Discovery of potent antiproliferative agents from selected oxygen heterocycles as EGFR tyrosine kinase inhibitors from the U.S. National Cancer Institute database by in silico screening and bioactivity evaluation.

A similarity search was conducted on the U.S. Enhanced National Cancer Institute Database Browser 2.2 to find structures related to 1,5-dihydroxy-9H-xanthen-9-one, a previously established EGFR-TK inhibitor. Compounds were virtually screened and selected for bioactivity testing revealed 5 candidates, mostly displayed stronger antiproliferative activities than erlotinib with IC50 values between 0.95 and 17.71 µM against overexpressed EGFR-TK cancer cell lines: A431 and HeLa. NSC107228 displayed the strongest antiproliferative effects with IC50 values of 2.84 and 0.95 µM against A431 and HeLa cancer cell lines, respectively. Three compounds, NSC81111, NSC381467 and NSC114126 inhibited EGFR-TK with IC50 values between 0.15 and 30.18 nM. NSC81111 was the best inhibitor with IC50 = 0.15 nM. Molecular docking analysis of the 3 compounds predicted hydrogen bonding and hydrophobic interactions with key residues were important for the bioactivities observed. Furthermore, calculations of the physicochemical properties suggest the compounds are drug-like and are potentially active orally.

Separation of three chromones from Saposhnikovia divaricata using macroporous resins followed by preparative high-performance liquid chromatography.

Prim-O-glucosylcimifugin, cimifugin, and 5-O-methylvisamminoside are three major chromone derivatives of Saposhnikovia divaricata that have many pharmacological activities, such as anti-inflammatory and antitumor activities. In the present work, an effective method for the simultaneous separation of prim-O-glucosylcimifugin, cimifugin, and 5-O-methylvisamminoside with high purities was established using HPD-300 resin coupled with preparative high-performance liquid chromatography. The adsorption kinetics curves of the three compounds on the HPD-300 resin were studied and found to fit well according to the pseudo-second-order equation. The adsorption isotherm results indicated that the adsorption process of the three compounds was exothermic. After a one-run treatment with the resin, the contents of prim-O-glucosylcimifugin, cimifugin, and 5-O-methylvisamminoside increased from 0.29, 0.06, and 0.37% to 13.07, 2.83, and 16.91% with recovery yields of 76.38, 78.25, and 76.73%, respectively. Finally, the purities of the three compounds were found to reach more than 95% after further separation using preparative high-performance liquid chromatography. The method developed in this study was effective and could simultaneously separate three chromones from Saposhnikovia divaricate. The experimental results also showed that the HPD-300 resin is suitable for the separation of chromone derivatives.

Differentiation of adipose tissue-derived stem cells towards vascular smooth muscle cells on modified poly(L-lactide) foils.

The aim of our research was to study the behaviour of adipose tissue-derived stem cells (ADSCs) and vascular smooth muscle cells (VSMCs) on variously modified poly(L-lactide) (PLLA) foils, namely on pristine PLLA, plasma-treated PLLA, PLLA grafted with polyethylene glycol (PEG), PLLA grafted with dextran (Dex), and the tissue culture polystyrene (PS) control. On these materials, the ADSCs were biochemically differentiated towards VSMCs by a medium supplemented with TGFß1, BMP4 and ascorbic acid (i.e. differentiation medium). ADSCs cultured in a non-differentiation medium were used as a negative control. Mature VSMCs cultured in both types of medium were used as a positive control. The impact of the variously modified PLLA foils and/or differences in the composition of the medium were studied with reference to cell adhesion, growth and differentiation. We observed similar adhesion and growth of ADSCs on all PLLA samples when they were cultured in the non-differentiation medium. The differentiation medium supported the expression of specific early, mid-term and/or late markers of differentiation (i.e. type I collagen, αSMA, calponin, smoothelin, and smooth muscle myosin heavy chain) in ADSCs on all tested samples. Moreover, ADSCs cultured in the differentiation medium revealed significant differences in cell growth among the samples that were similar to the differences observed in the cultures of VSMCs. The round morphology of the VSMCs indicated worse adhesion to pristine PLLA, and this sample was also characterized by the lowest cell proliferation. Culturing VSMCs in the differentiation medium inhibited their metabolic activity and reduced the cell numbers. Both cell types formed the most stable monolayer on plasma-treated PLLA and on the PS control. The behaviour of ADSCs and VSMCs on the tested PLLA foils differed according to the specific cell type and culture conditions. The suitable biocompatibility of both cell types on the tested PLLA foils seems to be favourable for vascular tissue engineering purposes.

Rare benzonaphthoxanthenones from Chinese folk herbal medicine Polytrichum commune and their anti-neuroinflammatory activities in vitro.

Two new (1-2) as well as five known (3-7) compounds were isolated from Polytrichum commune, a folk herbal medicine in China, and three of them (2, 4, 5) belong to benzonaphthoxanthenones that are rarely found in nature. Their structures were elucidated by the approach to 1D and 2D NMR spectra. The absolute configuration of 2 was assigned by comparing its experimental and calculated ECD data. 1-5 were investigated for their anti-neuroinflammatory activity against LPS-induced BV-2 cells. 1 and 3 exhibited well protective effect at a concentration of 2.5 µmol/mL. Molecular docking studies were adopted to further investigate the possible mechanism, whose results suggested that 1 might exert anti-neuroinflammatory effect by inhibiting activity of p38α, JNK2 and TAK1 to reduce the liberation of pro-inflammatory cytokines.

Ag Nanoparticles Stabilized on Cyclodextrin Polymer Decorated with Multi-Nitrogen Atom Containing Polymer: An Efficient Catalyst for the Synthesis of Xanthenes.

In attempt to broaden the use of cyclodextrin polymer for catalytic purposes, a novel covalent hybrid system was prepared through growth of multi-nitrogen atom containing polymer (PMelamine) derived from reaction of ethylenediamine and 2,4,6-trichloro-1,3,5-triazine on the functionalized cyclodextrin polymer (CDNS). The resulting hybrid system was then utilized as a catalyst support for the immobilization of silver nanoparticles through using Cuscuta epithymum extract as a naturally-derived reducing agent. The catalytic activity of the catalyst, Ag@CDNS-N/PMelamine, for the synthesis of xanthenes through reaction of aldehydes and dimedone in aqueous media was examined. The results showed high catalytic activity and recyclability of the catalyst. It was believed that cyclodextrin in the backbone of the catalyst could act both as a capping agent for Ag nanoparticles and phase transfer agent to bring the hydrophobic substrates in the vicinity of the catalytic active sites and accelerate the reaction rate. Multi-nitrogen atoms on the polymer, on the other hand, could improve the Ag NPs anchoring and suppress their leaching.

Metabolomic profiling of Saposhnikoviae Radix from Mongolia by LC-IT-TOF-MS/MS and multivariate statistical analysis.

Saposhnikoviae Radix (SR) is a commonly used crude drug that is obtained from the root and rhizome of Saposhnikovia divaricata which is distributed throughout China, Korea, Mongolia, and Russia. To evaluate the quality of Mongolian S. divaricata, metabolomic profiling of 43 plant specimens from different regions of Mongolia, as well as 8 SR samples and 2 plant specimens from China, were conducted by liquid chromatography-ion-trap-time-of-flight-mass spectrometer (LC-IT-TOF-MS). LC-MS profiles of the specimens showed uniformity and 30 compounds were tentatively identified, including 13 chromones and 17 coumarins. Among them, 16 compounds were isolated and unambiguously verified by comparing them with the spectroscopic data of standard compounds. Orthogonal partial least squares-discriminant analysis (OPLS-DA) based on LC-MS data from 7 Mongolian specimens and 8 Chinese SR samples as well as 2 plant specimens revealed that these 2 groups were clearly distinguishable and that Mongolian specimens were characterized by an abundance of prim-O-glucosylcimifugin (1). Moreover, the OPLS-DA of the Mongolian specimens showed that they can be discriminated by their growing regions based on the content of 8 chromones. The total content of dihydrofurochromones 1-3 was relatively higher in the specimens from Khalkhgol in the far eastern part of Mongolia, while contents of 10, 11, 15, and 16 were higher in those from Holonbuir in the eastern part. Based on this research, the roots of S. divaricata from Mongolia have potential as a new resource of SR in Kampo medicine.

Self-assembled micelles based on gambogenic acid-phospholipid complex for sustained-release drug delivery.

Objective: To improve the water solubility and enhance the oral bioavailability of gambogenic acid (GNA). Methods: GNA-phospholipid complex (GNA-PLC) micelles were successfully prepared by anti-solvent method. Results: The encapsulation efficiency of GNA-PLC micelles can reach 99.33 % (w/w). The average particle size of the GNA-PLC micelles was 291.23 nm which was approximate agreed with the transmission electron microscopy (TEM). In vitro release profile showed the GNA-PLC and GNA-PLC micelles have significant sustained-release of GNA compared with crude GNA. Pharmacokinetic parameters indicated that the area under concentration-time curve (AUC0→t) of GNA in cases of GNA-PLC and GNA-PLC micelles are 2.04- and 3.92-fold higher than crude GNA, respectively. Conclusions: The better water solubility and higher bioavailability of GNA in GNA-PLC micelles with significant sustained-release of GNA endow the nanoparticle with great potential in GNA delivery system.

Anticancer activity and underlying mechanism of neogambogic acid.

Garcinia, a kind of dry resin secreted by Garcinia hanburyi Hook. F. G., is a traditional Chinese medicine with various biological functions such as detoxification, anti-inflammatory, and anthelmintic activities. Recent studies suggest that garcinia has potential anticancer activity. Increasing evidences indicate that the main active monomer gambogic acid isolated from garcinia can inhibit the growth of various cancer cells. Neogambogic acid is an isolated compound with a similar chemical structure as gambogic acid. Preliminary studies show that the neogambogic acid can selectively inhibit the growth of various cancer cells, and has a broader antitumor activity and lower toxicity than gambogic acid. In this review, we summarize the advances made in the investigation of the anti-tumor effect of neogambogic acid in recent years.

Antioxidants from the Brown Alga Dictyopteris undulata.

An investigation of anti-oxidative compounds from the brown alga Dictyopteris undulata has led to the isolation and identification of isozonarol, isozonarone, chromazonarol, zonaroic acid and isozonaroic acid. Their structures were identified by comparison of MS and NMR spectra. Full NMR assignment and absolute configuration of isozonaroic acid are described. Isozonarol showed the most potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity among the compounds isolated.

[Quality Evaluation of Saposhnikoviae Radix (Differences between Wild-type and Cultivated Products)].

　Saposhnikoviae Radix ("Boufu") is an important crude drug used in Kampo formulation. It is extracted from wild-type plants. However, recently, extraction has become difficult because of a decrease in wild-type plants. Therefore, cultivated plants account for the majority of the market, from which the crude drug is extracted. However, the cultivation techniques used are not sufficient to obtain the desirable extracts. In this study, we compared the contents of the extract and the quantitative values of characteristic constituents obtained from wild-type and cultivated plants, and found a remarkable difference. Therefore, it is considered that these indicators play an important role in the establishment of better cultivation technology.

Inhibition of Suicidal Erythrocyte Death by Indirubin-3'-Monoxime.

BACKGROUND/AIMS: Qing Dai is a prized traditional Chinese medicine whose major component, indirubin, and its derivative, indirubin-3'-monoxime (IDM), have inhibitory effects on the growth of many human tumor cells and pronounced anti-leukemic activities. However, the effects of IDM on mature human erythrocytes are unclear. This study aimed to evaluate the potential impact of IDM on erythrocytes and the mechanisms underlying that impact. METHODS: Utilizing flow cytometry and confocal laser scanning microscopy, phosphatidylserine exposure at the cell surface was estimated by annexin V-fluorescein isothiocyanate (FITC). The relative cell size, expressed in arbitrary units, was evaluated by forward scatter in a flow cytometer. Fluo-3 fluorescence was used to bewrite changes in cytosolic Ca2+ activity, reactive oxygen species (ROS) formation was assessed by 2,7-dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescence, and ceramide abundance was evaluated by FITC-conjugated specific antibodies. RESULTS: The 24-h exposure of human erythrocytes to IDM (12 µM) significantly decreased the percentage of annexin V-binding erythrocytes and the intracellular calcium concentration ([Ca2+]i). IDM (3-12 µM) did not significantly modify the ceramide level or DCFH-DA fluorescence. Energy depletion (removal of glucose for 24 hours) significantly increased annexin V binding and Fluo-3 fluorescence and diminished forward scatter, and these effects were significantly mitigated by IDM (12 µM). Moreover, the Ca2+ ionophore ionomycin (1 µM, 60 min) and oxidative stress (30 min exposure to 0.05 mM tert-butyl hydroperoxide, t-BHP) similarly triggered eryptosis, which was also significantly suppressed by IDM. CONCLUSIONS: IDM is a novel inhibitor of suicidal erythrocyte death following ionomycin treatment, t-BHP treatment and energy depletion. Thus, IDM may counteract anemia and impairment of microcirculation, at least in part, by inhibition of Ca2+ entry into erythrocytes.

Affinity-Based Screen for Inhibitors of Bacterial Transglycosylase.

The rise of antibiotic resistance has created a mounting crisis across the globe and an unmet medical need for new antibiotics. As part of our efforts to develop new antibiotics to target the uncharted surface bacterial transglycosylase, we report an affinity-based ligand screen method using penicillin-binding proteins immobilized on beads to selectively isolate the binders from complex natural products. In combination with mass spectrometry and assays with moenomycin A and salicylanilide analogues (1-10) as reference inhibitors, we isolated four potent antibacterials confirmed to be benastatin derivatives (11-13) and albofungin (14). Compounds 11 and 14 were effective antibiotics against a broad-spectrum of Gram-positive and Gram-negative bacteria, including Acinetobacter baumannii, Clostridium difficile, Staphylococcus aureus, and drug-resistant strains with minimum inhibitory concentrations in the submicromolar to nanomolar range.

Exposure Assessment of Acetamide in Milk, Beef, and Coffee Using Xanthydrol Derivatization and Gas Chromatography/Mass Spectrometry.

Acetamide has been classified as a possible human carcinogen, but uncertainties exist about its levels in foods. This report presents evidence that thermal decomposition of N-acetylated sugars and amino acids in heated gas chromatograph injectors contributes to artifactual acetamide in milk and beef. An alternative gas chromatography/mass spectrometry protocol based on derivatization of acetamide with 9-xanthydrol was optimized and shown to be free of artifactual acetamide formation. The protocol was validated using a surrogate analyte approach based on d3-acetamide and applied to analyze 23 pasteurized whole milk, 44 raw sirloin beef, and raw milk samples from 14 different cows, and yielded levels about 10-fold lower than those obtained by direct injection without derivatization. The xanthydrol derivatization procedure detected acetamide in every food sample tested at 390 ± 60 ppb in milk, 400 ± 80 ppb in beef, and 39 000 ± 9000 ppb in roasted coffee beans.

Resazurin Live Cell Assay: Setup and Fine-Tuning for Reliable Cytotoxicity Results.

In vitro cytotoxicity tests allow for fast and inexpensive screening of drug efficacy prior to in vivo studies. The resazurin assay (commercialized as Alamar Blue®) has been extensively utilized for this purpose in 2D and 3D cell cultures, and high-throughput screening. However, improper or lack of assay validation can generate unreliable results and limit reproducibility. Herein, we report a detailed protocol for the optimization of the resazurin assay to determine relevant analytical (limits of detection, quantification, and linear range) and biological (growth kinetics) parameters, and, thus, provide accurate cytotoxicity results. Fine-tuning of the resazurin assay will allow accurate and fast quantification of cytotoxicity for drug discovery. Unlike more complicated methods (e.g., mass spectrometry), this assay utilizes fluorescence spectroscopy and, thus, provides a less costly alternative to observe changes in the reductase proteome of the cells.

In Vitro Comparative Study of the Inhibitory Effects of Mangiferin and Its Aglycone Norathyriol towards UDP-Glucuronosyl Transferase (UGT) Isoforms.

Mangiferin (MGF), the predominant constituent of extracts of the mango plant Mangifera Indica L., has been investigated extensively because of its remarkable pharmacological effects. In vitro recombinant UGTs-catalyzed glucuronidation of 4-methylumbelliferone (4-MU) was used to investigate the inhibition of mangiferin and aglycone norathyriol towards various isoforms of UGTs in our study, which evaluated the inhibitory capacity of MGF and its aglycone norathyriol (NTR) towards UDP-glucuronosyltransferase (UGT) isoforms. Initial screening experiment showed that deglycosylation of MGF into NTR strongly increased the inhibitory effects towards almost all the tested UGT isoforms at a concentration of 100 µM. Kinetic experiments were performed to further characterize the inhibition of UGT1A3, UGT1A7 and UGT1A9 by NTR. NTR competitively inhibited UGT1A3, UGT1A7 and UGT1A9, with an IC50 value of 8.2, 4.4, and 12.3 µM, and a Ki value of 1.6, 2.0, and 2.8 µM, respectively. In silico docking showed that only NTR could dock into the activity cavity of UGT1A3, UGT1A7 and UGT1A9. The binding free energy of NTR to UGT1A3, 1A7, 1A9 were -7.4, -7.9 and -4.0 kcal/mol, respectively. Based on the inhibition evaluation standard ([I]/Ki < 0.1, low possibility; 0.1 < [I]/Ki < 1, medium possibility; [I]/Ki > 1, high possibility), an in vivo herb-drug interaction between MGF/NTR and drugs mainly undergoing UGT1A3-, UGT1A7- or UGT1A9-catalyzed metabolism might occur when the plasma concentration of NTR is above 1.6, 2.0 and 2.8 µM, respectively.

High-Throughput Spheroid Screens Using Volume, Resazurin Reduction, and Acid Phosphatase Activity.

Mainstream adoption of physiologically relevant three-dimensional models has been slow in the last 50 years due to long, manual protocols with poor reproducibility, high price, and closed commercial platforms. This chapter describes high-throughput, low-cost, open methods for spheroid viability assessment which use readily available reagents and open-source software to analyze spheroid volume, metabolism, and enzymatic activity. We provide two ImageJ macros for automated spheroid size determination-for both single images and images in stacks. We also share an Excel template spreadsheet allowing users to rapidly process spheroid size data, analyze plate uniformity (such as edge effects and systematic seeding errors), detect outliers, and calculate dose-response. The methods would be useful to researchers in preclinical and translational research planning to move away from simplistic monolayer studies and explore 3D spheroid screens for drug safety and efficacy without substantial investment in money or time.

Tumor ablation using low-intensity ultrasound and sound excitable drug.

The cell membrane is a semi-fluid container that defines the boundary of cells, and provides an enclosed environment for vital biological processes. A sound excitable drug (SED) that is non-cytotoxic to cells is developed to disrupt the plasma membrane under gentle ultrasound insonation, 1MHz, 1W/cm2. The frequency and power density of insonation are within the physical therapy and medical imaging windows; thus the applied ultrasound is safe and not harmful to tissues. The insertion of SEDs into the plasma membrane is not toxic to cells; however, the intruding SEDs weaken the membrane's integrity. Under insonation, the ultrasound energy destabilized the SED disrupted membranes, resulting in membrane rupture and eventual cell death. In a xenograft breast tumor model, the SED alone or the ultrasound alone caused little adverse effects to tumor tissue, while the combined treatment triggered necrosis with a brief local insonation of 3min. The described sono-membrane rupture therapy could be a safe alternative to the currently used high-energy tissue ablation technology, which uses X-rays, gamma rays, electron beams, protons, or high-intensity focused ultrasound.

A new pyranoxanthone from Garcinia nervosa.

Phytochemical studies on the stem bark of Garcinia nervosa has resulted in the discovery of one new pyranoxanthone derivative, garner xanthone (1) and five other compounds, 1,5-dihydroxyxanthone (2), 6-deoxyisojacareubin (3), 12b-hydroxy-des-D-garcigerrin A (4) stigmasterol (5), and ß-sitosterol (6). The structures of these compounds were elucidated with the aid of spectroscopic techniques, such as NMR and MS. The crude extracts of the plant were assessed for their antimicrobial activity.

Determination of antibacterial activity and minimum inhibitory concentration of larval extract of fly via resazurin-based turbidometric assay.

BACKGROUND: Antimicrobial resistance is currently a major global issue. As the rate of emergence of antimicrobial resistance has superseded the rate of discovery and introduction of new effective drugs, the medical arsenal now is experiencing shortage of effective drugs to combat diseases, particularly against diseases caused by the dreadful multidrug-resistant strains, such as the methicillin-resistant Staphylococcus aureus (MRSA). The ability of fly larvae to thrive in septic habitats has prompted us to determine the antibacterial activity and minimum inhibitory concentrations (MICs) of larval extract of flies, namely Lucilia cuprina, Sarcophaga peregrina and Musca domestica against 4 pathogenic bacteria [Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), Pseudomonas aeruginosa and Escherichia coli] via a simple and sensitive antibacterial assay, resazurin-based turbidometric (TB) assay as well as to demonstrate the preliminary chemical profile of larval extracts using gas chromatography-mass spectrophotometry (GC-MS). RESULTS: The resazurin-based TB assay demonstrated that the L. cuprina larval extract was inhibitory against all tested bacteria, whilst the larval extract of S. peregrina and M. domestica were only inhibitory against the MRSA, with a MIC of 100 mg ml-1. Subsequent sub-culture of aliquots revealed that the larval extract of L. cuprina was bactericidal against MRSA whilst the larval extracts of S. peregrina and M. domestica were bacteriostatic against MRSA. The GC-MS analysis had quantitatively identified 20 organic compounds (fatty acids or their derivatives, aromatic acid esters, glycosides and phenol) from the larval extract of L. cuprina; and 5 fatty acid derivatives with known antimicrobial activities from S. peregrina and M. domestica. CONCLUSION: The resazurin-based turbidometric assay is a simple, reliable and feasible screening assay which evidently demonstrated the antibacterial activity of all fly larval extracts, primarily against the MRSA. The larval extract of L. cuprina exerted a broad spectrum antibacterial activity against all tested bacteria. The present study revealed probable development and use of novel and effective natural disinfectant(s) and antibacterial agent(s) from flies and efforts to screen more fly species for antibacterial activity using resazurin-based TB assay should be undertaken for initial screening for subsequent discovery and isolation of potential novel antimicrobial substances, particularly against the multi-drug resistant strains.

Cytotoxicity of seven naturally occurring phenolic compounds towards multi-factorial drug-resistant cancer cells.

INTRODUCTION: In medical oncology, multi-drug resistance (MDR) of cancer cells continues to be a major impediment. We are in quest of novel anti-proliferative agents to overcome drug-resistant tumor cells. METHODS: In the present study, we investigated the cytotoxicity of 7 naturally occurring phenolic compounds including two isoflavonoids alpinumisoflavone (1) and laburnetin (2), one biflavonoid amentoflavone (3), three lignans pycnanthulignene A (4), pycnanthulignene B (5), and syringaresinol (7) and one xanthone, euxanthone (6) against 9 drug-sensitive and MDR cancer cell lines. The resazurin reduction assay was used to evaluate the cytotoxicity of these compounds, whilst caspase-Glo assay was used to detect caspase activation. Cell cycle, mitochondrial membrane potential (MMP) and levels of reactive oxygen species (ROS) were all analyzed via flow cytometry. RESULTS: The IC50 values for the investigational phenolics ranged from 5.91 µM (towards leukemia CEM/ADR5000 cells) to 65.65 µM (towards drug-resistant breast adenocarcinoma MDA-MB-231-BCRP cells) for 1, 27.63 µM (towards leukemia CCRF-CEM cells) to 107.57 µM (towards MDA-MB-231-pcDNA cells) for 2, from 5.84 µM (towards CEM/ADR5000 cells) to 65.32 µM (towards colon carcinoma HCT116 (p53(-/-)) cells) for 4 and 0.20 µM (towards CCRF-CEM cells) to 195.12 µM (towards leukemia CEM/ADR5000) for doxorubicin. Phenolics 3, 5, 6 and 7 displayed selectivity cytotoxic effects on cancer cells lines. Compounds 1 and 4 induced apoptosis in CCRF-CEM cells, mediated by loss of MMP and increase ROS production. CONCLUSIONS: The studied phenolics and mostly isoflavonoid 1 and lignan 4 are potential cytotoxic natural products that deserve more investigations to develop novel antineoplastic drugs against multifactorial drug-resistant cancers.