scholarly journals In Vitro Activity of Human β-Defensin 2 against Pseudomonas aeruginosa in the Presence of Tear Fluid

2007 ◽  
Vol 51 (11) ◽  
pp. 3853-3860 ◽  
Author(s):  
Ling C. Huang ◽  
Rachel L. Redfern ◽  
Srihari Narayanan ◽  
Rose Y. Reins ◽  
Alison M. McDermott
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Peptide ◽  
Ocular Surface ◽  
Salt Content ◽  
Inhibitory Effect ◽  
Heat Inactivation ◽  
Binding Interaction ◽  
Cast Doubt

ABSTRACT Pseudomonas aeruginosa causes vision-threatening keratitis and is difficult to treat due to emerging resistance. Human β-defensin 2 (hBD-2) is an antimicrobial peptide expressed by ocular surface epithelia with broad-spectrum activity against various pathogens, including P. aeruginosa. The activity of hBD-2 against P. aeruginosa in the presence of human tears or NaCl was studied. In some experiments, tears were heat-inactivated, filtered, and separated into cationic/anionic fractions or mucin MUC5AC was removed by immunoprecipitation before use. Immunoprecipitation was performed to study the interaction between hBD-2 and MUC5AC. hBD-2 activity was reduced by 40 to 90% in the presence of 17.5 to 70% (vol/vol) tears. NaCl reduced hBD-2 activity, but at most it could account for only 36% of the inhibitory effect of tears. Heat inactivation and filtration attenuated the ability of tears to inhibit hBD-2 activity by 65 and 68%, respectively. Anionic tear fractions significantly reduced (86%) the activity of hBD-2, whereas only a 22% reduction was observed with the cationic fractions. In the absence of MUC5AC, the activity of hBD-2 was restored by 64%. Immunoprecipitation studies suggested that the loss of hBD-2 activity in tears is due to a direct binding interaction with MUC5AC. Our data showed that the antimicrobial activity of hBD-2 is sensitive to the presence of human tears and that this is partly due to the salt content and also the presence of MUC5AC. These data cast doubt on the effectiveness of hBD-2 as an antimicrobial peptide, and additional studies are required to conclusively elucidate its role in innate immunity at the ocular surface in vivo.

The Effect of Barbituric Acid Derivatives on Platelet Function in Vitro and in Vivo

1973 ◽  
Vol 30 (02) ◽  
pp. 315-326
Author(s):  
J. Heinz Joist ◽  
Jean-Pierre Cazenave ◽  
J. Fraser Mustard
Keyword(s):  
Platelet Aggregation ◽  
Platelet Function ◽  
Barbituric Acid ◽  
Platelet Rich Plasma ◽  
Inhibitory Effect ◽  
Primary Response ◽  
Sodium Pentobarbital ◽  
Barbituric Acid Derivatives

SummarySodium pentobarbital (SPB) and three other barbituric acid derivatives were found to inhibit platelet function in vitro. SPB had no effect on the primary response to ADP of platelets in platelet-rich plasma (PRP) or washed platelets but inhibited secondary aggregation induced by ADP in human PRP. The drug inhibited both phases of aggregation induced by epinephrine. SPB suppressed aggregation and the release reaction induced by collagen or low concentrations of thrombin, and platelet adherence to collagen-coated glass tubes. The inhibition by SPB of platelet aggregation was readily reversible and isotopically labeled SPB did not become firmly bound to platelets. No inhibitory effect on platelet aggregation induced by ADP, collagen, or thrombin could be detected in PRP obtained from rabbits after induction of SPB-anesthesia.

Inhibition of Human and Animal Platelet Adhesiveness to Glass Bead Columns by Adenosine, Dipyridamole, Chlorpromazine and Acetylsalicylic Acid

1976 ◽  
Vol 36 (02) ◽  
pp. 401-410 ◽  
Author(s):  
Buichi Fujttani ◽  
Toshimichi Tsuboi ◽  
Kazuko Takeno ◽  
Kouichi Yoshida ◽  
Masanao Shimizu
Keyword(s):  
Guinea Pig ◽  
Acetylsalicylic Acid ◽  
Guinea Pigs ◽  
Glass Bead ◽  
Animal Species ◽  
Inhibitory Effect ◽  
Rabbit Platelet ◽  
Platelet Adhesiveness

SummaryThe differences among human, rabbit and guinea-pig platelet adhesiveness as for inhibitions by adenosine, dipyridamole, chlorpromazine and acetylsalicylic acid are described, and the influence of measurement conditions on platelet adhesiveness is also reported. Platelet adhesiveness of human and animal species decreased with an increase of heparin concentrations and an increase of flow rate of blood passing through a glass bead column. Human and rabbit platelet adhesiveness was inhibited in vitro by adenosine, dipyridamole and chlorpromazine, but not by acetylsalicylic acid. On the other hand, guinea-pig platelet adhesiveness was inhibited by the four drugs including acetylsalicylic acid. In in vivo study, adenosine, dipyridamole and chlorpromazine inhibited platelet adhesiveness in rabbits and guinea-pigs. Acetylsalicylic acid showed the inhibitory effect in guinea-pigs, but not in rabbits.

Phenolic Acids Exert Anticholinesterase and Cognition-Improving Effects

2018 ◽  
Vol 15 (6) ◽  
pp. 531-543 ◽  
Author(s):  
Dominik Szwajgier ◽  
Ewa Baranowska-Wojcik ◽  
Kamila Borowiec
Keyword(s):  
Phenolic Acids ◽  
Ex Vivo ◽  
Amyloid Β ◽  
Inhibitory Effect ◽  
In Vivo Studies ◽  
Amyloid Β Peptide ◽  
Beneficial Effects ◽  
Aβ Fibrils

Numerous authors have provided evidence regarding the beneficial effects of phenolic acids and their derivatives against Alzheimer's disease (AD). In this review, the role of phenolic acids as inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) is discussed, including the structure-activity relationship. In addition, the inhibitory effect of phenolic acids on the formation of amyloid β-peptide (Aβ) fibrils is presented. We also cover the in vitro, ex vivo, and in vivo studies concerning the prevention and treatment of the cognitive enhancement.

Action of Thioglycosides of 1,2,4-Triazoles and Imidazoles on the Oxidative Stress and Glycosidases in Mice with Molecular Docking

2019 ◽  
Vol 16 (6) ◽  
pp. 696-710
Author(s):  
Mahmoud Balbaa ◽  
Doaa Awad ◽  
Ahmad Abd Elaal ◽  
Shimaa Mahsoub ◽  
Mayssaa Moharram ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Molecular Docking ◽  
Active Sites ◽  
Biological Activities ◽  
Imidazole Ring ◽  
Quantitative Structure Activity Relationship ◽  
Binding Interaction ◽  
Qsar Study

Background: ,2,3-Triazoles and imidazoles are important five-membered heterocyclic scaffolds due to their extensive biological activities. These products have been an area of growing interest to many researchers around the world because of their enormous pharmaceutical scope. Methods: The in vivo and in vitro enzyme inhibition of some thioglycosides encompassing 1,2,4- triazole N1, N2, and N3 and/or imidazole moieties N4, N5, and N6. The effect on the antioxidant enzymes (superoxide dismutase, glutathione S-transferase, glutathione peroxidase and catalase) was investigated as well as their effect on α-glucosidase and β-glucuronidase. Molecular docking studies were carried out to investigate the mode of the binding interaction of the compounds with α- glucosidase and β -glucuronidase. In addition, quantitative structure-activity relationship (QSAR) investigation was applied to find out the correlation between toxicity and physicochemical properties. Results: The decrease of the antioxidant status was revealed by the in vivo effect of the tested compounds. Furthermore, the in vivo and in vitro inhibitory effects of the tested compounds were clearly pronounced on α-glucosidase, but not β-glucuronidase. The IC50 and Ki values revealed that the thioglycoside - based 1,2,4-triazole N3 possesses a high inhibitory action. In addition, the in vitro studies demonstrated that the whole tested 1,2,4-triazole are potent inhibitors with a Ki magnitude of 10-6 and exhibited a competitive type inhibition. On the other hand, the thioglycosides - based imidazole ring showed an antioxidant activity and exerted a slight in vivo stimulation of α-glucosidase and β- glucuronidase. Molecular docking proved that the compounds exhibited binding affinity with the active sites of α -glucosidase and β-glucuronidase (docking score ranged from -2.320 to -4.370 kcal/mol). Furthermore, QSAR study revealed that the HBD and RB were found to have an overall significant correlation with the toxicity. Conclusion: These data suggest that the inhibition of α-glucosidase is accompanied by an oxidative stress action.

scholarly journals Stage-dependent effect of deferoxamine on growth of Plasmodium falciparum in vitro

Blood ◽  
1990 ◽  
Vol 76 (6) ◽  
pp. 1250-1255 ◽  
Author(s):  
S Whitehead ◽  
TE Peto
Keyword(s):  
Plasmodium Falciparum ◽  
Growth Inhibition ◽  
Antimalarial Activity ◽  
Clinical Malaria ◽  
Inhibitory Effect ◽  
Parasite Development ◽  
And Control ◽  
Speed Of Onset

Abstract Deferoxamine (DF) has antimalarial activity that can be demonstrated in vitro and in vivo. This study is designed to examine the speed of onset and stage dependency of growth inhibition by DF and to determine whether its antimalarial activity is cytostatic or cytocidal. Growth inhibition was assessed by suppression of hypoxanthine incorporation and differences in morphologic appearance between treated and control parasites. Using synchronized in vitro cultures of Plasmodium falciparum, growth inhibition by DF was detected within a single parasite cycle. Ring and nonpigmented trophozoite stages were sensitive to the inhibitory effect of DF but cytostatic antimalarial activity was suggested by evidence of parasite recovery in later cycles. However, profound growth inhibition, with no evidence of subsequent recovery, occurred when pigmented trophozoites and early schizonts were exposed to DF. At this stage in parasite development, the activity of DF was cytocidal and furthermore, the critical period of exposure may be as short as 6 hours. These observations suggest that iron chelators may have a role in the treatment of clinical malaria.

scholarly journals A novel BRD4 inhibitor suppresses osteoclastogenesis and ovariectomized osteoporosis by blocking RANKL-mediated MAPK and NF-κB pathways

2021 ◽  
Vol 12 (7) ◽  
Author(s):  
Ying Liu ◽  
Wenjie Liu ◽  
Ziqiang Yu ◽  
Yan Zhang ◽  
Yinghua Li ◽  
...  
Keyword(s):  
Bone Loss ◽  
Osteoporosis Treatment ◽  
Inhibitory Effect ◽  
Specific Gene ◽  
Actin Ring ◽  
Treatment Target ◽  
Significant Inhibitory Effect ◽  
Promising Treatment

AbstractBromodomain-containing protein 4 (BRD4) has emerged as a promising treatment target for bone-related disorders. (+)-JQ1, a thienotriazolodiazepine compound, has been shown to inhibit pro-osteoclastic activity in a BRD4-dependent approach and impede bone loss caused by ovariectomy (OVX) in vivo. However, clinical trials of (+)-JQ1 are limited because of its poor druggability. In this study, we synthesized a new (+)-JQ1 derivative differing in structure and chirality. One such derivative, (+)-ND, exhibited higher solubility and excellent inhibitory activity against BRD4 compared with its analogue (+)-JQ1. Interestingly, (-)-JQ1 and (-)-ND exhibited low anti-proliferative activity and had no significant inhibitory effect on RANKL-induced osteoclastogenesis as compared with (+)-JQ1 and (+)-ND, suggesting the importance of chirality in the biological activity of compounds. Among these compounds, (+)-ND displayed the most prominent inhibitory effect on RANKL-induced osteoclastogenesis. Moreover, (+)-ND could inhibit osteoclast-specific gene expression, F‐actin ring generation, and bone resorption in vitro and prevent bone loss in OVX mice. Collectively, these findings indicated that (+)-ND represses RANKL‐stimulated osteoclastogenesis and averts OVX-triggered osteoporosis by suppressing MAPK and NF-κB signalling cascades, suggesting that it may be a prospective candidate for osteoporosis treatment.

scholarly journals Gilteritinib overcomes lorlatinib resistance in ALK-rearranged cancer

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hayato Mizuta ◽  
Koutaroh Okada ◽  
Mitsugu Araki ◽  
Jun Adachi ◽  
Ai Takemoto ◽  
...  
Keyword(s):  
Gene Rearrangement ◽  
Kinase Inhibitors ◽  
Inhibitory Effect ◽  
In Vivo Model ◽  
Resistance Mutations ◽  
Lung Cancer Patients ◽  
Short Period ◽  
Tki Resistance

AbstractALK gene rearrangement was observed in 3%–5% of non-small cell lung cancer patients, and multiple ALK-tyrosine kinase inhibitors (TKIs) have been sequentially used. Multiple ALK-TKI resistance mutations have been identified from the patients, and several compound mutations, such as I1171N + F1174I or I1171N + L1198H are resistant to all the approved ALK-TKIs. In this study, we found that gilteritinib has an inhibitory effect on ALK-TKI–resistant single mutants and I1171N compound mutants in vitro and in vivo. Surprisingly, EML4-ALK I1171N + F1174I compound mutant-expressing tumors were not completely shrunk but regrew within a short period of time after alectinib or lorlatinib treatment. However, the relapsed tumor was markedly shrunk after switching to the gilteritinib in vivo model. In addition, gilteritinib was effective against NTRK-rearranged cancers including entrectinib-resistant NTRK1 G667C-mutant and ROS1 fusion-positive cancer.

scholarly journals CRISPR/Cas9-based generation of a recombinant double-reporter pseudorabies virus and its characterization in vitro and in vivo

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Peng-Fei Fu ◽  
Xuan Cheng ◽  
Bing-Qian Su ◽  
Li-Fang Duan ◽  
Cong-Rong Wang ◽  
...  
Keyword(s):  
Pseudorabies Virus ◽  
Fluorescent Protein ◽  
Antiviral Agents ◽  
Firefly Luciferase ◽  
Inhibitory Effect ◽  
Economic Losses ◽  
Green Fluorescent ◽  
Swine Herds

AbstractPseudorabies, caused by pseudorabies virus (PRV) variants, has broken out among commercial PRV vaccine-immunized swine herds and resulted in major economic losses to the pig industry in China since late 2011. However, the mechanism of virulence enhancement of variant PRV is currently unclear. Here, a recombinant PRV (rPRV HN1201-EGFP-Luc) with stable expression of enhanced green fluorescent protein (EGFP) and firefly luciferase as a double reporter virus was constructed on the basis of the PRV variant HN1201 through CRISPR/Cas9 gene-editing technology coupled with two sgRNAs. The biological characteristics of the recombinant virus and its lethality to mice were similar to those of the parental strain and displayed a stable viral titre and luciferase activity through 20 passages. Moreover, bioluminescence signals were detected in mice at 12 h after rPRV HN1201-EGFP-Luc infection. Using the double reporter PRV, we also found that 25-hydroxycholesterol had a significant inhibitory effect on PRV both in vivo and in vitro. These results suggested that the double reporter PRV based on PRV variant HN1201 should be an excellent tool for basic virology studies and evaluating antiviral agents.

scholarly journals A Novel Infection Protocol in Zebrafish Embryo to Assess Pseudomonas aeruginosa Virulence and Validate Efficacy of a Quorum Sensing Inhibitor In Vivo

Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 401
Author(s):  
Pauline Nogaret ◽  
Fatima El El Garah ◽  
Anne-Béatrice Blanc-Potard
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Animal Model ◽  
Quorum Sensing ◽  
Drug Testing ◽  
Drug Efficacy ◽  
Embryo Viability ◽  
Immersion Method ◽  
Opportunistic Human Pathogen

The opportunistic human pathogen Pseudomonas aeruginosa is responsible for a variety of acute infections and is a major cause of mortality in chronically infected cystic fibrosis patients. Due to increased resistance to antibiotics, new therapeutic strategies against P. aeruginosa are urgently needed. In this context, we aimed to develop a simple vertebrate animal model to rapidly assess in vivo drug efficacy against P. aeruginosa. Zebrafish are increasingly considered for modeling human infections caused by bacterial pathogens, which are commonly microinjected in embryos. In the present study, we established a novel protocol for zebrafish infection by P. aeruginosa based on bath immersion in 96-well plates of tail-injured embryos. The immersion method, followed by a 48-hour survey of embryo viability, was first validated to assess the virulence of P. aeruginosa wild-type PAO1 and a known attenuated mutant. We then validated its relevance for antipseudomonal drug testing by first using a clinically used antibiotic, ciprofloxacin. Secondly, we used a novel quorum sensing (QS) inhibitory molecule, N-(2-pyrimidyl)butanamide (C11), the activity of which had been validated in vitro but not previously tested in any animal model. A significant protective effect of C11 was observed on infected embryos, supporting the ability of C11 to attenuate in vivo P. aeruginosa pathogenicity. In conclusion, we present here a new and reliable method to compare the virulence of P. aeruginosa strains in vivo and to rapidly assess the efficacy of clinically relevant drugs against P. aeruginosa, including new antivirulence compounds.

scholarly journals Synthesis and Characterization of Polyvinylpyrrolidone-Modified ZnO Quantum Dots and Their In Vitro Photodynamic Tumor Suppressive Action

2021 ◽  
Vol 22 (15) ◽  
pp. 8106
Author(s):  
Tianming Song ◽  
Yawei Qu ◽  
Zhe Ren ◽  
Shuang Yu ◽  
Mingjian Sun ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Photodynamic Therapy ◽  
Inhibitory Effect ◽  
Therapeutic Effects ◽  
In Vivo Experiments ◽  
Potential Applications ◽  
Zno Quantum Dots ◽  
Zno Qds

Despite the numerous available treatments for cancer, many patients succumb to side effects and reoccurrence. Zinc oxide (ZnO) quantum dots (QDs) are inexpensive inorganic nanomaterials with potential applications in photodynamic therapy. To verify the photoluminescence of ZnO QDs and determine their inhibitory effect on tumors, we synthesized and characterized ZnO QDs modified with polyvinylpyrrolidone. The photoluminescent properties and reactive oxygen species levels of these ZnO/PVP QDs were also measured. Finally, in vitro and in vivo experiments were performed to test their photodynamic therapeutic effects in SW480 cancer cells and female nude mice. Our results indicate that the ZnO QDs had good photoluminescence and exerted an obvious inhibitory effect on SW480 tumor cells. These findings illustrate the potential applications of ZnO QDs in the fields of photoluminescence and photodynamic therapy.

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