditions and miniaturized, while achieving a robust assay (Z-factor > 0.8) and a significant assay window [signal-to-background ratio > 20] relative to fluorescent approaches. To validate the assay, the inhibition of the reference compound nor-NOHA (Nω-hydroxy-nor-L-arginine) was evaluated, and the IC50 measured to be in line with reported results (IC50 = 180 nM). The assay was then used to complete a screen of 175,000 compounds, demonstrating the high-throughput capacity of the approach. The label-free format also eliminates opportunities for false-positive results due to interference from library compounds and optical readouts. The assay methodology described here enables new opportunities for drug discovery for arginase and, due to the assay flexibility, can be more broadly applicable for measuring other amino acid-metabolizing enzymes.

Rapid screening for natural lipase inhibitors from Alisma orientale combining high-performance thin-layer chromatography-bioautography with mass spectrometry.

Lipase inhibitors are an attractive class of hypolipidemic compounds, which inhibit the activity of human pancreatic lipase, thereby preventing the absorption of triglycerides in vivo. As a library of promising lead compounds for drug development, traditional Chinese medicine (TCM) has gained growing attention in quick discovery and identification of enzyme inhibitors of natural-origin. The purpose of this work was to discover unknown lipase inhibitors from Alisma orientale by the activity oriented analysis method thin-layer chromatography-bioautography, then use electrospray ionization mass spectrometry technology via the elution based TLC-MS interface to identify their structures. As a result, eleven natural lipase inhibitors from Alisma orientale extracts were identified based on molecular mass and fragment ions obtained by HPTLC-MS, and further confirmed by a series of complementary means including UV spectra, 1H NMR characteristic proton signals and polarity of compounds, eleven lipase inhibitors were tentatively assigned as triterpenoids: alisol B (m/z 495.50 [M + Na]+), alisol B 23-acetate (m/z 537.58 [M + Na]+), 11-deoxy-alisol B (m/z 479.50 [M + Na]+), 11-deoxy-alisol B 23-acetate (m/z 521.50 [M + Na]+), alisol A/epialisol A (m/z 513.50 [M + Na]+), 16-oxo-11-deoxy-alisol A (m/z 511.50 [M + Na]+), 16-oxo-alisol A (527.50 [M + Na] +), alisol C (m/z 509.58 [M + Na]+), alisol C 23-acetate (m/z 551.50 [M + Na]+), alisol M 23-acetate (m/z 567.50 [M + Na]+), and alismanol Q/neoalisol (m/z 493.42 [M + Na]+). The integrated approach is an efficient method for rapid screening lipase inhibitors from complex plant extracts and provides a reasonable and favorable basis for the identification and separation of other enzymatic system and other important compounds with therapeutic values.