ABSTRACT
Fifteen stilbenoid derivatives, including five previously undescribed ones (albaphenols A-E, 1-5) with diverse scaffolds, were obtained from the well-known agricultural economic tree Morus alba. Their structures, including absolute stereochemistries, were fully characterized by detailed interpretation of spectroscopic data and quantum chemical computational analyses of nuclear magnetic resonance (NMR) and electric circular dichroism (ECD). Albaphenol A (1) features an unprecedented rearranged carbon skeleton incorporating a novel 2-oxaspiro[bicyclo[3.2.1]octane-6,3'-furan] motif; albaphenol C (3) is likely derived from a cometabolite through an interesting intramolecular transesterification reaction; and albaphenol E (5) bears a cleavage-reconnection scaffold via a dioxane ring. All of the compounds exhibited significant inhibition against the diabetic target α-glucosidase, with low to submicromole IC50 values (0.70-8.27 µM), and the binding modes of selected molecules with the enzyme were further investigated by fluorescence quenching, kinetics, and molecular docking experiments. The antidiabetic effect of the most active and abundant mulberrofuran G (6) was further assessed in vivo in diabetic mice, revealing potent antihyperglycemic activity and comparable antidiabetic efficacy to the clinical drug acarbose.
Subject(s)
Glycoside Hydrolase Inhibitors , Hypoglycemic Agents , Molecular Docking Simulation , Morus , Plant Extracts , Stilbenes , alpha-Glucosidases , Animals , Glycoside Hydrolase Inhibitors/chemistry , Glycoside Hydrolase Inhibitors/pharmacology , Mice , Hypoglycemic Agents/chemistry , Hypoglycemic Agents/pharmacology , Stilbenes/chemistry , Stilbenes/pharmacology , alpha-Glucosidases/chemistry , alpha-Glucosidases/metabolism , Male , Morus/chemistry , Plant Extracts/chemistry , Plant Extracts/pharmacology , Humans , Molecular Structure , Structure-Activity Relationship , KineticsABSTRACT
The effect and underlying mechanism of tetrabromobisphenol A (TBBPA), a plastic additive, on biofilm formation of methicillin-resistant Staphylococcus aureus (MRSA USA300) remain unknown. This study first investigated the impact of different concentrations of TBBPA on the growth and biofilm formation of USA300. The results indicated that a low concentration (0.5â¯mg/L) of TBBPA promoted the growth and biofilm formation of USA300, whereas high concentrations (5â¯mg/L and 10â¯mg/L) of TBBPA had inhibitory effects. Further exploration revealed that the low concentration of TBBPA enhance biofilm formation by promoting the synthesis of extracellular proteins, release of extracellular DNA (eDNA), and production of staphyloxanthin. RTqPCR analysis demonstrated that the low concentration of TBBPA upregulated genes associated with extracellular protein synthesis (sarA, fnbA, fnbB, aur) and eDNA formation (atlA) and increased the expression of genes involved in staphyloxanthin biosynthesis (crtM), suggesting a potential mechanism for enhanced resistance of USA300 to adverse conditions. These findings shed light on how low concentrations of TBBPA facilitate biofilm formation in USA300 and highlight the indirect impact of plastic additives on pathogenic bacteria in terms of human health. In the future, in-depth studies about effects of plastic additives on pathogenicity of pathogenic bacteria should be conducted. CAPSULE: The protein and eDNA contents in biofilms of methicillin-resistant Staphylococcus aureus are increased by low concentrations of TBBPA.
ABSTRACT
A focused chemical investigation into the polar fractions of a well-known traditional Chinese medicine called Sang-Bai-Pi (the root bark of Morus alba) yielded a panel of prenylated flavanones. The new compounds were identified as four pairs of enantiomers (1a/1b-4a/4b) featuring the same constitution structure, on the basis of HRMS, NMR and ECD analyses. Several previously reported known racemic co-metabolites were also analyzed and separated by HPLC on chiral columns, and the absolute configurations of pure enantiomers were established via ECD technique for the first time. The inhibition of these isolates against the antidiabetic target a-glycosidase was further tested, with most of them showing decent inhibitory activity compared with the positive control acarbose. The interaction mechanism of two selected compounds (3a & 4b) was explored by kinetics experiment, which revealed a mixed type of inhibition pattern toward the enzyme.
ABSTRACT
SCOPE: Naringenin (NAR) possesses unique anti-inflammatory, antiapoptosis effects and various bioactivities; however, its role against radiation-induced intestinal injury (RIII) remains unclear. This study aims to investigate whether NAR has protective effects against radiation-induced intestinal injury and the underlying mechanisms. METHODS AND RESULTS: C57BL/6J mice are exposed to a single dose of 13 Gy X-ray total abdominal irradiation (TAI), then gavaged with NAR for 7 days. NAR treatment prolongs the survival rate, protects crypts and villi from damage, alleviates the level of radiation-induced inflammation, and mitigates intestinal barrier damage in the irradiated mice. Additionally, NAR reduces immune cell infiltration and intestinal epithelial cell apoptosis. NAR also shows radioprotective effects in human colon cancer cells (HCT116) and human intestinal epithelial cells (NCM460). It reduces cell damage by reducing intracellular calcium ion levels and reactive oxygen species (ROS) levels. NAR-mediated radioprotection is associated with the downregulation of transient receptor potential vanilloid 6 (TRPV6), and inhibition of apoptosis pathway. Notably, treatment with NAR fails to further increase the protective effects of the TRPV6 inhibitor 2-APB, indicating that TRPV6 inhibition is essential for NAR activity. CONCLUSION: NAR inhibits the apoptosis pathway by downregulating TRPV6 and reducing calcium ion level, thereby alleviating RIII. Therefore, NAR is a promising therapeutic drug for RIII.
Subject(s)
Apoptosis , Flavanones , Mice, Inbred C57BL , Reactive Oxygen Species , TRPV Cation Channels , Animals , Flavanones/pharmacology , Humans , TRPV Cation Channels/metabolism , Apoptosis/drug effects , Reactive Oxygen Species/metabolism , Male , Mice , Radiation-Protective Agents/pharmacology , Intestinal Mucosa/drug effects , Intestinal Mucosa/radiation effects , Intestinal Mucosa/metabolism , HCT116 Cells , Calcium Channels/metabolism , Intestines/drug effects , Intestines/radiation effects , Calcium/metabolism , Radiation Injuries/drug therapyABSTRACT
Klinefelter syndrome (KS) is the most frequent genetic anomaly in infertile men. Given its unclear mechanism, we aim to investigate critical genes and pathways in the pathogenesis of KS based on three bulk and one single-cell transcriptome data sets from Gene Expression Omnibus. We merged two data sets (GSE42331 and GSE47584) with human KS whole blood samples. When comparing the control and KS samples, five hub genes, including defensin alpha 4 (DEFA4), bactericidal permeability increasing protein (BPI), myeloperoxidase (MPO), intelectin 1 (ITLN1), and Xg Glycoprotein (XG), were identified. Besides, infiltrated degree of certain immune cells such as CD56bright NK cell were positively associated with the expression of ITLN1 and XG. Kyoto Encyclopedia of Genes and Genomes analysis identified upregulated phosphatidylinositol 3-kinase (PI3K)/AKT pathway in KS. Gene set enrichment analysis followed by gene set variation analysis confirmed the upregulation of G2M checkpoint and heme metabolism in KS. Thereafter, the GSE200680 data set was used for external validation of the expression variation of hub genes from healthy to KS testicular samples, and each hub gene yielded excellent discriminatory capability for KS without exception. At the single-cell level, the GSE136353 data set was utilized to evaluate intercellular communication between different cell types in KS patient, and strong correlations were detected between macrophages/ dendritic cells/ NK cells and the other cell types. Collectively, we provided hub genes, pathways, immune cell infiltration degree, and cell-cell communication in KS, warranting novel insights into the pathogenesis of this disease.
ABSTRACT
Plasmonic nanostructures have great potential for improving the radiation properties of emitters. Here, the plasmonic Au nanorods-PVA nanocomposite films are used to uniformly improve the photoluminescence of Tb/Eu co-doped PMMA film within the local micro-region. Under the excitation of 292â nm, the maximum enhancement factor is 37.2-fold for emission at 612â nm and 21.6-fold for emission at 545â nm. Moreover, the finite different time domain simulations are developed to further explain the experimental results. It is indicated that the modulation of luminescence can be attributed to the increase of the local density of optical states through the Purcell effect and the improvement of the energy transfer efficiency between Tb and Eu. Under the excitation of 360â nm, the maximum enhancement factor is about 71.5-fold. In this case, the Au nanorods are mainly used for modulating the emission process at 612â nm, which deduced a greater enhancement factor at 612â nm. This study provides a deep understanding of the interactions between rare earth ions co-doped materials and plasmonic nanostructures, building a bridge to fabricate a useful platform for several applications, such as thin film-based detectors and sensors.
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INTRODUCTION: Nightclubs are entertainment and hospitality venues historically vulnerable to terrorist attacks. This study identified and characterized terrorist attacks targeting nightclubs and discotheques documented in the Global Terrorism Database (GTD) over a 50-y period. METHODS: A search of the Global Terrorism Database (GTD) was conducted from 1970 to 2019. Precoded variables for target type "business" and target subtype "entertainment/cultural/stadium/casino" were used to identify attacks potentially involving nightclubs. Nightclub venues were specifically identified using the search terms "club," "nightclub," and "discotheque." Two authors manually reviewed each entry to confirm the appropriateness for inclusion. Descriptive statistics were performed using R (3.6.1). RESULTS: A total of 114 terrorist attacks targeting nightclub venues were identified from January 1, 1970, through December 31, 2019. Seventy-four (64.9%) attacks involved nightclubs, while forty (35.1%) attacks involved discotheques. A bombing or explosion was involved in 84 (73.7%) attacks, followed by armed assault in 14 (12.3%) attacks. The highest number of attacks occurred in Western Europe and Sub-Saharan Africa. In total, 284 persons died, and 1175 persons were wounded in attacks against nightclub venues. CONCLUSIONS: While terrorist attacks against nightclub venues are infrequent, the risk for mass casualties and injuries can be significant, mainly when explosives and armed assaults are used.
Subject(s)
Mass Casualty Incidents , Terrorism , Humans , EuropeABSTRACT
ETHNOPHARMACOLOGICAL RELEVANCE: Morus alba L. (mulberry) is a well-known medicinal species that has been used by herbalist doctors for the treatment of diabetes for a long history, and modern ethnopharmacological studies have demonstrated the ameliorating effects of different mulberry extracts toward diabetes-related symptoms and identified a number of α-glucosidase inhibitors as hypoglycemic ingredients. AIM OF THE STUDY: The present study aims to explore new potent α-glucosidase inhibitors from the root bark of M. alba (known as Sang-Bai-Pi in traditional medicine) based on an in vivo antidiabetic evaluation of its extract fractions and further characterize the preliminary mechanism of the new active constituents. MATERIALS AND METHODS: α-Glucosidase inhibitory assay and diabetic mice model were used to locate and evaluate the active fractions from the extract. Diverse separation techniques (e.g. Sephadex LH-20 column chromatograph (CC) and HPLC) and spectroscopic methods (e.g. MS, NMR and ECD) were employed to isolate and structurally characterize the obtained constituents, respectively. Fluorescence quenching, kinetics and molecular docking experiments were conducted to investigate the enzyme inhibitory mechanism of the active compounds. RESULTS: The 80% ethanol eluate from the macroporous resin CC exerted good antidiabetic effects in the tested mice. Fifty-two flavonoids including 22 new ones were then separated and identified, and most of them showed strong inhibition against α-glucosidase with their structure-activity relationship being also discussed. The four new most active ingredients were further characterized to be mixed type of α-glucosidase inhibitors, and their binding modes with the enzyme were also explored. CONCLUSIONS: Our current work has demonstrated that the root bark of M. alba is an extremely rich source of flavonoids as potent α-glucosidase inhibitors and potential antidiabetic agents, which makes it a promising candidate species to develop new natural remedies for the prevention and treatment of diabetes.
Subject(s)
Diabetes Mellitus, Experimental , Morus , Mice , Animals , Glycoside Hydrolase Inhibitors/pharmacology , Glycoside Hydrolase Inhibitors/chemistry , alpha-Glucosidases/metabolism , Diabetes Mellitus, Experimental/drug therapy , Molecular Docking Simulation , Morus/chemistry , Hypoglycemic Agents/pharmacology , Hypoglycemic Agents/therapeutic use , Hypoglycemic Agents/chemistry , Plant Extracts/therapeutic use , Flavonoids/pharmacology , Flavonoids/therapeutic use , Flavonoids/chemistryABSTRACT
The combination of Cartesian grid and the adaptive mesh refinement (AMR) technology is an effective way to handle complex geometry and solve complex flow problems. Some high-efficiency Cartesian-based AMR libraries have been developed to handle dynamic changes of the grid in parallel but still can not meet the unique requirements of simulating flow around objects. In this paper, we propose an efficient Cartesian grid generation method and an information transmission approach for the wall boundary to parallelize the implementation of ghost-cell method (GCM). Also, the multi-valued ghost-cell method to handle multi-value points is improved to adapt to the parallel framework. Combining the mentioned methodologies with the open-source library p4est, an automatic and efficient simulation of compressible flow is achieved. The overall performance of the methodology is tested through a wide range of inviscid/viscous flow cases. The results indicate that the capability and parallel scalability of the present numerical methodology for solving multiple types of flows, involving shock and vortices, multi-body flow and unsteady flows are agreeable as compared with related reference data.