RESUMEN
Waterborne coatings with intrinsic antibacterial attributes have attracted significant attention due to their potential in mitigating microbial contamination while simultaneously addressing the environmental drawbacks of their solvent-based counterparts. Typically, antimicrobial coatings are designed to resist and eliminate microbial threats, encompassing challenges such as biofilm formation, fungal contamination, and proliferation of black mold. Iodine, when solubilized using ethylene glycol and incorporated as a complex into waterborne latex dispersions, has shown remarkable antimicrobial activity. Here, we demonstrate the effect of the film formation process of these iodinated latex dispersions on their antimicrobial properties. The effect of iodine on the surface morphology and mechanical, adhesion, and antimicrobial properties of the generated films was investigated. Complete integration and uniform distribution of iodine in the films were confirmed through UV-vis spectrophotometry and a laser Raman imaging system (LRIS). In terms of properties, iodinated films showed improved mechanical strength and adhesion compared with blank films. Further, the presence of iodine rendered the films rougher, making them susceptible to bacterial adhesion, but interestingly provided enhanced antibiofilm activity. Moreover, thicker films had a lower surface roughness and reduced biofilm growth. These observations are elucidated through the complex interplay among film thickness, surface morphology, and iodine properties. The insights into the interlink between the film formation process and antimicrobial properties of iodinated latex dispersions will facilitate their enhanced application as sustainable alternatives to solvent-based coatings.
Asunto(s)
Biopelículas , Yodo , Látex , Látex/química , Látex/farmacología , Yodo/química , Yodo/farmacología , Biopelículas/efectos de los fármacos , Propiedades de Superficie , Antiinfecciosos/química , Antiinfecciosos/farmacología , Antibacterianos/farmacología , Antibacterianos/química , Adhesión Bacteriana/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , HalogenaciónRESUMEN
Different cellulose nanocrystal (CNC) forms (dried vs never-dried) can lead to different degrees of CNC reassembly, the formation of nanofibril-like structures, in nanocomposite latex-based pressure-sensitive adhesive (PSA) formulations. CNC reassembly is also affected by CNC sonication and loading as well as the protocol used for CNC addition to the polymerization. In this study, carboxylated CNCs (cCNCs) were incorporated into a seeded, semibatch, 2-ethylhexyl acrylate/methyl methacrylate/styrene emulsion polymerization and cast as pressure-sensitive adhesive (PSA) films. The addition of CNCs led to a simultaneous increase in tack strength, peel strength, and shear adhesion, avoiding the typical trade-off between the adhesive and cohesive strength. Increased CNC reassembly resulted from the use of dried, redispersed, and sonicated cCNCs, along with increased cCNC loading and addition of the cCNCs at the seed stage of the polymerization. The increased degree of CNC reassembly was shown to significantly increase the shear adhesion by enhancing the elastic modulus of the PSA films.
Asunto(s)
Adhesivos , Celulosa , Látex , Nanopartículas , Celulosa/química , Adhesivos/química , Nanopartículas/química , Látex/química , Polimerizacion , Nanocompuestos/química , PresiónRESUMEN
Sustainability and circularity are key issues facing the global polymer industry. The search for biodegradable and environmentally-friendly polymers that can replace conventional materials is a difficult challenge that has been met with limited success. Alternatives must be cost-effective, scalable, and provide equivalent performance. We report that latexes made by the conventional emulsion polymerization of vinyl acetate and functional vinyl ester monomers are efficient thickeners for consumer products and biodegrade in wastewater. This approach uses readily-available starting materials and polymerization is carried out in water at room temperature, in one pot, and generates negligible waste. Moreover, the knowledge that poly(vinyl ester)s are biodegradable will lead to the design of new green polymer materials.
Asunto(s)
Emulsiones , Emulsiones/química , Polimerizacion , Polímeros/química , Álcalis/química , Biodegradación Ambiental , Látex/química , Compuestos de Vinilo/química , Aguas Residuales/químicaRESUMEN
Objective: To investigate the biological safety of commercially available natural rubber latex and synthetic polyurethane condoms. Methods: Natural rubber latex condom brands of A1 and A2 and polyurethane condom brands of B1 and B2 were purchased from large chain pharmacies in Chengdu, with three packages randomly selected for each brand. The study assessed the toxic effects of condom extracts on L-929 mouse fibroblasts according to GB/T standards. Gross observation and histopathological evaluation were conducted to assess the irritation reactions of condoms on the vagina and penis of rabbits (3 rabbits were used for each brand), as well as their sensitization effects on guinea pig skin. Additionally, the impact of continuous perfusion of condom extracts of the vaginas of SD rats for 30 days on their reproductive systems was evaluated, following GB/T standards (5 rats were used for each brand). Results: Extracts from natural rubber latex condom brands A1 and A2, at concentrations of 100% and 50%, exhibited significant cytotoxicity, with optical density (OD) values being significantly lower than those of the blank control group and the polyurethane condom brands B1 and B2 (P<0.01). There was no significant difference in cell morphology and OD values between the extracts of B1 and B2 and the blank control group (P>0.05). Vaginal congestion was found in 3 rabbits from A1 group and 1 rabbit from the A2 group, while no obvious congestion was noted in rabbits from the B1 and the B2 groups. Histopathological examination showed scattered inflammatory cell infiltration in the vaginal tissue of 3 rabbits from the A1 group and 2 rabbits from the A2 group, and slight congestion in the blood vessels of the lamina propria. No obvious pathological changes were observed in the vaginal tissue of polyurethane brand rabbits. Two rabbits from the A1 group and 1 rabbit from the A2 group showed transient and mild erythema on the penis during the experiment. Histopathological examination showed that 1 rabbit from A1 group had small foci of pericapillary lymphocytes in the dermis of the penis, while no significant pathological changes were observed in the penile tissue of A2, B1, and B2 groups. After 30 days of continuous vaginal perfusion with condom extract, 3 rats in A1 group and 2 rats in the A2 group had uterine congestion, with the degree of congestion being lower in the A2 group. No significant congestion or pathological changes were observed in the vaginal and penile tissues of rabbits, or in the uterine tissues of rats from the polyurethane groups. None of the 4 groups of guinea pigs showed significant skin allergic reactions to the condom extracts. Conclusion: Significant differences in biosafety exist among condoms of various materials and brands. To ensure product safety, it is crucial to strengthen quality control and regulatory oversight after condoms become commercially available.
Asunto(s)
Condones , Látex , Poliuretanos , Ratas Sprague-Dawley , Animales , Conejos , Femenino , Cobayas , Ratas , Masculino , Látex/química , Ratones , Vagina/patología , Fibroblastos/efectos de los fármacos , Ensayo de Materiales , Goma/efectos adversosRESUMEN
Euphorbiaceae, also known as the spurge family, is a large group of flowering plants. Despite being tropical natives, they are now widespread. Due to its medicinal and commercial importance, this family of plants attracted a lot of attention in the scientific community. The distinctive characteristic of the family is production of milky latex, which is a rich source of several lectins, the proteins that bind carbohydrates. Although their function is unclear, they are believed to defend plants against damaging phytopathogenic microorganisms, insects, and predatory animals. Additionally, they serve as crucial metabolic regulators under a variety of stressors. Detection, separation, purification, and characterization of lectins from the Euphorbiaceae family - mostly from the latex of plants - began over 40 years ago. This effort produced over 35 original research papers that were published. However, no systematic review that compiles these published data has been presented yet. This review summarizes and describes several procedures and protocols employed for extraction and purification of lectins belonging to this family. Physicochemical properties and biological activities of the lectins, along with their medicinal and pharmacological properties, have also been analyzed. Additionally, using examples of ricin and ricin agglutinin, we have structurally analyzed characteristics of the lectin known as Ribosome Inactivating Protein Type II (RIP-Type II) that belongs to this family. We anticipate that this review article will offer a useful compendium of information on this important family of lectins, show the scientists involved in lectin research the gaps in our knowledge, and offer insights for future research.
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Euphorbiaceae , Ricina , Animales , Ricina/química , Lectinas de Plantas/farmacología , Látex/química , PlantasRESUMEN
Polyethylene is the most commonly used plastic product, and its biodegradation is a worldwide problem. Latex clearing protein derived from Streptomyces sp. strain K30 (LcpK30) has been reported to be able to break the carbon-carbon double bond inside oxidized polyethylene and is an effective biodegradation enzyme for polyethylene. However, the binding of the substrate to the enzyme was difficult due to the hydrophobic nature of polyethylene. Therefore, to further improve the efficiency of LcpK30, the effect of different anchor peptides on the binding capacity of LcpK30 to the substrate was screened in this study. The results of fluorescence confocal microscopy showed that the anchoring peptide LCI had the most significant improvement in effect and was finally selected for further application in a UV-irradiated PE degradation system. The degradation results showed that LCI was able to improve the degradation efficiency of LcpK30 by approximately 1.15 times in the presence of equimolar amounts of protein compared with wild-type. This study further improves the application of LcpK30 in the field of polyethylene degradation by modification.
Asunto(s)
Látex , Streptomyces , Látex/química , Polietileno , Proteínas Bacterianas/química , Péptidos/metabolismo , Carbono/metabolismo , Biodegradación AmbientalRESUMEN
The latex of Ipomoea (Convolvulaceae) is a source of a special kind of acylsugars called resin glycosides, which are highly appreciated because of their biological activities (i.e. laxative, antimicrobial, cytotoxic etc.). Most research has been conducted in perennials with tuberous roots, where resin glycosides are stored. However, their content and variation are unknown in annual vines that lack this type of root, such as in the case of Ipomoea parasitica. This species contains research/biological and human value through its fast growth, survival in harsh environments, and employment in humans for mental/cognitive improvements. These qualities make I. parasitica an ideal system to profile resin glycosides and their variations in response to edaphoclimate. Topsoil samples (0-30 cm depth) and latex from petioles of I. parasitica were collected in two localities of central Mexico. The latex was analyzed through UHPLC-ESI-QTOF, and soil physico-chemical characteristics, the rainfall, minimum, average, and maximum temperatures were recorded. We also measured canopy (%), rockiness (%), and plant cover (%). A Principal Component Analysis was conducted to find associations between edaphoclimate and the resin glycosides. Forty-four resin glycosides were found in the latex of I. parasitica. Ten correlated significantly with three components (47.07%) and contained tetrasaccharide, pentasaccharide, and dimers of tetrasaccharide units. Five resin glycosides were considered constitutive because they were in all the plants. However, exclusive molecules to each locality were also present, which we hypothesize is in response to significant microhabitat conditions found in this study (temperature, clay content, pH, and potassium). Our results showed the presence of resin glycosides in I. parasitica latex and are the basis for experimentally testing the effect of the conditions above on these molecules. However, ecological, molecular, and biochemical factors should be considered in experiments designed to produce these complex molecules.
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Glicósidos , Ipomoea , Resinas de Plantas , Glicósidos/química , Ipomoea/química , Resinas de Plantas/química , México , Látex/química , Suelo/químicaRESUMEN
This work aims to fabricate antibacterial natural rubber latex composites by introducing different ratios of graphene oxide (GO) and nickel oxide (NiO) nanoparticles. The nanocomposites were prepared using latex mixing and a two-roll mill process, followed by molding with a heating hydraulic press. Detailed analyses were conducted to evaluate the rheological, chemical, physical, thermal, mechanical, and electrical performance of the composites. Fourier transform infrared spectroscopy (FTIR) was employed to analyze the interaction among different components, while the surface morphology was examined through the field emission scanning electron microscopy (FESEM) technique. The composites with a loading ratio of 1:2 of GO to NiO (optimized concentration) exhibited the highest tensile strength (24.9 MPa) and tear strength (47.4 N/ mm) among all the tested samples. In addition, the composites demonstrated notable antimicrobial activity against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans. The thermal stability of the composites was observed up to 315 °C, and their electrical resistivity lies in the insulating range across a temperature span of 25 °C to 50 °C. The research uncovers critical insights into advancing composite materials suitable for diverse applications, featuring inherent antibacterial attributes, robust mechanical properties, resilience to solvent, UV shielding properties, and controlled electrical resistivity capabilities.
Asunto(s)
Grafito , Nanopartículas , Níquel , Goma , Goma/química , Látex/química , Nanopartículas/química , Antibacterianos/farmacología , Antibacterianos/químicaRESUMEN
Natural Rubber Latex (NRL) has shown to be a promising biomaterial for use as a drug delivery system to release various bioactive compounds. It is cost-effective, easy to handle, biocompatible, and exhibits pro-angiogenic and pro-healing properties for both soft and hard tissues. NRL releases compounds following burst and sustained release kinetics, exhibiting first-order release kinetics. Moreover, its pore density can be adjusted for tailored kinetics profiles. In addition, biotechnological applications of NRL in amblyopia, smart mattresses, and neovaginoplasty have demonstrated success. This comprehensive review explores NRL's diverse applications in biotechnology and biomedicine, addressing challenges in translating research into clinical practice. Organized into eight sections, the review emphasizes NRL's potential in wound healing, drug delivery, and metallic nanoparticle synthesis. It also addresses the challenges in enhancing NRL's physical properties and discusses its interactions with the human immune system. Furthermore, examines NRL's potential in creating wearable medical devices and biosensors for neurological disorders. To fully explore NRL's potential in addressing important medical conditions, we emphasize throughout this review the importance of interdisciplinary research and collaboration. In conclusion, this review advances our understanding of NRL's role in biomedical and biotechnological applications, offering insights into its diverse applications and promising opportunities for future development.
Asunto(s)
Materiales Biocompatibles , Sistemas de Liberación de Medicamentos , Látex , Medicina Regenerativa , Goma , Humanos , Materiales Biocompatibles/química , Látex/química , Medicina Regenerativa/métodos , Goma/química , Cicatrización de Heridas/efectos de los fármacosRESUMEN
Solar steam generation (SSG) offers a sustainable approach to fresh water production. Herein, a novel dual-functional natural rubber/carbon black composite foam evaporator is presented for a cost-efficient SSG system that both produces fresh water and eliminates heavy metals present in the water. The composite foam is produced using the Dunlop process, and in its optimized form, it absorbed >96 % of sunlight. The foam evaporator exhibited a thermal conductivity of 0.052 W/mâ K, a water evaporation rate of 1.40 kg/m2/h, converted 83.38 % of light to heat under 1 sun irradiation, and showed outstanding stability. The technology required to produce this composite foam is already available to make large-scale production feasible, while the natural raw materials are abundant. On the basis of its performance qualities, the rubber foam composite appears to be an excellent candidate for application as a viable solar absorber for SSG to produce fresh, clean water for commercial purposes.
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Metales Pesados , Goma , Luz Solar , Goma/química , Metales Pesados/química , Látex/química , Purificación del Agua/métodos , Agua/química , Descontaminación/métodos , Vapor , Contaminantes Químicos del Agua/química , Hollín/químicaRESUMEN
OBJECTIVE: Determine the electrophoretic profiles of the extracts of Manihot esculenta, Actinidia Deliciosa and Persea Americana and their possible relationship with Latex-Fruit Syndrome. METHODS: Protein extracts of M. esculenta, P. Americana and A. Deliciosa were prepared through the processes of maceration and solvent extraction from plant samples. In the case of the avocado, a prior extraction by soxhlet was carried out to eliminate the fat. The extracts were vacuum filtered, dialyzed and finally lyophilized. Separation of proteins based on molecular weight was performed by SDS PAGE electrophoresis. The electrophoretic profiles obtained were compared with the allergenic proteins previously identified in the latex extract, in order to determine a possible relationship with Latex-Fruit Syndrome, depending on the molecular weight. RESULTS: The extracts of M. esculenta and P. Americana showed a wide range of protein fractions with molecular weights varying from 10 to 250 KD, finding that the region with the highest concentration of bands was between 20 and 89 KD, (60 and 65%), respectively. A 20-band profile was obtained for the M. esculenta extract (Figure 1), with seven bands sharing similar weights with the latex allergens (Hev b 1, Hev b 2, Hev b3, Hev b 4, Hev b 5, Hev b 6.03, Hev b 8 and Hev b 10) (3-5). For the P. Americana extract, 20 bands were also observed (Figure 2), seven of which presented approximate weights to the Latex allergens (Hev b 1, Hev b 2 Hev b 4 Hev b 6.01 Hev b 6.03 Hev b 8 , Hev b 10 Hev b 11 Hev b 14). The Kiwi extract showed two bands of 19.1 and 22.9 KD, with weights close to latex proteins (figure 3), (Hev b 3 and Hev b 6.01), and allergens (Act d 2 and Act d 6), reported in the literature for this fruit. CONCLUSIONS: When analyzing the relationship between the separated protein fractions and the latex allergens described in the literature, a possible association of 35% was found for the extracts of M. esculenta and P. Americana, and 10% for A. Delicious, with great relevance being the association found with the allergens Hev b 4, Hev b 2, Hev 8 and Hev b 11, which are involved in Latex-Fruit Syndrome. The electrophoretic profiles of the prepared extracts were determined and compared with the Latex allergens. This information generates a contribution for the development of new research and advances in the standardization of these extracts on a large scale and for their future use in diagnostic tests.
OBJETIVO: Determinar los perfiles electroforéticos de los extractos de Manihot esculenta, Actinidia deliciosa y Persea americana y su posible relación con el Síndrome de Látex Fruta. MÉTODOS: Se prepararon extractos proteicos de M. esculenta, P. Americana y A. Deliciosa, a través de los procesos de macerado y extracción con solventes a partir muestras vegetales. En el caso del aguacate, se realizó una extracción previa por soxhlet, para eliminar la grasa. Los extractos se filtraron al vacío, se sometieron a diálisis y por último se liofilizaron. La separación de las proteínas en función del peso molecular se realizó mediante electroforesis SDS PAGE. Se compararon los perfiles electroforéticos obtenidos con las proteínas alergénicas previamente identificadas en el extracto de látex, con el fin de determinar una posible relación con el Síndrome de Látex-Fruta, en función del peso molecular. RESULTADOS: Los extractos de M. esculenta y P. americana mostraron una amplia gama de fracciones proteicas con pesos moleculares que varían desde 10 a 250 KD, encontrando que la región con mayor concentración de bandas se situó entre 20 y 89 KD, (60 y 65 %), respectivamente. Se obtuvo un perfil de 20 bandas para el extracto de M. esculenta (figura 1), con siete bandas que comparten pesos similares con los alérgenos del látex (Hev b 1, Hev b 2, Hev b3, Hev b 4, Hev b 5, Hev b 6.03, Hev b 8 y Hev b 10) (3-5). Para el extracto de P. americana, también se observaron 20 bandas (figura 2), siete de las cuales presentaron pesos aproximados a los alérgenos de Látex (Hev b 1, Hev b 2 Hev b 4 Hev b 6.01 Hev b 6.03 Hev b 8, Hev b 10 Hev b 11 Hev b 14). El extracto de Kiwi mostró dos bandas de 19,1 y 22,9 KD, con pesos cercanos a proteínas de látex (figura 3), (Hev b 3 y Hev b 6.01), y los alérgenos (Act d 2 y Act d 6), reportados en la literatura para esta fruta. CONCLUSIONES: Al analizar la relación existente entre las fracciones proteicas separadas y los alérgenos de los látex descritos en la literatura, se encontró una posible asociación del 35% para los extractos de M. esculenta y P. Americana, y del 10% para A. Deliciosa, siendo de gran relevancia la asociación encontrada con los alérgenos Hev b 4, Hev b 2, Hev 8 y Hev b 11, los cuales se encuentran implicados en el Síndrome de Látex-Fruto. Se lograron determinar los perfiles electroforéticos de los extractos elaborados y se compararon con los alérgenos del Látex. Está información genera un aporte para el desarrollo de nuevas investigaciones y avances en la estandarización de estos extractos a gran escala y para su uso futuro en pruebas diagnósticas.
Asunto(s)
Actinidia , Alérgenos , Hipersensibilidad al Látex , Manihot , Persea , Proteínas de Plantas , Manihot/química , Alérgenos/análisis , Actinidia/química , Persea/química , Proteínas de Plantas/análisis , Proteínas de Plantas/inmunología , Frutas/química , Látex/química , Extractos Vegetales/química , Electroforesis en Gel de Poliacrilamida , Síndrome , Peso MolecularRESUMEN
This study presents the adsorption of methylene blue (MB) dye using latex char derived from pyrolysis of latex gloves. The adsorption process was investigated systematically using Response Surface Methodology (RSM) with a Central Composite Design (CCD). The effects of four key variables, namely pH, time, temperature, and adsorbent dosage, were studied using a factorial design enriched with center points and axial points. Experimental data were analyzed using a second-order polynomial regression model to construct a response surface model, which elucidated the relationship between the variables and MB removal efficiency. The study found that the char obtained at 800 °C exhibited the highest adsorption capacity due to its increased carbonization, expanded surface area, and diverse pore structure. Analysis of Variance (ANOVA) confirmed the significance of the quadratic model, with remarkable agreement between predicted and experimental outcomes. Diagnostic plots validated the model's reliability, while 3D contour graphs illustrated the combined effects of variables on MB removal efficiency. Optimization using DoE software identified optimal conditions resulting in a 99% removal efficiency, which closely matched experimental results. Additionally, adsorption isotherms revealed that the Freundlich model best described the adsorption behavior, indicating heterogeneous surface adsorption with multilayer adsorption. This comprehensive study provides valuable insights into the adsorption process of MB dye using latex char, with implications for wastewater treatment and environmental remediation.
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Látex , Azul de Metileno , Contaminantes Químicos del Agua , Azul de Metileno/química , Adsorción , Látex/química , Contaminantes Químicos del Agua/química , Aguas Residuales/química , Colorantes/química , Temperatura , Concentración de Iones de Hidrógeno , Eliminación de Residuos Líquidos/métodos , Carbón Orgánico/química , Purificación del Agua/métodosRESUMEN
Antimicrobial surfaces limit the spread of infectious diseases. To date, there is no antimicrobial coating that has widespread use because of short-lived and limited spectrum efficacy, poor resistance to organic material, and/or cost. Here, we present a paint based on waterborne latex particles that is supramolecularly associated with quaternary ammonium compounds (QACs). The optimal supramolecular pairing was first determined by immobilizing selected ions on self-assembled monolayers exposing different groups. The QAC surface loading density was then increased by using polymer brushes. These concepts were adopted to develop inexpensive paints to be applied on many different surfaces. The paint could be employed for healthcare and food production applications. Its slow release of QAC allows for long-lasting antimicrobial action, even in the presence of organic material. Its efficacy lasts for more than 90 washes, and importantly, once lost, it can readily be restored by spraying an aqueous solution of the QAC. We mainly tested cetyltrimethylammonium as QAC as it is already used in consumer care products. Our antimicrobial paint is broad spectrum as it showed excellent antimicrobial efficiency against four bacteria and four viruses.
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Compuestos de Amonio Cuaternario , Compuestos de Amonio Cuaternario/química , Compuestos de Amonio Cuaternario/farmacología , Antiinfecciosos/farmacología , Antiinfecciosos/química , Pintura , Propiedades de Superficie , Látex/química , Látex/farmacología , Pruebas de Sensibilidad Microbiana , Bacterias/efectos de los fármacosRESUMEN
The spurge Euphorbia characias is known for its latex, which is rich in antioxidant enzymes and anti-phytopathogen molecules. In this study, we identified a novel polyubiquitin protein in the latex and leaves, leading to the first molecular characterization of its coding gene and expressed protein in E. characias. Using consensus-degenerate hybrid oligonucleotide primers (CODEHOP) and rapid amplification of cDNA ends (5'/3'-RACE), we reconstructed the entire open reading frame (ORF) and noncoding regions. Our analysis revealed that the polyubiquitin gene encodes five tandemly repeated sequences, each coding for a ubiquitin monomer with amino acid variations in four of the five repeats. In silico studies have suggested functional differences among monomers. Gene expression peaked during the summer, correlating with high temperatures and suggesting a role in heat stress response. Western blotting confirmed the presence of polyubiquitin in the latex and leaf tissues, indicating active ubiquitination processes. These findings enhance our understanding of polyubiquitin's regulatory mechanisms and functions in E. characias, highlighting its unique structural and functional features.
Asunto(s)
Euphorbia , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas , Poliubiquitina , Euphorbia/genética , Poliubiquitina/genética , Poliubiquitina/metabolismo , Proteínas de Plantas/genética , Estaciones del Año , Látex/metabolismo , Látex/química , Hojas de la Planta/genética , Hojas de la Planta/metabolismo , FilogeniaRESUMEN
Latex clearing proteins (Lcps) catalyze the oxidative cleavage of the C = C bonds in cis-1,4-polyisoprene (natural rubber), producing oligomeric compounds that can be repurposed to other materials. The active catalytic site of Lcps is buried inside the protein structure, thus raising the question of how the large hydrophobic rubber chains can access the catalytic center. To improve our understanding of hydrophobic polymeric substrate binding to Lcps and subsequent catalysis, we investigated the interaction of a substrate model containing ten carbon-carbon double bonds with the structurally characterized LcpK30, using multiple computational tools. Prediction of the putative tunnels and cavities in the LcpK30 structure, using CAVER-Pymol plugin 3.0.3, fpocket and Molecular Dynamic (MD) simulations provided valuable insights on how substrate enters from the surface to the buried active site. Two dominant tunnels were discovered that provided feasible routes for substrate binding, and the presence of two hydrophobic pockets was predicted near the heme cofactor. The larger of these pockets is likely to accommodate the substrate and to determine the size distribution of the oligomers. Protein-ligand docking was carried out using GOLD software to predict the conformations and interactions of the substrate within the protein active site. Deeper insight into the protein-substrate interactions, including close-contacts, binding energies and potential cleavage sites in the cis-1,4-polyisoprene, were obtained from MD simulations. Our findings provide further justification that the protein-substrate complexation in LcpK30 is mainly driven by the hydrophobic interactions accompanied by mutual conformational changes of both molecules. Two potential binding modes were identified, with the substrate in either extended or folded conformations. Whilst binding in the extended conformation was most favorable, the folded conformation suggested a preference for cleavage of a central double bond, leading to a preference for oligomers with 5 to 6 C = C bonds. The results provide insight into further enzyme engineering studies to improve catalytic activity and diversify the substrate and product scope of Lcps.
Asunto(s)
Hemiterpenos , Látex , Simulación de Dinámica Molecular , Unión Proteica , Hemiterpenos/metabolismo , Hemiterpenos/química , Látex/química , Látex/metabolismo , Simulación del Acoplamiento Molecular , Proteínas de Plantas/metabolismo , Proteínas de Plantas/química , Dominio Catalítico , Interacciones Hidrofóbicas e Hidrofílicas , Sitios de Unión , Butadienos/química , Butadienos/metabolismoRESUMEN
The latex of Euphorbia peplus and its major component 20-deoxyingenol-3-angelate (DI3A) displayed significant nematicidal activity against Caenorhabditis elegans and Panagrellus redivivus. DI3A treatment inhibited the growth and development of nematodes and caused significantly negative effects on locomotion behavior, reproduction, and accumulation of reactive oxygen species. Transcriptome analysis indicated that differential expression genes in DI3A-treated C. elegans were mainly associated with the metabolism, growth, and development process, which were further confirmed by RT-qPCR experiments. The expression level of TPA-1 gene encoding a protein kinase C isotype was obviously upregulated by DI3A treatment, and knockdown of TPA-1 by RNAi technology in the nematode could relieve the growth-inhibitory effect of DI3A. Metabolic analysis indicated that DI3A was hardly metabolized by C. elegans, but a glycosylated indole derivative was specifically accumulated likely due to the activation of detoxification. Overall, our findings suggested that DI3A from E. peplus latex exerted a potent nematicidal effect through the gene TPA-1, which provides a potential target for the control of nematodes and also suggests the potential application value of E. peplus latex and DI3A as botanical nematicides.
Asunto(s)
Antinematodos , Caenorhabditis elegans , Euphorbia , Látex , Proteína Quinasa C , Animales , Caenorhabditis elegans/efectos de los fármacos , Caenorhabditis elegans/genética , Caenorhabditis elegans/enzimología , Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/crecimiento & desarrollo , Látex/química , Látex/metabolismo , Antinematodos/farmacología , Antinematodos/química , Antinematodos/metabolismo , Euphorbia/química , Proteína Quinasa C/metabolismo , Proteína Quinasa C/genética , Extractos Vegetales/farmacología , Extractos Vegetales/químicaRESUMEN
As a result of increasing drug resistance, crossover resistance development, prolonged therapy, and the absence of different agents with innovative methods for implementation, the efficacy of recent antileishmanial medications is severely declining. So, it is vital to look for other medications from botanical remedies that have antileishmanial activity. The latex of Euphorbia abyssinica (E abyssinica) and the leaves of Clematis simensis fresen (C simensis) were macerated in methanol (80%). In vitro antileishmanial activity of the preparation was tried on promastigotes of Leishmania aethiopica (L aethiopica) and Leishmania donovani (L donovani) using resazurin assay, and fluorescence intensity was measured. One percent of dimethyl sulfoxide (DMSO) and media as negative control and amphotericin B as positive control were used. Additionally, hemolytic & phytochemical tests of the preparation were done. The mean and standard errors of each extract were evaluated and interpreted for statistical significance using one-way analysis of variance. From sigmoidal dose-response curves of % inhibition, half maximal inhibitory concentration (IC50) values were determined by GraphPad Prism and Microsoft Excel; outcomes were presented as meanâ ±â standard error of mean of triplicate trials. Pâ <â .05 was statistical significance. The phytochemical screening of C simensis and E abyssinica confirmed the existence of steroids, phenols, tannins, saponins, alkaloids, terpenoids, flavonoids and glycosides. C simensis possesses antileishmanial activity with IC50 outcomes of 46.12â ±â 0.03 and 8.18â ±â 0.10 µg/mL on the promastigotes of L aethiopica and L donovani, respectively. However, E abyssinica showed stronger activity with IC50 outcomes of 16.07â ±â 0.05 µg/mL and 4.82â ±â 0.07 µg/mL on L aethiopica and L donovani, respectively. C simensis and E abyssinica have a less hemolytic effect on human red blood cells at low concentrations. The outcomes from this investigation demonstrated that the preparation of C simensis and E abyssinica indicated significant antileishmanial activity. Therefore, further in vivo assessment of antileishmanial, cytotoxicity activity and quantitative identification of secondary metabolites are highly recommended.
Asunto(s)
Antiprotozoarios , Euphorbia , Látex , Extractos Vegetales , Hojas de la Planta , Extractos Vegetales/farmacología , Euphorbia/química , Látex/farmacología , Látex/química , Antiprotozoarios/farmacología , Hojas de la Planta/química , Humanos , Leishmania donovani/efectos de los fármacos , Concentración 50 Inhibidora , Leishmania/efectos de los fármacos , Metanol , Solventes , Hemólisis/efectos de los fármacosRESUMEN
In Brazil, latex from Euphorbia umbellata (African milk tree) has been increasingly used in folk medicine to treat several types of cancer, including melanoma. The effect of lyophilized latex (LL), its hydroethanolic extract (E80), triterpene (F-TRI)- and diterpene (F-DIT)-enriched fractions, along with six isolated phorbol esters from LL and phorbol 12-myristate 13-acetate (PMA) on J774A.1, THP-1, SK-MEL-28, and B16-F10 cell line viability were evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) method. The compounds were identified by 2D-NMR and HRESIMS. The effect of the LL, extract and fractions on cell viability was also assessed through a resazurin reduction assay. At 100 µg/ml, LL, and its fractions moderately inhibited J774A.1 (37.5-59.5%) and THP-1 (12.6-43.6%) metabolism. LL (IC50 70 µg/ml) and F-TRI (IC50 68 µg/ml) were barely more effective against B16-F10 cells, and only F-TRI exerted an inhibitory effect on SK-MEL-28 cells (IC50 66-75 µg/ml). The samples did not effectively inhibit THP-1 growth (IC50 69-87 µg/ml, assessed by MTT). B16-F10 was susceptible to PMA (IC50 53 µM) and two 12-phenylacetate esters (IC50 56-60 µM), while SK-MEL-28 growth was inhibited (IC50 58 µM) by one of these kinds of esters with an additional 4ß-deoxy structure. Synagrantol A (IC50 39 µM) was as effective as PMA (IC50 47 µM) in inhibiting J774A.1 growth in a dose-dependent manner. Furthermore, an in silico study with target receptors indicated a high interaction of the compounds with the PKC proteins. These results provide useful knowledge on the effect of tigliane-type diterpenes on tumor cell from the perspective of medicinal chemistry.
Asunto(s)
Euphorbia , Látex , Ésteres del Forbol , Euphorbia/química , Látex/química , Ésteres del Forbol/farmacología , Humanos , Ratones , Animales , Línea Celular Tumoral , Estructura Molecular , Extractos Vegetales/farmacología , Extractos Vegetales/química , Brasil , Monocitos/efectos de los fármacos , Fitoquímicos/farmacología , Fitoquímicos/aislamiento & purificación , Supervivencia Celular/efectos de los fármacos , Diterpenos/farmacología , Diterpenos/aislamiento & purificación , Terpenos/farmacología , Terpenos/aislamiento & purificación , Antineoplásicos Fitogénicos/farmacología , Antineoplásicos Fitogénicos/aislamiento & purificación , Acetato de Tetradecanoilforbol , Melanoma/tratamiento farmacológicoRESUMEN
Cancer is a fatal disease, and unfortunately, the anticancer drugs harm normal cells. Plant's extracts are the golden key to solving this issue. In this research, fig latex - from Ficus carica- was encapsulated using cellulose acetate (CA) and poly (ethylene oxide) (PEO) polymers via electrospinning method (Fig@CA/PEO). Fig@CA/PEO nanofiber scaffold was characterized by thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). The average fiber diameter was decreased with an increase in latex concentration from 715 nm to 583 nm. FT-IR spectroscopy indicated the presence of fig latex in Fig@CA/PEO nanofibers. Compared to 5-fluorouracil, Fig@CA/PEO nanofiber scaffold considered safe towards normal cells (WI-38). Moreover, the nanofiber scaffold was efficient against colon cancer cells (Caco) and liver cancer cells (HepG2) as it demonstrated IC50 values for cells by 23.97 µg/mL and 23.96 µg/mL, respectively. Besides, the nanofiber scaffold revealed mechanistic variations in apoptotic oncogenes; described by the upregulation of BCL2 and P21, combined by downregulation of p53 and TNF. Moreover, the nanofiber scaffold showed antioxidant activity counting 33.4, 36 and 41 % of DPPH scavenging as the fig latex concentration increased. The results demonstrate that the Fig@CA/PEO nanofiber scaffold is a promising substitute to traditional chemotherapy.
Asunto(s)
Antineoplásicos , Antioxidantes , Celulosa , Ficus , Látex , Nanofibras , Polietilenglicoles , Nanofibras/química , Celulosa/química , Celulosa/análogos & derivados , Celulosa/farmacología , Humanos , Ficus/química , Polietilenglicoles/química , Antioxidantes/farmacología , Antioxidantes/química , Látex/química , Látex/farmacología , Antineoplásicos/farmacología , Antineoplásicos/química , Apoptosis/efectos de los fármacos , Células Hep G2 , Espectroscopía Infrarroja por Transformada de Fourier , Línea Celular TumoralRESUMEN
Abstract This study aimed to evaluate the anthelmintic and ultrastructural effects of Calotropis procera latex on Haemonchus contortus. C. procera latex was twice centrifuged at 10,000×g and dialyzed to obtain a fraction rich in proteins, named LP (latex protein), and at 3,000 rpm to obtain a fraction rich in secondary metabolites, named LNP (latex non-protein). Specimens of H. contortus exposed to LNP, LP and PBS in the Adult Worm Motility Test (AWMT) were submitted to scanning (SEM) and transmission (TEM) electron microscopy to verify changes in their ultrastructure. Phytochemical tests in the LNP indicated the presence of phenols, steroids, alkaloids and cardenolides. High-Performance Liquid Chromatography (HPLC) characterized the presence of the compounds gallic acid and quercetin in the LNP. The protein content in the LP was 43.1 ± 1.1 mg/mL and 7.7 ± 0.3 mg/mL in LNP. In AWMT, LNP and LP inhibited the motility of 100% of the nematodes, with LNP being more effective than LP and ivermectin more effective than both (p <0.05). Cuticle changes were observed by SEM and TEM in nematodes treated with LP and LNP. Calotropis procera latex has anthelmintic effects against H. contortus, causing damage to its cuticle and other alterations in its ultrastructure.
Resumo Este estudo objetivou avaliar os efeitos anti-helmínticos e ultraestruturais do látex de Calotropis procera sobre Haemonchus contortus. Látex de C. procera foi centrifugado duas vezes à a 10.000xg e dialisado para obter uma fração rica em proteínas, denominada proteínas do látex (LP). E centrifugado e centrifugado a 3.000 rpm, para obter uma fração rica em metabólitos secundários, denominada LNP (látex não proteico). Espécimes de H. contortus expostos à LNP, LP e PBS no Teste de Motilidade dos Nematoides Adultos (TMNA) foram submetidos a microscopia eletrônica de varredura (MEV) e de transmissão (MET), para verificar alterações em sua ultraestrutura. Testes fitoquímicos em LNP indicaram a presença de fenóis, esteroides, alcaloides e cardenolídeos. A presença dos compostos ácido gálico e quercetina em LNP foi caracterizada por Cromatografia Líquida de Alta Eficiência (CLAE). O conteúdo de proteínas em LP foi de 43,1 ± 1,1 mg/mL e de 7,7 ± 0,3 mg/mL em LNP. No TMNA, LNP e LP inibiram a motilidade de 100% dos nematoides, sendo LNP mais eficaz que LP, e a ivermectina mais eficaz que ambos (p <0,05). Alterações na cutícula de nematoides tratados com LP e LNP foram observadas por MEV e MET. O látex de C. procera apresenta efeito anti-helmíntico sobre H. contortus, causando danos à sua cutícula e outras alterações em sua ultraestrutura.