Antibacterial activity of nonantibiotics is orthogonal to standard antibiotics.

Numerous nonantibiotic drugs have potent antibacterial activity and can adversely affect the human microbiome. The mechanistic underpinning of this toxicity remains largely unknown. We investigated the antibacterial activity of 200 drugs using genetic screens with thousands of barcoded Escherichia coli knockouts. We analyzed 2 million gene-drug interactions underlying drug-specific toxicity. Network-based analysis of drug-drug similarities revealed that antibiotics clustered into modules that are consistent with the mode of action of their established classes, whereas nonantibiotics remained unconnected. Half of the nonantibiotics clustered into separate modules, potentially revealing shared and unexploited targets for new antimicrobials. Analysis of efflux systems revealed that they widely affect antibiotics and nonantibiotics alike, suggesting that the impact of nonantibiotics on antibiotic cross-resistance should be investigated closely in vivo.

Inhibitory effects on bovine babesial infection by iron chelator, 1-(N-acetyl-6-aminohexyl)- 3-hydroxy-2-methylpyridin-4-one (CM1), and antimalarial drugs.

BACKGROUND: Babesiosis is an infectious disease caused by protozoa of the apicomplexan phylum, genus Babesia. It is a malaria-like parasitic disease that can be transmitted via tick bites. The apicomplexan phylum of eukaryotic microbial parasites has had detrimental impacts on human and veterinary medicine. There are only a few drugs currently available to treat this disease; however, parasitic strains that are resistant to these commercial drugs are increasing in numbers. Plasmodium and Babesia are closely related as they share similar biological features including mechanisms for host cell invasion and metabolism. Therefore, antimalarial drugs may be useful in the treatment of Babesia infections. In addition to antimalarials, iron chelators also inhibit parasite growth. In this study, we aimed to evaluate the in vitro inhibitory efficacy of iron chelator and different antimalarials in the treatment of Babesia bovis. METHODS: Cytotoxicity of antimalarial drugs; pyrimethamine, artefenomel, chloroquine, primaquine, dihydroarthemisinine, and the iron chelator, 1-(N-acetyl-6-aminohexyl)- 3-hydroxy-2 methylpyridin-4-one (CM1), were evaluated against Madin Darby Bovine Kidney (MDBK) cells and compared to diminazene aceturate, which is the currently available drug for animal babesiosis using an MTT solution. Afterwards, an evaluation of the in vitro growth-inhibitory effects of antimalarial drug concentrations was performed and monitored using a flow cytometer. Half maximal inhibitory concentrations (IC50) of each antimalarial and iron chelator were determined and compared to the antibabesial drug, diminazine aceturate, by interpolation using a curve-fitting technique. Subsequently, the effect of the drug combination was assessed by constructing an isobologram. Values of the sum of fractional inhibitions at 50% inhibition were then estimated. RESULTS: Results indicate that all drugs tested could safely inhibit babesia parasite growth, as high as 2500 µM were non-toxic to mammalian cells. Although no drugs inhibited B. bovis more effectively than diminazine aceturate in this experiment, in vitro growth inhibition results with IC50 values of pyrimethamine 6.25 ± 2.59 µM, artefenomel 2.56 ± 0.67 µM, chloroquine 2.14 ± 0.76 µM, primaquine 22.61 ± 6.72 µM, dihydroarthemisinine 4.65 ± 0.22 µM, 1-(N-acetyl-6-aminohexyl)- 3-hydroxy-2 methylpyridin-4-one (CM1) 9.73 ± 1.90 µM, and diminazine aceturate 0.42 ± 0.01 µM, confirm that all drugs could inhibit B. bovis and could be used as alternative treatments for bovine babesial infection. Furthermore, the efficacy of a combination of the iron chelator, CM1, in combination with artefenomel dihydroarthemisinin or chloroquine, and artefenomel in combination with the iron chelator, CM1, dihydroarthemisinin or chloroquine, exhibited synergism against B. bovis in vitro. CONCLUSION: Our evaluation of the inhibitory efficacy of the iron chelator CM1, antimalarial drugs, and a combination of these drugs against B. bovis could be potentially useful in the development and discovery of a novel drug for the treatment of B. bovis in the future.

Characterization of bacterial diversity and capacity to remove lead of a consortium from mining soil / Caracterización de la diversidad bacteriana y capacidad de remoción de plomo de un consorcio en suelo minero

Introduction: At present, the presence of lead (Pb2+) continues to be a problem in water bodies due to its continuous use and high toxicity. The aim of this study was to investigate the bacterial diversity of a potential consortium used as a biosorbent for the removal of lead in an aqueous solution. Methods: The minimum inhibitory concentration and the mean lethal dose of the consortium were determined, and then the optimal variables of pH and temperature for the removal process were obtained. With the optimal conditions, the kinetic behavior was evaluated, and adjustments were made to different mathematical models. A Fourier transform infrared spectroscopy analysis was performed to determine the functional groups of the biomass participating in the removal process, and the diversity of the bacterial consortium was evaluated during Pb2+ removal by an Ion Torrent Personal Genome Machine System. Results: It was found that the intraparticle diffusion model was the one that described the adsorption kinetics showing a higher rate constant with a higher concentration of Pb2+, while the Langmuir model was that explained the isotherm at 35 °C, defining a maximum adsorption load for the consortium of 54 mg/g. In addition, it was found that Pb2+ modified the diversity and abundance of the bacterial consortium, detecting genera such as Pseudomonas, Enterobacter, Citrobacter, among others. Conclusions: Thus, it can be concluded that the bacterial consortium from mining soil was a biosorbent with the ability to tolerate high concentrations of Pb2+ exposure. The population dynamics during adsorption showed enrichment of Proteobacteria phyla, with a wide range of bacterial families and genera capable of resisting and removing Pb2+ in solution.(AU)

Anti-Biofilm: Machine Learning Assisted Prediction of IC50 Activity of Chemicals Against Biofilms of Microbes Causing Antimicrobial Resistance and Implications in Drug Repurposing.

Biofilms are one of the leading causes of antibiotic resistance. It acts as a physical barrier against the human immune system and drugs. The use of anti-biofilm agents helps in tackling the menace of antibiotic resistance. The identification of efficient anti-biofilm chemicals remains a challenge. Therefore, in this study, we developed 'anti-Biofilm', a machine learning technique (MLT) based predictive algorithm for identifying and analyzing the biofilm inhibition of small molecules. The algorithm is developed using experimentally validated anti-biofilm compounds with half maximal inhibitory concentration (IC50) values extracted from aBiofilm resource. Out of the five MLTs, the Support Vector Machine performed best with Pearson's correlation coefficient of 0.75 on the training/testing data set. The robustness of the developed model was further checked using an independent validation dataset. While analyzing the chemical diversity of the anti-biofilm compounds, we observed that they occupy diverse chemical spaces with parent molecules like furanone, urea, phenolic acids, quinolines, and many more. Use of diverse chemicals as input further signifies the robustness of our predictive models. The three best-performing machine learning models were implemented as a user-friendly 'anti-Biofilm' web server (https://bioinfo.imtech.res.in/manojk/antibiofilm/) with different other modules which make 'anti-Biofilm' a comprehensive platform. Therefore, we hope that our initiative will be helpful for the scientific community engaged in identifying effective anti-biofilm agents to target the problem of antimicrobial resistance.

New antiprotozoal sesquiterpene derivatives from Dorema glabrum Fisch & C.A.Mey.

Seven undescribed sesquiterpene derivatives, Azerins A-G (3-6, 8, 14 and 15), three known sesquiterpene phenols, kopetdaghin A (1), kopetdaghin B (2) and latisectin (7), together with five known sesquiterpene coumarins (9-13), were isolated from the roots of Dorema glabrum. The structures were elucidated by comprehensive 1D- and 2D-NMR spectral analysis as well as HR-ESI-MS. Compounds were assessed for their in vitro antiprotozoal activity against Trypanosoma brucei rhodesiense, T. cruzi, Leishmania donovani, and Plasmodium falciparum. Cytotoxic potentials of the compounds were also tested on L6 rat skeletal myoblasts. Azerin G (15) showed a potent preferential growth inhibitory activity against T. b. rhodesiense with IC50 value of 0.01 µM and selectivity index of 329. Compounds 1, 4, 7 and 8 were also found as the most active compounds with selective growth inhibitory effects toward P. falciparum with selectivity indices ranging from 11.6 to 16.7 (IC50: 1.8-24.6 µM).

Switching from Aromatase Inhibitors to Dual Targeting Flavonoid-Based Compounds for Breast Cancer Treatment.

Despite the significant outcomes attained by scientific research, breast cancer (BC) still represents the second leading cause of death in women. Estrogen receptor-positive (ER+) BC accounts for the majority of diagnosed BCs, highlighting the disruption of estrogenic signalling as target for first-line treatment. This goal is presently pursued by inhibiting aromatase (AR) enzyme or by modulating Estrogen Receptor (ER) α. An appealing strategy for fighting BC and reducing side effects and resistance issues may lie in the design of multifunctional compounds able to simultaneously target AR and ER. In this paper, previously reported flavonoid-related potent AR inhibitors were suitably modified with the aim of also targeting ERα. As a result, homoisoflavone derivatives 3b and 4a emerged as well-balanced submicromolar dual acting compounds. An extensive computational study was then performed to gain insights into the interactions the best compounds established with the two targets. This study highlighted the feasibility of switching from single-target compounds to balanced dual-acting agents, confirming that a multi-target approach may represent a valid therapeutic option to counteract ER+ BC. The homoisoflavone core emerged as a valuable natural-inspired scaffold for the design of multifunctional compounds.

A bivalent ß-carboline derivative inhibits macropinocytosis-dependent entry of pseudorabies virus by targeting the kinase DYRK1A.

Pseudorabies virus (PRV) has become a "new life-threatening zoonosis" since the human-originated PRV strain was first isolated in 2020. To identify novel anti-PRV agents, we screened a total of 107 ß-carboline derivatives and found 20 compounds displaying antiviral activity against PRV. Among them, 14 compounds showed better antiviral activity than acyclovir. We found that compound 45 exhibited the strongest anti-PRV activity with an IC50 value of less than 40 nM. Our in vivo studies showed that treatment with 45 significantly reduced the viral loads and protected mice challenged with PRV. To clarify the mode of action of 45, we conducted a time of addition assay, an adsorption assay, and an entry assay. Our results indicated that 45 neither had a virucidal effect nor affected viral adsorption while significantly inhibiting PRV entry. Using the FITC-dextran uptake assay, we determined that 45 inhibits macropinocytosis. The actin-dependent plasma membrane protrusion, which is important for macropinocytosis, was also suppressed by 45. Furthermore, the kinase DYRK1A (dual-specificity tyrosine phosphorylation-regulated kinase 1A) was predicted to be a potential target for 45. The binding of 45 to DYRK1A was confirmed by drug affinity responsive target stability and cellular thermal shift assay. Further analysis revealed that knockdown of DYRK1A by siRNA suppressed PRV macropinocytosis and the tumor necrosis factor alpha-TNF-induced formation of protrusions. These results suggested that 45 could restrain PRV macropinocytosis by targeting DYRK1A. Together, these findings reveal a unique mechanism through which ß-carboline derivatives restrain PRV infection, pointing to their potential value in the development of anti-PRV agents.

Correlation between in vitro toxicity of pesticides and in vivo risk guidelines in support of complex operating site risk management: A meta-analysis.

In vitro cell systems can support hazard characterization and identify mechanisms involved in toxicity; however, using in vitro data for risk assessment still is challenging. As part of an effort to develop approaches for a complex operating site used for biocide packaging and distribution, we evaluated in vitro assays that could be used in a site management format. Across 66 studies, 108 pesticides were assessed on ten human-derived cell types at four endpoints. In vitro IC50s were compared to in vivo guidelines, NOEL/NOAELs, and ADIs using Spearman correlation and linear regression models. While human neuroblastoma cells (SH-SY5Y) were the most sensitive, HepG2 was the most used cell line in evaluating the toxicity of pesticides. Amongst the ten human cell lines, the IC50s derived from SH-SY5Y cells, using MTT-24 & 48 h (the most used assay) correlated (rho = 0.56-0.79; p < 0.05) with ADIs and NOEL/NOAELs. Although in vitro cell systems have some limitations, the correlation between in vitro data derived from SH-SY5Y cells and in vivo safety guidelines can provide site investigators with a tool to survey and prioritize areas and media of concern at complex operating sites impacted by pesticide mixtures.

IC50: an unsuitable measure for large-sized prostate cancer spheroids in drug sensitivity evaluation.

Preclinical models of tumors have the potential to become valuable tools for commercial drug research and development, and 3D culture systems are gaining traction in this area, particularly in prostate cancer (PCa) research. However, nearly all 3D drug design and screening assessments are based on 2D experiments, suggesting limitations of 3D drug testing. To simulate the natural response of human cells to the drug, we detected the half-maximal inhibitory concentration (IC50) changes of 2D/3D LNCaP cells in the drug docetaxel, as well as the sensitivity of different morphologies of 2D/3D LNCaP to docetaxel treatment. In contrast to 2D LNCaP cells, the evaluation of LNCaP spheroids' susceptibility to treatment was more complicated; the fitness of IC50 curves of 2D and 3D tumor cell preclinical models differs significantly. IC50 curves were unsuitable for large-sized LNCaP spheroids. More evaluation indexes (such as max inhibition) and experiments (such as spheroids formation) should be explored and performed to evaluate the susceptibility systematically.

Integrating nonlinear analysis and machine learning for human induced pluripotent stem cell-based drug cardiotoxicity testing.

Utilizing recent advances in human induced pluripotent stem cell (hiPSC) technology, nonlinear analysis and machine learning we can create novel tools to evaluate drug-induced cardiotoxicity on human cardiomyocytes. With cardiovascular disease remaining the leading cause of death globally it has become imperative to create effective and modern tools to test the efficacy and toxicity of drugs to combat heart disease. The calcium transient signals recorded from hiPSC-derived cardiomyocytes (hiPSC-CMs) are highly complex and dynamic with great degrees of response characteristics to various drug treatments. However, traditional linear methods often fail to capture the subtle variation in these signals generated by hiPSC-CMs. In this work, we integrated nonlinear analysis, dimensionality reduction techniques and machine learning algorithms for better classifying the contractile signals from hiPSC-CMs in response to different drug exposure. By utilizing extracted parameters from a commercially available high-throughput testing platform, we were able to distinguish the groups with drug treatment from baseline controls, determine the drug exposure relative to IC50 values, and classify the drugs by its unique cardiac responses. By incorporating nonlinear parameters computed by phase space reconstruction, we were able to improve our machine learning algorithm's ability to predict cardiotoxic levels and drug classifications. We also visualized the effects of drug treatment and dosages with dimensionality reduction techniques, t-distributed stochastic neighbor embedding (t-SNE). We have shown that integration of nonlinear analysis and artificial intelligence has proven to be a powerful tool for analyzing cardiotoxicity and classifying toxic compounds through their mechanistic action.

A comprehensive evaluation of regression-based drug responsiveness prediction models, using cell viability inhibitory concentrations (IC50 values).

MOTIVATION: Predicting drug response is critical for precision medicine. Diverse methods have predicted drug responsiveness, as measured by the half-maximal drug inhibitory concentration (IC50), in cultured cells. Although IC50s are continuous, traditional prediction models have dealt mainly with binary classification of responsiveness. However, since there are few regression-based IC50 predictions, comprehensive evaluations of regression-based IC50 prediction models, including machine learning (ML) and deep learning (DL), for diverse data types and dataset sizes, have not been addressed. RESULTS: Here, we constructed 11 input data settings, including multi-omics settings, with varying dataset sizes, then evaluated the performance of regression-based ML and DL models to predict IC50s. DL models considered two convolutional neural network architectures: CDRScan and residual neural network (ResNet). ResNet was introduced in regression-based DL models for predicting drug response for the first time. As a result, DL models performed better than ML models in all the settings. Also, ResNet performed better than or comparable to CDRScan and ML models in all settings. AVAILABILITY AND IMPLEMENTATION: The data underlying this article are available in GitHub at https://github.com/labnams/IC50evaluation. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Numerical learning of deep features from drug-exposed cell images to calculate IC50 without staining.

To facilitate rapid determination of cellular viability caused by the inhibitory effect of drugs, numerical deep learning algorithms was used for unlabeled cell culture images captured by a light microscope as input. In this study, A549, HEK293, and NCI-H1975 cells were cultured, each of which have different molecular shapes and levels of drug responsiveness to doxorubicin (DOX). The microscopic images of these cells following exposure to various concentrations of DOX were trained with the measured value of cell viability using a colorimetric cell proliferation assay. Convolutional neural network (CNN) models for the study cells were constructed using augmented image data; the predicted cell viability using CNN models was compared to the cell viability measured by colorimetric assay. The linear relationship coefficient (r2) between measured and predicted cell viability was determined as 0.94-0.95 for the three cell types. In addition, the measured and predicted IC50 values were not statistically different. When drug responsiveness was estimated using allogenic models that were trained with a different cell type, the correlation coefficient decreased to 0.004085-0.8643. Our models could be applied to label-free cells to conduct rapid and large-scale tests while minimizing cost and labor, such as high-throughput screening for drug responsiveness.

Curcumin-rich extract from Central Brazil Curcuma longa protects human umbilical vein endothelial cells under oxidative stress / Extrato rico em Curcumina do Brasil Central Curcuma longa protege células endoteliais de veias umbilicais humanas sob estresse oxidativo

INTRODUCTION: In vascular diseases, the interruption of the local blood flow and the subsequent reperfusion of oxygen can cause deleterious oxidative effects on the cells. Turmeric (Curcuma longa L.) presents the capacity to neutralize free radicals along with preventive and therapeutic effects for several diseases. OBJECTIVE: To analyze the bioactive compounds and the antioxidant capacity of the ethanolic extract of Curcuma (EEC), to evaluate its effect on human umbilical vein endothelial cells, and to analyze its effect on cellular signaling pathways. METHODS: Cells were exposed to different concentrations of EEC for 24, 48, and 72 h. Folin-Ciocalteau test, HPLC-Fluorescence analysis, and DPPH method were used to determine the phenolic compounds, curcumin content, and antioxidant action, respectively; the tetrazolium salt reduction to obtain cell viability, cytotoxicity, and the concentration that inhibits 50% of cell viability; and the immunocytochemistry technique to analyze the expression of caspase3, SIRT1, and mTOR. RESULTS: We found the presence of polyphenols in the classes of phenolic acids and curcuminoids in EEC, with 16.7% curcumin content. The number of antioxidants needed to reduce the initial DPPH concentration by 50% was 18.1 µmol/g. The extract mitigated cell damage at a dosage of 100 µg/ml, decreased the immunoexpression of caspase3, and promoted the signaling of the SIRT1 and mTOR survival pathways. CONCLUSION: EEC had a protective effect on human umbilical vein endothelial cells, subjected to oxidative stress, with decreased apoptosis (caspase3) at lower concentrations, cytoprotection by maintaining essential cell functions (mTOR), and signaling of the survival pathway (SIRT1).

INTRODUÇÃO: Em doenças vasculares, a interrupção do fluxo sanguíneo locale subsequente reperfusão de oxigênio pode causar efeitos deletérios e danos irreparáveis às células. Curcuma (Curcuma longa L.) neutraliza radicais livres além de apresentar efeitos preventivos e terapêuticos. OBJETIVO: Caracterizar os compostos bioativos e a capacidade antioxidante do extrato etanólico de cúrcuma (EEC); avaliar seu efeito nas células endoteliais da veia umbilical humana, e analisar a expressão de vias de sinalização celular. MÉTODOS: As células foram expostas a diferentes concentrações de EEC por 24, 48 e 72 horas. Utilizamos o teste de Folin-Ciocalteau, análise por HPLC-Fluorescência e método DPPH para determinar os compostos fenólicos, conteúdo de curcumina e ação antioxidante, respectivamente; o método de redução de tetrazólio para viabilidade celular, a citotoxicidade e a concentração que inibe 50% da viabilidade celular; e a técnica de imunocitoquímica para analisar a expressão de caspase3, SIRT1 e mTOR. RESULTADOS: Observou-se presença de polifenóis nas classes de ácidos fenólicos e curcuminóides no EEC, com teor de curcumina de 16,7%. A quantidade de antioxidante necessária para reduzir a concentração inicial de DPPH em 50% foi de 18,1 µmol/g. O extrato mitigou o dano celular na dosagem de 100 µg/ml, diminuiu a imunoexpressão da caspase3 e promoveu a sinalização das vias de sobrevivência SIRT1 e mTOR. CONCLUSÃO: O EEC teve efeito protetor nas células endoteliais de veia umbilical humana, submetidas ao estresse oxidativo, com diminuição da apoptose (caspase3) em concentrações mais baixas, citoproteção pela manutenção das funções celulares essenciais (mTOR) e sinalização da via de sobrevivência (SIRT1).

Impact of Short-Term Storage on Ex Vivo Antimalarial Susceptibilities of Fresh Ugandan Plasmodium falciparum Isolates.

We measured susceptibilities of Ugandan Plasmodium falciparum isolates assayed on the day of collection or after storage at 4°C. Samples were incubated with serial dilutions of 8 antimalarials, and susceptibilities were determined from 72-h growth inhibition assays. Storage was associated with decreased growth and lower 50% inhibitory concentration values, but differences between assays beginning on day 0 or after 1 or 2 days of storage were modest, indicating that short-term storage before drug susceptibility determination is feasible.

S-20, a steroidal saponin from the berries of black nightshade, exerts anti-multidrug resistance activity in K562/ADR cells through autophagic cell death and ERK activation.

Multidrug resistance (MDR) is a major cause of chemotherapy failure. Adriamycin (ADR) has been widely used to treat cancer, however, as a substrate of the adenosine triphosphate binding cassette (ABC) transporter, it is easy to develop drug resistance during the treatment. Here, we demonstrated that steroidal saponin S-20 isolated from the berries of black nightshade has comparable cytotoxicity in ADR-sensitive and resistant K562 cell lines. Autophagy is generally considered to be a protective mechanism to mediate MDR during treatment. However, we found that S-20-induced cell death in K562/ADR is associated with autophagy. We further explored the underlying mechanisms and found that S-20 induces caspase-dependent apoptosis in ADR-sensitive and resistant K562 cell lines. Most importantly, S-20-induced autophagy activates the ERK pathway and then inhibits the expression of drug resistance protein, which is the main reason to overcome K562/ADR resistance, rather than apoptosis. Taken together, our findings emphasize that S-20 exerts anti-multidrug resistance activity in K562/ADR cells through autophagic cell death and ERK activation, which may be considered as an effective strategy.

The impact of legacy and novel perfluoroalkyl substances on human cytochrome P450: An in vitro study on the inhibitory potential and underlying mechanisms.

Per- and polyfluoroalkyl substances (PFASs) are a group of synthetic compounds with a wide range of industrial applications. PFOA and PFOS have been the most extensively studied and have been associated with hepatotoxicity. Recently, the interaction with cytochrome P450 (CYP) has been proposed as a potential key molecular event leading to PFAS-induced hepatotoxicity. In the present study, we aimed to determine a structure-activity relationship between thirteen PFASs and their inhibitory potential on the activities of four CYPs (CYP2E1, CYP2D6, CYP3A4 and CYP2C19). The influence of PFASs (5-3200 µM) on CYP enzyme activities was measured using the Vivid® P450 metabolism assays. Using the same assays, Michaelis-Menten saturation curves were determined to explore the type of PFAS-induced CYP inhibition. Most PFASs were capable of inhibiting activity of the tested CYPs, as shown by their IC50 values. CYP2E1 is particularly inhibited by 3:1 FTOH, PFOA, and PFOS, whereas CYP2D6 is inhibited by PFHxS, PFHpA, PFOA, PFOS, PFNA, and PFDA. Additionally, CYP3A4 is most strongly inhibited by PFHxS, PFOA, PFOS, PFNA, and PFDA. Finally, CYP2C19 is inhibited by PFBS, PFHxS, PFHpA, PFOA, PFOS, PFNA, and PFDA. Interestingly, PFHxA and PFHxS induced an increase in CYP2E1 activity, whereas 4:2 FTOH strongly induced CYP2D6 activity. The mechanism of inhibition of CYPs by PFASs differed per CYP isoenzyme. CYP3A4 was competitively inhibited by PFBS, PFHxS, PFOS, PFNA and PFDA and non-competitively by PFOA. Additionally, CYP2C19 was competitively inhibited by PFHxA, PFOS and PFNA, whereas PFBS and PFHxS induced a mixed inhibition. Inhibition of CYP2C19 by PFHpA was atypical with an increased Vmax and a decreased Km. Finally, PFHxS competitively inhibited CYP2D6, whereas PFBS, PFOA, PFOS, PFDA and PFNA induced an atypical inhibition. Our results show that CYP inhibition by PFASs appears to be structure-dependent as well as CYP dependent. Inhibition of CYP2D6, CYP2C19 and CYP3A4 increased with increasing chain-lengths between six and nine carbons. The PFTOHs were only able to inhibit CYP2E1 and did not affect any of the other CYPS. Some PFASs remarkably induced the enzyme activity of CYPs. These results indicate that in addition to PFOA and PFOS, multiple novel PFASs may alter drug metabolism by the interference with CYPs.

New ent-Kaurane and cleistanthane diterpenoids with potential cytotoxicity from Phyllanthus acidus (L.) Skeels.

Six diterpenoids including three ent-kauranes (1-2, 4) and three cleistanthanes (3, 5-6) were isolated from the roots and stems of Phyllanthus acidus (L.) Skeels. Of them, (16S)-ent-16,17,18-tri-hydroxy-19-nor-kaur-4-en-3-one (1), phyllanthone A (2), and 6-hydroxycleistanthol (3) are new compounds, while the ent-kaurane diterpenoids were reported from the titled plant for the first time. Their structures were elucidated on the basis of the extensive spectroscopic analyses. Compounds 2 and 4-6 displayed cytotoxic potential with IC50 values ranging from 1.96 to 29.15 µM. They also showed moderate anti-inflammatory activities (IC50 = 6.30-12.05 µM). Particularly, the new ent-kaurane 2 displayed cytotoxic potential against HL-60 (IC50 = 2.00 µM) and MCF-7 (IC50 = 3.55 µM) cells, and anti-inflammatory activity (IC50 = 6.47 µM).

Investigation of the chemical structure of anti-amyloidogenic constituents extracted from Thamnolia vermicularis.

ETHNOPHARMACOLOGICAL RELEVANCE: Thamnolia vermicularis (Sw.) Schaer (T. vermicularis) is known to have therapeutic effects on various diseases in Southwest China. Recent research has highlighted that T. vermicularis may suppress Aß level and Tau hyperphosphorylation to improve the pathological characteristics of Alzheimer's disease, indicating that it might have the potential to treat Alzheimer's disease. AIM OF THE STUDY: The objective of this study was to evaluate the inhibitory effect of T. vermicularis on the fibril formation of a typical amyloidogenic protein, hen egg white lysozyme (HEWL), and to identify the effective components that could potentially enable an extract of T. vermicularis to be used in the development of novel therapeutic agents. MATERIALS AND METHODS: A water extract was prepared from T. vermicularis (TVWE) and its inhibitory effect on amyloid fibrillation in vitro was investigated using thioflavin T and 8-anilinonapthalene-1-sulfonic acid spectrofluorometric analyses. The anti-amyloidogenic components of TVWE were separated and qualitatively analyzed using thin layer chromatography (TLC), supercritical carbon dioxide extraction (SFE-CO2), and liquid chromatography-mass spectrometry. Finally, the effect of the bioactive components on the structure of HEWL in the early stages of fibrillogenesis was determined by molecular docking simulation. RESULTS: TVWE strongly inhibited the ability of HEWL to form an amyloid fibril, yielding an IC50 of 0.018 mg/mL for the inhibition of fibrillogenesis. The chemical constituents in the various TVWE fractions resolved by TLC were qualitatively identified by liquid chromatography-quadrupole/time-of-flight mass spectrometry (LC-Q-TOF-MS). The target components were predicted by reviewing the existing literature on T. vermicularis, in which the components of T. vermicularis, along with three small molecules (molecular weight: 182) were preliminarily identified. Molecular docking simulation showed that these small molecules were bound to the core region of HEWL, affecting its stability. Finally, the active anti-amyloidogenic components were extracted from whole T. vermicularis using SFE-CO2 and then identified. CONCLUSION: The potential components of TVWE that could prevent HEWL fibrillogenesis were primarily identified using TLC, LC-Q-TOF-MS, and SFE-CO2. The candidate small-molecule compounds were further predicted by combining the LC-Q-TOF-MS results with molecular docking analysis. The effective components of T. vermicularis were extracted using SFE-CO2. Together, these methods could constitute a practical strategy for the isolation and identification of anti-amyloidogenic components from a traditional Chinese medicine.

Differential Growth Rates and In Vitro Drug Susceptibility to Currently Used Drugs for Multiple Isolates of Naegleria fowleri.

The free-living amoeba Naegleria fowleri, which typically dwells within warm, freshwater environments, can opportunistically cause primary amoebic meningoencephalitis (PAM), a disease with a mortality rate of >97%. The lack of positive treatment outcomes for PAM has prompted the discovery and development of more effective therapeutics, yet most studies utilize only one or two clinical isolates. The inability to assess possible heterogenic responses to drugs among isolates from various geographical regions hinders progress in the discovery of more effective drugs. Here, we conducted drug efficacy and growth rate determinations for 11 different clinical isolates by applying a previously developed CellTiter-Glo 2.0 screening technique and flow cytometry. We found significant differences in the susceptibilities of these isolates to 7 of 8 drugs tested, all of which make up the cocktail that is recommended to physicians by the U.S. Centers for Disease Control and Prevention. We also discovered significant variances in growth rates among isolates, which draws attention to the differences among the amoeba isolates collected from different patients. Our results demonstrate the need for additional clinical isolates of various genotypes in drug assays and highlight the necessity for more targeted therapeutics with universal efficacy across N. fowleri isolates. Our data establish a needed baseline for drug susceptibility among clinical isolates and provide a segue for future combination therapy studies as well as research related to phenotypic or genetic differences that could shed light on mechanisms of action or predispositions to specific drugs. IMPORTANCE Naegleria fowleri, also known as the brain-eating amoeba, is ubiquitous in warm freshwater and is an opportunistic pathogen that causes primary amoebic meningoencephalitis. Although few cases are described each year, the disease has a case fatality rate of >97%. In most laboratory studies of this organism, only one or two well-adapted lab strains are used; therefore, there is a lack of data to discern if there are major differences in potency of currently used drugs for multiple strains and genotypes of the amoeba. In this study, we found significant differences in the susceptibilities of 11 N. fowleri isolates to 7 of the 8 drugs currently used to treat the disease. The data from this study provide a baseline of drug susceptibility among clinical isolates and suggest that new drugs should be tested on a larger number of isolates in the future.

Synthesis and characterization of novel combretastatin analogues of 1,1-diaryl vinyl sulfones, with antiproliferative potential via in-silico and in-vitro studies.

Novel 1,1-diaryl vinyl-sulfones analogues of combretastatin CA-4 were synthesized via Suzuki-Miyaura coupling method and screened for in-vitro antiproliferative activity against four human cancer cell lines: MDA-MB 231(breast cancer), HeLa (cervical cancer), A549 (lung cancer), and IMR-32 (neuroblast cancer), along with a normal cell line HEK-293 (human embryonic kidney cell) by employing 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. The compounds synthesised had better cytotoxicity against the A549 and IMR-32 cell lines compared to HeLa and MDA-MB-231 cell lines. The synthesized compounds also showed significant activity on MDA-MB-231 cancer cell line with IC50 of 9.85-23.94 µM, and on HeLa cancer cell line with IC50 of 8.39-11.70 µM relative to doxorubicin having IC50 values 0.89 and 1.68 µM respectively for MDA-MB-231 and HeLa cell lines. All the synthesized compounds were not toxic to the growth of normal cells, HEK-293. They appear to have a higher binding affinity for the target protein, tubulin, PDB ID = 5LYJ (beta chain), relative to the reference compounds, CA4 (- 7.1 kcal/mol) and doxorubicin (- 7.2 kcal/mol) except for 4E, 4M, 4N and 4O. The high binding affinity for beta-tubulin did not translate into enhanced cytotoxicity but the compounds (4G, 4I, 4J, 4M, 4N, and 4R, all having halogen substituents) that have a higher cell permeability (as predicted in-silico) demonstrated an optimum cytotoxicity against the tested cell lines in an almost uniform manner for all tested cell lines. The in-silico study provided insight into the role that cell permeability plays in enhancing the cytotoxicity of this class of compounds and as potential antiproliferative agents.