Green Synthesis and Characterization of Novel Silver Nanoparticles Using Achillea maritima subsp. maritima Aqueous Extract: Antioxidant and Antidiabetic Potential and Effect on Virulence Mechanisms of Bacterial and Fungal Pathogens.

Novel silver nanoparticles were synthesized based on a simple and non-toxic method by applying the green synthesis technique, using, for the first time, the aqueous extract of an extremophile plant belonging to the Achillea maritima subsp. maritima species. AgNP characterization was performed via UV-Visible, front-face fluorescence spectroscopy, and FTIR and XRD analyses. AgNP formation was immediately confirmed by a color change from yellow to brown and by a surface plasmon resonance peak using UV-Vis spectroscopy at 420 nm. The biosynthesized AgNPs were spherical in shape with a size ranging from approximatively 14.13 to 21.26 nm. The presented silver nanoparticles exhibited strong antioxidant activity following a DPPH assay compared to ascorbic acid, with IC50 values of about 0.089 µg/mL and 22.54 µg/mL, respectively. The AgNPs showed higher antidiabetic capacities than acarbose, by inhibiting both alpha amylase and alpha glucosidase. The silver nanoparticles could affect various bacterial mechanisms of virulence, such as EPS production, biofilm formation and DNA damage. The silver nanoparticles showed no lysozyme activity on the cell walls of Gram-positive bacteria. The AgNPs also had a strong inhibitory effect on the Candida albicans virulence factor (extracellular enzymes, biofilm formation). The microscopic observation showed abnormal morphogenesis and agglomeration of Candida albicans exposed to AgNPs. The AgNPs showed no cytotoxic effect on human cells in an MTT assay. The use of novel silver nanoparticles is encouraged in the formulation of natural antimicrobial and antidiabetic agents.

Chemical Composition and Bioactivities of Quercus canariensis Flour Acorns Extracts Growing in Tunisia.

The current study was conducted to investigate the chemical composition of Quercus canariensis flour acorns extracts as well as its biological activities in regards to the growing area using spectrophotometric and chromatographic techniques. The phenolic profile was composed of 19 compounds identified through HPLC-DAD analysis. Coumarin was the most abundant compound quantified in BniMtir, Nefza and ElGhorra and gallic (12.58-20.52 %), syringic (4.70-7.64 %) and trans-ferulic (2.28-2.94 %) acids were the abundant phenolic acids while kaempferol was the major flavonoid compounds quantified only in Quercus canariensis growing in BniMtir. On the other hand, Ain Snoussi acorn extract was characterized by its high content in luteolin-7-O-glucoside (58.46 %). The in-vitro antioxidant activities of the studied extracts were investigated and the results showed that Nefza ethanolic extract's has the highest activities. A bactericidal effect against Staphylococcus aureus was observed only by Elghorra population. On the other hand, Ain Snoussi acorn extract was efficient to inhibit growth of pathogenic bacteria, mentioned the highest activity against Escherichia coli. These results is the first study highlighted that zeen oak acorns are an excellent source of natural antioxidants and antibacterial compounds related to their lysozyme activity which could be exploited in the pharmaceutical and food sectors.

Production and Characterization of New Biosurfactants/Bioemulsifiers from Pantoea alhagi and Their Antioxidant, Antimicrobial and Anti-Biofilm Potentiality Evaluations.

The present work aimed to develop rapid approach monitoring using a simple selective method based on a positive hemolysis test, oil spreading activity and emulsification index determinations. It is the first to describe production of biosurfactants (BS) by the endophytic Pantoea alhagi species. Results indicated that the new BS evidenced an E24 emulsification index of 82%. Fourier-transform infrared (FTIR) results mentioned that the described BS belong to the glycolipid family. Fatty acid profiles showed the predominance of methyl 2-hyroxydodecanoate in the cell membrane (67.00%) and methyl 14-methylhexadecanoate (12.05%). The major fatty acid in the BS was oleic acid (76.26%), followed by methyl 12-methyltetradecanoate (10.93%). Markedly, the BS produced by the Pantoea alhagi species exhibited antimicrobial and anti-biofilm activities against tested human pathogens. With superior antibacterial activity against Escherchia coli and Staphylococcus aureus, a high antifungal effect was given against Fusarium sp. with a diameter of zone of inhibition of 29.5 mm, 36 mm and 31 mm, obtained by BS dissolved in methanol extract. The DPPH assay indicated that the BS (2 mg/mL) showed a higher antioxidant activity (78.07 inhibition percentage). The new BS exhibited specific characteristics, encouraging their use in various industrial applications.

First Report of the Biosynthesis and Characterization of Silver Nanoparticles Using Scabiosa atropurpurea subsp. maritima Fruit Extracts and Their Antioxidant, Antimicrobial and Cytotoxic Properties.

Candida and dermatophyte infections are difficult to treat due to increasing antifungal drugs resistance such as fluconazole, as well as the emergence of multi-resistance in clinical bacteria. Here, we first synthesized silver nanoparticles using aqueous fruit extracts from Scabiosa atropurpurea subsp. maritima (L.). The characterization of the AgNPs by means of UV, XRD, FTIR, and TEM showed that the AgNPs had a uniform spherical shape with average sizes of 40-50 nm. The biosynthesized AgNPs showed high antioxidant activity when investigated using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. The AgNPs displayed strong antibacterial potential expressed by the maximum zone inhibition and the lowest MIC and MBC values. The AgNPs revealed a significant antifungal effect against the growth and biofilm of Candida species. In fact, the AgNPs were efficient against Trichophyton rubrum, Trichophyton interdigitale, and Microsporum canis. The antifungal mechanisms of action of the AgNPs seem to be due to the disruption of membrane integrity and a reduction in virulence factors (biofilm and hyphae formation and a reduction in germination). Finally, the silver nanoparticles also showed important cytotoxic activity against the human multiple myeloma U266 cell line and the human breast cancer cell line MDA-MB-231. Therefore, we describe new silver nanoparticles with promising biomedical application in the development of novel antimicrobial and anticancer agents.

Green synthesis of silver nanoparticles using mixed leaves aqueous extract of wild olive and pistachio: characterization, antioxidant, antimicrobial and effect on virulence factors of Candida.

In this study, a successfully rapid, simple approach was applied for biosynthesis of silver nanoparticles AgNPs using for the first time the mixed leaves extract of Olea europaea subsp. europaea var. sylvestris and Pistacia lentiscus from natural association aimed to enhance their antimicrobial potential. The plant extract acts both as reducing and capping agents. When the aqueous extract was added to AgNO3 solution, the color was changed from pale to yellow to brown indicating the reduction of Ag ions and synthesis of silver nanoparticles (AgNPs) without any solvent or hazardous reagents. The green synthesized AgNPs were characterized by UV-Vis spectrophotometer, FTIR spectrum and the X-ray crystallography. The AgNPs showed superior antioxidant activity measured by DPPH, Ferric Antioxidant Reducing Power (FRAP) as well as the total antioxidant activity methods. Moreover, the analysis of phytochemical constituents including flavonoids, tannins, alkaloids and total polyphenols contents mentioned the most richness of the silver nanoparticles compared to plant extract. The new synthesized AgNPs demonstrated the bactericidal and fungicidal effects against all the tested bacterial and fungal strains and found to limit the spore germination of filamentous fungi. AgNPs also gave an anti-biofilm activity and synergistic effect with the conventional antibiotic's drugs. Here we firstly describe the silver nanoparticles effect on virulence factors of Candida species by reduction of enzymes like proteinase and phospholipase, inhibition of morphogenesis of Candida albicans cells. This natural product, acquiring these properties, should be promoted to be used in pharmaceutical and medical industries in future.

Biosynthesis and Characterization of Silver Nanoparticles from the Extremophile Plant Aeonium haworthii and Their Antioxidant, Antimicrobial and Anti-Diabetic Capacities.

The present paper described the first green synthesis of silver nanoparticles (AgNPs) from the extremophile plant Aeonium haworthii. The characterization of the biosynthesized silver nanoparticles was carried out by using UV-Vis, FTIR and STM analysis. The antioxidant, antidiabetic and antimicrobial properties were also reported. The newly described AgNPs were spherical in shape and had a size of 35-55 nm. The lowest IC50 values measured by the DPPH assay indicate the superior antioxidant behavior of our AgNPs as opposed to ascorbic acid. The silver nanoparticles show high antidiabetic activity determined by the inhibitory effect of α amylase as compared to the standard Acarbose. Moreover, the AgNPs inhibit bacterial growth owing to a bactericidal effect with the MIC values varying from 0.017 to 1.7 µg/mL. The antifungal action was evaluated against Candida albicans, Candida tropicalis, Candida glabrata, Candida sake and non-dermatophytic onychomycosis fungi. A strong inhibitory effect on Candida factors' virulence was observed as proteinase and phospholipase limitations. In addition, the microscopic observations show that the silver nanoparticles cause the eradication of blastospores and block filamentous morphogenesis. The combination of the antioxidant, antimicrobial and antidiabetic behaviors of the new biosynthesized silver nanoparticles highlights their promising use as natural phytomedicine agents.

Potentialities and Characterization of an Antifungal Chitinase Produced by a Halotolerant Bacillus licheniformis.

The chitinases are gaining much attention based on their role in the defense against pathogen attacks and harmful insects. The partially chitinase produced by Bacillus licheniformis strain J24 exhibited a large antifungal spectrum, and the highest activity was obtained toward Fusarium species in vitro on PDA and in vivo on corn seeds. The chitinase was inducible by the presence of autoclaved Fusarium conidia in the medium culture and it was active at 70 °C and pH 7 and not affected by the tested chemical agents EDTA and SDS. The nucleotide and amino acid sequences encoding chitinase showed the close phylogenetic relation with chitinase from Bacillus paralicheniformis species. Based on the analysis of the putative domain active, the described chitinase from strain J24 was belonging to the GH family-18 and the novelty of its structure was revealed. Here the combination of functional and structural antifungal extremely chitinase proves its importance in biotechnology area.

Antioxidant and Antimicrobial Potentials of Seed Oil from Carthamus tinctorius L. in the Management of Skin Injuries.

Infection of skin injuries by pathogenic microbial strains is generally associated if not treated with a lasting wound bed oxidative stress status, a delay in healing process, and even wound chronicity with several human health complications. The aim of the current study was to explore the antioxidant and antimicrobial potentialities of safflower (Carthamus tinctorius L.) extracted oil from seeds by cold pressing which would be beneficial in the management of skin wounds. Antioxidant capacity of the oil was evaluated (scavenging ability against 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and 2,2'-azino-bis 3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and ferric reducing antioxidant power (FRAP)). Total phenolic, total flavonoid, total carotenoid, and total chlorophyll contents were determined. Antimicrobial activities of safflower oil were tested against 10 skin pathogenic microorganisms: 4 bacterial strains (Escherichia coli, Enterobacter cloacae, Staphylococcus aureus, and Streptococcus agalactiae), 3 yeast species strains (Candida albicans, Candida parapsilosis, and Candida sake), and 3 fungi species (Aspergillus niger, Penicillium digitatum, and Fusarium oxysporum). A notable antioxidant capacity was demonstrated for the tested oil that exhibited moreover high antibacterial effects by both bacteriostatic and bactericidal pathways including lysozyme activity. An antifungal effect was further observed on the spore's germination. Safflower oil could be considered as a good natural alternative remedy in the management of skin wounds and their possible microbial infections.

Phenotypical and molecular characterization of Microsporum canis strains in North-Tunisia.

In this study, 40 Microsporum canis isolates were obtained from different patients from the Mycology Unit of the Hospital La Rabta (Tunis) during a 3 month period. The phenotypic identification was done by morphological characterization and biochemical tests. Molecular analysis was performed by amplification of the ITS region of rDNA, the amplified region was subjected to enzymatic digestion and sequenced to evaluate phylogenetic relationships. The morphological analysis showed a considerable diversity of colonies as well as different morphologies of conidia and we have noted variability in the assimilation of the nitrogen and carbon sources. The PCR-RFLP results showed only one restriction pattern for each enzyme. The phylogenetic tree proves that all the strains from Tunisian patients are clonal and related with other strains from different origins. The classical methods used in the mycological laboratories are time-consuming, the PCR-RFLP analysis of the ITS is a reliable tool for the identification of M. canis strains. M. canis from infected Tunisian patients are clonal, although the isolates had different phenotypic characteristics.

Synthesis, crystal structure and potential antimicrobial activities of di (4-sulfamoyl-phenyl-ammonium) sulphate.

A new organic-inorganic hybrid SO4[C6H9N2O2S]2, has been synthesized and characterized by X-ray diffraction. This compound crystallizes in the orthorhombic system, spaces group Pbcn. In the title compound, the packing is stabilized by intermolecular N-H⋯O hydrogen bonds and π-π stacking interactions between the phenyl rings, linking the molecules into three-dimensional network. The in vitro antimicrobial activity of di (4-sulfamoyl-phenyl-ammonium) sulphate was determined by the broth dilution method against several strains selected to define their spectrum and potency. Here we show that the synthetic sulfanilamide exhibits promising antibacterial potency. High inhibition was also detected against Candida albicans. In this paper we firstly showed the antifungal activity of the sulfanilamide against two serious phytopathogenic fungi. Interestingly, the new compound was able to suppress mycelial growth as well as the spores germination of tested fungi, values of spore germination vary from 97.6% to 37.5%, respectively for Botrytis cinerea and Fusarium species. The minimal inhibitory concentrations (MIC) ranging from 8 to 100 µg ml(-1) and IC50 values varying from 5.81 to less than 100 µg ml(-1)), showed that the sulfanilamide sulphate had high activity against bacteria, yeast and fungi, compared to others published antifungal compounds.