Crithmum maritimum L. Volatile Compound's Diversity Through Tunisian Populations: Use of a Plant Organ-Based Statistical Approach for Chemotype Identification.

This work aimed to investigate the variability of the chemical composition of the aromatic halophyte Crithmum maritimum L. essential oils according to the geographical origin and separated organs, using a statistical approach based on the multiple analysis of variance and the Principal Component Analyses. One hundred twenty samples were collected from three distinct bioclimatic regions (10 samples×3 provenances×4 organs). Hydrodistillation of separated organs (roots, stems, leaves and flowers) yielded 0.13 to 1.75 % of the dry matter. Chemical investigation of the volatile compounds by Gas chromatography-mass spectrometry showed that C. maritimum essential oils were dominated by monoterpenes hydrocarbons, oxygenated monoterpenes, and phenylpropanoids varying, respectively, from 33.3 to 66.9, from 7.8 to 46.6 and from 4.5 to 57.2 % according to organs and localities. Statistical analyses identified three different chemotypes depending on the geographic origin as follow: γ-Terpinene-Thymol methyl ether / Dillapiole / Thymol methyl ether-Dillapiole.

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.

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.

Oil, protein, antioxidants and free radical scavenging activity of stone from wild olive trees (Olea europaea L.).

The wild olive trees or oleaster (var. sylvestris) and the cultivated olive trees (var. europaea) constitute the two botanical varieties of Olea europaea L. from Mediterranean. In this study, a partial chemical profile was conducted including the total lipids, the fatty acid profiles, soluble proteins, polyphenols, flavanoids contents and antioxidants activities of stone from six oleaster trees. The comparison was made by two olive cultivars cultivated in the same region. The oleaster and cultivar stones were richer in oil content having an average of 8.99 and 7.38 % dry weight basis (DW), respectively. Qualitatively, all studied oils have the same fatty acids profile with the oleic acid C18:1n-9 as the major fatty acid. The oleaster stone oils were richer in monounsaturated fatty acids having an average of 64.87%. They, also, richer in protein content with an average of 198.86 mg/g DW.The globulin is the major fraction, followed by the albumin, the prolamin and the glutemin fractions. The oleaster stone extracts contain polyphenols, flavonoids with an average of 151.14 and 11.91 mg gallic acid equivalent/100g of DW, respectively. The studied extracts showed antioxidant activity using the free radical scavenging activity determined by DPPH and ABTS. The unexploited oleaster stone seems to be a source of oil with good fatty acids balance, in protein and antioxidants metabolites and would be useful for the formulation of supplements and/or pharmaceutical ingredients.

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.

Maceration and liquid-liquid extractions of phenolic compounds and antioxidants from Algerian olive oil mill wastewater.

Olive oil mill wastewater (OMW) is a major waste stream generated in olive oil industry. It is highly polluted due to phenolic compounds. The present study focused on the physicochemical properties of OMW as well as the quantitative and qualitative effects of two extraction methods of phenolic compounds which were liquid-liquid and maceration methods. Spectrophotometry and high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS) were adopted to quantify the phytochemical contents and the phenolic compounds. The extract obtained by the maceration method showed the highest yields of total polyphenol, flavonoid, and tannin contents. The LC-MS results revealed the presence of 16 phenolic compounds in the macerated, and only 12 phenolic compounds were found in the extract of the second method. Quinic acid was identified as the most abundant compound. Moreover, the macerated extracts possessed the highest antioxidant potential as evidenced by their strong ferric reducing antioxidant power (FRAP) and their 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) radical scavenging activities. The phytochemical contents, as well as the antioxidant potentials of OMW after extraction using maceration, were significantly greater than using liquid-liquid method. Therefore, maceration seemed to be the most effective method for extracting phenolic compounds from OMW. The OMW constitute a rich source of natural phenolic compounds that could be used as a potential source of natural antioxidants.

Effect of Geographical Location on the Phenolic and Mineral Composition of Chetoui Olive Leaves.

In this study, we investigated the influence of pedological parameters and variation of altitude on the mineral nutrients, phenolic compounds, and antioxidant activities of olive leaves. Samples of the Chetoui cultivar were collected from eight geographical locations with different altitudes. Levels of phenolic compounds varied according to the altitude. Classification of the locations revealed that altitude 1 (>500 m) was characterized by high levels of secoiridoids and simple phenols, while altitude 2 (500-300 m) and altitude 3 (<300 m) were higher in flavonoids. Levels of Mn, Ca and B in the leaves and level of Zn in the soil were significantly correlated with the abundance of oleuropein and luteolin-7-O glucoside, the most important phenols in Chetoui olive leaves. The results suggest that, in addition to pedological criteria, environmental conditions also influence the formation of phenolic compounds.

Minor lipid components of some Acacia species: potential dietary health benefits of the unexploited seeds.

BACKGROUND: Oilseed samples from four Acacia species ( A. cyclops, A. ligulata, A. salicina and A. cyanophylla) were analyzed in order to evaluate the potential nutritional value of their unexploited seeds. METHODS: Samples were collected from different Tunisian geographic locations. Seed oils were extracted and carotenoids, tocopherols and sterols were analyzed using chromatographic methods. RESULTS: The studied Acacia seeds seem to be quite rich in lipids (from 6% to 12%). All Acacia species contain mainly the xanthophylls zeaxanthin and lutein compounds: from ca. 38 mg.kg⁻¹ of total lipids (A. cyclops) to ca. 113 mg.kg⁻¹ of total lipids (A. cyanophylla). Total tocopherols varied from ca. 221 mg.kg⁻¹ of total lipids (A. cyclops) to ca. 808 mg.kg-1 of total lipids (A. ligulata). Sterols are highly present and their contents ranged between ca. 7 g. kg⁻¹ of total lipids (A. salicina) and 11 g. kg⁻¹ of total lipids (A. cyclops). CONCLUSION: This study highlights that these unexploited seeds might have a potential nutritional value and encourages researchers to more explore and find developments for these plants for healthy purposes.

Seasonal changes in rosemary species: A chemotaxonomic assessment of two varieties based on essential oil compounds, antioxidant and antibacterial activities.

Rosemary (Rosmarinus officinalis L.) is a popular herb in cooking, traditional healing, and aromatherapy. This study was conducted to evaluate the effects of meteorological conditions plant growth stage and genetic factors on the yield, quantitative and qualitative composition, on the antioxidant and antimicrobial activities of rosemary essential oil from two Tunisian locations (El Fahs and Matmata) during two successive years. The composition of the essential oils obtained by hydrodistilation from rosemary plants were carried out annually using GC and GC/MS. Results showed the the main constituents were camphor (18.2-28.1%), 1,8-cineole (6.4-18.0%), α-pinene (9.7-13.5%), borneol (4.4-9.5%), and camphene (5.1-8.7%). The principal component and heatmapper analyses showed group segregation of the two studied varities based on major essential oil compounds. Additionally, in vitro antimicrobial and antioxidant activities showed that rosemary essential oils had an important ability in scavenging DPPH, as well as a higher bactericidal effect. The seasonal variation, growth stage and genetic pools seemed to be a factors of significant variation of the composition, antimicrobial and the antioxidant activities of the rosemary essential oils. These finding would be taken to use the chemotaxonomy tools to develop a program for Rosmary protection conservation and identification based on essential oil composition.

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.

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.

[Influence of the geographical locations on the agronomical and technological potentialities of the olive tree (Olea europaea L.) in Tunisia]. / Influence du site géographique sur les potentialités agronomiques et technologiques de l'olivier (Olea europaea L.) en Tunisie.

This study aims at characterization four cultivars of the olive trees, Chétoui, Chemlali, Gerboui, and Chaïbi, cultivated in three different geographical locations, from pomological and technological points of view. The pomological characters of the fruit are influenced by the geographical location. Each individual of the same cultivar expresses different pomological characters. We have noted a significant fluctuation of the flush percentage in three Chaïbi individuals according to their geographical site; it varies from 49.06 to 82.19%. The three Gerboui individuals showed a significant variability of the fruit weight (from 1.13 to 3.17 g). Fluctuations of olive oil contents were also observed. Several fatty acid compositions showed some variation. The oleic and linoleic acid contents varied among individuals from Chétoui and Chaïbi. Moreover, the individuals of the cultivar Chemlali showed a variation of their content in palmitic and palmitoleic acids. Indeed, each individual of a cultivar showed its own potentialities, which are reflected by its pomological and technological characters. According to their geographical location, individuals from a given cultivar displayed diverse potentialities.

Antioxidant capacities of phenolic compounds and tocopherols from Tunisian pomegranate (Punica granatum) fruits.

This article aims to determine the phenolic, tocopherol contents, and antioxidant capacities from fruits (juices, peels, and seed oils) of 6 Tunisian pomegranate ecotypes. Total anthocyanins were determined by a differential pH method. Hydrolyzable tannins were determined with potassium iodate. The tocopherol (α-tocopherol, γ-tocopherol, and δ-tocopherol) contents were, respectively, 165.77, 107.38, and 27.29 mg/100 g from dry seed. Four phenolic compounds were identified and quantified in pomegranate peel and pulp using the high-performance liquid chromatography/ultraviolet method: 2 hydroxybenzoic acids (gallic and ellagic acids) and 2 hydroxycinnamic acids (caffeic and p-coumaric acids). Juice, peel, and seed oil antioxidants were confirmed by ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) methods. The highest values were recorded in peels with 25.63 mmol trolox equivalent/100 g and 22.08 mmol TE/100 g for FRAP and ORAC assay, respectively. Results showed that the antioxidant potency of pomegranate extracts was correlated with their phenolic compound content. In particular, the highest correlation was reported in peels. High correlations were also found between peel hydroxybenzoic acids and FRAP ORAC antioxidant capacities. Identified tocopherols seem to contribute in major part to the antioxidant activity of seed oil. The results implied that bioactive compounds from the peel might be potential resources for the development of antioxidant function dietary food.