In vitro antileishmanial activities of hydro-methanolic crude extracts and solvent fractions of Clematis simensis fresen leaf, and Euphorbia abyssinica latex.

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 mean ±â€…standard error of mean of triplicate trials. P < .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 46.12 ±â€…0.03 and 8.18 ±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 16.07 ±â€…0.05 µg/mL and 4.82 ±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.

The Effect of Cellulose Nanocrystal Reassembly on Latex-Based Pressure-Sensitive Adhesive Performance.

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.

[Analysis of the electrophoretic profiles of the protein extracts of the species Manihot esculenta (Crantz, 1975), Persea Americana (Mill., 1768) and Actinidia delicious (A. Chevalier., 1984), and their association with the latex-fruit syndrome for searching for potential allergens]. / Análisis de los perfiles electroforéticos de los extractos proteicos de las especies Manihot esculenta (Crantz,1975), Persea americana (Mill.,1768) y Actinidia deliciosa (A. Chevalier., 1984), y su asociación con el síndrome látex-fruta para la búsqueda de alérgenos potenciales.

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.

Film Formation of Iodinated Latex Dispersions and Its Role in Their Antimicrobial Activity.

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.

Natural rubber latex-based biomaterials for drug delivery and regenerative medicine: Trends and directions.

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.

Nematicidal Activity of 20-Deoxyingenol-3-angelate from Euphorbia peplus Latex Through Protein Kinase C Isotype TPA-1.

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.

Enhancement in antimicrobial efficacy and biodegradation of natural rubber latex through graphene oxide/nickel oxide nanoparticles.

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.

Enhanced biodegradation activity toward polyethylene by fusion protein of anchor peptide and Streptomyces sp. strain K30 latex clearing protein.

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.

Enhancing the heterologous expression of latex clearing protein from Streptomyces sp. strain K30 in Escherichia coli through fermentation condition optimization and molecular modification.

Latex clearing protein from Streptomyces sp. strain K30 (LcpK30) is a natural oxidoreductase that can catalyse the cleavage of rubber through dioxygenation. It has significant potential applications in polymer degradation. However, its limited expression in engineered strains restricts its utility. This study aimed to enhance the soluble expression and enzyme activity of LcpK30 in E. coli BL21 (DE3) by optimizing fermentation conditions and making molecular modifications. The enzyme activity reached 5.05 U·mL-1 by optimizing the induction conditions, adding cofactors, and using chemical chaperones, which was 237.1 % of the initial case. Further enhancements in soluble expression were achieved through site mutations guided by the PROSS server, resulting in 8 out of 13 mutants with increased protein expression, a high positive mutation rate of 61.5 %. Subsequently, combined mutants were created by merging single mutants with enhanced protein expression and enzyme activity. The top three double mutants, G91D/S149A, G91D/A210H, and G91D/H296P, displayed expression levels at 173.3 %, 173.3 %, and 153.3 % of the wild-type LcpK30, respectively. These mutants also exhibited enhanced fermentation enzyme activity, reaching 149.5 %, 250.0 %, and 420.2 % compared to the wild-type, along with improved specific activities. This study provides insights for the efficient production of LcpK30 and a practical foundation for its application.

Unveiling the Potent Fibrino(geno)lytic, Anticoagulant, and Antithrombotic Effects of Papain, a Cysteine Protease from Carica papaya Latex Using κ-Carrageenan Rat Tail Thrombosis Model.

While fibrinolytic enzymes and thrombolytic agents offer assistance in treating cardiovascular diseases, the existing options are associated with a range of adverse effects. In our previous research, we successfully identified ficin, a naturally occurring cysteine protease that possesses unique fibrin and fibrinogenolytic enzymes, making it suitable for both preventing and treating cardiovascular disorders linked to thrombosis. Papain is a prominent cysteine protease derived from the latex of Carica papaya. The potential role of papain in preventing fibrino(geno)lytic, anticoagulant, and antithrombotic activities has not yet been investigated. Therefore, we examined how papain influences fibrinogen and the process of blood coagulation. Papain is highly stable at pH 4-11 and 37-60 °C via azocasein assay. In addition, SDS gel separation electrophoresis, zymography, and fibrin plate assays were used to determine fibrinogen and fibrinolysis activity. Papain has a molecular weight of around 37 kDa, and is highly effective in degrading fibrin, with a molecular weight of over 75 kDa. Furthermore, papain-based hemostatic performance was confirmed in blood coagulation tests, a blood clot lysis assay, and a κ-carrageenan rat tail thrombosis model, highlighting its strong efficacy in blood coagulation. Papain shows dose-dependent blood clot lysis activity, cleaves fibrinogen chains of Aα, Bß, and γ-bands, and significantly extends prothrombin time (PT) and activated partial thromboplastin time (aPTT). Moreover, the mean length of the infarcted regions in the tails of Sprague-Dawley rats with κ-carrageenan was shorter in rats administered 10 U/kg of papain than in streptokinase-treated rats. Thus, papain, a cysteine protease, has distinct fibrin and fibrinogenolytic properties, suggesting its potential for preventing or treating cardiovascular issues and thrombosis-related diseases.

Norsesquiterpenes from the Latex of Euphorbia dentata and Their Chemical Defense Mechanisms against Helicoverpa armigera.

Euphorbia dentata (Euphorbiaceae), an invasive weed, is rarely eaten by herbivorous insects and could secrete a large amount of white latex, causing a serious threat to local natural vegetation, agricultural production and human health. In order to prevent this plant from causing more negative effects on humans, it is necessary to understand and utilize the chemical relationships between the latex of E. dentata and herbivorous insects. In this study, three new norsesquiterpenes (1-3), together with seven known analogues (4-10), were isolated and identified from the latex of E. dentata. All norsesquiterpenes (1-10) showed antifeedant and growth-inhibitory effects on H. armigera with varying levels, especially compounds 1 and 2. In addition, the action mechanisms of active compounds (1-3) were revealed by detoxifying enzyme (AchE, CarE, GST and MFO) activities and corresponding molecular docking analyses. Our findings provide a new idea for the development and utilization of the latex of E. dentata, as well as a potential application of norsesquiterpenes in botanical insecticides.

A Comprehensive Review on Euphorbiaceae lectins: Structural and Biological Perspectives.

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.

Interactions of REF1 and SRPP1 rubber particle proteins from Hevea brasiliensis with synthetic phospholipids: Effect of charge and size of lipid headgroup.

According to the fatty acid and headgroup compositions of the phospholipids (PL) from Hevea brasiliensis latex, three synthetic PL were selected (i.e. POPA: 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphate POPC: 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine and POPG: 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol) to investigate the effect of PL headgroup on the interactions with two major proteins of Hevea latex, i.e. Rubber Elongation Factor (REF1) and Small Rubber Particle Protein (SRPP1). Protein/lipid interactions were screened using two models (lipid vesicles in solution or lipid monolayers at air/liquid interface). Calcein leakage, surface pressure, ellipsometry, microscopy and spectroscopy revealed that both REF1 and SRPP1 displayed stronger interactions with anionic POPA and POPG, as compared to zwitterionic POPC. A particular behavior of REF1 was observed when interacting with POPA monolayers (i.e. aggregation + modification of secondary structure from α-helices to ß-sheets, characteristic of its amyloid aggregated form), which might be involved in the irreversible coagulation mechanism of Hevea rubber particles.

The impact of non-deproteinization on physicochemical and biological properties of natural rubber latex for biomedical applications.

Latex is a colloidal suspension derived from the Hevea brasiliensis tree, derived from natural rubber, poly(isoprene), and assorted constituents including proteins and phospholipids. These constituents are inherent to both natural rubber and latex serum. This investigation was undertaken to examine the impact of the deproteinization process on chemical and biological dynamics of natural rubber latex. Natural Rubber (NR) extracted from the pure latex (LNCP) was obtained through centrifugation, followed by six rounds of solvent purification (LP6). The structure was characterized using Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), swelling test, surface zeta potential (ζ), scanning electron microscopy (SEM) and in vitro assay. The results revealed that the LP6 group presented decreased swelling kinetics, reduced cell adhesion and proliferation, and a smoother surface with decreased negative surface charge. Conversely, the LNCP group shown accelerated swelling, heightened adhesion and cellular growth, and a more negatively charged and rougher surface. As such, the attributes of latex serum and proteins have potential usage across numerous biomedical applications.

Proteomic analysis of Cryptostegia grandiflora latex, purification, characterization, and biological activity of two osmotin isoforms.

Although latex fluids are found in >20,000 plant species, the biochemical composition and biological function of their proteins are still poorly explored. Thus, this work aimed to conduct a proteomic analysis of Cryptostegia grandiflora latex (CgLP) for subsequent purification and characterization of an antifungal protein. After 2D-SDS-PAGE and mass spectrometry, 27 proteins were identified in CgLP, including a polygalacturonase inhibitor, cysteine peptidases, pathogenesis-related proteins (PR-4), and osmotins. Then, two osmotin isoforms (CgOsm) were purified, and a unique N-terminal sequence was determined (1ATFDIRSNCPYTVWAAAVPGGGRRLDRGQTWTINVAPGTA40). The PCR products revealed a cDNA sequence of 609 nucleotides for CgOsm, which encoded a polypeptide with 203 amino acid residues. The structure of CgOsm has features of typical osmotin or thaumatin-like proteins (TLPs), such as 16 conserved Cys residues, REDDD and FF motifs, an acidic cleft, and three main domains. Atomic force microscopy (AFM) and bioinformatics suggested that CgOsm is associated with three chain units. This result was interesting since the literature describes osmotins and TLPs as monomers. AFM also showed that Fusarium falciforme spores treated with CgOsm were drastically damaged. Therefore, it is speculated that CgOsm forms pores in the membrane of these cells, causing the leakage of cytoplasmic content.

Calotropis procera (Aiton) Dryand (Apocynaceae): State of the art of its uses and Applications.

Calotropis procera (Aiton) Dryand (Apocynaceae), popularly known as milkweed, has been traditionally used to treat diseases particularly associated with gastric disorders, skin disease and inflammatory processes. The present study aimed to review the current scientific evidence regarding the pharmacological effects of C. procera extracted phytochemicals and possible research opportunities as complementary and alternative medicine. Scientific publications were searched in various electronic databases (PubMed, Scopus, Web of Science, Google Scholar, Springer, Wiley, and Mendeley) using the following search terms: Calotropis procera, medicinal plants, toxicity, phytochemical characterization, and biological effects. Collected data showed that cardenolides, steroid glycoside and flavonoids are the main classes of phytochemicals identified in C. procera latex and leaves. In addition, lignans, terpenes, coumarins, and phenolic acids have been reported. These metabolites have been correlated with their biological activities, including mainly antioxidant, anti-inflammatory, antitumoral, hypoglycemic, gastric protective, anti-microbial, insecticide, anti-fungal, anti-parasitic, among others. However, some of the studies were carried out with only a single dose or with a high dose not achievable under physiological conditions. Therefore, the validity of C. procera biological activity may be questionable. Not less important to highlight are the risks associated with its use and the possibility of accumulation of heavy metals that can be toxic. Furthermore, there are no clinical trials with C. procera to date. In conclusion, the need of bioassayguided isolation of bioactive compounds, bioavailability and efficacy, as well as pharmacological and toxicity studies, are needed using in vivo models and clinical trials in order to support the traditionally claimed health benefits.

Durable and rechargeable antimicrobial cotton driven by enhanced UV stability and real-time detection of biocidal factors.

In this study, graphene oxide/N-halamine nanocomposite was synthesized through Pickering miniemulsion polymerization, which was then coated on cotton surface. The modified cotton exhibited excellent superhydrophobicity, which could effectively prevent microbial infestation and reduce the probability of hydrolysis of active chlorine, with virtually no active chlorine released in water after 72 h. Deposition of reduced graphene oxide nanosheets endowed cotton with ultraviolet-blocking properties, attributing to enhanced UV adsorption and long UV paths. Moreover, encapsulation of polymeric N-halamine resulted in improved UV stability, thus extending the life of N-halamine-based agents. After 24 h of irradiation, 85 % of original biocidal component (active chlorine content) was retained, and approximately 97 % of initial chlorine could be regenerated. Modified cotton has been proven to be an effective oxidizing material against organic pollutants and a potential antimicrobial substance. Inoculated bacteria were completely killed after 1 and 10 min of contact time, respectively. An innovative and simple scheme for determination of active chlorine content was also devised, and real-time inspection of bactericidal activity could be achieved to assure antimicrobial sustainability. Moreover, this method could be utilized to evaluate hazard classification of microbial contamination in different locations, thus broadening the application scope of N-halamine-based cotton fabrics.

Peptidomic Analysis and Antimicrobial Activity of Serum Peptide from Hevea brasiliensis Clone BPM24.

BACKGROUND: Hevea brasiliensis is severely affected by the fungal disease caused by Phytophthora spp. Significant loss of rubber yield is widespread and extensive use of chemical fungicides has resulted in health and environmental problems. OBJECTIVE: This work aims to extract and identify the latex serum peptides from a disease tolerant clone of H. brasiliensis, and study the inhibitory efficacy against pathogenic bacteria and fungi. METHODS: Serum peptides were extracted from H. brasiliensis BPM24 using mixed lysis solution. Low molecular weight peptides were screened and fractionated by solid-phase extraction and then identified by tandem mass spectrometry. Total and fractionated serum peptides were assayed for bacterial and fungal inhibition using broth microdilution and poisoned food methods. An inhibitory control study in the greenhouse was also performed using susceptible clones for pre and postinfection with Phytophthora spp. RESULTS: Forty-three serum peptide sequences were successfully identified. Thirty-four peptides matched with the proteins associated with plant defense response signaling, host resistance, and adverse environmental factors. The inhibitory study of total serum peptides demonstrated antibacterial and anti-fungal properties. The greenhouse study exhibited disease inhibitory efficacy of 60% for the treatment of Phytophthora spp. in post-infected plants and 80% for pre-treated samples. CONCLUSION: Latex serum peptides from disease tolerant H. brasiliensis revealed several proteins and peptides associated with plant defense and disease resistance. The peptides play a vital role for defense against bacteria and fungi pathogens, including Phytophthora spp. Enhanced disease protection can be obtained when the extracted peptides were applied to the susceptible plants before exposure to the fungi. These findings provided an insight and may pave the way for the development of biocontrol peptides from natural resources.

Rod-like Cellulose Regenerated by Bottom-Up Assembly in Natural Rubber Latex and Its Reinforcement.

As a renewable biomass material, nano-cellulose has been investigated as a reinforcing filler in rubber composites but has seen little success because of its strong inclination towards aggregating. Here, a bottom-up self-assembly approach was proposed by regenerating cellulose crystals from a mixture of cellulose solution and natural rubber (NR) latex. Different co-coagulants of both cellulose solution and natural rubber latex were added to break the dissolution equilibrium and in-situ regenerate cellulose in the NR matrix. The SEM images showed that the sizes and morphologies of regenerated cellulose (RC) varied greatly with the addition of different co-coagulants. Only when a 5 wt% acetic acid aqueous solution was used, the RC particles showed an ideal rod-like structure with small sizes of about 100 nm in diameter and 1.0 µm in length. The tensile test showed that rod-like RC (RRC)-endowed NR vulcanizates with pronounced reinforcement had a drastic upturn in stress after stretching to 200% strain. The results of XRD and the Mullins effect showed that this drastic upturn in stress was mainly attributed to the formation of rigid RRC-RRC networks during stretching instead of the strain-induced crystallization of NR. This bottom-up approach provided a simple way to ensure the effective utilization of cellulosic materials in the rubber industry.

Defensive Specialized Metabolites from the Latex of Euphorbia jolkinii.

Plant latex is sequestered in laticiferous structures and exuded immediately from damaged plant tissues. The primary function of plant latex is related to defense responses to their natural enemies. Euphorbia jolkinii Boiss. is a perennial herbaceous plant that greatly threaten the biodiversity and ecological integrity of northwest Yunnan, China. Nine triterpenes (1-9), four non-protein amino acids (10-13) and three glycosides (14-16) including a new isopentenyl disaccharide (14), were isolated and identified from the latex of E. jolkinii. Their structures were established on the basis of comprehensive spectroscopic data analyses. Bioassay revealed that meta-tyrosine (10) showed significant phytotoxic activity, inhibiting root and shoot growth of Zea mays, Medicago sativa, Brassica campestris, and Arabidopsis thaliana, with EC50 values ranging from 4.41 ± 1.08 to 37.60 ± 3.59 µg/mL. Interestingly, meta-tyrosine inhibited the root growth of Oryza sativa, but promoted their shoot growth at the concentrations below 20 µg/mL. meta-Tyrosine was found to be the predominant constituent in polar part of the latex extract from both stems and roots of E. jolkinii, but undetectable in the rhizosphere soil. In addition, some triterpenes showed antibacterial and nematicidal effects. The results suggested that meta-tyrosine and triterpenes in the latex might function as defensive substances for E. jolkinii against other organisms.