Potent Inhibitory Agent Research Articles

In silico Analysis of Selected Four-Leaf Water Clover (Marsilea species) Constituents as Human Acetyl Cholinesterase (hAchE), Carbonic Anhydrase II (hCA-II), and Protein Tyrosine Phosphatase 1B (PTP1B) Inhibitory Agents

ABSTRACT A four-leaf water clover (Marsilea species) has been reported to exhibit various biological activities. In the present study, we aimed to evaluate 23 selected constituents of a four-leaf water clover (Marsilea species) as potent inhibitory agents of human acetyl cholinesterase (hAchE), carbonic anhydrase II (hCA-II), and protein tyrosine phosphatase 1B (hPTP-1B) using an in silico method. The 23 selected constituents of the four-leaf water clover (Marsilea species) were studied on the docking behavior of hAchE, hCA-II, and hPTP-1B by using the Webina docking method. In addition to docking, toxicity analysis was also performed using the pkCSM web server. Toxicity analysis has shown that 10 ligands (44%) of the four-leaf water clover (Marsilea species) were predicted to have hERG II (human ether-a-go-go-related gene) inhibition activity. The docking analysis showed that marsilin has exhibited the maximum binding energy (-11.3 kcal/mol) with the hAchE, whereas it fails to dock with both the target enzymes (hCA-II and hPTP-1B). Thus, the present find provides a new understanding about the 23 selected ligands of the four-leaf water clover (Marsilea species) as potent inhibitory agents of human acetyl cholinesterase (hAchE), carbonic anhydrase II (hCA-II), and protein tyrosine phosphatase 1B (hPTP-1B).

In Silico Analysis of Selected Mikania Constituents As Human HMG-CoA Reductase, Human Inducible Nitric Oxide Synthase, and Human Squalene Synthase Inhibitory Agents.

Background Numerous pharmacological activities have been reportedin Mikania species. In the present investigation, we aimed to evaluate 26 selected constituents of Mikania as potent inhibitory agents of human HMG-CoA reductase (hHMGR), human inducible nitric oxide synthase (hiNOS), and human squalene synthase (hSQS) using the in silico method. Methodology Twenty-six selected constituents of Mikania were investigated based on the docking behavior of three target enzymes, namely hHMGR, hiNOS, and hSQS, using the Cdocker method (Discovery Studio® 3.1, Accelrys, Inc., San Diego, CA). Results Docking analysis showed that methyl-3,5-di-O-caffeoyl quinate (MCQ) has the maximum binding energy (BE) (-39.63, -50.65, and -58.56 kcal/mol) with hHMGR, hiNOS, and hSQS enzymes. On the other hand, six ligands (kaurenoic acid (KAA), stigmasterol (SS), grandifloric acid (GA), kaurenol (KA), spathlenol (SP), and taraxerol (TA)) of Mikania failed to dock with either of the targetenzymes (hHMGR, hiNOS, or hSQS). Conclusions The findings of the current study provide new insight regarding 26 selected ligands of Mikania as potent inhibitory agents of hHMGR, hiNOS, and hSQS.

Molecular Docking Analysis of Selected Urtica dioica Constituents As Human Carbonic Anhydrase II (hCA-II), Human 11 Beta-Hydroxysteroid Dehydrogenases Type 1 (h11beta-HSD1), and Human Dual Specificity Phosphatase (hCDC25B) Inhibitory Agents.

Background Urtica dioica (Stinging nettle)has been reported to exhibit various pharmacological activities. In the present study, we aimed to evaluate 24 selected constituents of U. dioica as potent inhibitory agents of human carbonic anhydrase II (hCA-II), human 11 beta-hydroxysteroid dehydrogenases type 1 (h11beta-HSD1), and human dual specificity phosphatase (hCDC25B)using in silico method. Methodology The 24 selected constituents of U. dioica (Stinging nettle) were studied on the docking behavior of hCA-II, h11beta-HSD1, andhCDC25B by using the Webina docking method. In addition to docking, toxicity analysis was also performed using the pkCSM free web server, respectively. Results Toxicity analysis has shown that six ligands (25%) of U. dioica (Stinging nettle) are predicted to have hERG II (Human ether-a-go-go-related gene) inhibition activity. The docking analysis showed that afzelin, stigmastane-3, 6-diol, and astragalin of U. dioica have shown the maximum binding energy (-7.2, -9.5, and -8.5 kcal/mol) with the hCA-II, h11beta-HSD1 and hCDC25B, respectively. Conclusions Thus, the current finding provides new knowledge about the 24 selected ligands of U. dioica (Stinging nettle) as potent inhibitory agents of human carbonic anhydrase II (hCA-II), human 11 beta-hydroxysteroid dehydrogenases type 1 (h11beta-HSD1) and human dual specificity phosphatase (hCDC25B).

In silico analysis of selected nutrition rich fruit of Bunch berry (Lantana camara) constituents as human acetylcholinesterase (hAchE), carbonic anhydrase II (hCA-II) and carboxylesterase 1 (hCES-1) inhibitory agents

BackgroundBunch berry (Lantana camara) is primarily composed of flavonoids and vitamin C; therefore, it has been shown to possess various medical characteristics, including the ability to relieve fever, inflammation, and urinary tract infections. ObjectiveIn this study, we intended to assess twenty chosen constituents of Bunch berry as potent inhibitory agents of human acetylcholinesterase (hAchE), carbonic anhydrase II (hCA-II) and carboxylesterase 1 (hCES-1) employing in silico techniques. MethodsThe twenty chosen Bunch berry components were examined about docking behaviour of hAchE, hCA-II and hCES-I by using the Swissdock method. Apart from to docking, Molecular physico-chemical, drug-likeness, ADME (ingesting, dispersing, metabolising, and excreting), and toxicity assessments were also performed utilising the Molinspiration, Swiss ADME, pkCSM, and STITCH web sites, correspondingly. ResultsEight ligands (40 %) have exhibited strict adherence to Lipinski's rule of five (Ro5), according to molecular physico-chemical study. Drug-likeness property analysis has shown that five ligands (25 %) of Bunch berry predicted to exhibit moderate bioactivity score against all the descriptors. ADME analysis has shown that five ligands (25 %) of Bunch berry are predicted to possess high gastrointestinal absorption property Toxicity analysis has shown that six ligands (30 %) of Bunch berry are predicted to have hERG II (Human ether-a-go-go-related gene) inhibition activity. According to the docking analysis, lantic acid has the lowest atomic binding energy for all three target enzymes, hAchE (-6.23 kcal/mol), hCA-II (-4.46 kcal/mol), and hCES-I (-5.99 kcal/mol), respectively. ConclusionsThus the current find provides an advanced understanding the twenty selected ligands of Bunch berry as potent inhibitory agents of human acetylcholinesterase (hAchE), carbonic anhydrase II (hCA-II) and carboxylesterase 1 (hCES-1).

Protective Autophagy Attenuates the Cytotoxicity of MTI-31 in Renal Cancer Cells by Activating the ERK Pathway.

Themammaliantargetof rapamycin (mTOR)is a key regulatory molecular target to treat cancer, and MTI-31 is a potent mTOR inhibitory agent for the therapeutically target of the renal cell carcinoma (RCC). However, the therapeutic efficacy of MTI-31 is limited by multiple factors, including autophagy. MTI-31 can activate cells to generate autophagy, which may in turn indirectly affect cell proliferation and apoptosis. We aimed to observe changes in cell protective autophagy via the ERK pathway and explore the potential mechanism underlying drug resistance of RCC cells to MTI-31. Different concentrations of 786-O and RCC4 cells were co-cultured with MTI-31 for distinct durations. The result of autophagy marker detection by Western blot showed that MTI-31 could induce RCC cells to produce autophagy in a dose and time-dependent manner. After treating the RCC cells with the autophagy inhibitor chloroquine (CQ), CCK8 and Western blot assays demonstrated that CQ could effectively enhance cell apoptosis induced by MTI-31 and that the autophagy induced by MTI-31 was cytoprotective. In addition, CCK8 and Western blot demonstrated that MTI-31 exerted its effect by activating the ERK pathway rather than the JNK or p38 pathway. The use of the ERK inhibitor AZD6244 to block the ERK pathway could effectively promote cell apoptosis induced by MTI-31. AZD6244 attenuated the autophagy induced by MTI-31 and increased the cytotoxicity of MTI-31. Western blot also demonstrated that MTI-31-induced autophagy was mediated by the downstream regulators of ERK pathways, including Beclin-1 and Bcl-2. It demonstrated that the MTI-31 mediated activation ERK pathway is associated with the induction of autophagy, and autophagy can attenuate the cytotoxicity of MTI-31 on RCC cells. In summary, inhibition of ERK pathway-mediated autophagy can rectify drug resistance to MTI-31 effectively.

Identification of a novel spirocyclic Nek2 inhibitor using high throughput virtual screening

NIMA Related Kinase 2 (Nek2) kinase is an attractive target for the development of therapeutic agents for several types of highly invasive cancers. Despite this, no small molecule inhibitor has advanced to the late clinical stages thus far. In this work, we have identified a novel spirocyclic inhibitor (V8) of Nek2 kinase, utilizing a high-throughput virtual screening (HTVS) approach. Using recombinant Nek2 enzyme assays, we show that V8 can inhibit Nek2 kinase activity (IC50 = 2.4 ± 0.2 µM) by binding to the enzyme’s ATP pocket. The inhibition is selective, reversible and is not time dependent. To understand the key chemotype features responsible for Nek2 inhibition, a detailed structure–activity relationships (SAR) was performed. Using molecular models of the energy-minimized structures of Nek2-inhibitory complexes, we identify key hydrogen-bonding interactions, including two from the hinge-binding region, likely responsible for the observed affinity. Finally, using cell-based studies, we show that V8 attenuates (a) pAkt/PI3 Kinase signaling in a dose-dependent manner, and (b) proliferative and migratory phenotypes of highly aggressive human MDA-MB-231 breast and A549 lung cancer cell lines. Thus, V8 is an important novel lead compound for the development of highly potent and selective Nek2 inhibitory agents.

Short Communication: Antimicrobial of lemongrass (Cymbopogon citratus L.) volatile oil and cytotoxic effects against L20B and MCF-7cell lines

Abstract. Hasan ZYM, Al-Halbosiy MMF, Al-Lihaibi RK, Al-Nauimi EH. 2022. Short Communication: Antimicrobial of lemongrass (Cymbopogon citratus L.) volatile oil and cytotoxic effects against L20B and MCF-7cell lines. Biodiversitas 23: 5298-5301. Lemongrass (Cymbopogon citratus L.) has been used in different countries in folk remedies for coughs, malaria, pneumonia, and others for many years. The development of bacterial resistance to available antibiotics has obligated finding for new agents to serve as potent antibacterial drugs. The present investigation deals with the effect of volatile lemongrass oil cultivated in Iraq, on different bacterial species and evaluates the cytotoxic activity of the extracted oil on L20B and MCF-7cell cancer cell lines. The plant samples were collected from the college of science /Baghdad University /scientific garden and classified as C. citratus L. by the plant herbarium at the same college. The volatile plant oil was extracted from fresh leaves at the laboratory of the plant biotechnology department of Biotechnology Research Center at Al-Nahrain university/Iraq. With the aid of the Clevenger apparatus, a hydro-distillation method was employed to quantify the lemon grass’s volatile oil. The extracted essential oil and the plant crud maceration were screened for their antibacterial activity against two Gram-negative bacteria (Escherichia coli, and Vibrio cholera) and two Gram-positive bacteria (Bacillus cereus and Staphylococcus aureus) using the well-diffusion method and disc diffusion method. The biological survey also included the cytotoxic effect of oil subjected to the anticancer activity in vitro on two cancer cell lines; L20B mouse cell line that expresses the genes for human cellular receptors for polioviruses, and the second line was the MCF-7 breast cancer cell line. As a result of this screening study, it was shown that the plant seemed to be rich in essential oil content. The Iraqi cultivated plant produced 1.5%v/w essential oil. The volatile oil affected both Gram-negative and Gram-positive strains in comparison to the crud plant extract among the selected bacterial cultures, the highest antibacterial activity was recorded against the Gram-positive strain S. aureus by well diffusion method. Besides, the plant oil showed an inhibitory effect on L20B cell line with a percent inhibitory growth rate reaching 47.1% at 1.125 ?l/mL of the oil concentration. While for the other cell line, MCF-7 cell line, the inhibitory growth rate percentage appeared for almost all concentrations in comparison with control after 24 hours, and even at a concentration of 0.3125?l/mL, the inhibitory growth rate percentage reached up to 86%. This study was conducted to high lightened the benefits of this plant as little study had been done for an Iraqi cultivated plant and the results showed the potent biological effects of the plant especially the volatile oil as an antimicrobial and as a potent cancer inhibitory agent.

Investigations of AGEs' inhibitory and nephroprotective potential of ursolic acid towards reduction of diabetic complications.

In diabetes, interactions between AGEs (advanced glycation end products) and RAGEs (receptors of AGEs) are responsible for chronic complications and the current work reports the potential of ursolic acid as a RAGE inhibitor. The three-dimensional crystal structure of RAGE was first docked with target molecules by 'AutodockVina' using GROMOS 96 4381 parameters. Druggability and pharmacokinetic properties were calculated from the SwissADME server. In vitro bovine serum albumin (BSA)-glucose fluorescence and BSA-methylglyoxal fluorescence assays were also performed. Finally, alloxan-induced diabetic mice were administered ursolic acid and metformin standards (at 1, 50, 100mg/kg) for 50days. Blood glucose levels, several blood parameters, blood lipid profiles, supernatants of homogenized kidney and plasma of mice were examined. In the computational study, ursolic acid showed greater binding affinity (-7.5kcal/mol) for RAGE with an ADMET profiles and lead-likeness compared to metformin as a standard antidiabetic. In the in vitro fluorescence assays, the IC50 value for ursolic acid was much less than that of metformin standard. During the in vivo study, significant reduction in the levels of blood glucose, HbA1C (glycated hemoglobin), creatinine, uric acid, BUN (blood urea nitrogen), AST (aspartate aminotransferase), ALT (alanine aminotransferase), ALP (alkaline phosphatase) were observed in the ursolic acid and metformin-treated mice. Substantial inhibition of AGEs' formation in the plasma and kidney were also detected. Finally, the histopathological examinations of the kidney revealed reversal of cellular necrosis. Hence, ursolic acid is proved to be a potent AGE inhibitory agent in managing the diabetic complications.

In silico molecular docking and ADME/T analysis of Quercetin compound with its evaluation of broad-spectrum therapeutic potential against particular diseases

Progression in computational research has made it possible for the in silico methods to offer epochal benefits to both regulatory needs and the pharmaceutical industry to assess the safety profile. Myriad amounts of flavonoids are present in the human diet. They showed potential therapeutic effects against a wide range of illnesses. One of the most ubiquitously distributed and extensively studied flavonoids is flavonol Quercetin (Quercetin). The current study aspires to reveal Quercetin as a potent inhibitor against Tuberculosis, Malaria, Inflammatory diseases, Breast cancer, Obesity, and Alzheimer's disease in analogy to the standard drugs of each disease. A molecular docking study of Quercetin with specific proteins associated with the diseases was done using Schrodinger Maestro (v11.1) software. The QikProp module of Schrodinger Maestro was used for ADME prediction, and the admetSAR online database evaluated the toxicity of the ligand. Molecular docking results also showed higher scores than commercially available standard drugs. Moreover, ADME properties of Quercetin are delineated with no carcinogenicity and mutagenicity along with lower rat acute toxicity & acceptable oral acute toxicity level. Quercetin possessed higher scores (−9.00, −6.36, −8.53, −7.28, −7.89, −6.68 kcal/mol) as Anti-tuberculosis, Anti-malarial, Anti-inflammatory, Antineoplastic (Breast –cancer), Anti-obesity and Anti-Alzheimers drugs, respectively when compared to the standard drugs. Therefore, from the docking score, we can conclude that Quercetin can be a more potent inhibitory potential agent against selected diseases than the drugs available in the market. However, congenial clinical and empirical studies are required to explicit Quercetin as an effectual candidate drug with equitable treatment of the above-referred diseases.

Delivery of Ursolic Acid by Polyhydroxybutyrate Nanoparticles for Cancer Therapy: in silico and in vitro Studies.

Ursolic acid (UA), a pentacyclic triterpenoid and a phytochemical, is a potent inhibitory agent against proliferation of various tumors. Polyhydroxybutyrate nanoparticles (PHB NPs) are preferred in therapeutics due to their drug-stabilizing property and enhanced biological activity. In this study, PHB NPs were utilized to deliver and enhance the bioavailability of UA against cancer cells (HeLa). Further, molecular docking and dynamic studies were conducted to calculate the binding affinity and stability of UA at the active site of target protein (epidermal growth factor receptor-EGFR). The PHB NPs revealed the average size as 150-200 nm in TEM, which were used in subsequent experiments. The cytoplasmic uptake of nanoparticles was confirmed by florescent microscopy. The encapsulation potential of PHB NPs with UA was assessed by UV-visible spectrophotometer as 54%. Besides, the drug release behavior, cytotoxicity and the regulation of apoptosis were investigated in vitro. The cytotoxicity results revealed that the maximum efficiency of drug delivery was at 96th hour.

Racemic xanthine and dihydroxydopamine conjugates from Cyclopelta parva and their COX-2 inhibitory activity

Seven new compounds including three pairs of enantiomeric xanthine analogues (1–3), a pair of enantiomeric hypoxanthine analogue (4), and three pairs of enantiomeric N-acetyldopamine dimers (6–8), together with a known one (5) were isolated from the insect Cyclopelta parva. Their structures including absolute configurations were assigned by using spectroscopic and computational methods. Chiral HPLC was used to separate racemic 1–8. Biological evaluation found that 6b and 7a are potent COX-2 inhibitory agents with IC50 values at 385.2 nM and 868.8 nM respectively.

Isolation and Identification of α-Glucosidase Inhibitor From Aspergillus Terreus F38

Controlled postprandial glucose level is an important strategy in preventing DM type 2. Inhibitors of α-glucosidase have been postulated to be useful agents in managements of DM type 2. This research aims to isolate and identify of α-glucosidase inhibitor from Aspergillus terreus F38 by liquid fermentation. The mycelium extract of A. terreus F38showed strong activity against α-glucosidase with IC 50 value of 9.65 μg/mL. Separation and purification of mycelium ectract yielded compound I (Butyrolactone III). The structure was establish on the basis of spectral analysis, according to the data obtained by NMR and LCMS-MS experiments. Compound I showed potential activity against α-glucosidase with IC 50 value of 13.87 μg/mL. Therefore, the metabolites from A . terreus F38 can be used as lead compound to design potent α-glucosidase inhibitory agents.

Cardiotoxic effects of the novel approved anti-ErbB2 agents and reverse cardioprotective effects of ranolazine.

PurposePertuzumab, a novel anti-epidermal growth factor receptor 2 humanized monoclonal antibody, and trastuzumab-emtansine (TDM1), a novel antibody–drug conjugate made up of trastuzumab covalently linked to the highly potent microtubule inhibitory agent DM1, have been recently approved by the US Food and Drug Administration for increasing the efficiency and safety of breast cancer therapy with trastuzumab. We investigated for the first time the potential cardiotoxic effects of pertuzumab and TDM1, which are not yet fully elucidated, and we tested whether ranolazine could blunt their cardiotoxicity.MethodsThe cardiotoxic effects were tested in vitro on rat cardiomyoblasts, human fetal cardiomyocytes, adult-like cardiomyocytes, and in vivo on a mouse model.ResultsAll the treated cardiac cell lines were significantly affected by treatment with the tested drugs. Surprisingly, TDM1 showed stronger inhibitory effects on cardiac cells with respect to trastuzumab and pertuzumab by more significantly reducing the cell viability and by changing the morphology of these cells. TDM1 also affected the beating phenotype of adult-like cardiomyocytes in vitro and reduced fractional shortening and ejection fraction in vivo in a mouse model. We also found that ranolazine attenuated not only the cardiotoxic side effects of trastuzumab but also those of pertuzumab and TDM1, when used in combinatorial treatments both in vitro and in vivo, as demonstrated by the recovery of fractional shortening and ejection fraction values in mice pretreated with TDM1.ConclusionWe demonstrated that it is possible to predict the eventual cardiotoxic effects of novel approved anticancer drugs early by using in vitro and in vivo approaches, which can also be useful to screen in advance the cardioprotective agents, so as to avoid the onset of unwanted cardiotoxic side effects.

Ranolazine and TDM1 treatment: Cardioprotective effects in vitro and in vivo.

e23102 Background: Ado trastuzumab emtansine (TDM1) is a novel antibody–drug conjugate consisting of trastuzumab (TRAS) covalently linked to the highly potent microtubule inhibitory agent DM1 via a stable thioether linker. TDM1 is used in metastatic ErbB2 positive breast cancer patients. Although, the potential cardiotoxic effects of TDM1 have not yet been fully elucidated, they can include changes in Ca2+ regulation related to blockade of ErbB2, PI3K-Akt and MAPK pathways. Here, we aim to elucidate whether Ranolazine (R), administered after TDM1 treatment, blunts or not cardiotoxicity in vivo and in vitro. Methods: In vitro, human fetal cardiomyocytes (HFC) were treated with TDM1 for 3 days and then treated in the absence or presence of R for 3 days. Cell viability was assessed by cell counting and MTT assay. To evaluate cardiac function in vivo, C57/BL6 mice, 2-4 months old, were daily treated with TDM1 (44.4 mg/kg/day). At day 0 and after 7 days, fractional shortening (FS) and ejection fraction (EF) were measured, by M/B mode echocardiography, and radial and longitudinal strain (RS and LS) were evaluated using 2D speckle-stracking. These measurements were repeated after 5 days of R treatment (305 mg/Kg/day), started at the end of TDM1 treatment. Results: R reduces TDM1 toxicity in HFC, as evidenced by the higher percentage of viable cells treated with TDM1+ R with respect to the cells treated with TDM1 alone (p < 0.01). In in vivo studies: after 7 days with TDM1 administration, FS decreased to 53.6±0.9%, versus 61.0±0.8 % (sham), (p < 0.01), and EF decreased to 85.5±3.5 % versus 91.0±0.8% (sham), (p < 0.01). Moreover, RS decreased to 20.92±3.2 % versus 42.2±10.1% (sham) (p < 0.01), and LS decreased to -15.5±2.8 % versus -23.6±6.7% (sham), (p < 0.01).In mice treated with TDM1 and, successively treated with R for 5 days, the indices of cardiac function partially recovered: FS 58±2.4 % (p < 0.05), EF 88.8±1.7 %, (p < 0.05), RS (35.7±8.2 %, p > 0.05), whereas the alteration of LS persists even after treatment with R (-17.3±3.7 %, p > 0.05) Conclusions: Here we show that in vivo R post-treatment reduces cardiotoxic effects due to TDM1, as demonstrated by the recovery of FS, EF and RS values. As expected, R increases cell viability of HFC treated with TDM1.

Micellar nano-carriers for the delivery of STAT3 dimerization inhibitors to melanoma.

The objective of this research was to develop polymeric micellar formulations of inhibitors of signal transducer and activator of transcription 3 (STAT3) dimerization, i.e., S3I-1757 and S3I-201, and evaluate the activity of successful formulations in B16-F10 melanoma, a STAT3 hyperactive cancer model, in vitro and in vivo. STAT3 inhibitory agents were encapsulated in methoxy poly(ethylene oxide)-b-poly(ε-caprolactone) (PEO114-b-PCL22) and methoxy poly(ethylene oxide)-b-poly(α-benzyl carboxylate-ε-caprolactone) (PEO114-b-PBCL20) micelles using co-solvent evaporation. Polymeric micelles of S3I-1757 showed high encapsulation efficiency (>88%), slow release profile (<32% release in 24h) under physiological conditions, and a desirable average diameter for tumor targeting (33-54 nm). The same formulations showed low encapsulation efficiencies and rapid drug release for S3I-201. Further studies evidenced the delivery of functional S3I-1757 by polymeric micelles to B16-F10 melanoma cells, leading to a dose-dependent inhibition of cell growth and vascular endothelial growth factor (VEGF) production comparable with that of free drug. Encapsulation of S3I-1757 in polymeric micelles significantly reduced its cytotoxicity in normal bone marrow-derived dendritic cells (DCs). Micelles of S3I-1757 were able to significantly improve the function of B16-F10 tumor-exposed immunosuppressed DCs in the production of IL-12, an indication for functionality in the induction of cell-mediated immune response. In a B16-F10 melanoma mouse model, S3I-1757 micelles inhibited tumor growth and enhanced the survival of tumor-bearing mice more than free S3I-1757. Our findings show that both PCL- and PBCL-based polymeric micelles have potential for the solubilization and delivery of S3I-1757, a potent STAT3 inhibitory agent.

Mycosynthesized Silver Nanoparticles as Potent Growth Inhibitory Agents Against Selected Waterborne Human Pathogens

Search for innovative technologies for eradication of water contamination and thereby reducing waterborne diseases is a global need. Use of antimicrobial metal nanoparticles for water purification processes has opened up new possibilities to combat waterborne diseases. The present study demonstrates the synthesis of antibacterial silver nanoparticles by using fungal filtrates of Fusarium oxysporum and Phoma sorghina. Transmission electron microscopy confirmed the synthesis of isotropic, spherical nanoparticles with 20–25 nm as mean size. The mycosynthesized nanoparticles were evaluated for their growth inhibition activity against waterborne pathogens. Staphylococcus aureus was found to be the most susceptible organism to the silver nanoparticles synthesized from P. sorghina; whereas, high bacteriostatic activity of silver nanoparticles was observed against Brevibacillus borstelensis. The present findings indicate the potential of silver nanoparticles for use in water purification processes.

Antimicrobial Activity and Mechanism of Inhibition of Silver Nanoparticles against Extreme Halophilic Archaea.

Haloarchaea are salt-loving halophilic microorganisms that inhabit marine environments, sea water, salterns, and lakes. The resistance of haloarchaea to physical extremities that challenge organismic survival is ubiquitous. Metal and antibiotic resistance of haloarchaea has been on an upsurge due to the exposure of these organisms to metal sinks and drug resistance genes augmented in their natural habitats due to anthropogenic activities and environmental pollution. The efficacy of silver nanoparticles (SNPs) as a potent and broad spectrum inhibitory agent is known, however, there are no reports on the inhibitory activity of SNPs against haloarchaea. In the present study, we have investigated the antimicrobial potentials of SNPs synthesized using aqueous leaf extract of Cinnamomum tamala against antibiotic resistant haloarchaeal isolates Haloferax prahovense RR8, Haloferax lucentense RR15, Haloarcula argentinensis RR10 and Haloarcula tradensis RR13. The synthesized SNPs were characterized by UV-Vis spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, dynamic light scattering, X-ray diffraction and Fourier transform infrared spectroscopy. The SNPs demonstrated potent antimicrobial activity against the haloarchaea with a minimum inhibitory concentration of 300–400 μg/ml. Growth kinetics of haloarchaea in the presence of SNPs was studied by employing the Baranyi mathematical model for microbial growth using the DMFit curve fitting program. The C. tamala SNPs also demonstrated cytotoxic activity against human lung adenocarcinoma epithelial cell line (A540) and human breast adenocarcinoma cell line (MCF-7). The mechanism of inhibition of haloarchaea by the SNPs was investigated. The plausible mechanism proposed is the alterations and disruption of haloarchaeal membrane permeability by turbulence, inhibition of respiratory dehydrogenases and lipid peroxidation causing cellular and DNA damage resulting in cell death.

Purification and characterization of manganese peroxidases from native and mutant Trametes versicolor IBL-04

Extracellular manganese peroxidases (MnPs) produced by native and mutant strains of Trametes versicolor IBL-04 (EB-60, EMS-90) were purified by ammonium sulphate precipitation and dialysis, followed by ion-exchange and gel-permeation chromatography. The purified enzymes elucidated a single band in the 43-kDa region on sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The optimum pH and temperature of the purified enzymes were found to be 5.0 and 40 °C, respectively. Mutant strain MnPs exhibited a broader active pH range and higher thermal stability than native MnP. Purified MnPs from selected mutants showed almost identical properties to native MnP in electrophoresis, steady-state kinetics, and metal ion and endocrine-disrupting compound (EDC) degradation efficiency. Although the fastest reaction rates occurred with Mn2+, MnPs displayed the highest affinity for ABTS, methoxyhydroquinone, 4-aminophenol and reactive dyes. MnP activity was significantly enhanced by Mn2+ and Cu2+, and inhibited in the presence of Zn2+, Fe2+, ethylenediaminetetraacetic acid and cysteine to various extents, with Hg2+ as the most potent inhibitory agent. MnPs from all sources efficiently catalyzed the degradation of the EDCs, nonylphenol and triclosan, removing over 80% after 3 h of treatment, which was further increased up to 90% in the presence of MnP-mediator system. The properties of T. versicolor MnPs, such as high pH and thermal stability, as well as unique Michaelis-Menten kinetic parameters and high EDC elimination efficiency, render them promising candidates for industrial exploitation.

Potential adverse effects of proton pump inhibitors mimicking other conditions

Proton pump inhibitors, the most potent and safest acid inhibitory agents available, irreversibly bind and inhibit H+, K+-ATPase. They inhibit all phases of gastric acid secretion. Proton pump inhibitors are considered extremely safe and are regularly prescribed. They may, however, have side effects. They affect the clearance of other medicines. And the reactions to them may mimic other conditions and side effects of other medicines.

Potent and selective double-headed thiophene-2-carboximidamide inhibitors of neuronal nitric oxide synthase for the treatment of melanoma.

Selective inhibitors of neuronal nitric oxide synthase (nNOS) are regarded as valuable and powerful agents with therapeutic potential for the treatment of chronic neurodegenerative pathologies and human melanoma. Here, we describe a novel hybrid strategy that combines the pharmacokinetically promising thiophene-2-carboximidamide fragment and structural features of our previously reported potent and selective aminopyridine inhibitors. Two inhibitors, 13 and 14, show low nanomolar inhibitory potency (Ki = 5 nM for nNOS) and good isoform selectivities (nNOS over eNOS [440- and 540-fold, respectively] and over iNOS [260- and 340-fold, respectively]). The crystal structures of these nNOS–inhibitor complexes reveal a new hot spot that explains the selectivity of 14 and why converting the secondary to tertiary amine leads to enhanced selectivity. More importantly, these compounds are the first highly potent and selective nNOS inhibitory agents that exhibit excellent in vitro efficacy in melanoma cell lines.