Search results for "CLASSIFICATION"
showing 10 items of 29475 documents
Paracentrin 1, a synthetic antimicrobial peptide from the sea-urchin Paracentrotus lividus, interferes with staphylococcal and Pseudomonas aeruginosa…
2014
The rise of antibiotic-resistance as well as the reduction of investments by pharmaceutical companies in the development of new antibiotics have stimulated the investigation for alternative strategies to conventional antibiotics. Many antimicrobial peptides show a high specificity for prokaryotes and a low toxicity for eukaryotic cells and, due to their mode of action the development of resistance is considered unlikely. We recently characterized an antimicrobial peptide that was called Paracentrin 1 from the 5-kDa peptide fraction from the coelomocyte cytosol of the Paracentrotus lividus. In this study, the chemically synthesized Paracentrin 1, was tested for its antimicrobial and antibiof…
Synthesis, computational evaluation and pharmacological assessment of acetylsalicylic esters as anti-inflammatory agents
2019
A convenient approach to the synthesis of alkyl esters of aspirin (ASA-OR) has been developed. The synthesis of ASA-OR has been realized in two steps: (1) direct esterification of salicylic acid with alcohols in the presence of dicyclohexylcarbodiimide to give alkyl salicylates (SAL-OR); (2) acetylation of SAL-OR with acetyl chloride to yield ASA-OR. Molecular mechanics simulations, performed to calculate the kinetic radii of several ASA-OR, indicated that the pentyl and hexyl acetylsalicylates possess the best properties to cross cell membranes. The in vitro biological tests demonstrate their anti-inflammatory activity, superimposable to that of aspirin. The results of our study suggest th…
Targeting Orthosteric and Allosteric Pockets of Aromatase via Dual-Mode Novel Azole Inhibitors
2020
[Image: see text] Breast cancer (BC) is the most diffused cancer type in women and the second leading cause of death among the female population. Effective strategies to fight estrogen responsive (ER+) BC, which represents 70% of all BC cases, rely on estrogen deprivation, via the inhibition of the aromatase enzyme, or the modulation of its cognate estrogen receptor. Current clinical therapies significantly increased patient survival time. Nevertheless, the onset of resistance in metastatic BC patients undergoing prolonged treatments is becoming a current clinical challenge, urgently demanding to devise innovative strategies. In this context, here we designed, synthesized, and performed in …
Investigations on the Steroidal Anti-Inflammatory Activity of Triterpenoids fromDiospyros leucomelas*
1995
Three triterpenes were isolated from Diospyros leucomelas and identified as betulin, betulinic acid, and ursolic acid. They showed anti-inflammatory activity in the carrageenan and serotonin paw edema tests and TPA and EPP ear edema tests. The blockade of their effects by progesterone, actinomycin D, and cycloheximide has served to determine the mechanism of action in relationship with that of glucocorticoids. Betulinic acid was the most affected and therefore a mode of action similar to these drugs may be postulated for it.
Morelloflavone, a novel biflavonoid inhibitor of human secretory phospholipase A2 with anti-inflammatory activity
1997
Abstract The flavanonylflavone morelloflavone inhibited secretory phospholipase A 2 (PLA 2 ) in vitro , with a high potency on the human recombinant synovial and bee venom enzymes ( IC 50 = 0.9 and 0.6 μM, respectively). The inhibition was apparently irreversible. In contrast, the compound was inactive on cytosolic PLA 2 activity from human monocytes. Morelloflavone scavenged reactive oxygen species generated by human neutrophils ( IC 50 = 2.7 and 1.8 μM for luminol and lucigenin, respectively) but did not modify cellular responses such as degranulation or eicosanoid release. This biflavonoid exerted anti-inflammatory effects in animal models, with a potent inhibition of 12-O-tetradecanoylp…
Description of an improved method for Blastocystis hominis culture and axenization
1996
An improved method for Blastocystis hominis culture and axenization was developed in the present study. Stool samples were cultured in prereduced Boeck-Drbohlav NHI modified medium (with several modifications) supplemented with antibiotics (0.4% ampicillin, 0.1% streptomycin, 0.0006% amphotericin B). Axenization was performed by the combination of partial purification of B. hominis by Ficoll-metrizoic acid gradient and inoculation in fresh medium containing active antibiotics against remaining bacteria. A total of 25 strains were obtained by this procedure. The time required for axenization ranged between 3 and 5 weeks. The generation time of axenic strains ranged from 6.6 to 12.1 h (mean +…
Differential Effects of Antibiotic Therapy on the Structure and Function of Human Gut Microbiota
2013
The human intestinal microbiota performs many essential functions for the host. Antimicrobial agents, such as antibiotics (AB), are also known to disturb microbial community equilibrium, thereby having an impact on human physiology. While an increasing number of studies investigate the effects of AB usage on changes in human gut microbiota biodiversity, its functional effects are still poorly understood. We performed a follow-up study to explore the effect of ABs with different modes of action on human gut microbiota composition and function. Four individuals were treated with different antibiotics and samples were taken before, during and after the AB course for all of them. Changes in the…
The affinities of monoclonal antibodies against core antigen of hepatitis B virus
1994
Four monoclonal antibodies generated against the recombinant core antigen of hepatitis B virus are investigated for antigen binding. All exhibit a similar affinity to polystyrene-sorbed antigen but only one of them interacts with native form of HBcAg (an assembled particle) in solution. The presence of 0.1% sodium dodecylsulphate is required for the binding of other three antibodies. The phenomenon can be interpreted as inaccessibility of the corresponding epitopes unless the multimeric antigen structure is disrupted. The core antigen coated on polystyrene is considered as a similar exposed structure.
Modular Solid-Phase Synthesis of Antiprotozoal Barnesin Derivatives
2020
Here, we applied and optimized a solid support (SP)-based Horner-Wadsworth-Emmons reagent to prepare SP-bound vinylogous amino acids. Subsequent SP-based peptide synthesis, global deprotection, and chemical modifications yielded 14 lipodipeptides carrying vinylogous amino acids, including the natural product barnesin A (1). Biological evaluation revealed that several synthesized derivatives show micromolar to nanomolar inhibitory activity against papain-like cysteine proteases, human cathepsin L, and rhodesain.
Anti-phospholipase A2 and anti-inflammatory activity of Santolina chamaecyparissus
2000
The activity of the Santolina chamaecyparissus methanol extract was tested against the phospholipase A2 (PLA2)-induced mouse paw edema and in vitro inhibition of PLA2 activity. After fractionation, only the dichloromethane extract was active against the PLA2 in vitro test. In addition, it reduced the edema induced by arachidonic acid, and by 12-O-tetradecanoylphorbol-13-acetate in a multidose test. After chromatography on silicagel and gel filtration on Sephadex, and using an in vitro anti-PLA2 assay-guided process, we have isolated and identified from the dichloromethane extract the flavone nepetin and four sesquiterpenes.