RESUMEN

Four synthetic Schiff bases (PSB1 [(E)-2-(((4-aminopyridin-3-yl)imino)methyl)-4,6-dibromophenol], PSB2 [(E)-2-(((4-aminopyridin-3-yl)imino)methyl)-4,6-diiodophenol], PSB3 [(E)-2-(((4-aminopyridin-3-yl)imino)methyl)-4-iodophenol], and PSB4 [(E)-2-(((4-aminopyridin-3-yl)imino)methyl)-4-chloro-6-iodophenol]) were fully characterized. These compounds exhibit an intramolecular hydrogen bond between the hydroxyl group of the phenolic ring and the nitrogen of the azomethine group, contributing to their stability. Their antimicrobial activity was evaluated against various Gram-negative and Gram-positive bacteria, and it was found that the synthetic pyridine Schiff bases, as well as their precursors, showed no discernible antimicrobial effect on Gram-negative bacteria, including Salmonella Typhi (and mutant derivatives), Salmonella Typhimurium, Escherichia coli, and Morganella morganii. In contrast, a more pronounced biocidal effect against Gram-positive bacteria was found, including Bacillus subtilis, Streptococcus agalactiae, Streptococcus pyogenes, Enterococcus faecalis, Staphylococcus aureus, and Staphylococcus haemolyticus. Among the tested compounds, PSB1 and PSB2 were identified as the most effective against Gram-positive bacteria, with PSB2 showing the most potent biocidal effects. Although the presence of reactive oxygen species (ROS) was noted after treatment with PSB2, the primary mode of action for PSB2 does not appear to involve ROS generation. This conclusion is supported by the observation that antioxidant treatment with vitamin C only partially mitigated bacterial inhibition, indicating an alternative biocidal mechanism.

Asunto(s)

Antibacterianos , Pruebas de Sensibilidad Microbiana , Piridinas , Bases de Schiff , Bases de Schiff/química , Bases de Schiff/farmacología , Bases de Schiff/síntesis química , Piridinas/química , Piridinas/farmacología , Piridinas/síntesis química , Antibacterianos/farmacología , Antibacterianos/síntesis química , Antibacterianos/química , Bacterias Grampositivas/efectos de los fármacos , Bacterias Gramnegativas/efectos de los fármacos , Halógenos/química , Antiinfecciosos/farmacología , Antiinfecciosos/síntesis química , Antiinfecciosos/química , Estructura Molecular

RESUMEN

Recent research has demonstrated the increasing interest in using insects for the extraction of bioactive compounds, particularly peptides. These compounds offer a spectrum of beneficial physiological effects. The aim of this study was to standardize a methodology for obtaining bioactive peptides from Tenebrio molitor and evaluate its physicochemical characterization, antioxidant, and antimicrobial potential. Six assays were carried out to hydrolyse larvae protein, with variations in Alcalase concentration (0.04 to 0.08%) and reaction time (3 to 8 h). The results indicated that the process applied to defatted mealworm flour was effective in reducing lipids by 82.5%. Consequently, it was an observed increase of 38.4% in protein content. Additionally, an increase in glycogen content was found in defatted mealworm flour (177 µmol glucose g-1 sample) and peptides (152.81 µmol glucose g-1 sample). The degree of hydrolysis was higher in assays with longer hydrolysis durations (8.14 - 8.38%). The antioxidant capacity was 12 to 14% lower in assays with an incubation time of 8h. In this sense, the methodology proposed in the present study proved to be efficient in obtaining bioactive peptides from T. molitor.

Asunto(s)

Antioxidantes , Péptidos , Tenebrio , Tenebrio/química , Animales , Antioxidantes/farmacología , Antioxidantes/análisis , Antioxidantes/química , Péptidos/análisis , Péptidos/química , Péptidos/farmacología , Péptidos/aislamiento & purificación , Antiinfecciosos/farmacología , Antiinfecciosos/química , Antiinfecciosos/análisis , Pruebas de Sensibilidad Microbiana

RESUMEN

This study evaluated push-out bond test (POBT), surface roughness, and antimicrobial properties against Enterococcus faecalis of bioceramic sealers supplemented with silver nanoparticles (AgNPs). The sealers tested were CeraSeal®, EndoSequence® BC SealerTM, and Bio-C® Sealer. The POBT was measured with a Universal Testing Machine, and the type of failure was evaluated with a stereomicroscope. The roughness average (Sa) and peak-valley height (Sy) values were evaluated by atomic force microscopy. The bacterial growth inhibition was evaluated using a disk diffusion test, and antimicrobial activity was determined with the plate microdilution method. The POBT showed no significant difference between sealers with and those without NPs in cervical and apical thirds (p > 0.05). In the middle third, the adhesion force was significant for Endosequence BC Sealer® (p < 0.05). The results showed that the Sa and Sy parameters, when AgNPs were added, did not show a statistically significant difference compared to the groups without nanoparticles (p > 0.05). All tested sealers showed bacterial growth inhibition, but no significant difference was found. Their efficacy, in descending order of antibacterial activity when AgNPs were added, is as follows: EndoSequence® BC SealerTM > Bio-C® Sealer > CeraSeal®. The incorporation of AgNPs into bioceramics improves antimicrobial activity without affecting mechanical properties.

Asunto(s)

Enterococcus faecalis , Nanopartículas del Metal , Materiales de Obturación del Conducto Radicular , Plata , Propiedades de Superficie , Plata/química , Plata/farmacología , Nanopartículas del Metal/química , Materiales de Obturación del Conducto Radicular/química , Materiales de Obturación del Conducto Radicular/farmacología , Enterococcus faecalis/efectos de los fármacos , Enterococcus faecalis/crecimiento & desarrollo , Antiinfecciosos/farmacología , Antiinfecciosos/química , Antibacterianos/farmacología , Antibacterianos/química , Ensayo de Materiales , Humanos , Pruebas de Sensibilidad Microbiana , Cerámica/química , Cerámica/farmacología , Microscopía de Fuerza Atómica , Fosfatos de Calcio , Combinación de Medicamentos , Óxidos , Silicatos

RESUMEN

The rapid resistance developed by pathogenic microorganisms against the current antimicrobial pool represents a serious global public health problem, leading to the search for new antibiotic agents. The scorpion Tityus stigmurus, an abundant species in Northeastern Brazil, presents a rich arsenal of bioactive molecules in its venom, with high potential for biotechnological applications. However, venom cytotoxicity constitutes a barrier to the therapeutic application of its different components. The objective of this study was to produce T. stigmurus-venom-loaded cross-linked chitosan nanoparticles (Tsv/CN) at concentrations of 0.5% and 1.0% to improve their biological antimicrobial activity. Polymeric nanoparticles were formed with a homogeneous particle size and spherical shape. Experimental formulation parameters were verified in relation to mean size (<180 nm), zeta potential, polydispersity index and encapsulation efficiency (>78%). Tsv/CN 1.0% demonstrated an ability to increase the antimicrobial venom effect against Staphylococcus aureus bacteria, exhibiting an MIC value of 44.6 µg/mL. It also inhibited different yeast species of the Candida genus, and Tsv/CN 0.5% and 1.0% led to a greater inhibitory effect of C. tropicalis and C. parapsilosis strains, presenting MIC values between 22.2 and 5.5 µg/mL, respectively. These data demonstrate the biotechnological potential of these nanosystems to obtain a new therapeutic agent with potential antimicrobial activity.

Asunto(s)

Quitosano , Pruebas de Sensibilidad Microbiana , Nanopartículas , Venenos de Escorpión , Escorpiones , Quitosano/química , Quitosano/farmacología , Nanopartículas/química , Animales , Venenos de Escorpión/química , Venenos de Escorpión/farmacología , Escorpiones/química , Staphylococcus aureus/efectos de los fármacos , Antiinfecciosos/farmacología , Antiinfecciosos/química , Candida/efectos de los fármacos , Tamaño de la Partícula , Antibacterianos/farmacología , Antibacterianos/química , Animales Ponzoñosos

RESUMEN

Because of the exoskeleton, arthropods must have flexible areas to be able to move. Such regions are called arthrodial membranes and are particularly vulnerable to bacteria and fungi. Here, we analyzed the secretion in the glands underneath it in a Neotropical harvester Mischonyx squalidus (Arachnida: Opiliones) and tested whether it has antiseptical properties. Wepuncturedthemembrane,collectedand quantified ina spectrophotometer. We also fractionated and analyzed the samples in reversed-phase high-performance liquid chromatography (RP-HPLC) and then incubated the treated fractions and determined growth inhibition by measuring absorbance. The secretions resulted in 100 fractions, among which two had activity against the Gram-positive bacteria Micrococcus luteus and against the yeast Candida albicans. The low concentrations at which the secretions were active are relevant from a biotechnological point of view. For the organism, the secretions possibly prevent infections, including when they are attacked in these regions by predators that pick that spot to bite.

Asunto(s)

Arácnidos , Animales , Arácnidos/metabolismo , Candida albicans/efectos de los fármacos , Micrococcus luteus/efectos de los fármacos , Antiinfecciosos/metabolismo , Antiinfecciosos/química , Antiinfecciosos/farmacología

RESUMEN

OBJECTIVE: Analyze the effects of the functionalization of pre-functionalized GIC particles with chlorhexidine on the physicochemical properties and antimicrobial activity. MATERIALS AND METHODS: Four groups were prepared: (1) GIC (Bioglass R - Biodinamica) - control group; (2) GIC-CHX 1%: Group containing 1% pre-reacted CHX particles; (3) GIC-CHX 2.5%: Group containing 2.5% pre-reacted CHX particles; (4) GIC-CHX 5%: Group containing 5% pre-reacted CHX particles. Hourglass-shaped specimens (10 mm × 2 mm x 1 mm) were fabricated for mechanical tests including cohesive strength (n = 12), modulus of elasticity (n = 12) and microhardness (n = 10). Discs (10 mm × 2 mm) were prepared for the analysis of Ca+2, PO4- and F- ions release (n = 3), and roughness (n = 12). To evaluate the setting time, a Gilmore needle was used according to ISO 9917-1:2016. Disk-shaped specimens (5 × 1mm) were manufactured and subjected to bacterial activity (n = 9) (Streptococcus mutans ATCC 159). RESULTS: Modulus, roughness, setting time and ions release (Ca+2, PO4-, and F-) there were no statistically significant differences among the groups (p > 0.05). The setting time did not change with the incorporation of CHX. The GIC-CHX 2.5% and GIC-CHX 5% groups exhibited superior antibacterial activity compared to the control group and GIC-CHX 1% (p < 0.001). The GIC-CHX 5% group showed the highest microhardness values (p < 0.041), cohesive strength (p < 0.009) when compared to the control group. CONCLUSION: The pre-reacted CHX in GICs was able to confer antimicrobial activity, improve cohesive strength, microhardness, and did not impair ion release, setting time, and roughness.

Asunto(s)

Clorhexidina , Cementos de Ionómero Vítreo , Ensayo de Materiales , Clorhexidina/química , Clorhexidina/farmacología , Cementos de Ionómero Vítreo/química , Cementos de Ionómero Vítreo/farmacología , Antiinfecciosos/farmacología , Antiinfecciosos/química , Streptococcus mutans/efectos de los fármacos , Dureza , Fenómenos Mecánicos , Propiedades de Superficie , Fenómenos Químicos , Antibacterianos/farmacología , Antibacterianos/química

RESUMEN

The objective of this work was to prepare and characterize liposomes containing co-encapsulated ascorbic acid (AA) and ascorbyl palmitate (AP), as well as to evaluate their stability, cytotoxicity, antioxidant, and antimicrobial activity. Through the pre-formulation studies, it was possible to improve the formulation, as leaving it more stable and with a greater antioxidant activity, resulting in a formulation designated LIP-AAP, with 161 nm vesicle size, 0.215 polydispersity index, -31.7 mV zeta potential, and pH of 3.34. Encapsulation efficiencies were 37% for AA and 79% for AP, and the content was 1 mg/mL for each compound. The optimized liposomes demonstrated stability under refrigeration for 60 days, significant antioxidant activity (31.4 µMol of TE/mL), and non-toxicity, but no antimicrobial effects against bacteria and fungi were observed. These findings confirm that the co-encapsulated liposomes are potent, stable antioxidants that maintain their physical and chemical properties under optimal storage conditions.

Asunto(s)

Antiinfecciosos , Antioxidantes , Ácido Ascórbico , Estabilidad de Medicamentos , Liposomas , Ácido Ascórbico/química , Ácido Ascórbico/farmacología , Ácido Ascórbico/análogos & derivados , Liposomas/química , Antioxidantes/química , Antioxidantes/farmacología , Antiinfecciosos/farmacología , Antiinfecciosos/química , Humanos , Bacterias/efectos de los fármacos , Tamaño de la Partícula , Hongos/efectos de los fármacos , Hongos/crecimiento & desarrollo , Composición de Medicamentos

RESUMEN

Acne affects most of the world's population, causing an impact on the self-esteem of adolescents and young adults. One of the causes is the presence of the bacteria Cutibacterium acnes which are part of the natural microbiota of the skin. Topical treatments consist of anti-inflammatory and antibiotics, which could select resistant strains. Alternatives to the antibiotic are biocomposites that have antimicrobial activity like biosurfactants which are produced by bacteria. An innovative way of applying these compounds is bioadhesive polymeric films that adhere to the skin and release the active principle topically. Rhamnolipids have great potential to be used in the treatment of acne because they present antimicrobial activity against C. acnes in low and safe concentrations (MIC of 15.62 µg/mL, CBM of 31.25 µg/mL and CC50 of 181.93 µg/mL). Four films with different rhamnolipids concentrations (0.0; 0.1; 0.2; and 0.3%, w/w) were obtained as to visual appearance, mass variation, thickness, density, solubility, pH, water vapor transmission, mechanical properties (folding endurance, bioadhesion strength, tensile strength, elongation at break and Young's modulus), scanning electron microscopy and infrared. The results show that these formulations had a homogeneous appearance; elastic mechanical properties; pH similar to human skin and bioadhesive. The polymeric films containing rhamnolipids were effective against C. acnes, in the in vitro test, at the three concentrations tested, the film with the highest concentration (0.3%, w/w) being the most promising for presenting the highest antimicrobial activity. Thus, the polymeric film containing rhamnolipids has the potential to be used in the treatment of acne.

Asunto(s)

Glucolípidos , Pruebas de Sensibilidad Microbiana , Polímeros , Glucolípidos/química , Glucolípidos/administración & dosificación , Glucolípidos/farmacología , Polímeros/química , Pruebas de Sensibilidad Microbiana/métodos , Antibacterianos/farmacología , Antibacterianos/administración & dosificación , Antibacterianos/química , Administración Tópica , Propionibacterium acnes/efectos de los fármacos , Acné Vulgar/tratamiento farmacológico , Humanos , Piel/efectos de los fármacos , Solubilidad , Antiinfecciosos/farmacología , Antiinfecciosos/administración & dosificación , Antiinfecciosos/química , Resistencia a la Tracción , Química Farmacéutica/métodos

RESUMEN

The importance of bioactive compounds in agro-industrial by-products of plant origin lies in their direct impacts on human health. These compounds have been shown to possess antioxidant, anti-inflammatory, and antimicrobial properties, contributing to disease prevention and strengthening the immune system. In particular, the antimicrobial action of these compounds emerges as an important tool in food preservation, providing natural alternatives to synthetic preservatives and contributing to combating antimicrobial resistance. Using agro-industrial by-products of plant origin not only addresses the need to reduce waste and promote sustainability but also inaugurates a new era in the formulation of functional foods. From fruit peels to pulps and seeds, these by-products are emerging as essential ingredients in the creation of products that can promote health. Continued research in this area will unveil new applications and properties of these by-products and open doors to a food paradigm in which health and sustainability converge, paving the way to a healthier and more equitable future. The present review presents an overview of our knowledge of agro-industrial by-products and some of their more relevant health-promoting bioactivities.

Asunto(s)

Antiinfecciosos , Antioxidantes , Antioxidantes/farmacología , Antioxidantes/química , Antiinfecciosos/farmacología , Antiinfecciosos/química , Humanos , Agricultura , Plantas/química

RESUMEN

(1) Introduction: Curcumin and Lippia origanoides essential oils have a broad spectrum of biological activities; however, their physicochemical instability, low solubility, and high volatility limit their therapeutic use. Encapsulation in liposomes has been reported as a feasible approach to increase the physicochemical stability of active substances, protect them from interactions with the environment, modulate their release, reduce their volatility, improve their bioactivity, and reduce their toxicity. To date, there are no reports on the co-encapsulation of curcumin and Lippia origanoides essential oils in liposomes. Therefore, the objective of this work is to prepare and physiochemical characterize liposomes loaded with the mixture of these compounds and to evaluate different in vitro biological activities. (2) Methods: Liposomes were produced using the thin-layer method and physiochemical characteristics were calculated. The antimicrobial and cytotoxic activities of both encapsulated and non-encapsulated compounds were evaluated. (3) Results: Empty and loaded nanometric-sized liposomes were obtained that are monodisperse and have a negative zeta potential. They inhibited the growth of Staphylococcus aureus and did not exhibit cytotoxic activity against mammalian cells. (4) Conclusions: Encapsulation in liposomes was demonstrated to be a promising strategy for natural compounds possessing antimicrobial activity.

Asunto(s)

Curcumina , Liposomas , Lippia , Aceites Volátiles , Staphylococcus aureus , Liposomas/química , Curcumina/química , Curcumina/farmacología , Aceites Volátiles/química , Aceites Volátiles/farmacología , Lippia/química , Humanos , Staphylococcus aureus/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Antiinfecciosos/farmacología , Antiinfecciosos/química , Antibacterianos/farmacología , Antibacterianos/química , Supervivencia Celular/efectos de los fármacos , Tamaño de la Partícula

RESUMEN

Drug biotransformation studies emerges as an alternative to pharmacological investigations of metabolites, development of new drug candidates with reduced investment and most efficient production. The present study aims to evaluate the capacity of biotransformation of rifampicin by the filamentous fungus Aspergillus niger ATCC 9029. After incubation for 312 h, the drug was metabolized to two molecules: an isomer (m/z 455) and the rifampicin quinone (m/z 821). The monitoring of metabolite formation was performed by high-performance liquid chromatography, followed by their identification through ultra-high-performance liquid chromatography coupled to tandem mass spectrometer. In vitro antimicrobial activity of the proposed metabolites was evaluated against Staphylococus aureus microorganism, resulting in the loss of inhibitory activity when compared with the standards, with minimum inhibitory concentration of 7.5 µg/ml. The significant biotransformation power of the ATCC 9029 strain of A. niger was confirmed in this study, making this strain a candidate for pilot studies in fermentation tanks for the enzymatic metabolization of the antimicrobial rifampicin. The unprecedented result allows us to conclude that the prospect of new biotransforming strains in species of anemophilic fungi is a promising choice.

Asunto(s)

Aspergillus niger , Biotransformación , Pruebas de Sensibilidad Microbiana , Rifampin , Espectrometría de Masas en Tándem , Aspergillus niger/metabolismo , Aspergillus niger/efectos de los fármacos , Rifampin/farmacología , Rifampin/metabolismo , Cromatografía Líquida de Alta Presión/métodos , Espectrometría de Masas en Tándem/métodos , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/metabolismo , Antiinfecciosos/farmacología , Antiinfecciosos/metabolismo , Antiinfecciosos/química

RESUMEN

Currently, the search for new alternatives to conventional antibiotics to combat bacterial resistance is an urgent task, as many microorganisms threaten human health due to increasing bacterial resistance to traditional medicines. Thus, new molecules such as antimicrobial peptides have emerged as promising alternatives because of their low induction of resistance and broad spectrum of action. In this context, in the past few years, our research group has synthesized and characterized a peptide derived from the C-terminal region of the Lys49 PLA2-like BthTX-I, named p-BthTX-I. After several studies, the peptide (p-BthTX-I)2K was proposed as the molecule with the most considerable biotechnological potential. As such, the present work aimed to evaluate whether the modifications made on the peptide (p-BthTX-I)2K can be applied to other molecules originating from the C-terminal region of PLA2-like Lys49 from snake venoms. The peptides were obtained through the solid-phase peptide synthesis technique, and biochemical and functional characterization was carried out using dichroism techniques, mass spectrometry, antimicrobial activity against ESKAPE strains, hemolytic activity, and permeabilization of lipid vesicles. The antimicrobial activity of the peptides was promising, especially for the peptides (p-AppK)2K and (p-ACL)2K, which demonstrated activity against all strains that were tested, surpassing the model molecule (p-BthTX-I)2K in most cases and maintaining low hemolytic activity. The modifications initially proposed for the (p-BthTX-I)2K peptide were shown to apply to other peptides derived from Lys49 PLA2-like from snake venoms, showing promising results for antimicrobial activity. Future assays comparing the activity of the dimers obtained through this strategy with the monomers of these peptides should be carried out.

Asunto(s)

Fosfolipasas A2 , Fosfolipasas A2/farmacología , Fosfolipasas A2/química , Hemólisis/efectos de los fármacos , Péptidos Antimicrobianos/farmacología , Péptidos Antimicrobianos/química , Péptidos Antimicrobianos/síntesis química , Animales , Pruebas de Sensibilidad Microbiana , Antibacterianos/farmacología , Antibacterianos/síntesis química , Antibacterianos/química , Humanos , Antiinfecciosos/farmacología , Antiinfecciosos/química , Antiinfecciosos/síntesis química , Bacterias/efectos de los fármacos

RESUMEN

Thechemical composition, antioxidant and antimicrobial activities of the essential oil from aerial parts (leaves and flowers) of Chuquiraga arcuataHarling grown in the Ecuadorian Andes were studied. One hundred and twenty-six compounds were identified in the essential oil. Monoterpene hydrocarbons (45.8%) and oxygenated monoterpenes (44.1%) had the major percentages. The most abundant compounds were camphor (21.6%), myrcene (19.5%), and 1,8-cineole (13.4%). Antioxidant activity was examined using DPPH, ABTS,and FRAP assays. The essential oil had a moderate scavenging effect and reduction of ferric ion capacity through FRAP assay. Antimicrobial activity of the essential oil was observed against four pathogenic bacteria and a fungus. The essential oil exhibited activity against all microorganism strains under test, particularly against Candida albicansand Staphylococcus aureuswith MICs of 2.43-12.10 µg/mL.

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Se estudió la composición química, actividades antioxidantes y antimicrobianas del aceite esencial procedente de las partes aérea (hojas y flores) de Chuquiraga arcuataHarling cultivadas en los Andes ecuatorianos. Se identificaron 126 compuestos en el aceite esencial. Los hidrocarburos monoterpénicos (45,8%) y los monoterpenos oxigenados (44,1%) tuvieron el mayor porcentaje. Los compuestos más abundantes fueron alcanfor (21,6%), mirceno (19,5%) y 1,8-cineol (13,4%). La actividadantioxidante se examinó mediante ensayos DPPH, ABTS y FRAP. El aceite esencial tuvo un efecto eliminador moderado y una reducción de la capacidad de iones férricos mediante el ensayo FRAP. Se observó actividad antimicrobiana del aceite esencial contra cuatro bacterias y un hongo patógenos. El aceite esencial mostró actividad contra todas las cepas de microorganismos bajo prueba, particularmente contra Candida albicansy Staphylococcus aureuscon CMI de 2,43-12,10 µg/mL.

Asunto(s)

Aceites Volátiles/química , Extractos Vegetales/química , Asteraceae/química , Antiinfecciosos/química , Antioxidantes/química , Bacterias/efectos de los fármacos , Aceites Volátiles/farmacología , Extractos Vegetales/farmacología , Cromatografía de Gases , Hojas de la Planta/química , Monoterpenos/análisis , Ecuador , Hidrocarburos/análisis , Antiinfecciosos/farmacología , Antioxidantes/farmacología

RESUMEN

The present study provides a comprehensive analysis of the chemical composition of essential oils from species of the Myrcia genus and their applications. The compiled results highlight the chemical diversity and biological activities of these oils, emphasizing their potential importance for various therapeutic and industrial applications. The findings reveal that Myrcia essential oils present a variety of bioactive compounds, such as monoterpenes and sesquiterpenes, which demonstrate antimicrobial activities against a range of microorganisms, including Gram-positive and Gram-negative bacteria, as well as yeasts. Furthermore, this study highlights the phytotoxic activity of these oils, indicating their potential for weed control. The results also point to the insecticidal potential of Myrcia essential oils against a range of pests, showing their viability as an alternative to synthetic pesticides. Additionally, species of the genus Myrcia have demonstrated promising hypoglycemic effects, suggesting their potential in diabetes treatment. This comprehensive synthesis represents a significant advancement in understanding Myrcia essential oils, highlighting their chemical diversity and wide range of biological activities. However, the need for further research is emphasized to fully explore the therapeutic and industrial potential of these oils, including the identification of new compounds, understanding of their mechanisms of action, and evaluation of safety and efficacy in different contexts.

Asunto(s)

Aceites Volátiles , Aceites Volátiles/farmacología , Aceites Volátiles/química , Antiinfecciosos/farmacología , Antiinfecciosos/química , Insecticidas/química , Insecticidas/farmacología , Myrtaceae/química , Humanos , Hipoglucemiantes/farmacología , Hipoglucemiantes/química , Animales , Aceites de Plantas/farmacología , Aceites de Plantas/química

RESUMEN

This study presents fibers based on methacrylic acid-methyl methacrylate (Eudragit L100) as Cu(II) adsorbents, resulting in antimicrobial complexes. Eudragit L100, an anionic copolymer synthesized by radical polymerization, was electrospun in dimethylformamide (DMF) and ethanol (EtOH). The electrospinning process was optimized through a 22-factorial design, with independent variables (copolymer concentration and EtOH/DMF volume ratio) and three repetitions at the central point. The smallest average fiber diameter (259 ± 53 nm) was obtained at 14% w/v Eudragit L100 and 80/20 EtOH/DMF volume ratio. The fibers were characterized using scanning electron microscopy (SEM), infrared spectroscopy in attenuated total reflectance mode (FTIR-ATR), and differential scanning calorimetry (DSC). The pseudo-second-order mechanism explained the kinetic adsorption toward Cu(II). The fibers exhibited a maximum adsorption capacity (qe) of 43.70 mg/g. The DSC analysis confirmed the Cu(II) absorption, indicating complexation between metallic ions and copolymer networks. The complexed fibers showed a lower degree of swelling than the non-complexed fibers. The complexed fibers exhibited bacteriostatic activity against Gram-negative (Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus) bacteria. This study successfully optimized the electrospinning process to produce thin fibers based on Eudragit L100 for potential applications as adsorbents for Cu(II) ions in aqueous media and for controlling bacterial growth.

Asunto(s)

Cobre , Ácidos Polimetacrílicos , Cobre/química , Ácidos Polimetacrílicos/química , Antiinfecciosos/farmacología , Antiinfecciosos/química , Adsorción , Espectroscopía Infrarroja por Transformada de Fourier , Staphylococcus aureus/efectos de los fármacos , Metacrilatos/química , Cinética , Rastreo Diferencial de Calorimetría , Pruebas de Sensibilidad Microbiana

RESUMEN

In this work, a group of ten sesquiterpene drimanes, including polygodial (1), isopolygodial (2), and drimenol (3) obtained from the bark of Drimys winteri F. and seven synthetic derivatives, were tested in vitro against a unique panel of bacteria, fungi, and oomycetes with standardized procedures against bacterial strains K. pneumoniae, S. tiphy, E. avium, and E. coli. The minimum inhibitory concentrations and bactericidal activities were evaluated using standardized protocols. Polygodial (1) was the most active compound, with MBC 8 µg/mL and MIC 16 µg/mL in E. avium; MBC 16 µg/mL and MIC 32 µg/mL in K. pneumoniae; MBC 64 µg/mL and MIC 64 µg/mL in S. typhi; and MBC 8 µg/mL and MIC 16 µg/mL and MBC 32 µg/mL and MIC 64 µg/mL in E. coli, respectively. The observed high potency could be attributed to the presence of an aldehyde group at the C8-C9 position. The antifungal activity of 1 from different microbial isolates has been evaluated. The results show that polygodial affects the growth of normal isolates and against filamentous fungi and oomycetes with MFC values ranging from 8 to 64 µg/mL. Sesquiterpene drimanes isolated from this plant have shown interesting antimicrobial properties.

Asunto(s)

Antiinfecciosos , Drimys , Pruebas de Sensibilidad Microbiana , Sesquiterpenos , Sesquiterpenos/farmacología , Sesquiterpenos/química , Sesquiterpenos/aislamiento & purificación , Antiinfecciosos/farmacología , Antiinfecciosos/química , Drimys/química , Sesquiterpenos Policíclicos/farmacología , Sesquiterpenos Policíclicos/química , Antibacterianos/farmacología , Antibacterianos/química , Extractos Vegetales/farmacología , Extractos Vegetales/química , Escherichia coli/efectos de los fármacos , Hongos/efectos de los fármacos , Bacterias/efectos de los fármacos

RESUMEN

Polyphenols from agro-food waste represent a valuable source of bioactive molecules that can be recovered to be used for their functional properties. Another option is to use them as starting material to generate molecules with new and better properties through semi-synthesis. A proanthocyanidin-rich (PACs) extract from avocado peels was used to prepare several semi-synthetic derivatives of epicatechin by acid cleavage in the presence of phenol and thiol nucleophiles. The adducts formed by this reaction were successfully purified using one-step centrifugal partition chromatography (CPC) and identified by chromatographic and spectroscopic methods. The nine derivatives showed a concentration-dependent free radical scavenging activity in the DPPH assay. All compounds were also tested against a panel of pathogenic bacterial strains formed by Listeria monocytogenes (ATCC 7644 and 19115), Staphylococcus aureus (ATCC 9144), Escherichia coli (ATCC 11775 and 25922), and Salmonella enterica (ATCC 13076). In addition, adducts were tested against two no-pathogenic strains, Limosilactobacillus fermentum UCO-979C and Lacticaseibacillus rhamnosus UCO-25A. Overall, thiol-derived adducts displayed antimicrobial properties and, in some specific cases, inhibited biofilm formation, particularly in Listeria monocytogenes (ATCC 7644). Interestingly, phenolic adducts were inactive against all the strains and could not inhibit its biofilm formation. Moreover, depending on the structure, in specific cases, biofilm formation was strongly promoted. These findings contribute to demonstrating that CPC is a powerful tool to isolate new semi-synthetic molecules using avocado peels as starting material for PACc extraction. These compounds represent new lead molecules with antioxidant and antimicrobial activity.

Asunto(s)

Antioxidantes , Catequina , Persea , Proantocianidinas , Persea/química , Antioxidantes/farmacología , Antioxidantes/química , Antioxidantes/síntesis química , Proantocianidinas/química , Proantocianidinas/farmacología , Proantocianidinas/síntesis química , Proantocianidinas/aislamiento & purificación , Catequina/química , Catequina/farmacología , Extractos Vegetales/química , Extractos Vegetales/farmacología , Pruebas de Sensibilidad Microbiana , Antiinfecciosos/farmacología , Antiinfecciosos/química , Antiinfecciosos/síntesis química , Compuestos de Sulfhidrilo/química , Antibacterianos/farmacología , Antibacterianos/química , Antibacterianos/síntesis química , Antibacterianos/aislamiento & purificación , Fenoles/química , Fenoles/farmacología , Fenoles/aislamiento & purificación , Fenoles/síntesis química

RESUMEN

Nosocomial infections or healthcare-associated infections, normally develops after the healthcare treatment in the hospital. Most of them are caused by infected medical devices. Plastics are the most common materials for manufacturing these devices because of their good processability, sterilization efficacy, ease of handling and harmlessness, however, it usually do not display antimicrobial properties. Here, in order to infer antimicrobial activity to poly(lactic acid), it was modified by maleation, followed by l-lysine grafting to its structure. The chemical modifications were confirmed by FTIR and 1H NMR analysis, indicating the success of the reactions. The antimicrobial activity was tested using Escherichia coli and Staphylococcus aureus and the results showed that the sample was capable of inhibiting about 99 % of the S. aureus growth by contact. The samples cytotoxicity was also tested using the L929 mouse cells and the results indicated no cytotoxic effect. These results indicated the sample antimicrobial potential, without affect the normal eukaryotic cells. In addition, the processability of the modified PLA (PLA-g-Lys) was improved without compromising its mechanical properties, as shown by thermal analysis and tensile tests. Thus, this novel PLA derivative can be seen as a promising material for future applications in the manufacturing of biomedical devices.

Asunto(s)

Escherichia coli , Lisina , Poliésteres , Staphylococcus aureus , Poliésteres/química , Poliésteres/farmacología , Lisina/química , Staphylococcus aureus/efectos de los fármacos , Ratones , Animales , Escherichia coli/efectos de los fármacos , Antiinfecciosos/farmacología , Antiinfecciosos/química , Pruebas de Sensibilidad Microbiana , Antibacterianos/farmacología , Antibacterianos/química , Línea Celular

RESUMEN

OBJECTIVES: This study aimed to assess antimicrobial efficacy, cytotoxicity, and cytokine release (IL-1b, IL-6, IL-10, TNF-α) from human dental pulp stem cells (hDPSCs) of chitosan (CH) and hydroxyapatite (HAp)-modified glass ionomer cements (GIC). METHODS: GICs with varied CH and HAp concentrations (0 %, 0.16 %, 2 %, 5 %, 10 %) were tested against S. mutans for 24 h or 7 days. Antimicrobial activity was measured using an MTT test. Cytotoxicity evaluation followed for optimal concentrations, analyzing mitochondrial activity and apoptosis in hDPSCs. Cytokine release was assessed with MAGPIX. Antimicrobial analysis used Shapiro-Wilk, Kruskal-Wallis, and Dunnett tests. Two-way ANOVA, Tukey, and Dunnett tests were applied for hDP metabolism and cytokine release. RESULTS: CH 2 % and HAp 5 % significantly enhanced GIC antimicrobial activity, especially after seven days. In immediate analysis, all materials showed reduced mitochondrial activity compared to the control. After 24 h, CH demonstrated mitochondrial metabolism similar to the control. All groups exhibited mild cytotoxicity (∼30 % cell death). Only IL-6 was influenced, with reduced release in experimental groups. SIGNIFICANCE: CH 2 % and HAp 5 % were most effective for antibacterial effects. GIC-CH 2 % emerged as the most promising formula, displaying significant antibacterial effects with reduced hDPSC toxicity.

Asunto(s)

Quitosano , Citocinas , Pulpa Dental , Durapatita , Cementos de Ionómero Vítreo , Quitosano/química , Quitosano/farmacología , Cementos de Ionómero Vítreo/toxicidad , Cementos de Ionómero Vítreo/farmacología , Cementos de Ionómero Vítreo/química , Humanos , Durapatita/química , Durapatita/farmacología , Pulpa Dental/citología , Pulpa Dental/efectos de los fármacos , Citocinas/metabolismo , Streptococcus mutans/efectos de los fármacos , Antiinfecciosos/farmacología , Antiinfecciosos/química , Ensayo de Materiales , Células Cultivadas , Células Madre/efectos de los fármacos , Apoptosis/efectos de los fármacos

RESUMEN

Essential oils show several biological properties, such as antimicrobial activity, but have limitations regarding their availability and stability. To maximize their antimicrobial effect and protection against environmental conditions, Pickering-type emulsions were used to vehiculate oregano essential oil (OEO) using cellulose nanofibers (CNF) as emulsion stabilizer. Enzymatic hydrolysis was used to produce CNF from a food industry waste (cassava peel), obtaining an environmentally sustainable emulsion stabilizer. It was evaluated how the different properties of the nanofibers affected the stability of the emulsions. Furthermore, the composition of the dispersed phase was varied (different ratios of OEO and sunflower oil-SO) in view of the target application in biodegradable active coatings. Even at very low concentration (0.01 % w/w), CNF was able to form kinetically stable emulsions with small droplet sizes using oil mixtures (OEO + SO). The stabilization mechanism was not purely Pickering, as there was a reduction in interfacial tension. Excellent antimicrobial activity was observed against bacteria and the fungus Alternaria alternata, demonstrating the ability to apply these emulsions in active systems such as coatings and films. An improvement in the stability of emulsions was observed when using a mixture of oils, which is extremely advantageous considering costs and stability to heat treatments, since the desired antimicrobial activity is maintained for the final application.

Asunto(s)

Antiinfecciosos , Celulosa , Emulsiones , Nanofibras , Aceites Volátiles , Origanum , Nanofibras/química , Emulsiones/química , Aceites Volátiles/química , Aceites Volátiles/farmacología , Celulosa/química , Celulosa/farmacología , Antiinfecciosos/farmacología , Antiinfecciosos/química , Origanum/química , Alternaria/efectos de los fármacos