Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 21
Filter
Add more filters











Publication year range
1.
Peptides ; 146: 170644, 2021 12.
Article in English | MEDLINE | ID: mdl-34464592

ABSTRACT

Host defense peptides (HDPs) exhibit a broad range of antimicrobial and immunomodulatory activities. In this sense, both functions are like different sides of the same coin. The direct antimicrobial side was discovered first, and widely studied for the development of anti-infective therapies. In contrast, the immunomodulatory side was recognized later and in the last 20 years the interest in this field has been continuously growing. Different to their antimicrobial activities, the immunomodulatory activities of host defense peptides are more effective in vivo. They offer a great opportunity for new therapeutic applications in the fields of anti-infective therapy, chronic inflammatory diseases treatment, novel vaccine adjuvants development and anticancer immunotherapy. These immune related functions of HDPs includes chemoattraction of leukocytes, modulation of inflammation, enhancement of antigen presentation and polarization of adaptive immune responses. Our attempt with this review is to make a careful evaluation of different aspects of the less explored, but attractive immunomodulatory side of the HDP functional coin.


Subject(s)
Antimicrobial Cationic Peptides/pharmacology , Immunologic Factors/pharmacology , Animals , Anti-Infective Agents/pharmacology , Humans , Immune System/drug effects
2.
Biomolecules ; 11(5)2021 05 17.
Article in English | MEDLINE | ID: mdl-34067685

ABSTRACT

Cm-p5 is a snail-derived antimicrobial peptide, which demonstrated antifungal activity against the pathogenic strains of Candida albicans. Previously we synthetized a cyclic monomer as well as a parallel and an antiparallel dimer of Cm-p5 with improved antifungal activity. Considering the alarming increase of microbial resistance to conventional antibiotics, here we evaluated the antimicrobial activity of these derivatives against multiresistant and problematic bacteria and against important viral agents. The three peptides showed a moderate activity against Pseudomonas aeruginosa, Klebsiella pneumoniae Extended Spectrum ß-Lactamase (ESBL), and Streptococcus agalactiae, with MIC values > 100 µg/mL. They exerted a considerable activity with MIC values between 25-50 µg/mL against Acinetobacter baumanii and Enterococcus faecium. In addition, the two dimers showed a moderate activity against Pseudomonas aeruginosa PA14. The three Cm-p5 derivatives inhibited a virulent extracellular strain of Mycobacterium tuberculosis, in a dose-dependent manner. Moreover, they inhibited Herpes Simplex Virus 2 (HSV-2) infection in a concentration-dependent manner, but had no effect on infection by the Zika Virus (ZIKV) or pseudoparticles of Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2). At concentrations of >100 µg/mL, the three new Cm-p5 derivatives showed toxicity on different eukaryotic cells tested. Considering a certain cell toxicity but a potential interesting activity against the multiresistant strains of bacteria and HSV-2, our compounds require future structural optimization.


Subject(s)
Anti-Bacterial Agents/pharmacology , Antimicrobial Cationic Peptides/chemistry , Antiviral Agents/pharmacology , Drug Resistance, Multiple, Bacterial/drug effects , Herpesvirus 2, Human/drug effects , Amino Acid Sequence , Animals , Anti-Bacterial Agents/chemistry , Antimicrobial Cationic Peptides/pharmacology , Antiviral Agents/chemistry , Candida albicans/drug effects , Cell Line , Cell Survival/drug effects , Dimerization , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Humans , Microbial Sensitivity Tests , SARS-CoV-2/drug effects
3.
ACS Omega ; 4(21): 19081-19095, 2019 Nov 19.
Article in English | MEDLINE | ID: mdl-31763531

ABSTRACT

Following the information obtained by a rational design study, a cyclic and helical-stabilized analogue of the peptide Cm-p5 was synthetized. The cyclic monomer showed an increased activity in vitro against Candida albicans and Candida parapsilosis, compared to Cm-p5. Initially, 14 mutants of Cm-p5 were synthesized following a rational design to improve the antifungal activity and pharmacological properties. Antimicrobial testing showed that the activity was lost in each of these 14 analogues, suggesting, as a main conclusion, that a Glu-His salt bridge could stabilize Cm-p5 helical conformation during the interaction with the plasma membrane. A derivative, obtained by substitution of Glu and His for Cys, was synthesized and oxidized with the generation of a cyclic monomer with improved antifungal activity. In addition, two dimers were generated during the oxidation procedure, a parallel and antiparallel one. The dimers showed a helical secondary structure in water, whereas the cyclic monomer only showed this conformation in SDS. Molecular dynamic simulations confirmed the helical stabilizations for all of them, therefore indicating the possible essential role of the Glu-His salt bridge. In addition, the antiparallel dimer showed a moderate activity against Pseudomonas aeruginosa and a significant activity against Listeria monocytogenes. Neither the cyclic monomer nor the dimers were toxic against macrophages or THP-1 human cells. Due to its increased capacity for fungal control compared to fluconazole, its low cytotoxicity, together with a stabilized α-helix and disulfide bridges, that may advance its metabolic stability, and in vivo activity, the new cyclic Cm-p5 monomer represents a potential systemic antifungal therapeutic candidate.

4.
Int J Pharm ; 555: 356-367, 2019 Jan 30.
Article in English | MEDLINE | ID: mdl-30453018

ABSTRACT

In the last years, the antimicrobial resistance against antibiotics has become a serious health issue, arise as global threat. This has generated a search for new strategies in the progress of new antimicrobial therapies. In this context, different nanosystems with antimicrobial properties have been studied. Specifically, magnetic nanoparticles seem to be very attractive due to their relatively simple synthesis, intrinsic antimicrobial activity, low toxicity and high versatility. Iron oxide NPs (IONPs) was authorized by the World Health Organization for human used in biomedical applications such as in vivo drug delivery systems, magnetic guided therapy and contrast agent for magnetic resonance imaging have been widely documented. Furthermore, the antimicrobial activity of different magnetic nanoparticles has recently been demonstrated. This review elucidates the recent progress of IONPs in drug delivery systems and focuses on the treatment of infectious diseases and target the possible detrimental biological effects and associated safety issues.


Subject(s)
Anti-Infective Agents/administration & dosage , Drug Delivery Systems , Magnetite Nanoparticles , Animals , Anti-Infective Agents/pharmacology , Communicable Diseases/drug therapy , Communicable Diseases/microbiology , Drug Resistance, Microbial , Ferric Compounds/chemistry , Humans
5.
Rev. cuba. med. trop ; 69(2): 1-13, may.-ago. 2017. ilus
Article in Spanish | LILACS | ID: biblio-901243

ABSTRACT

El aumento en la incidencia de las enfermedades infecciosas en los últimos años se ha favorecido por diferentes causas. Entre estas se destacan las inmunodeficiencias adquiridas (sida, trasplantes de órganos, quimioterapia oncológica), la migración de personas que trae consigo la posibilidad de importar enfermedades hacia poblaciones susceptibles, así como el excesivo empleo de antibióticos. Debido a esta situación se ha incrementado la búsqueda de nuevos candidatos terapéuticos para el desarrollo de terapias más efectivas. En este sentido los péptidos antimicrobianos constituyen una opción promisoria, pues presentan un amplio espectro de actividad frente a varios microorganismos patógenos. Además, se encuentran ampliamente distribuidos en la naturaleza, desde organismos unicelulares hasta mamíferos. Algunos péptidos antimicrobianos ya están siendo evaluados en estudios clínicos aunque muchos de ellos no han tenido resultados favorables in vivo debido a su poca estabilidad metabólica y toxicidad, entre otros. Con el fin de optimizar estas propiedades de los péptidos antimicrobianos se han trazado diferentes estrategias como la modificación química de su estructura y la conjugación con nanopartículas magnéticas. Es por eso que este artículo tiene el objetivo de revisar las potenciales aplicaciones terapéuticas de estas moléculas, teniendo en cuenta la información publicada al respecto en MedLine, Web of Science y Scopus en los últimos años


The growing incidence of infectious disease in recent years may be attributed to several causes, among them acquired immunodeficiencies (AIDS, organ transplant, oncological chemotherapy), human migration and the consequent import of diseases into susceptible populations, and the excessive use of antibiotics. This situation has fostered the search for new therapeutic candidates for the development of more effective treatments. Antimicrobial peptides are a promising alternative in this respect, due to their broad spectrum of activity against several pathogenic microorganisms. Moreover, they are widely distributed in nature, from unicellular organisms to mammals. Some antimicrobial peptides are already being evaluated in clinical studies, though many of them have not produced any favorable results in vivo due to their low metabolic stability and their toxicity, among other factors. Several strategies have been developed to overcome the above mentioned drawbacks, among them conjugation of microbial peptides with magnetic nanoparticles and chemical modification of their structure. The present study is aimed at reviewing the potential therapeutic applications of these molecules based on information published in MedLine, the Web of Science and Scopus in recent years.

7.
Biochim Biophys Acta ; 1858(7 Pt A): 1488-98, 2016 Jul.
Article in English | MEDLINE | ID: mdl-27063608

ABSTRACT

Recently, several peptides have been studied regarding the defence process against pathogenic microorganisms, which are able to act against different targets, with the purpose of developing novel bioactive compounds. The present work focuses on the structural and functional evaluation of the palindromic antimicrobial peptide Pa-MAP2, designed based on the peptide Pa-MAP from Pleuronectes americanus. For a better structural understanding, molecular modelling analyses were carried out, together with molecular dynamics and circular dichroism, in different media. Antibacterial activity against Gram-negative and positive bacteria was evaluated, as well as cytotoxicity against human erythrocytes, RAW 264.7, Vero and L6 cells. In silico docking experiments, lipid vesicle studies, and atomic force microscopy (AFM) imaging were carried out to explore the activity of the peptide. In vivo studies on infected mice were also done. The palindromic primary sequence favoured an α-helix structure that was pH dependent, only present on alkaline environment, with dynamic N- and C-terminals that are stabilized in anionic media. Pa-MAP2 only showed activity against Gram-negative bacteria, with a MIC of 3.2 µM, and without any cytotoxic effect. In silico, lipid vesicles and AFM studies confirm the preference for anionic lipids (POPG, POPS, DPPE, DPPG and LPS), with the positively charged lysine residues being essential for the initial electrostatic interaction. In vivo studies showed that Pa-MAP2 increases to 100% the survival rate of mice infected with Escherichia coli. Data here reported indicated that palindromic Pa-MAP2 could be an alternative candidate for use in therapeutics against Gram-negative bacterial infections.


Subject(s)
Anti-Bacterial Agents/chemistry , Antimicrobial Cationic Peptides/chemistry , Escherichia coli Infections/drug therapy , Peptidomimetics/chemistry , Alanine/chemistry , Amino Acid Sequence , Animals , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/pharmacology , Antimicrobial Cationic Peptides/isolation & purification , Cell Survival/drug effects , Chlorocebus aethiops , Cholesterol/chemistry , Erythrocytes/drug effects , Escherichia coli/drug effects , Escherichia coli/growth & development , Escherichia coli Infections/microbiology , Escherichia coli Infections/mortality , Flounder/metabolism , Humans , Lipopolysaccharides/chemistry , Mice , Molecular Dynamics Simulation , Molecular Sequence Data , Peptidomimetics/chemical synthesis , Peptidomimetics/pharmacology , Phosphatidylcholines/chemistry , Phosphatidylglycerols/chemistry , Phosphatidylserines/chemistry , Protein Structure, Secondary , Protein Structure, Tertiary , Survival Analysis , Unilamellar Liposomes/chemistry , Vero Cells
8.
Org Lett ; 17(11): 2728-31, 2015 Jun 05.
Article in English | MEDLINE | ID: mdl-25994574

ABSTRACT

A new solid-phase protocol for the synthesis of N-substituted and tetrazolo peptides is described. The strategy relies on the combination of aminocatalysis-mediated on-resin Ugi reactions and peptide couplings for the N-alkylation of peptides at selected sites, including the N-terminal double lipidation, the simultaneous lipidation/biotinylation, and the steroid/lipid conjugation via tetrazole ring formation. The solid-phase Ugi four-component reactions were enabled by on-resin transimination steps prior to addition of the acid and isocyanide components. The strategy proved to be suitable for the feasible incorporation of complex N-substituents at both termini and at internal positions, which is not easily achievable by other solid-phase methods.


Subject(s)
Lipopeptides/chemical synthesis , Steroids/chemistry , Tetrazoles/chemical synthesis , Alkylation , Lipopeptides/chemistry , Molecular Structure , Solid-Phase Synthesis Techniques , Tetrazoles/chemistry
9.
FASEB J ; 29(8): 3315-25, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25921828

ABSTRACT

Antimicrobial peptides form part of the first line of defense against pathogens for many organisms. Current treatments for fungal infections are limited by drug toxicity and pathogen resistance. Cm-p5 (SRSELIVHQRLF), a peptide derived from the marine mollusk Cenchritis muricatus peptide Cm-p1, has a significantly increased fungistatic activity against pathogenic Candida albicans (minimal inhibitory concentration, 10 µg/ml; EC50, 1.146 µg/ml) while exhibiting low toxic effects against a cultured mammalian cell line. Cm-p5 as characterized by circular dichroism and nuclear magnetic resonance revealed an α-helical structure in membrane-mimetic conditions and a tendency to random coil folding in aqueous solutions. Additional studies modeling Cm-p5 binding to a phosphatidylserine bilayer in silico and isothermal titration calorimetry using lipid monophases demonstrated that Cm-p5 has a high affinity for the phospholipids of fungal membranes (phosphatidylserine and phosphatidylethanolamine), only moderate interactions with a mammalian membrane phospholipid, low interaction with ergosterol, and no interaction with chitin. Adhesion of Cm-p5 to living C. albicans cells was confirmed by fluorescence microscopy with FITC-labeled peptide. In a systemic candidiasis model in mice, intraperitoneal administration of Cm-p5 was unable to control the fungal kidney burden, although its low amphiphaticity could be modified to generate new derivatives with improved fungicidal activity and stability.


Subject(s)
Antifungal Agents/pharmacology , Gastropoda/metabolism , Mollusca/metabolism , Peptides/pharmacology , Animals , Candida albicans/drug effects , Candidiasis/drug therapy , Cell Membrane/drug effects , Cell Membrane/metabolism , Circular Dichroism/methods , Female , Hydrophobic and Hydrophilic Interactions , Mice , Mice, Inbred BALB C , Microbial Sensitivity Tests/methods , Phosphatidylethanolamines/metabolism , Phosphatidylserines/metabolism , Phospholipids/metabolism , Protein Structure, Secondary
10.
Nanoscale ; 7(14): 6238-46, 2015 Apr 14.
Article in English | MEDLINE | ID: mdl-25776264

ABSTRACT

Candida albicans is a common human-pathogenic fungal species with the ability to cause several diseases including surface infections. Despite the clear difficulties of Candida control, antimicrobial peptides (AMPs) have emerged as an alternative strategy for fungal control. In this report, different concentrations of antifungal Cm-p1 (Cencritchis muricatus peptide 1) were electrospun into nanofibers for drug delivery. The nanofibers were characterized by mass spectrometry confirming the presence of the peptide on the scaffold. Atomic force microscopy and scanning electronic microscopy were used to measure the diameters, showing that Cm-p1 affects fiber morphology as well as the diameter and scaffold thickness. The Cm-p1 release behavior from the nanofibers demonstrated peptide release from 30 min to three days, leading to effective yeast control in the first 24 hours. Moreover, the biocompatibility of the fibers were evaluated through a MTS assay as well as ROS production by using a HUVEC model, showing that the fibers do not affect cell viability and only nanofibers containing 10% Cm-p1-PVA improved ROS generation. In addition, the secretion of pro-inflammatory cytokines IL-6 and TNF-α by the HUVECs was also slightly modified by the 10% Cm-p1-PVA nanofibers. In conclusion, the electrospinning technique applied here allowed for the manufacture of biodegradable biomimetic nanofibrous extracellular membranes with the ability to control fungal infection.


Subject(s)
Antifungal Agents , Aquatic Organisms/chemistry , Candida albicans/growth & development , Human Umbilical Vein Endothelial Cells/metabolism , Nanofibers/chemistry , Peptides , Antifungal Agents/chemistry , Antifungal Agents/pharmacology , Delayed-Action Preparations/chemistry , Delayed-Action Preparations/pharmacology , Human Umbilical Vein Endothelial Cells/cytology , Humans , Interleukin-6/metabolism , Materials Testing/methods , Microscopy, Atomic Force , Nanofibers/ultrastructure , Peptides/chemistry , Peptides/pharmacology , Tumor Necrosis Factor-alpha/metabolism
11.
Front Microbiol ; 4: 389, 2013 Dec 17.
Article in English | MEDLINE | ID: mdl-24409171

ABSTRACT

Lipopolysaccharides (LPSs) are the major molecular component of the outer membrane of Gram-negative bacteria. This molecule is recognized as a sign of bacterial infection, responsible for the development of local inflammatory response and, in extreme cases, septic shock. Unfortunately, despite substantial advances in the pathophysiology of sepsis, there is no efficacious therapy against this syndrome yet. As a consequence, septic shock syndrome continues to increase, reaching mortality rates over 50% in some cases. Even though many preclinical studies and clinical trials have been conducted, there is no Food and Drug Administration-approved drug yet that interacts directly against LPS. Cationic host-defense peptides (HDPs) could be an alternative solution since they possess both antimicrobial and antiseptic properties. HDPs are small, positively charged peptides which are evolutionarily conserved components of the innate immune response. In fact, binding to diverse chemotypes of LPS and inhibition of LPS-induced pro-inflammatory cytokines from macrophages have been demonstrated for different HDPs. Curiously, none of them have been isolated by their affinity to LPS. A diversity of supports could be useful for such biological interaction and suitable for isolating HDPs that recognize LPS. This approach could expand the rational search for anti-LPS HDPs.

12.
Biopolymers ; 98(4): 251-67, 2012.
Article in English | MEDLINE | ID: mdl-23193590

ABSTRACT

Host defense peptides are conserved components of innate immune response present among all classes of life. These peptides are potent, broad spectrum antimicrobial agents with potential as novel therapeutic compounds. Also, the ability of host defense peptides to modulate immunity is an emerging therapeutic concept since its selective modulation is a novel antiinfective strategy. Their mechanisms of action and the fundamental differences between pathogens and host cells surfaces mostly lead to a not widely extended microbial resistance and to a lower toxicity toward host cells. Biological libraries and rational design are novel tools for developing such molecules with promising applications as therapeutic drugs.


Subject(s)
Anti-Infective Agents/metabolism , Immunologic Factors/metabolism , Peptides/metabolism , Animals , Anti-Infective Agents/immunology , Humans , Immunologic Factors/immunology , Peptides/immunology
13.
Curr Microbiol ; 64(5): 501-5, 2012 May.
Article in English | MEDLINE | ID: mdl-22367403

ABSTRACT

Marine organisms represent approximately half of the world's biodiversity by virtue of the sea being an immense reservoir of bioactive molecules. Here, antimicrobial crude extract activities of different marine invertebrates from the Caribbean Sea were evaluated. One of the most active, crude extracts was that marine snail Cenchritis muricatus, it was capable of totally inhibiting the development of Staphylococcus aureus and also showed a growth inhibition of 95.9% in Escherichia coli. Aiming to isolate molecules that confirm antimicrobial activity, the crude extract was purified by reversed-phase HPLC C-18 chromatography. Thereafter, one of the obtained fractions preserved this antibacterial activity. Furthermore, SDS-PAGE analysis (15%) showed the presence of two proteins of molecular masses with approximately 10 and 15 kDa, respectively. The first 19 amino acids of both proteins were sequenced by using Edman degradation, yielding unidentified primary structures compared against sequences deposited at NCBI databank. This is the first report of antibacterial proteins isolated from the mollusk Cenchritis muricatus and these proteins could be used as antibiotic alternatives in the aquacultural industry, as well as in agricultural or biomedical research.


Subject(s)
Anti-Bacterial Agents/pharmacology , Escherichia coli/drug effects , Mollusca/chemistry , Proteins/pharmacology , Staphylococcus aureus/drug effects , Amino Acid Sequence , Animals , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/metabolism , Caribbean Region , Drug Evaluation, Preclinical , Escherichia coli/growth & development , Microbial Sensitivity Tests , Molecular Sequence Data , Mollusca/classification , Mollusca/metabolism , Proteins/chemistry , Proteins/metabolism , Staphylococcus aureus/growth & development
14.
Biochimie ; 94(4): 968-74, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22210491

ABSTRACT

Antimicrobial peptides have been found in mollusks and other sea animals. In this report, a crude extract of the marine snail Cenchritis muricatus was evaluated against human pathogens responsible for multiple deleterious effects and diseases. A peptide of 1485.26 Da was purified by reversed-phase HPLC and functionally characterized. This trypsinized peptide was sequenced by MS/MS technology, and a sequence (SRSELIVHQR), named Cm-p1 was recovered, chemically synthesized and functionally characterized. This peptide demonstrated the capacity to prevent the development of yeasts and filamentous fungi. Otherwise, Cm-p1 displayed no toxic effects against mammalian cells. Molecular modeling analyses showed that this peptide possible forms a single hydrophilic α-helix and the probable cationic residue involved in antifungal activity action is proposed. The data reported here demonstrate the importance of sea animals peptide discovery for biotechnological tools development that could be useful in solving human health and agribusiness problems.


Subject(s)
Antifungal Agents/isolation & purification , Peptide Fragments/isolation & purification , Amino Acid Sequence , Animals , Antifungal Agents/chemistry , Antifungal Agents/pharmacology , Cell Survival/drug effects , Cells, Cultured , Chromatography, Reverse-Phase , Erythrocytes , Fungi/drug effects , Humans , Hydrophobic and Hydrophilic Interactions , Mice , Microbial Sensitivity Tests , Models, Molecular , Molecular Sequence Data , Peptide Fragments/chemistry , Peptide Fragments/pharmacology , Protein Structure, Secondary , Sequence Analysis, Protein , Snails , Surface Properties
15.
Front Microbiol ; 2: 232, 2011.
Article in English | MEDLINE | ID: mdl-22125552

ABSTRACT

In the last few years, the number of bacteria with enhanced resistance to conventional antibiotics has dramatically increased. Most of such bacteria belong to regular microbial flora, becoming a real challenge, especially for immune-depressed patients. Since the treatment is sometimes extremely expensive, and in some circumstances completely inefficient for the most severe cases, researchers are still determined to discover novel compounds. Among them, host-defense peptides (HDPs) have been found as the first natural barrier against microorganisms in nearly all living groups. This molecular class has been gaining attention every day for multiple reasons. For decades, it was believed that these defense peptides had been involved only with the permeation of the lipid bilayer in pathogen membranes, their main target. Currently, it is known that these peptides can bind to numerous targets, as well as lipids including proteins and carbohydrates, from the surface to deep within the cell. Moreover, by using in vivo models, it was shown that HDPs could act both in pathogens and cognate hosts, improving immunological functions as well as acting through multiple pathways to control infections. This review focuses on structural and functional properties of HDP peptides and the additional strategies used to select them. Furthermore, strategies to avoid problems in large-scale manufacture by using molecular and biochemical techniques will also be explored. In summary, this review intends to construct a bridge between academic research and pharmaceutical industry, providing novel insights into the utilization of HDPs against resistant bacterial strains that cause infections in humans.

16.
Rev. cuba. med. trop ; 63(2): 171-176, mayo.-ago. 2011.
Article in Spanish | LILACS | ID: lil-615556

ABSTRACT

Introducción: los moluscos marinos constituyen un reservorio natural de moléculas con potencialidades terapéuticas para el tratamiento de enfermedades infecciosas en momentos en que se han descrito numerosas cepas resistentes a los antibióticos convencionales. Objetivo: comparar 3 soluciones: ácido acético 30 por ciento, metanol 50 por ciento y salina-ácida (NaCl 0,6 mol/L, HCl 1 por ciento) atendiendo a sus capacidades extractivas de moléculas con actividad antibacteriana del molusco marino Cenchritis muricatus. Métodos: para el procesamiento del material biológico se utilizaron las 3 soluciones de extracción y se analizaron los extractos obtenidos de acuerdo con la concentración de proteínas totales y la inhibición del crecimiento bacteriano de cepas de Staphylococcus aureus y Escherichia coli, mediante un bioensayo turbidimétrico en microplacas de 96 pocillos en medio Luria-Bertani. Resultados: se obtuvo mayor concentración de proteínas totales (7,8 mg/mL) con el extracto total de C. muricatus obtenido con la solución salina-ácida. Además con 200 mg/mL de proteínas totales del extracto se obtuvo inhibición significativa (p< 0,001) del crecimiento de S. aureus (12,64 por ciento) y E. coli (12,1 por ciento) respecto al control positivo de inhibición del crecimiento por cloranfenicol. Conclusiones: de acuerdo con los resultados de la comparación entre las soluciones, la solución salina-ácida resultó ser la más eficiente en la extracción de moléculas antibacterianas, probablemente péptidos antimicrobianos de C. muricatus.


Introduction: marine mollusks are natural reservoirs of molecules with therapeutic potential for the treatment of infectious diseases, at a time when many antibiotic-resistant strains are being described. Objective: to compare three solutions: 30 percent acetic acid, 50 percent methanol and saline-acid (NaCl 0.6 mol/L, 1 percent HCl) according to their capacities to extract molecules with antimicrobial activity from the marine mollusk Cenchritis muricatus. Methods: the three extraction solutions were used to process the biological material, and then, the obtained extracts were analyzed in terms of total protein concentration and the bacterial growth inhibition of Staphylococcus aureus and Escherichia coli strains by means of a turbidimetric bioassay using 96 well microplates in Luria-Bertani (LB) culture medium. Results: the highest total protein concentration (7.8 mg/mL) was found in the C. muricatus extract from the saline-acid solution. Additionally, 200 mg/mL of total proteins from the extract caused significant growth inhibition (p<0.001) of S. aureus (12.64 percent) and E. coli (12.1 percent) compared to the positive control of growth inhibition using chloramphenicol. Conclusions: according to these results, the saline-acid solution proved to be more efficient in extracting molecules with antibacterial activity that are likely to be antimicrobial peptides from C. muricatus.


Subject(s)
Animals , Anti-Bacterial Agents/isolation & purification , Complex Mixtures/isolation & purification , Gastropoda , Solutions
17.
Rev Cubana Med Trop ; 63(2): 171-5, 2011.
Article in Spanish | MEDLINE | ID: mdl-23437527

ABSTRACT

INTRODUCTION: marine mollusks are natural reservoirs of molecules with therapeutic potential for the treatment of infectious diseases, at a time when many antibiotic-resistant strains are being described. OBJECTIVE: to compare three solutions: 30 % acetic acid, 50 % methanol and saline-acid (NaCl 0.6 mol/L, 1 % HCl) according to their capacities to extract molecules with antimicrobial activity from the marine mollusk Cenchritis muricawus. METHODS: the three extraction solutions were used to process the biological material, and then, the obtained extracts were analyzed in terms of total protein concentration and the bacterial growth inhibition of Staphylococcus aureus and Escherichia coli strains by means of a turbidimetric bioassay using 96 well microplates in Luria-Bertani (LB) culture medium. RESULTS: the highest total protein concentration (7.8 microg/mL) was found in the C. muricatus extract from the saline-acid solution. Additionally, 200 microg/mL of total proteins from the extract caused significant growth inhibition (p< 0.001) of S. aureus (12.64 %) and E. coli (12.1 %) compared to the positive control of growth inhibition using chloramphenicol. CONCLUSIONS: according to these results, the saline-acid solution proved to be more efficient in extracting molecules with antibacterial activity that are likely to be antimicrobial peptides from C. muricatus.


Subject(s)
Anti-Bacterial Agents/isolation & purification , Complex Mixtures/isolation & purification , Gastropoda , Animals , Solutions
18.
Rev. cuba. med. trop ; 62(3): 167-179, sep.-dic. 2010.
Article in Spanish | LILACS | ID: lil-584949

ABSTRACT

Se hizo una valoración del impacto de los ensayos inmunoenzimáticos en la analítica de base inmunoquímica en las últimas 4 décadas, en la detección de agentes infecciosos o los productos asociado a su presencia y(o) actividad patogénica. Además se hace una incursión en algunos diseños y formatos que han tenido estos inmunoensayos desde los métodos electroquímicos de detección, los ensayos para detectar actividad proteolítica de origen microbiano y sus inhibidores como posibles blancos terapéuticos, los inmunoensayos directos de triple anticuerpo para lograr mayor sensibilidad, reveladores alternativos de la actividad enzimática, ensayos para el estudio de la serología viral con un mínimo de determinaciones, así como ensayos de competencia para evaluar la efectividad de candidatos vacunales basados en combinaciones peptídicas seleccionadas. Se concluyó con una rápida visión del futuro inmediato de este tipo de inmunoensayos a la luz de las tecnologías analíticas emergentes de detección.


This paper assessed the impact of the immunoenzymatic assays on the field of the immunochemistry-based analytics for the last 40 years, and on the detection of infectious agents or the products related to their presence and/or pathogenic activity. It also addressed some designs and formats of these immunoassays from electrochemical methods of detection, assays to determine proteolytic microbial activity and their inhibitors as possible therapeutical targets, more sensitive direct triple antibody systems, alternative enzymatic activity detectors, assays for viral serology of minimal determinations to competitive assays for evaluation of vaccinal candidate effectiveness based on selected peptide combinations. Finally, it provided a rapid overview of the near future of this type of immunoassays in the light of the emerging detection analytical technologies.


Subject(s)
Humans , Immunoenzyme Techniques/methods , Infections/microbiology
19.
Rev. cuba. med. trop ; 62(2): 85-92, Mayo-ago. 2010.
Article in Spanish | LILACS | ID: lil-584944

ABSTRACT

En este trabajo se presentó la historia y evolución, desde el descubrimiento, de los anticuerpos, así como la elucidación de su compleja estructura y función que ha servido de base metodológica para crear paradigmas inimaginables en su momento, como la fina especificidad de reconocimiento; también derrumbar otros, aparentemente inamovibles, como la invariabilidad y universalidad del genoma celular. Se revisó la evolución de los sistemas analíticos basados en la reacción antígeno-anticuerpos para llegar al estado actual y problemática de las enfermedades infecciosas y el determinante papel que desempeñan en su control la detección y el monitoreo de agentes infecciosos. La extraordinaria capacidad de los anticuerpos para discriminar estructuras antigénicamente similares, les permite ser parte fundamental de los inmunoensayos como herramientas básicas de lo que es hoy día una disciplina productiva muy bien establecida: la inmunotecnología.


This paper presented the history and evolution of the antibodies since their discovery. It also elucidated their complex structure and function that have served at a given time as methodological basis for creating unimaginable paradigms such as fine recognition specificity, and also for destroying other apparently immutable ones as invariability and universality of the cellular genome. A review was made of the evolution of antigen-antibody reaction-based analytical systems up to the present, the situation of infectious diseases and the determining role that detection and monitoring of infectious agents play in their control. The extraordinary capability of antibodies to discriminate antigenically similar structures allows them to be fundamental tools in immunoassays and also in a well-established discipline at present, that is, immunotechnology.


Subject(s)
Humans , Antibodies/analysis , Infections/immunology , Infections/microbiology , Immunoenzyme Techniques
20.
Rev Cubana Med Trop ; 62(2): 85-92, 2010.
Article in Spanish | MEDLINE | ID: mdl-23431618

ABSTRACT

This paper presented the history and evolution of the antibodies since their discovery. It also elucidated their complex structure and function that have served at a given time as methodological basis for creating unimaginable paradigms such as fine recognition specificity, and also for destroying other apparently immutable ones as invariability and universality of the cellular genome. A review was made of the evolution of antigen-antibody reaction-based analytical systems up to the present, the situation of infectious diseases and the determining role that detection and monitoring of infectious agents play in their control. The extraordinary capability of antibodies to discriminate antigenically similar structures allows them to be fundamental tools in immunoassays and also in a well-established discipline at present, that is, immunotechnology.


Subject(s)
Antibodies/analysis , Infections/immunology , Infections/microbiology , Humans , Immunoenzyme Techniques
SELECTION OF CITATIONS
SEARCH DETAIL