ABSTRACT
Nanotechnology has become a dire need of the current era and the green synthesis of nanoparticles offers several advantages over other methods. Nanobiotechnology is an emerging field that contributes to many domains of human life, such as the formulation of nanoscale drug systems or nanomedicine for the diagnosis and treatment of diseases. Medicinal plants are the main sources of lead compounds, drug candidates and drugs. This work reports the green synthesis of Ag nanoparticles (AgNPs) using the aqueous bark extract of Zanthozylum armatum, which was confirmed by a UV absorption at 457 nm. XRD analysis revealed an average size of 18.27 nm and SEM showed the particles' spherical shape, with few irregularly shaped particles due to the aggregation of the AgNPs. FT-IR revealed the critical functional groups of phytochemicals which acted as reducing and stabilizing agents. The bark extract showed rich flavonoids (333 mg RE/g) and phenolic contents (82 mg GAE/g), which were plausibly responsible for its high antioxidant potency (IC50 = 14.61 µg/mL). Extract-loaded AgNPs exhibited the highest but equal inhibition against E. coli and P. aeruginosa (Z.I. 11.0 mm), whereas methanolic bark extract inhibited to a lesser extent, but equally to both pathogens (Z.I. 6.0 mm). The aqueous bark extract inhibited P. aeruginosa (Z.I. 9.0 mm) and (Z.I. 6.0 mm) E. coli. These findings-especially the biosynthesis of spherical AgNPs of 18.27 nm-provide promise for further investigation and for the development of commercializable biomedical products.
Subject(s)
Anti-Bacterial Agents , Escherichia coli/growth & development , Metal Nanoparticles/chemistry , Plant Extracts/chemistry , Pseudomonas aeruginosa/growth & development , Silver , Zanthoxylum/chemistry , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Silver/chemistry , Silver/pharmacology , Spectroscopy, Fourier Transform InfraredABSTRACT
Lactoferrin (LF) is a multifunctional protein with a broad spectrum of antimicrobial activities. In this study, we investigated the antimicrobial activity of LF against the potato common scab pathogen Streptomyces scabiei, which causes severe damage to potato tubers. LF derived from bovine (bLF) had much higher activity against S. scabiei than human LF. The minimal inhibitory concentration of bLF was 3.9 µM. The effects of both apo-bLF (iron-free) and holo-bLF (iron-saturated) on S. scabiei were not different. Bovine lactoferricin (LFcinB), a short peptide with a length of 25 amino acid residues located in the N-terminal region of bLF, showed antimicrobial activity against S. scabiei, similar to that of bLF. These results indicated that the antimicrobial activity of bLF against S. scabiei cannot be attributed to its iron-chelating effect but to the bioactivity of its peptides. When S. scabiei was treated with the fusion protein of mCherry-LFcinB (red fluorescent protein) expressed in Escherichia coli, the pseudohyphal cells instantly glowed, indicating that the peptide electrostatically binds to the surface of S. scabiei. An assay of synthetic peptides, with modified number of arginine (Arg) and tryptophan (Trp) residues based on the antimicrobial center (RRWQWR) of LFcinB showed that Trp residues are implicated in the antimicrobial activity against S. scabiei; however, Arg residues are also necessary to carry Trp residues to the cell surface to fully exert its activity. Although the single amino acid effect of Trp had low activity, Trp derivatives showed much higher activity against S. scabiei, suggesting that the derivatives effectively bind to the cell surface (cell membrane) by themselves without a carrier. Thus, amino acid derivatives might be considered effective and alternative antimicrobial substances.
Subject(s)
Anti-Bacterial Agents/pharmacology , Lactoferrin/pharmacology , Solanum tuberosum/microbiology , Streptomyces/growth & development , Animals , Anti-Bacterial Agents/chemistry , Cattle , Escherichia coli/growth & development , Humans , Lactoferrin/chemistryABSTRACT
Resuscitation and detection of stressed total coliforms in chlorinated water samples is needed to assess and prevent health effects from adverse exposure. In this study, we report that the addition of a growth enhancer mix consisting of trehalose, sodium pyruvate, magnesium chloride, and 1× trace mineral supplement improved growth of microorganisms from chlorinated secondary effluent in the base medium with Colilert-18. Improving growth of chlorine stressed microorganisms from secondary effluent is crucial to decreased detection time from 18 to 8 h.
Subject(s)
Bacterial Load/methods , Chlorine/toxicity , Culture Media/chemistry , Environmental Monitoring/methods , Escherichia coli/growth & development , Sewage/microbiology , Fluoridation , Magnesium Chloride/metabolism , Pyruvates/metabolism , Trehalose/metabolism , Water MicrobiologyABSTRACT
There is a need for new antimicrobial systems due to increased global resistance to current antimicrobials. Pomegranate rind extract (PRE) and Zn (II) ions both possess a level of antimicrobial activity and work has previously shown that PRE/Zn (II) in combination possesses synergistic activity against Herpes simplex virus and Micrococcus luteus. Here, we determined whether such synergistic activity extended to other, more pathogenic, bacteria. Reference strains of methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus epidermidis, Escherichia coli, and Pseudomonas aeruginosa were cultured and subjected to challenge by PRE, Zn (II), or PRE + Zn (II), in time-kill assays. Data were obtained independently by two researchers using different PRE preparations. Statistically significant synergistic activity for PRE + Zn (II) was shown for all four bacterial strains tested compared to untreated controls, although the extent of efficacy and timescales varied. Zn (II) exerted activity and at 1 h, it was not possible to distinguish with PRE + Zn (II) combination treatment in all cases. PRE alone showed low activity against all four bacteria. Reproducible synergistic bactericidal activity involving PRE and Zn (II) has been confirmed. Potential mechanisms are discussed. The development of a therapeutic system that possesses demonstrable antimicrobial activity is supported which lends itself particularly to topical delivery applications, for example MRSA infections.
Subject(s)
Escherichia coli/growth & development , Methicillin-Resistant Staphylococcus aureus/growth & development , Plant Extracts/pharmacology , Pomegranate/chemistry , Pseudomonas aeruginosa/growth & development , Staphylococcus epidermidis/growth & development , Zinc/pharmacology , Drug Synergism , Escherichia coli/drug effects , Methicillin-Resistant Staphylococcus aureus/drug effects , Microbial Sensitivity Tests , Microbial Viability/drug effects , Plant Extracts/chemistry , Pseudomonas aeruginosa/drug effects , Staphylococcus epidermidis/drug effectsABSTRACT
Plants from the Ilex genus are known for properties such as antimicrobial and anti-inflammatory activity, can act as antiobesity agents and thus can be helpful in medicine. Some holly species, such as Ilex paraguariensis (widely known in the form of popular beverage: yerba mate), have been investigated, while others have been partially researched or remain unknown. Therefore, we performed qualitative and quantitative phytochemical analyses and screened antimicrobial properties of lesser-studied species (I. aquifolium L., I. aquifolium 'Argentea Marginata' and I. × meserveae 'Blue Angel'). I. paraguariensis was used as a standard species for comparison purposes. Investigations were performed on water extracts due to their expected activity and composition. Antimicrobial research included evaluating minimal inhibitory, bactericidal (Staphylococcus aureus and Escherichia coli) and fungicidal concentration (Candida albicans, Alternaria alternata, Fusarium oxysporum, and Aspergillus niger) of extracts. The influence of the extracts on the production, eradication, and viability of bacterial biofilms was also analysed. It was established that Ilex paraguariensis possesses the richest profile of hydroxycinnamic acids derivatives in terms of component concentration and diversity. Ilex spp., especially I. × meserveae, contain a slightly higher amount of flavonoids and more different flavonoid derivatives than I. paraguariensis. However, the strongest antibacterial activity was shown by I. aquifolium L. and its cultivar 'Argentea Marginata' in terms of minimal inhibitory, bactericidal and fungicidal concentration, and biofilm assays. Extracts from both species significantly reduced the biofilm viability of S. aureus as well, which may be of use in the production of multicomponent lavaseptics, antiseptics, diuretics (supporting urinary tract infection therapy) and, due to their action on fungi, additives to growth media for specific fungi. The significant content of saponins enables Ilex extracts to be used as natural emulsifiers, for example, in cosmetics. Moreover, relatively high chlorogenic acid and rutin content may suggest use of Ilex spp. to treat obesity, digestive problems, in chemoprevention, and as preservatives in the food industry.
Subject(s)
Anti-Bacterial Agents , Antifungal Agents , Ilex paraguariensis/chemistry , Phytochemicals , Plant Extracts , Plant Leaves/chemistry , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Antifungal Agents/chemistry , Antifungal Agents/pharmacology , Escherichia coli/growth & development , Fungi/growth & development , Phytochemicals/chemistry , Phytochemicals/pharmacology , Plant Extracts/chemistry , Plant Extracts/pharmacology , Staphylococcus aureus/growth & development , Water/chemistryABSTRACT
Nettle (Urtica dioica L), as a plant rich in biologically active compounds, is one of the most important plants used in herbal medicine. Studies have shown that this plant has antioxidant, antiplatelet, hypoglycemic and hypocholesterolemia effects. In this study, we characterized three Alternaria endophytic fungi isolated from their host U. dioica. We hypothesized that these endophytic fungi can produce new bioactive metabolites, which may possess the bioactive property with potential application in the medical and pharmaceutical industries. The antibacterial activity was evaluated against reference and isolated strains, including Methicillin-Resistant Staphylococcus aureus. A wide range of antimicrobial activities similar to those measured in nettle leaves was detected especially for Alternaria sorghi. Furthermore, the highest antioxidant activity detected with DPPH free radical scavenging was measured for A. sorghi and nettle leaves ethyl acetate extracts. In addition, whereas catalase activity was similar in the three isolated fungi and nettle leaves, total thiol content and superoxide dismutase activity were significantly higher in leaves. A. sorghi showed the best activities compared to other isolated fungi. The characterization and further production of bioactive compounds produced by this endophyte should be investigated to fight bacteria and especially those that develop drug multi-resistance.
Subject(s)
Alternaria/chemistry , Anti-Bacterial Agents/pharmacology , Antioxidants/pharmacology , Endophytes/chemistry , Plant Leaves/chemistry , Urtica dioica/chemistry , Alternaria/physiology , Bacillus cereus/drug effects , Bacillus cereus/growth & development , Biological Products/pharmacology , Endophytes/physiology , Escherichia coli/drug effects , Escherichia coli/growth & development , Free Radical Scavengers/pharmacology , Host-Pathogen Interactions , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/growth & development , Methicillin-Resistant Staphylococcus aureus/drug effects , Methicillin-Resistant Staphylococcus aureus/growth & development , Microbial Sensitivity Tests/methods , Plant Extracts/pharmacology , Plant Leaves/microbiology , Plants, Medicinal/chemistry , Plants, Medicinal/microbiology , Staphylococcus aureus/drug effects , Staphylococcus aureus/growth & development , Urtica dioica/microbiologyABSTRACT
We evaluated phytochemical composition, antibacterial, antifungal, anti-oxidant and cytotoxic properties of aqueous (water) and organic extracts (methanol, ethyl acetate and n-hexane) of Chenopodium glaucum. Highest phenolic content 45 mg gallic acid equivalents (GAE)/g d.w was found in aqueous extract followed by ethyl acetate (41mg GAE/g d.w) and methanol extract (34.46 mg GAE/g d.w). Antibacterial potential of aqueous and organic extracts of C. glaucum was examined against Acinetobacter baumannii, Klebsiella pneumoniae, Escherichia coli and Staphylococcus epidermidis. The aqueous, methanolic, ethyl acetate, and n-hexane extract showed antibacterial activity against A. baumannii, K. pneumoniae, E. coli and S. epidermidis. However, against A. baumannii significantly higher inhibition zone (19 mm and 18.96 mm respectively) was shown by ethyl acetate and methanol extracts. Aqueous extract possessed highest growth inhibition (11 mm) against E. coli. Aqueous, ethyl acetate and methanol extracts showed 9 mm, 10 mm, and 10.33 mm zone of inhibition against the K. pneumoniae. For antifungal activity, the extracts were less effective against Aspergillus niger but showed strong antifungal activity against Aspergillus flavus (A. flavus). The antioxidant activity was measured as DPPH (2, 2-diphenyl-1-picrylhydrazyl), H2O2 and ABTS (2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) scavenging activity of free radicals. All the organic extracts of C. glaucum possessed ABTS, DPPH and H2O2 scavenging properties. The highest cytotoxic activity measured as half maximal inhibitory concentration (IC50) against human lungs carcinoma cells was recorded for methanolic (IC50 = 16 µg/mL) and n-hexane (IC50 = 25 µg/mL) extracts, respectively. The Gas chromatography-mass spectrometry (GC-MS) analysis showed 4 major and 26 minor compounds in n-hexane extract and 4 major and 7 minor compounds in methanol extract of the C. glaucum. It is concluded that aqueous and organic extracts of C. glaucum would be potential therapeutic agents and could be exploited on a pilot scale to treat human pathogenic diseases.
Subject(s)
Anti-Bacterial Agents/pharmacology , Antifungal Agents/pharmacology , Antineoplastic Agents/pharmacology , Chenopodium/chemistry , Lung Neoplasms/drug therapy , Plant Extracts/pharmacology , Acinetobacter baumannii/drug effects , Acinetobacter baumannii/growth & development , Antioxidants/pharmacology , Aspergillus/drug effects , Aspergillus/growth & development , Cell Line, Tumor , Cytotoxins/pharmacology , Escherichia coli/drug effects , Escherichia coli/growth & development , Humans , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/growth & development , Microbial Sensitivity Tests , Phytochemicals/pharmacology , Staphylococcus epidermidis/drug effects , Staphylococcus epidermidis/growth & developmentABSTRACT
The recent emergence of Zika virus (ZIKV) in Brazil and the increasing resistance developed by pathogenic bacteria to nearly all existing antibiotics should be taken as a wakeup call for the international authority as this represents a risk for global public health. The lack of antiviral drugs and effective antibiotics on the market triggers the need to search for safe therapeutics from medicinal plants to fight viral and microbial infections. In the present study, we investigated whether a mangrove plant, Bruguiera gymnorhiza (L.) Lam. (B. gymnorhiza) collected in Mauritius, possesses antimicrobial and antibiotic potentiating abilities and exerts anti-ZIKV activity at non-cytotoxic doses. Microorganisms Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 70603, methicillin-resistant Staphylococcus aureus ATCC 43300 (MRSA), Salmonella enteritidis ATCC 13076, Sarcina lutea ATCC 9341, Proteus mirabilis ATCC 25933, Bacillus cereus ATCC 11778 and Candida albicans ATCC 26555 were used to evaluate the antimicrobial properties. Ciprofloxacin, chloramphenicol and streptomycin antibiotics were used for assessing antibiotic potentiating activity. ZIKVMC-MR766NIID (ZIKVGFP) was used for assessing anti-ZIKV activity. In silico docking (Autodock 4) and ADME (SwissADME) analyses were performed on collected data. Antimicrobial results revealed that Bruguiera twig ethyl acetate (BTE) was the most potent extract inhibiting the growth of all nine microbes tested, with minimum inhibitory concentrations ranging from 0.19-0.39 mg/mL. BTE showed partial synergy effects against MRSA and Pseudomonas aeruginosa when applied in combination with streptomycin and ciprofloxacin, respectively. By using a recombinant ZIKV-expressing reporter GFP protein, we identified both Bruguiera root aqueous and Bruguiera fruit aqueous extracts as potent inhibitors of ZIKV infection in human epithelial A549 cells. The mechanisms by which such extracts prevented ZIKV infection are linked to the inability of the virus to bind to the host cell surface. In silico docking showed that ZIKV E protein, which is involved in cell receptor binding, could be a target for cryptochlorogenic acid, a chemical compound identified in B. gymnorhiza. From ADME results, cryptochlorogenic acid is predicted to be not orally bioavailable because it is too polar. Scientific data collected in this present work can open a new avenue for the development of potential inhibitors from B. gymnorhiza to fight ZIKV and microbial infections in the future.
Subject(s)
Anti-Bacterial Agents/pharmacology , Antifungal Agents/pharmacology , Antiviral Agents/pharmacology , Plant Extracts/pharmacology , Rhizophoraceae/chemistry , Zika Virus/growth & development , Anti-Bacterial Agents/chemistry , Antifungal Agents/chemistry , Antiviral Agents/chemistry , Brazil , Candida albicans/drug effects , Candida albicans/growth & development , Computer Simulation , Drug Synergism , Escherichia coli/drug effects , Escherichia coli/growth & development , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/growth & development , Mauritius , Microbial Sensitivity Tests , Microbial Viability/drug effects , Plant Extracts/chemistry , Proteus mirabilis/drug effects , Proteus mirabilis/growth & development , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/growth & development , Staphylococcus aureus/drug effects , Staphylococcus aureus/growth & development , Zika Virus/drug effectsABSTRACT
Essential oils (EOs) have been used in cosmetics and food due to their antimicrobial and antiviral effects. However, the applications of EOs are compromised because of their poor aqueous solubility and high volatility. Qiai (Artemisia argyi Levl. et Van. var. argyi cv. Qiai) is a traditional Chinese herb and possesses strong antibacterial activity. Herein, we report an innovative formulation of EO as nanohydrogels, which were prepared through co-assembly of Qiai EO (QEO) and Pluronic F108 (PEG-b-PPG-b-PEG, or PF108) in aqueous solution. QEO was efficiently loaded in the PF108 micelles and formed nanohydrogels by heating the QEO/PF108 mixture solution to 37 °C, by the innate thermo-responsive property of PF108. The encapsulation efficiency and loading capacity of QEO reached 80.2% and 6.8%, respectively. QEO nanohydrogels were more stable than the free QEO with respect to volatilization. Sustained QEO release was achieved at body temperature using the QEO nanohydrogels, with the cumulative release rate reaching 95% in 35 h. In vitro antibacterial test indicated that the QEO nanohydrogels showed stronger antimicrobial activity against S. aureus and E. coli than the free QEO due to the enhanced stability and sustained-release characteristics. It has been attested that thermo-responsive QEO nanohydrogels have good potential as antibacterial cosmetics.
Subject(s)
Anti-Bacterial Agents/chemical synthesis , Artemisia/chemistry , Escherichia coli/growth & development , Oils, Volatile/chemical synthesis , Staphylococcus aureus/growth & development , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Delayed-Action Preparations , Drug Compounding , Escherichia coli/drug effects , Micelles , Microbial Viability/drug effects , Nanoparticles/chemistry , Oils, Volatile/chemistry , Oils, Volatile/pharmacology , Particle Size , Plant Extracts/chemistry , Poloxamer/chemistry , Staphylococcus aureus/drug effects , ThermodynamicsABSTRACT
Rising incidents of urinary tract infections (UTIs) among catheterized patients is a noteworthy problem in clinic due to their colonization of uropathogens on abiotic surfaces. Herein, we have examined the surface modification of urinary catheter by embedding with eco-friendly synthesized phytomolecules-capped silver nanoparticles (AgNPs) to prevent the invasion and colonization of uropathogens. The preliminary confirmation of AgNPs production in the reaction mixture was witnessed by the colour change and surface resonance plasmon (SRP) band at 410nm by UV-visible spectroscopy. The morphology, size, crystalline nature, and elemental composition of attained AgNPs were further confirmed by the transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray diffraction (XRD) technique, Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The functional groups of AgNPs with stabilization/capped phytochemicals were detected by Fourier-transform infrared spectroscopy (FTIR). Further, antibiofilm activity of synthesized AgNPs against biofilm producers such as Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were determined by viability assays and micrographically. AgNPs coated and coating-free catheters performed to treat with bacterial pathogen to analyze the mat formation and disruption of biofilm formation. Synergistic effect of AgNPs with antibiotic reveals that it can enhance the activity of antibiotics, AgNPs coated catheter revealed that, it has potential antimicrobial activity and antibiofilm activity. In summary, C. carandas leaf extract mediated synthesized AgNPs will open a new avenue and a promising template to embed on urinary catheter to control clinical pathogens.
Subject(s)
Anti-Bacterial Agents/pharmacology , Apocynaceae/chemistry , Biofilms/drug effects , Escherichia coli/drug effects , Phytochemicals/pharmacology , Pseudomonas aeruginosa/drug effects , Staphylococcus aureus/drug effects , Anti-Bacterial Agents/chemical synthesis , Biofilms/growth & development , Ciprofloxacin/pharmacology , Escherichia coli/growth & development , Escherichia coli/pathogenicity , Escherichia coli Infections/drug therapy , Escherichia coli Infections/microbiology , Gentamicins/pharmacology , Green Chemistry Technology , Humans , Metal Nanoparticles/chemistry , Metal Nanoparticles/ultrastructure , Microbial Sensitivity Tests , Particle Size , Phytochemicals/chemistry , Plant Extracts/chemistry , Plant Leaves/chemistry , Pseudomonas Infections/drug therapy , Pseudomonas Infections/microbiology , Pseudomonas aeruginosa/growth & development , Pseudomonas aeruginosa/pathogenicity , Silver/chemistry , Silver/pharmacology , Staphylococcal Infections/drug therapy , Staphylococcal Infections/microbiology , Staphylococcus aureus/growth & development , Staphylococcus aureus/pathogenicity , Trimethoprim/pharmacology , Urinary Catheters/microbiology , Urinary Tract InfectionsABSTRACT
Croton ferrugineus Kunth is an endemic species of Ecuador used in traditional medicine both for wound healing and as an antiseptic. In this study, fresh Croton ferrugineus leaves were collected and subjected to hydrodistillation for extraction of the essential oil. The chemical composition of the essential oil was determined by gas chromatography equipped with a flame ionization detector and gas chromatography coupled to a mass spectrometer using a non-polar and a polar chromatographic column. The antibacterial activity was assayed against three Gram-positive bacteria, one Gram-negative bacterium and one dermatophyte fungus. The radical scavenging properties of the essential oil was evaluated by means of DPPH and ABTS assays. The chemical analysis allowed us to identify thirty-five compounds representing more than 99.95% of the total composition. Aliphatic sesquiterpene hydrocarbon trans-caryophyllene was the main constituent with 20.47 ± 1.25%. Other main compounds were myrcene (11.47 ± 1.56%), ß-phellandrene (10.55 ± 0.02%), germacrene D (7.60 ± 0.60%), and α-humulene (5.49 ± 0.38%). The essential oil from Croton ferrugineus presented moderate activity against Candida albicans (ATCC 10231) with an MIC of 1000 µg/mL, a scavenging capacity SC50 of 901 ± 20 µg/mL with the ABTS method, and very strong antiglucosidase activity with an IC50 of 146 ± 20 µg/mL.
Subject(s)
Anti-Infective Agents/chemistry , Antioxidants/chemistry , Croton/chemistry , Enzyme Inhibitors/chemistry , Oils, Volatile/chemistry , Plant Leaves/chemistry , Acyclic Monoterpenes/chemistry , Acyclic Monoterpenes/isolation & purification , Alkenes/chemistry , Alkenes/isolation & purification , Anti-Infective Agents/isolation & purification , Anti-Infective Agents/pharmacology , Antioxidants/isolation & purification , Antioxidants/pharmacology , Benzothiazoles/antagonists & inhibitors , Biphenyl Compounds/antagonists & inhibitors , Candida albicans/drug effects , Candida albicans/growth & development , Cyclohexane Monoterpenes/chemistry , Cyclohexane Monoterpenes/isolation & purification , Enzyme Inhibitors/isolation & purification , Enzyme Inhibitors/pharmacology , Escherichia coli/drug effects , Escherichia coli/growth & development , Gram-Positive Bacteria/drug effects , Gram-Positive Bacteria/growth & development , Microbial Sensitivity Tests , Monocyclic Sesquiterpenes/chemistry , Monocyclic Sesquiterpenes/isolation & purification , Picrates/antagonists & inhibitors , Polycyclic Sesquiterpenes/chemistry , Polycyclic Sesquiterpenes/isolation & purification , Sesquiterpenes, Germacrane/chemistry , Sesquiterpenes, Germacrane/isolation & purification , Sulfonic Acids/antagonists & inhibitors , alpha-Glucosidases/chemistryABSTRACT
This study is aimed at identifying the chemical composition of the essential oil extracted from the Syzygium aromaticum seeds, as well as investigating its biological activities, insecticide effect, and allelopathic properties. The extraction yield was about 14.3 and 7.14% for grounded and ungrounded seeds, respectively. The GC-MS analysis allowed the identification of 17 heterogeneous compounds, including eugenol (68.7-87.4%), as major compound, cyperene (20.5-7.2%), phenethyl isovalerate (6.4-3.6%), and cis-thujopsene (1.9-0.8%), respectively, for grounded and ungrounded seeds. Concerning the antibacterial activity, the diameter of the inhibition zone reached 35 mm when the essential oil extracted from grounded seeds was applied against Escherichia coli. Regarding the antioxidant activity via the DPPH radical scavenging test, the IC50 varied from 1.2 ± 0.1 to 2.8 ± 0.5 µg/mL. With respect to reducing power, the efficient concentration EC50 ranged from 32 to 50 µg/mL. The essential oil exhibited also an allelopathic effect against seeds of Hyoscyamus niger, as well as an insecticide effect against Sitophilus oryzae with a DL50 value of 252.4 µL/L air. These findings enhance the use of this spice as a natural food preservative and encourage its use in several fields, including pharmaceutical, cosmetics, agriculture, and therapy, that could be a strategic way to guarantee the consumer's health.
Subject(s)
Anti-Bacterial Agents/chemistry , Antioxidants/chemistry , Insecticides/chemistry , Oils, Volatile/chemistry , Syzygium/chemistry , Animals , Anti-Bacterial Agents/isolation & purification , Anti-Bacterial Agents/pharmacology , Antioxidants/isolation & purification , Antioxidants/pharmacology , Disk Diffusion Antimicrobial Tests , Escherichia coli/drug effects , Escherichia coli/growth & development , Food Safety , Gas Chromatography-Mass Spectrometry , Hyoscyamus/drug effects , Hyoscyamus/growth & development , Insecticides/isolation & purification , Insecticides/pharmacology , Microbial Viability/drug effects , Oils, Volatile/isolation & purification , Oils, Volatile/pharmacology , Plant Oils/chemistry , Plant Oils/isolation & purification , Seeds/chemistry , Weevils/drug effects , Weevils/growth & developmentABSTRACT
In this study, novel active films based on pullulan and carboxylated cellulose nanocrystal (C-CNC) incorporated with tea polyphenol (TP) was prepared by solution casting method. The effect of TP addition on the microstructural, mechanical, barrier, optical, functional properties of the resultant pullulan/C-CNC/TP (PC-TP) bionanocomposite films was systematically evaluated. Scanning electron microscopy showed that an appropriate TP adding was well distributed within the PC-TP bionanocomposite matrix. Fourier-transform infrared further revealed that new hydrogen bond was formed among the pullulan, C-CNC, TP. Addition of TP at an appropriate level (3%, w/w, on a dry basis of the weight of pullulan and C-CNC) led to stronger intermolecular interactions and more compact microstructure, and thus enhanced the water barrier properties, thermal stability and tensile strength of the resultant bionanocomposite films. Nevertheless, overloading of TP in the bionanocomposite films might produce some aggregations and thus have negative effects on their performance. In addition, the incorporation of TP significantly improved the UV-barrier properties, antioxidant activity and antimicrobial activity of PC-TP bionanocomposite films, while induced a decrease in the transmittance. These results revealed that PC-TP bionanocomposite films with TP at appropriate levels had potential to be used as active food packaging.
Subject(s)
Anti-Infective Agents/pharmacology , Antioxidants/pharmacology , Camellia sinensis , Cellulose, Oxidized/chemistry , Food Packaging , Glucans/chemistry , Nanocomposites , Nanoparticles , Polyphenols/pharmacology , Anti-Infective Agents/isolation & purification , Antioxidants/chemistry , Antioxidants/isolation & purification , Biphenyl Compounds/chemistry , Camellia sinensis/chemistry , Escherichia coli/drug effects , Escherichia coli/growth & development , Hydrogen Bonding , Nanotechnology , Picrates/chemistry , Polyphenols/chemistry , Polyphenols/isolation & purification , Staphylococcus aureus/drug effects , Staphylococcus aureus/growth & development , Tensile Strength , Water/chemistryABSTRACT
This research aimed to enhance the antibacterial activity of silver nanoparticles (AgNPs) synthesized from silver nitrate (AgNO3) using aloe vera extract. It was performed by means of incorporating AgNPs on an activated carbon nanoparticle (ACNPs) under ultrasonic agitation (40 kHz, 2 × 50 watt) for 30 min in an aqueous colloidal medium. The successful AgNPs synthesis was clarified with both Ultraviolet-Visible (UV-Vis) and Fourier Transform Infrared (FTIR) spectrophotometers. The successful AgNPs-ACNPs incorporation and its particle size analysis was performed using Transmission Electron Microscope (TEM). The brown color suspension generation and UV-Vis's spectra maximum wavelength at around 480 nm confirmed the existence of AgNPs. The particle sizes of the produced AgNPs were about 5 to 10 nm in the majority number, which collectively surrounded the aloe vera extract secondary metabolites formed core-shell like nanostructure of 8.20 ± 2.05 nm in average size, while ACNPs themselves were about 20.10 ± 1.52 nm in average size formed particles cluster, and 48.00 ± 8.37 nm in average size as stacking of other particles. The antibacterial activity of the synthesized AgNPs and AgNPs-immobilized ACNPs was 57.58% and 63.64%, respectively (for E. coli); 61.25%, and 93.49%, respectively (for S. aureus). In addition, when the AgNPs-immobilized ACNPs material was coated on the cotton and polyester fabrics, the antibacterial activity of the materials changed, becoming 19.23% (cotton; E. coli), 31.73% (polyester; E. coli), 13.36% (cotton; S. aureus), 21.15% (polyester; S. aureus).
Subject(s)
Anti-Bacterial Agents , Charcoal , Escherichia coli/growth & development , Green Chemistry Technology , Metal Nanoparticles/chemistry , Silver , Staphylococcus aureus/growth & development , Textiles , Aloe/chemistry , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Charcoal/chemistry , Charcoal/pharmacology , Plant Extracts/chemistry , Silver/chemistry , Silver/pharmacologyABSTRACT
Antibacterial activity of ethanolic and aqueous extracts of two medicinal plants including Oxalis corniculata (EtOc, AqOc) and Artemisia annua (EtAa, AqAa) as well as A. annua essential oil (EoAa) was investigated on multi-drug resistance (MDR) E. coli. Microdilution and agar well diffusion methods were used to determine the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) as well as the inhibition zone. The phytconstituents of these products were analyzed using Reverse-phase High- performance liquid chromatography (RP-HPLC) and gas chromatography-mass spectrometry (GC-mass). The order of bacteriostatic and bacteriocide rate of the products can be shown as follows: EoAa>AqOc>EtAa = AqAa>EtOc, but the bactericidal effect of A. annua extracts is higher than of O. corniculata based on the MIC/MBC ratio and the order is as follows: EoAa>EtAa = AqAa>EtOc>AqOc. The most potent product, i.e. EoAa with a 56.7% inhibition of all isolates, has the potential to substitute 13 used antibiotics including oxacillin, amoxicillin, ampicillin, amoxicillin-clavulanic acid, tetracycline, streptomycin, ciprofloxacin, ceftriaxone, cefazolin, cefuroxime, cefotaxime, ceftazidime and cefixime (P <0.05). Different terpenoids were detected and measured in EoAa and catechin flavonoids in extracts of both plants, quercetin in extracts of O. corniculata but it was only possible to detect chlorogenic acid polyphenol in AqAa. Due to the antibacterial activities of the studied products, more effective than some antibiotics and their edible consumption, these products can be suggested as an alternative to some antibiotics and food preservatives to fight against MDR E. coli.
Subject(s)
Anti-Bacterial Agents , Artemisia annua/chemistry , Drug Resistance, Multiple, Bacterial , Escherichia coli Infections/drug therapy , Escherichia coli/growth & development , Oxalidaceae/chemistry , Plant Extracts , Plants, Medicinal/chemistry , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Female , Humans , Male , Microbial Sensitivity Tests , Plant Extracts/chemistry , Plant Extracts/pharmacologyABSTRACT
L-asparaginase II (ASNase) is the biopharmaceutical of choice for the treatment of acute lymphoblastic leukaemia. In this study, E. coli BL21 (DE3) transformed with the pET15b + asnB vector which expresses recombinant ASNase was used as a source to obtain this enzyme. The ideal conditions to produce ASNase would be a high level of secretion into the extracellular medium, which depends not only on the application of molecular biology techniques but also on the development of a strategy to modify cell permeability such as the addition of substances to the culture medium that stimulate destabilisation of structural components of the cell. Thus, the growth of E. coli BL21 (DE3) in modified Luria-Bertani broth, supplemented with 0.8% (w/v) glycine and 6% (v/v) n-dodecane, increased the total yield of ASNase by about 50% (15,108 IU L-1) and resulted in a 16-fold increase in extracellular enzymatic productivity (484 IU L-1 h-1), compared to production using the same medium without addition of these substances. Most of the enzyme (89%) was secreted into the culture medium 24 h after the induction step. This proposed approach presents a simple strategy to increase extracellular production of ASNase in E. coli.
Subject(s)
Asparaginase , Escherichia coli , Alkanes , Asparaginase/biosynthesis , Culture Media , Escherichia coli/growth & development , Escherichia coli/metabolism , Glycine , Recombinant Proteins/biosynthesisABSTRACT
Novel peppermint oil (PO)-loaded composite microcapsules (CM) with hydroxypropyl methyl cellulose (HPMC)/chitosan/silica shells were effectively fabricated by PO Pickering emulsion, which were stabilized with chitosan-decorated silica nanoparticles (CSN). The surface modification of chitosan could improve the hydrophobicity of silica nanoparticles and favor their adsorption at the oil-water interface of PO Pickering emulsions. The microcapsule composite shells were formed dependent on the electrostatic adsorption of HPMC and CSN, and further subjected to spray-drying. The peppermint oil-loaded composite microcapsules with 100% HPMC as wall material (PO-CM@100%HPMC) seemed to be optimum formulation based on the prolonged release, acceptable entrapment efficiency (89.1%) and drug loading (25.5%). The PO-CM@100%HPMC could remarkably prolong the stability of PO. Moreover, the PO-CM@100%HPMC had a long-term antimicrobial activity (85.4%) against S. aureus and E. coli even after storage for 60 days. Therefore, the Pickering emulsions based microcapsules seemed to be a promising strategy for antibacterial application for PO.
Subject(s)
Anti-Bacterial Agents/pharmacology , Chitosan/chemistry , Drug Carriers , Escherichia coli/drug effects , Nanoparticles , Plant Oils/pharmacology , Silicon Dioxide/chemistry , Staphylococcus aureus/drug effects , Adsorption , Anti-Bacterial Agents/chemistry , Capsules , Delayed-Action Preparations , Drug Compounding , Drug Liberation , Drug Stability , Emulsions , Escherichia coli/growth & development , Hydrophobic and Hydrophilic Interactions , Hypromellose Derivatives/chemistry , Mentha piperita , Plant Oils/chemistry , Staphylococcus aureus/growth & development , Time FactorsABSTRACT
Environmental fluctuations are a common challenge for single-celled organisms; enteric bacteria such as Escherichia coli experience dramatic changes in nutrient availability, pH, and temperature during their journey into and out of the host. While the effects of altered nutrient availability on gene expression and protein synthesis are well known, their impacts on cytoplasmic dynamics and cell morphology have been largely overlooked. Here, we discover that depletion of utilizable nutrients results in shrinkage of E. coli's inner membrane from the cell wall. Shrinkage was accompanied by an â¼17% reduction in cytoplasmic volume and a concurrent increase in periplasmic volume. Inner membrane retraction after sudden starvation occurred almost exclusively at the new cell pole. This phenomenon was distinct from turgor-mediated plasmolysis and independent of new transcription, translation, or canonical starvation-sensing pathways. Cytoplasmic dry-mass density increased during shrinkage, suggesting that it is driven primarily by loss of water. Shrinkage was reversible: upon a shift to nutrient-rich medium, expansion started almost immediately at a rate dependent on carbon source quality. A robust entry into and recovery from shrinkage required the Tol-Pal system, highlighting the importance of envelope coupling during shrinkage and recovery. Klebsiella pneumoniae also exhibited shrinkage when shifted to carbon-free conditions, suggesting a conserved phenomenon. These findings demonstrate that even when Gram-negative bacterial growth is arrested, cell morphology and physiology are still dynamic.
Subject(s)
Cytoplasm/physiology , Escherichia coli/physiology , Carbon/deficiency , Carbon/pharmacology , Cytoplasm/drug effects , DNA Replication/drug effects , Down-Regulation/drug effects , Escherichia coli/drug effects , Escherichia coli/growth & development , Escherichia coli Proteins/metabolism , Ion Channels/metabolism , Mechanotransduction, Cellular/drug effects , Nitrogen/analysis , Phosphorus/analysisABSTRACT
Ocimum cufodontii ((Lanza) A.J.Paton) has been traditionally used in Ethiopia against bacteria. The extracts of the leaves and roots of O. cufodontii after silica gel column chromatography furnished compounds 1-5, compounds 3 and 4 are new natural products. The oil from the hydro-distillation of the leaves, after analyzed with GC-MS, has led to the identification of ß-caryophyllene as a principal component, suggesting the essential oil as medicine and spices to enhance the taste of food. The constituents of O. cufodontii were assessed for their antibacterial activity against E. coli, K. pneumonia, S. typhymurium and S. aureus. The best activity was displayed against S. aureus by the hexane extract of the roots, compound 4, and the essential oil with an inhibition zone of 17, 15, and 19 mm, respectively. Molecular docking analysis revealed that compound 1 has better docking efficiency and forms hydrophobic interactions with five amino acids (ARG192, PHE196, GLU185, GLU193, and LYS189). This suggests that the compounds may act as potential inhibitors of DNA gyrase. The constituents were also assessed for their antioxidant activities using DPPH, ferric thicyanate and ferric reducing power assay. The hexane extracts of the roots inhibited the DPPH radical and peroxide formation by 90.5 and 83%, respectively, suggesting the potential of the extract as an antioxidant. Furthermore, the hexane extract of the roots of O. cufodontii exhibited the maximum reducing power compared with the EtOAc and methanol extracts. Hence, the activity displayed herein indicated as the plant has great potential as a remedy for diseases caused by bacteria and radicals.
Subject(s)
Anti-Bacterial Agents/pharmacology , Antioxidants/pharmacology , Ocimum/chemistry , Oils, Volatile/pharmacology , Plant Extracts/pharmacology , Anti-Bacterial Agents/chemistry , Antioxidants/chemistry , Escherichia coli/drug effects , Escherichia coli/growth & development , Gas Chromatography-Mass Spectrometry , Microbial Sensitivity Tests , Molecular Docking Simulation , Oils, Volatile/chemistry , Plant Extracts/chemistry , Plant Leaves/chemistry , Staphylococcus aureus/drug effects , Staphylococcus aureus/growth & developmentABSTRACT
This study aimed to produce soluble potato starch ultrafine fibers for the encapsulation of pinhão coat extract (PCE), evaluating their relative crystallinity (RC), thermal stability, antioxidant activity, antimicrobial activity against Escherichia coli and Staphylococcus aureus, as well as in vitro biological digestion. In the simulation of in vitro biological digestion, the phenolic compounds release profile was also evaluated. The ultrafine fibers were produced by electrospinning, based on a polymeric solution composed of soluble potato starch (50% w/v) and formic acid. Then, PCE was incorporated at various concentrations (0.5%, 1.0%, and 1.5%, w/w, dry basis). The endothermic event of free PCE was not observed in the ultrafine fibers, which suggests its encapsulation. The RC decreased according to the increase in PCE concentration in the ultrafine fibers. The PCE resisted thermal treatments when encapsulated into the ultrafine fibers (100 and 180°C), and the ultrafine fibers with 1% PCE presented the highest amount of preserved phenolic compounds. Regarding antioxidant activity, the free PCE presented 85% of DPPH inhibition and the ultrafine fibers had 18% inhibition, not differing among the PCE concentrations (p < 0.05). The free PCE and the ultrafine fibers with 0.5% PCE showed inhibitory effect against S. aureus and the ones with 1.5% PCE showed controlled release of phenolic compounds during the simulation of in vitro digestion. Starch ultrafine fibers showed potential to be applied in food industries due to their capacity of protecting phenolic compounds when submitted to high temperatures or gastrointestinal conditions. Nevertheless, their application depends on the end use of the product. PRACTICAL APPLICATION: The encapsulation of pinhão coat extract (PCE) in ultrafine starch fibers promotes greater preservation of phenolic compounds. Thus, it can be incorporated into different foods that are produced using the ultra-high temperature (UHT) process-at 135-145°C for 5 to 10 s, or some other equivalent time/temperature combination. Another possibility is the incorporation of ultrafine fibers in active packaging: compounds can migrate to food, improving sensory characteristics, increasing shelf life, preventing chemical and microbiological deterioration, and ensuring food safety.