Acute oral toxicity of damnacanthal and its anticancer activity against colorectal tumorigenesis.

Damnacanthal is an anthraquinone, extracted, and purified from the root of Morinda citrifolia in Thailand. This study aimed to measure acute oral toxicity and to investigate the anticancer activity of damnacanthal in colorectal tumorigenesis. We found that the growth of human colorectal cancer cells was inhibited by damnacanthal in a dose- and a time-dependent manner. The growth inhibitory effect of damnacanthal was better than that of 5-FU used as a positive control in colorectal cancer cells, along with the downregulation of cell cycle protein cyclin D1. Similarly, an oral treatment of damnacanthal effectively inhibited the growth of colorectal tumor xenografts in nude mice, which was approximately 2-3-fold higher as compared to 5-FU by tumor size as well as expression of bioluminescence. Furthermore, the study of acute oral toxicity in mice exhibited a relatively low toxicity of damnacanthal with a LD50 cut-off value of 2500 mg/kg according to OECD Guideline 423. These results reveal the potential therapeutic activity of a natural damnacanthal compound as an anti-colorectal cancer drug.

From structure to function - Ligand recognition by myeloid C-type lectin receptors.

The relevance of protein-glycan interactions in immunity has long been underestimated. Yet, the immune system possesses numerous classes of glycan-binding proteins, so-called lectins. Of specific interest is the group of myeloid C-type lectin receptors (CLRs) as they are mainly expressed by myeloid cells and play an important role in the initiation of an immune response. Myeloid CLRs represent a major group amongst pattern recognition receptors (PRRs), placing them at the center of the rapidly growing field of glycoimmunology. CLRs have evolved to encompass a wide range of structures and functions and to recognize a large number of glycans and many other ligands from different classes of biopolymers. This review aims at providing the reader with an overview of myeloid CLRs and selected ligands, while highlighting recent insights into CLR-ligand interactions. Subsequently, methodological approaches in CLR-ligand research will be presented. Finally, this review will discuss how CLR-ligand interactions culminate in immunological functions, how glycan mimicry favors immune escape by pathogens, and in which way immune responses can be affected by CLR-ligand interactions in the long term.

Ginsengenin derivatives synthesized from 20(R)-panaxotriol: Synthesis, characterization, and antitumor activity targeting HIF-1 pathway.

Background: Ginseng possesses antitumor effects, and ginsenosides are considered to be one of its main active chemical components. Ginsenosides can further be hydrolyzed to generate secondary saponins, and 20(R)-panaxotriol is an important sapogenin of ginsenosides. We aimed to synthesize a new ginsengenin derivative from 20(R)-panaxotriol and investigate its antitumor activity in vivo and in vitro. Methods: Here, 20(R)-panaxotriol was selected as a precursor and was modified into its derivatives. The new products were characterized by 1H-NMR, 13C-NMR and HR-MS and evaluated by molecular docking, MTT, luciferase reporter assay, western blotting, immunofluorescent staining, colony formation assay, EdU labeling and immunofluorescence, apoptosis assay, cells migration assay, transwell assay and in vivo antitumor activity assay. Results: The derivative with the best antitumor activity was identified as 6,12-dihydroxy-4,4,8,10,14-pentamethyl-17-(2,6,6-trimethyltetrahydro-2H-pyran-2-yl)hexadecahydro-1H-cyclopenta[a]phenanthren-3-yl(tert-butoxycarbonyl)glycinate (A11). The focus of this research was on the antitumor activity of the derivatives. The efficacy of the derivative A11 (IC50 < 0.3 µM) was more than 100 times higher than that of 20(R)- panaxotriol (IC50 > 30 µM). In addition, A11 inhibited the protein expression and nuclear accumulation of the hypoxia-inducible factor HIF-1α in HeLa cells under hypoxic conditions in a dose-dependent manner. Moreover, A11 dose-dependently inhibited the proliferation, migration, and invasion of HeLa cells, while promoting their apoptosis. Notably, the inhibition by A11 was more significant than that by 20(R)-panaxotriol (p < 0.01) in vivo. Conclusion: To our knowledge, this is the first study to report the production of derivative A11 from 20(R)-panaxotriol and its superior antitumor activity compared to its precursor. Moreover, derivative A11 can be used to further study and develop novel antitumor drugs.

Antifungal compounds of Chinese prickly ash against drug-resistant Candida albicans.

The leaf of Chinese prickly ash, a unique spice having typical pungent sensation, is a popular food in Southwest China with antipruritic, insecticidal and fungicidal functions, but its bioactive constituents of fungistatic capacity remain unknown. In present investigation, twenty-nine compounds were isolated from leaf of Chinese prickly ash, and their antifungal bioactivity against drug-resistant Candida albicans were evaluated in vitro and in vivo. As a result, three compounds 3, 10, 29 showed antifungal bioactivity by damage of the fungal biofilm, and they might recover sensitive of drug resistant C. albicans to Fluconazole. Then Chinese prickly ash leaf was proved to be a functional food against fungus for the first time in experiment.

Generation of an in vitro model for peripheral neuropathy in Fabry disease using CRISPR-Cas9 in the nociceptive dorsal root ganglion cell line 50B11.

Fabry disease is a glycosphingolipid storage disorder that is caused by a genetic deficiency of the lysosomal enzyme alpha-galactosidase A (AGA, EC 3.2.1.22). As a result, the glycolipid substrate, globotriaosylceramide (Gb3) accumulates in various cell types throughout the body producing a multisystem disease that affects the vascular, cardiac, renal, and nervous systems. A hallmark of this disorder is neuropathic pain that occurs in up to 80% of Fabry patients and has been characterized as a small fiber neuropathy. The molecular mechanism by which changes in AGA activity produce neuropathic pain is not clear, in part due to a lack of relevant model systems. Using 50B11 cells, an immortalized dorsal root ganglion neuron with nociceptive characteristics derived from rat, we used CRISPR-Cas9 gene editing of the galactosidase alpha (GLA) gene for AGA to create two stable knock-out clones that have the phenotypic characteristics of Fabry cells. The cell lines show severely reduced lysosomal AGA activity in homogenates as well as impaired degradation of Gb3 in cultured cells. This phenotype is stable over long-term culture. Similar to the unedited 50B11 cell line, the clones differentiate in response to forskolin and extend neurites. Flow cytometry experiments demonstrate that the gene-edited cells express TRPV1 pain receptor at increased levels compared to control, suggesting a possible mechanism for increased pain sensitization in Fabry patients. Our 50B11 cell lines show phenotypic characteristics of Fabry disease and grow well under standard cell culture conditions. These cell lines can provide a convenient model system to help elucidate the molecular mechanism of pain in Fabry patients.

Towards discovery of inhibitors of the undecaprenyl-pyrophosphate phosphatase BacA by virtual high-throughput screening.

Increasing resistance to common antibiotics is becoming a major challenge that requires the development of new antibacterial agents. Peptidoglycan is an essential heteropolymer of the bacterial envelope that ensures the integrity and shape of all bacteria and is also an important target for antibiotics. The biosynthesis of peptidoglycan depends on a lipid carrier, undecaprenyl phosphate. As a byproduct of peptidoglycan polymerization, the lipid carrier is released as undecaprenyl pyrophosphate, which must be recycled to allow new polymerization cycles. To this end, it undergoes a dephosphorylation process catalyzed by the membrane phosphatase BacA, which is specific and highly conserved in bacteria. In the present study, we identified small molecules displaying inhibitory potency towards BacA. We began by preparing a commercial compound library, followed by high-throughput virtual screening by ensemble docking using the 3D structure of BacA and molecular dynamics snapshots to account for the flexibility of the protein. Of 83 compounds computationally selected and tested in a biochemical assay, one sulfamoylthiophene molecule showed significant inhibition of the undecaprenyl pyrophosphate dephosphorylation activity catalyzed by BacA. Subsequently, an additional 33 scaffold analogs were selected and acquired, of which 6 compounds exhibited BacA inhibition. The IC50 values of these compounds ranged from 42 to 366 µM. In addition, significant antibacterial activity against Escherichia coli was observed in TolC/PAP2-depleted strains. We believe that the overall strategy followed in this study and the identified class of inhibitors provide a solid foundation for the further development of potent BacA-targeted inhibitors and the discovery of novel antibacterial compounds.

Extract of Xylopia aethiopica and its kaurene diterpene, xylopic acid, improve learning and memory in mice.

Background: Cognitive dysfunction, presenting as learning and memory impairment, is a common manifestation in many chronic diseases of the nervous system. Some of these diseases include depression, epilepsy, and Alzheimer's disease. To date, few drugs or medicinal products have shown ability to improve learning and memory deficits. Neuroprotection is one of the mechanisms by which memory could be improved. The extract of Xylopia aethiopica and its kaurene derivative, xylopic acid, have previously demonstrated neuroprotective effects in animal models. The aim of the present study was to investigate the effect of an extract of Xylopia aethiopica fruit and xylopic acid, on learning and memory using murine models. Materials and methods: Unripe Xylopia aethiopica fruits were collected, dried, and extracted using 70% v/v ethanol. Xylopic acid was isolated from the fruits using petroleum ether, concentrated with ethyl acetate and then recrystallized with petroleum ether before purifying with ethanol (96%v/v). Institute of Cancer Research (ICR) mice received oral doses of the extract of Xylopia aethiopica (XAE; 30, 100 and 300 mg/kg), xylopic acid (XA; 30, 100 and mg/kg), citicoline (300 mg/kg), piracetam (300 mg/kg) or ketamine (30 mg/kg) and saline (vehicle). The animals were then taken through the Morris water maze test (MWM), spontaneous alternation Y-maze test (Y-maze), and novel object recognition test (NOR), to assess learning and memory. Results: In the NOR test, XAE (30, 100 and 300 mg/kg) and XA (30, 100 and 300 mg/kg) increased the percentage exploration and recognition index (p = 0.0005 and p < 0.0001, respectively) when compared to both vehicle and ketamine groups. Similarly, doses of XAE and XA as used in the NOR test increased the percentage alternation in the Y-maze test. Although XAE and XA treatments decreased the latencies to find hidden platform in the MWM test, it was not significantly different from the vehicle group. However, this decrease in latency differed significantly when compared to the ketamine group. Interestingly, both XAE and XA treatments increased the percentage frequency to the target quadrant in the probe trial of the MWM. It is noteworthy that in all the three models used, both the extract and xylopic acid performed better than piracetam and citicoline, the reference drugs. Conclusion: The ethanolic extract of Xylopia aethiopica fruit and xylopic acid improved exploratory learning and recognition memory, spatial working, recognition, and reference memories in the behavioral tests.

Free energy perturbation (FEP)-guided scaffold hopping.

Scaffold hopping refers to computer-aided screening for active compounds with different structures against the same receptor to enrich privileged scaffolds, which is a topic of high interest in organic and medicinal chemistry. However, most approaches cannot efficiently predict the potency level of candidates after scaffold hopping. Herein, we identified potent PDE5 inhibitors with a novel scaffold via a free energy perturbation (FEP)-guided scaffold-hopping strategy, and FEP shows great advantages to precisely predict the theoretical binding potencies ΔG FEP between ligands and their target, which were more consistent with the experimental binding potencies ΔG EXP (the mean absolute deviations | Δ G FEP - Δ G EXP |  < 2 kcal/mol) than those ΔG MM-PBSA or ΔG MM-GBSA predicted by the MM-PBSA or MM-GBSA method. Lead L12 had an IC50 of 8.7 nmol/L and exhibited a different binding pattern in its crystal structure with PDE5 from the famous starting drug tadalafil. Our work provides the first report via the FEP-guided scaffold hopping strategy for potent inhibitor discovery with a novel scaffold, implying that it will have a variety of future applications in rational molecular design and drug discovery.

Kombucha - An ancient fermented beverage with desired bioactivities: A narrowed review.

Kombucha, originated in China 2000  years ago, is a sour and sweet-tasted drink, prepared traditionally through fermentation of black tea. During the fermentation of kombucha, consisting of mainly acidic compounds, microorganisms, and a tiny amount of alcohol, a biofilm called SCOBY forms. The bacteria in kombucha has been generally identified as Acetobacteraceae. Kombucha is a noteworthy source of B complex vitamins, polyphenols, and organic acids (mainly acetic acid). Nowadays, kombucha is tended to be prepared with some other plant species, which, therefore, lead to variations in its composition. Pre-clinical studies conducted on kombucha revealed that it has desired bioactivities such as antimicrobial, antioxidant, hepatoprotective, anti-hypercholestorelomic, anticancer, anti-inflammatory, etc. Only a few clinical studies have been also reported. In the current review, we aimed to overhaul pre-clinical bioactivities reported on kombucha as well as its brief compositional chemistry. The literature data indicate that kombucha has valuable biological effects on human health.

Administration of Aspergillus oryzae suppresses DSS-induced colitis.

Aspergillus oryzae, a filamentous fungus, has long been used for the production of traditional Japanese foods. Here, we analyzed how A. oryzae administration affects the intestinal environment in mice. The results of 16S rRNA gene sequencing of the gut microbiota indicated that after the administration of heat-killed A. oryzae spores, the relative abundance of an anti-inflammatory Bifidobacterium pseudolongum strain became 2.0-fold greater than that of the control. Next, we examined the effect of A. oryzae spore administration on the development of colitis induced by dextran sodium sulfate in mice; we found that colitis was alleviated by not only heat-killed A. oryzae spores, but also the cell wall extracted from the spores. Our findings suggest that A. oryzae holds considerable potential for commercial application in the production of both traditional Japanese fermented foods and new foods with prebiotic functions.

Synthesis and anti-Toxoplasma activity of indole-triazole compounds on tachyzoites of RH strain.

BACKGROUND: Conventional treatment for toxoplasmosis have severe side effects and the inability to completely eradicate the disease. Therefore, the acquisition of new anti-Toxoplasma drugs has always been of interest among researchers. In the present study, we prepare a new indole-triazole derivatives and evaluated their potential anti-parasitic activity against tachyzoites of Toxoplasma RH strain. MATERIALS AND METHODS: In this study, after synthesis of the two new compounds of indole-triazole, the effect of their different concentrations (2-1024 µg/ml) were determined on Toxoplasma tachyzoites using flow cytometry. Furthermore, tachyzoites were exposed to different concentrations of compounds (4, 16, 64, 265, 1024 µg/ml) for 1.5 h and their infectivity were evaluated in BALB/c mice. RESULTS: The flow cytometry results indicated the benzyl derivative of indole-triazole in various concentrations had a lethal effect on tachyzoites between 11.93% and 89.66%, while the naphthalene derivative had a lethality of 26.63%-66.82%. The infectivity analysis showed that the survival time of mice at concentrations of 1024 µg/ml and 512 µg/ml of benzyl derivatives was significantly increased (P = 0.008 and P = 0.016, respectively), compared to that in the negative control group. Furthermore, survival time of mice was statistically significant at the concentration of 1024 µg/ml for naphthyl derivative (P = 0.012). CONCLUSION: Findings of the current study suggested indole triazole compounds, based on their structure and enzymes targeting, have a considerable effect on tachyzoites of T. gondii RH strain and can be considered as a new anti-Toxoplasma agent.

Piper crocatum Ruiz & Pav. ameliorates wound healing through p53, E-cadherin and SOD1 pathways on wounded hyperglycemia fibroblasts.

INTRODUCTION: Piper crocatum Ruiz & Pav (P. crocatum) has been reported to accelerate the diabetic wound healing process empirically. Some studies showed the benefits of P. crocatum in treating various diseases but its mechanisms in diabetic wound healing have never been reported. In the present study we investigated the diabetic wound healing activity of the active fraction of P. crocatum on wounded hyperglycemia fibroblasts (wHFs). METHODS: Bioassay-guided fractionation was performed to get the most active fraction. The selected active fraction was applied to wHFs within 72 h incubation. Mimicking a diabetic condition was done using basal glucose media containing an additional 17 mMol/L D-glucose. A wound was simulated via the scratch assay. The collagen deposition was measured using Picro-Sirius Red and wound closure was measured using scratch wound assay. Underlying mechanisms through p53, αSMA, SOD1 and E-cadherin were measured using western blotting. RESULTS: We reported that FIV is the most active fraction of P. crocatum. We confirmed that FIV \(7.81 µg/ml, 15.62 µg/ml, 31.25 µg/ml, 62.5 µg/ml, and 125 µg/ml) induced the collagen deposition and wound closure of wHFs. Furthermore, FIV treatment (7.81 µg/ml, 15.62 µg/ml, 31.25 µg/ml) down-regulated the protein expression level of p53 and up-regulated the protein expression levels of αSMA, E-cadherin, and SOD1. DISCUSSION/CONCLUSIONS: Our findings suggest that ameliorating collagen deposition and wound closure through protein regulation of p53, αSMA, E-cadherin, and SOD1 are some of the mechanisms by which FIV of P. crocatum is involved in diabetic wound healing therapy.

MC5R Contributes to Sensitivity to UVB Waves and Barrier Function in Mouse Epidermis.

MC5R is known for its role in the exocrine function of sebaceous glands, but other functions in the epidermis remain unclear. This study focused on the relationship between MC5R and homeostasis in the epidermis and examined the role of MC5R in mice whose skin was irradiated with UVB waves. UVB irradiation-induced skin ulcers and severe inflammation at lower doses in homozygotes of MC5R-deficient (i.e., MC5R -/- ) mice (150 mJ/cm2) than the doses in wild-type mice (500 mJ/cm2). Transepidermal water loss was increased (approximately 10-fold) in adult MC5R -/- mice compared with that in wild-type mice. In neonates, a dye exclusion assay showed no remarkable difference between MC5R -/- and wild-type mice. After UVB irradiation, compared with wild-type mice, MC5R -/- mice showed increased inflammatory cell infiltration in the dermis of the ulcerative region, significantly increased thickness of the epidermis in the nonulcerative region, significantly more prickle cells in the nonulcerative region, and increased serum IL-6 levels but decreased IL-10 levels. Transmission electron microscopy revealed fewer lamellar granules, less lipid secretion, and an expansion of the trans-Golgi network in the epidermis in MC5R -/- mice. This study elucidated the increased sensitivity to UVB irradiation and decreased barrier function in MC5R -/- mice.

Comparative urinary globotriaosylceramide analysis by thin-layer chromatography-immunostaining and liquid chromatography-tandem mass spectrometry in patients with Fabry disease.

In Fabry disease, accumulation of glycolipids, predominantly globotriaosylceramide (Gb3), affects the kidneys, and nephropathy is one of the important disorders that influence the disease severity and prognosis of patients. Urinary Gb3 has been analyzed for diagnosis and monitoring of Fabry disease. In this study, we analyzed urinary Gb3 by thin-layer chromatography (TLC)-immunostaining and liquid chromatography (LC)-tandem mass spectrometry (MS/MS). An improved qualitative method, TLC-immunostaining, revealed excessive urinary Gb3 excretion in 100 (8/8), 88 (14/16), and 74% (45/61) of the classic Fabry males, later-onset Fabry males, and Fabry females examined, respectively. This authentic method is robust, easy, economic, and hardly affected by abundant urinary sediment, and this is useful for diagnosing individual Fabry patients. LC-MS/MS can determine the level of Gb3 in urine with high sensitivity, and it revealed that the Gb3 excretion level was higher in the order of classic Fabry males, later-onset Fabry males, Fabry females, and controls, respectively, and this is expected to be a useful quantitative method not only for diagnosis but also for predicting the progression of Fabry nephropathy. As to the relation of the urinary Gb3 level and renal events, our study revealed that the urinary Gb3 level in Fabry patients experiencing renal events tended to be higher than that in ones who did not have any renal events in each phenotypic group of the disease.

Discovery of a potent and dual-selective bisubstrate inhibitor for protein arginine methyltransferase 4/5.

Protein arginine methyltransferases (PRMTs) have been implicated in the progression of many diseases. Understanding substrate recognition and specificity of individual PRMT would facilitate the discovery of selective inhibitors towards future drug discovery. Herein, we reported the design and synthesis of bisubstrate analogues for PRMTs that incorporate a S-adenosylmethionine (SAM) analogue moiety and a tripeptide through an alkyl substituted guanidino group. Compound AH237 is a potent and selective inhibitor for PRMT4 and PRMT5 with a half-maximal inhibition concentration (IC50) of 2.8 and 0.42 nmol/L, respectively. Computational studies provided a plausible explanation for the high potency and selectivity of AH237 for PRMT4/5 over other 40 methyltransferases. This proof-of-principle study outlines an applicable strategy to develop potent and selective bisubstrate inhibitors for PRMTs, providing valuable probes for future structural studies.

In vitro fecal fermentation characteristics of bamboo shoot (Phyllostachys edulis) polysaccharide.

The effects of Moso bamboo (Phyllostachys edulis) shoot polysaccharide (BSP) on the human gut microbiota composition and volatile metabolite components were investigated by in vitro fermentation. After fermentation for 48 h, BSP utilization reached 40.29% and the pH of the fermentation solution decreased from 6.89 to 4.57. Moreover, the total short-chain fatty acid concentration significantly (P < 0.05) increased from 13.46 mM (0 h) to 43.20 mM (48 h). 16S rRNA analysis revealed several differences in the gut microbiota community structure of the BSP-treated and water-treated (control) cultures. In the BSP group, the abundance of Firmicutes, Actinobacteria, and Proteobacteria was significantly increased, while that of Bacteroidetes and Fusobacteria significantly decreased. Moreover, the concentrations of benzene, its substituted derivatives, and carbonyl compounds in the volatile metabolites of the BSP-treated group decreased, while that of organic acids significantly increased after 48 h of fermentation. These results demonstrate that BSP improves gastrointestinal health.

Crystal structure of a homotrimeric verrucomicrobial exo-ß-1,4-mannosidase active in the hindgut of the wood-feeding termite Reticulitermes flavipes.

The termite Reticulitermes flavipes causes extensive damage due to the high efficiency and broad specificity of the ligno- and hemicellulolytic enzyme systems produced by its symbionts. Thus, the R. flavipes gut microbiome is expected to constitute an excellent source of enzymes that can be used for the degradation and valorization of plant biomass. The symbiont Opitutaceae bacterium strain TAV5 belongs to the phylum Verrucomicrobia and thrives in the hindgut of R. flavipes. The sequence of the gene with the locus tag opit5_10225 in the Opitutaceae bacterium strain TAV5 genome has been classified as a member of glycoside hydrolase family 5 (GH5), and provisionally annotated as an endo-ß-mannanase. We characterized biochemically and structurally the opit5_10225 gene product, and show that the enzyme, Op5Man5, is an exo-ß-1,4-mannosidase [EC 3.2.1.25] that is highly specific for ß-1,4-mannosidic bonds in mannooligosaccharides and ivory nut mannan. The structure of Op5Man5 was phased using electron cryo-microscopy and further determined and refined at 2.2 Šresolution using X-ray crystallography. Op5Man5 features a 200-kDa large homotrimer composed of three modular monomers. Despite insignificant sequence similarity, the structure of the monomer, and homotrimeric assembly are similar to that of the GH42-family ß-galactosidases and the GH164-family exo-ß-1,4-mannosidase Bs164 from Bacteroides salyersiae. To the best of our knowledge Op5Man5 is the first structure of a glycoside hydrolase from a bacterial symbiont isolated from the R. flavipes digestive tract, as well as the first example of a GH5 glycoside hydrolase with a GH42 ß-galactosidase-type homotrimeric structure.

Mycobacterium abscessus biofilms produce an extracellular matrix and have a distinct mycolic acid profile.

A non-tuberculous mycobacterium, Mycobacterium abscessus is an emerging opportunistic pathogen associated with difficult to treat pulmonary infections, particularly in patients suffering from cystic fibrosis. It is capable of forming biofilms in vitro that result in an increase of already high levels of antibiotic resistance in this bacterium. Evidence that M. abscessus forms biofilm-like microcolonies in patient lungs and on medical devices further implicated the need to investigate this biofilm in detail. Therefore, in this study we characterized the M. abscessus pellicular biofilm, formed on a liquid-air interface, by studying its molecular composition, and its transcriptional profile in comparison to planktonic cells. Using scanning electron micrographs and fluorescence microscopy, we showed that M. abscessus biofilms produce an extracellular matrix composed of lipids, proteins, carbohydrates and extracellular DNA. Transcriptomic analysis of biofilms revealed an upregulation of pathways involved in the glyoxylate shunt, redox metabolism and mycolic acid biosynthesis. Genes involved in elongation and desaturation of mycolic acids were highly upregulated in biofilms and, mirroring those findings, biochemical analysis of mycolates revealed molecular changes and an increase in mycolic acid chain length. Together these results give us an insight into the complex structure of M. abscessus biofilms, the understanding of which may be adapted for clinical use in treatment of biofilm infections, including strategies for dispersing the extracellular matrix, allowing antibiotics to gain access to bacteria within the biofilm.

Design, synthesis, and biological evaluation of quinazolin-4(3H)-one derivatives co-targeting poly(ADP-ribose) polymerase-1 and bromodomain containing protein 4 for breast cancer therapy.

This study was aimed to design the first dual-target small-molecule inhibitor co-targeting poly (ADP-ribose) polymerase-1 (PARP1) and bromodomain containing protein 4 (BRD4), which had important cross relation in the global network of breast cancer, reflecting the synthetic lethal effect. A series of new BRD4 and PARP1 dual-target inhibitors were discovered and synthesized by fragment-based combinatorial screening and activity assays that together led to the chemical optimization. Among these compounds, 19d was selected and exhibited micromole enzymatic potencies against BRD4 and PARP1, respectively. Compound 19d was further shown to efficiently modulate the expression of BRD4 and PARP1. Subsequently, compound 19d was found to induce breast cancer cell apoptosis and stimulate cell cycle arrest at G1 phase. Following pharmacokinetic studies, compound 19d showed its antitumor activity in breast cancer susceptibility gene 1/2 (BRCA1/2) wild-type MDA-MB-468 and MCF-7 xenograft models without apparent toxicity and loss of body weight. These results together demonstrated that a highly potent dual-targeted inhibitor was successfully synthesized and indicated that co-targeting of BRD4 and PARP1 based on the concept of synthetic lethality would be a promising therapeutic strategy for breast cancer.

Discovery of thiosemicarbazone derivatives as effective New Delhi metallo-ß-lactamase-1 (NDM-1) inhibitors against NDM-1 producing clinical isolates.

New Delhi metallo-ß-lactamase-1 (NDM-1) is capable of hydrolyzing nearly all ß-lactam antibiotics, posing an emerging threat to public health. There are currently less effective treatment options for treating NDM-1 positive "superbug", and no promising NDM-1 inhibitors were used in clinical practice. In this study, structure-activity relationship based on thiosemicarbazone derivatives was systematically characterized and their potential activities combined with meropenem (MEM) were evaluated. Compounds 19bg and 19bh exhibited excellent activity against 10 NDM-positive isolate clinical isolates in reversing MEM resistance. Further studies demonstrated compounds 19bg and 19bh were uncompetitive NDM-1 inhibitors with Ki = 0.63 and 0.44 µmol/L, respectively. Molecular docking speculated that compounds 19bg and 19bh were most likely to bind in the allosteric pocket which would affect the catalytic effect of NDM-1 on the substrate meropenem. Toxicity evaluation experiment showed that no hemolysis activities even at concentrations of 1000 mg/mL against red blood cells. In vivo experimental results showed combination of MEM and compound 19bh was markedly effective in treating infections caused by NDM-1 positive strain and prolonging the survival time of sepsis mice. Our finding showed that compound 19bh might be a promising lead in developing new inhibitor to treat NDM-1 producing superbug.