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Research background. Microalgae represent an emergent sustainable source of bioactive compounds such as antioxidants, vitamins, minerals and polyunsaturated fatty acids that can ameliorate the nutritional characteristics of foods. The biochemical composition of microalgae could be modulated by varying the culture conditions to enhance the accumulation of biomolecules of interest. The aim of this work is to optimise the nutri-functional properties of two microalgae that can be used in food production. Experimental approach. Nannochloropsis gaditana L2 and Chlorella sp. SM1 were screened for growth, biochemical composition and radical scavenging activity employing four different growth media (algal, BG-11, f/2 and Conway) with different nutrient composition. The feasibility of using Chlorella sp. SM1 cultivated in BG-11 medium, in an under-investigated Mediterranean dairy product ricotta cheese and its effect on the sensory attributes was investigated. Additionally, Arthrospira platensis was used as reference in sensory analysis. Results and conclusions. Nitrate- and phosphate-rich media (BG-11 and algal) enhanced the biomass productivity. However, the highest lipid production (23.10 and 11.86 mg/(L·day) by strains SM1 and L2 respectively) and carbohydrate content (34.79 and 44.84% by SM1 and L2 respectively) were obtained with the nitrate-deficient f/2 medium. Regardless of the used medium, the lipid profile of Chlorella sp. SM1 and N. gaditana L2 remained adequate for different applications with >50% C16-18 as the main fatty acids. Significant increase in oleic acid (C18:1) content was recorded in response to nitrogen deficiency, being the highest in SM1 in f/2 medium (34%). Nitrogen deficiency was also found to enhance phenolic compound (expressed as gallic acid equivalents, 48.8 and 35.1 mg/g in SM1 and L2 respectively) and carotenoid contents (2.2 and 2.0 mg/g in SM1 and L2 respectively). Due to its interesting antioxidant potential, Chlorella sp. SM1 was used at different mass fractions (0.2, 1 and 1.5%) to enrich the ricotta cheese. The sample with 0.2% Chlorella sp. SM1 was found to give the most appreciated product. Novelty and scientific contribution. This study presents the production of an innovative ricotta cheese using Chlorella sp. as a functional ingredient, without altering the manufacturing procedure, while maintaining acceptable sensorial characteristics. The biochemical composition of the used strains varied depending on the culture medium composition, which enabled the accumulation of phytonutrients of interest., Pozadina istraživanja. Mikroalge su sve češći održivi izvor bioaktivnih spojeva, poput antioksidansa, vitamina, minerala i polinezasićenih masnih kiselina, kojima se mogu poboljšati nutritivna svojstva hrane. Biokemijski se sastav mikroalgi može izmijeniti promjenom sastava podloge za uzgoj, s ciljem povećanja prirasta željenih biomolekula. Svrha je ovoga rada bila optimirati hranjiva i funkcionalna svojstva dviju vrsta mikroalgi koje se mogu primijeniti u proizvodnji hrane. Eksperimentalni pristup. Analizirani su rast, biokemijski sastav te sposobnost uklanjanja slobodnih radikala mikroalgi Nannochloropsis gaditana L2 i Chlorella sp. SM1 uzgojenih u četiri podloge različitog sastava (hranjiva podloga za uzgoj algi, BG-11, f-2 i hranjiva podloga Conway). Ispitana je mogućnost primjene alge Chlorella sp. SM1 uzgojene u BG-11 podlozi u proizvodnji sira tipa ricotta, mediteranskog mliječnog proizvoda koji je slabo istražen, te njezinog utjecaja na senzorska svojstva sira. Uz to, mikroalga Arthrospira platensis upotrijebljena je za izradu kontrolnog uzorka za senzorsku analizu. Rezultati i zaključci. Proizvodnja se biomase povećala u podlogama bogatim nitratima i fosfatima (BG-11 i hranjiva podloga za uzgoj algi). Međutim, najveća proizvodnja lipida (dnevno 23,10 mg/L u soju SM1 i 11,86 mg/L u soju L2) i najveći udjel ugljikohidrata (34,79 % u soju SM1 i 44, 84 % u soju L2) postignuti su uzgojem u podlozi f/2 siromašnoj nitratima. Bez obzira na sastav podloge, sastav lipida u mikroalgama Chlorella sp. SM1 i N. gaditana L2, s više od 50 % C16-18 kao glavnim masnim kiselinama, bio je prikladan za različite primjene. Nedostatak dušika doveo je do znatnog povećanja udjela oleinske kiseline (C18:1), i to najviše u soju SM1 uzgojenom u podlozi f/2 (34 %). Također su opaženi povećani udjeli fenolnih spojeva (48,8 mg/L u soju SM1 i 35,1 mg/g u soju L2, izraženo kao ekvivalent galne kiseline) i karotenoida (2,2 mg/g u soju SM1 i 2,0 mg/g u soju L2). Zbog svog zanimljivog antioksidacijskog potencijala, mikroalga Chlorella sp. SM1 primijenjena je u različitim masenim udjelima (0,2; 1 i 1,5 %) za obogaćivanje sira tipa ricotta. Proizvod s najboljiim karakteristikama dobiven je s dodatkom 0,2 % ove mikroalge. Novina i znanstveni doprinos. U radu je prikazana proizvodnja novog sira tipa ricotta s dodatkom mikroalge Chlorella sp. kao funkcionalnim sastojkom, pri čemu se nije mijenjao postupak proizvodnje, a zadržane su prihvatljive senzorske značajke sira. Biokemijski je sastav korištenih sojeva mikroalgi ovisio o sastavu hranjive podloge, pa je time bilo moguće povećati proizvodnju željenih fitonutrijenata.

Background The in vitro activity of the brown seaweed Dictyota spiralis against both Leishmania amazonensis and Trypanosoma cruzi was evaluated in a previous study. Processing by bio-guided fractionation resulted in the isolation of three active compounds, classified as diterpenes. In the present study, we performed several assays to detect clinical features associated to cell death in L. amazonensis and T. cruzi with the aim to elucidate the mechanism of action of these compounds on parasitic cells. Methods The aims of the experiments were to detect and evaluate specific events involved in apoptosis-like cell death in the kinetoplastid, including DNA condensation, accumulation of reactive oxygen species and changes in ATP concentration, cell permeability and mitochondrial membrane potential, respectively, in treated cells. Results The results demonstrated that the three isolated diterpenes could inhibit the tested parasites by inducing an apoptosis-like cell death. Conclusions These results encourage further investigation on the isolated compounds as potential drug candidates against both L. amazonensis and T. cruzi. Graphical Abstract

Background: The effects of vegetable oils on human health depend on their components. Therefore, their profiles of lipid nutrients and polyphenols were determined. Objective: To establish and compare the fatty acid, tocopherol, phytosterol and polyphenol profiles of Mediterranean oils: cosmetic and dietary argan oils (AO; Morocco: Agadir, Berkane); olive oils (OO; Morocco, Spain, Tunisia); milk thistle seed oils (MTSO; Tunisia: Bizerte, Sousse, Zaghouane); nigella seed oil (NSO). Methods: The biochemical profiles were determined by gas chromatography-flame ionization, high performance liquid chromatography and gas chromatography, coupled with mass spectrometry as required. The antioxidant and cytoprotective activities were evaluated with the KRL (Kit Radicaux Libres) and the fluorescein diacetate tests on nerve cells treated with 7-ketocholesterol (7KC). Results: The fatty acid profile revealed high linoleic acid (C18:2 n-6) content in AO, OO, MTSO and NSO. The highest levels of oleic acid (C18:1 n-9) were found in AO and OO. The tocopherol profile showed that Agadir AO contained the highest amount of α-tocopherol, also present at high level in MTSO and Tunisian OO; Berkane AO was rich in γ-tocopherol. The phytosterol profile indicated that β-sitosterol was predominant in the oils, except AO; spinasterol was only present in AO. Polyphenol profiles underlined that OO was the richest in polyphenols; hydroxytyrosol was only found in OO; few polyphenols were detected in AO. The oils studied have antioxidant activities, and all of them, except NSO, prevented 7KC-induced cell death. The antioxidant characteristics of AO were positively correlated with procatechic acid and compestanol levels. Conclusion: Based on their biochemical profiles, antioxidant and cytoprotective characteristics, AO, OO, and MTSO are potentially beneficial to human health.

Argan, olive, and milk thistle seed oils are characterized by high levels of tocopherols, mainly α-tocopherol. They are also rich in oleic acid (C18:1 n-9) and linoleic acid (C18:2 n-6) and contain small quantities of several polyphenols. As tocopherols and polyphenols have antioxidant properties and are able to cross the blood-brain barrier, it is suggested that argan, olive, and milk thistle seed oils could be useful in the prevention of neurodegenerative disorders since these are characterized by an enhancement of oxidative stress leading to neurodegeneration. This hypothesis is supported by the antioxidant properties of these oils determined by different assays KRL (Kit Radicaux Libres), FRAP (ferric-reducing antioxidant power), and DPPH [2,2-diphenyl-1-picryl-hydrazyl)] and by cytoprotective properties of these oils which are able to prevent major side effects associated with oxysterols-induced neurodegeneration such as oxidative stress, mitochondrial dysfunction, and cell death of nerve cells.

In the last decades, the consumption of whole wheat has increased because consumers’ awareness has increased toward healthy food. However, breeders’ focus was always attributed to the major components of wheat, but less attention was paid to micronutrients. The aim of this study was to provide new insights on the influence of breeding on total polyphenol content (TPC), phenolic profile, and total antioxidant capacity (TAC) using a set of Tunisian durum wheat landraces, old and modern varieties. Ultra-liquid chromatography multi-stage mass spectrometry (UHPLC–MSn) allowed the identification of eight phenolic acids, which were found in the bound form, while only p-coumaric acid was found in the free form. A significant genotype effect on the TPC (bound, free and total), TAC, and phenolic acid profile was observed. Regarding breeding effect, TPC concentrations were in the order modern > landraces > old. Principal component analysis (PCA) confirmed that the phenolic profile of the studied varieties was mainly conditioned by their genotypic characteristics, and no trend was observed as a function of breeding history. Likewise, clustering analysis highlighted an important genetic diversity, suggesting that the modern variety ‘‘Om Rabia’’ possesses the most interesting phenolic profile. These findings might be useful to breed genetically different and phenolic-rich new varieties.

The aim of this work is to study the extraction of the essential oil as a process that appeared to obtain the bioactive substances among the several extraction processes. A great number of extraction processes are available. In this study, the recent processes were compared with the conventional ones. Also, the economic evaluation of the extraction process plant including energy cost, manual labor, raw materials, and fixed costs were studied. We assessed the costs involved in the extraction process of the bioactive compounds. Carbon dioxide is the most desirable solvent for Supercritical Fluid Extraction (SFE). Its attraction for the extraction of the heat-sensitive compounds is due to its critical temperature (304 °K). Solvent extraction and steam distillation process (SE‒SD) may overcome many disadvantages that conventional solvent extraction and hydrodistillation bring about in the extraction of essential oil. This combination technology has been used in the extraction of essential oil from plant material for high quality, simple technology, and low cost. The microwave assisted hydro-distillation (MAHD) is less tedious and minimizes the risk of the compound degradation at high temperatures. The MAHD presents distinct advantages for the fast and reproducible production process. The study of the ultrasound-enhanced subcritical water extraction process (USWE) showed many advantages such as: time-saving, environment-friendliness, and high efficiency.

The main concern of this work was to find a new biological antisprouting product for potatoes during storage. Ruta chalepensis L. essential oil (RCEO) was for the first time used as a potential sprouting inhibitor for potatoes. To confirm RCEO antisprouting effect, evolution of sprout length and weight loss of potato tubers was determined during a storage period of six weeks under three RCEO different treatments (2%, 4%, and 6%). Sprout final weight was also computed. Then, a screening of RCEO chemical composition was performed. An outstanding antisprouting effect of 6% emulsions concentrations was observed as compared to 2% and 4% emulsions concentrations. Final sprout weight (SW) of untreated samples was 4.66%, while 6% treated samples scored 0.98%. These results were endorsed by high Pearson correlation coefficients (>0.9). Indeed, increasing treatment concentration enhanced the sprout growth inhibition. Identification of RCEO major components showed that 2-undecanone represented 87.18% of total identified components suggesting that this component is the possible active agent of RCEO against potatoes sprouting.

Free-living amoebae of genus Acanthamoeba are opportunistic pathogens widely distributed in the environment, and are the causative agents of several humans’ infections, such as Acanthamoeba keratitis, Granulomatous Amoebic Encephalitis and also disseminated infections. The existence of the cyst stage complicates Acanthamoeba therapy as it is highly resistant to antibiotics and physical agents. All these facts reinforced the necessity to find and develop an effective therapy against Acanthamoeba infections. In the present study, we are interested to several seaweeds species collected from the Tunisian coasts and belonging to the 3 phyla (brown, green and red algae). The aim was to quantify the Total Phenolic Compounds in different organic extract, to evaluate antioxidant capacity (DPPH and ABTS) and to study the antiprotozoal activity against A. castellanii Neff. The parasites have been inhibited by all extracts with an IC50 ranged from 52,3±1.8 μg/mL for ethyl acetate extract, to 134,6±0.7 μg/mL for the hexanic one for the various species studied.

Because of the continuous increase in the prevalence of gluten-related disorders, selection of wheat with a low content of immunogenic gluten epitopes could be an innovative alternative for prevention. In this review, the focus is on literature data concerning the deallergenization tools of wheat, which are mainly related to breeding approaches (classic and advanced) and processing operations (germination and fermentation). Until now, no safe wheat genotype has been identified, whereas decreasing wheat allergenicity is possible. On the other hand, the decrease of gluten or some of its epitopes can strongly affect technological properties. Thus, obtaining celiac-safe gluten without affecting the technological properties of wheat could be considered as a new challenge that scientists will be facing. Celiac-safe wheat-based product development could be a great revolution in the market of foods for special medical purposes. The present paper is aiming to: (a) review the strategies and the approaches used, or that can be used, for developing low allergenic wheat: their utilities and limits were also discussed and (b) screen the impact of gluten reduction or removal on the quality of wheat end-use products.

The aim of this study was to compare immunogenic and toxic gluten peptides related to celiac disease (CD). 100 accessions of genotypes selected during the 20th century in Tunisia were in vitro digested and then analyzed by UPLC/ESI-MS technique using an isotopically labeled internal standard. The first MANOVA confirmed a high variability in the content of immunogenic and toxic peptides reflecting high genetic diversity in the germplasm released during the past century in Tunisia, consistently with PCA and clustering analysis results. Our finding showed also important variability in CD epitopes due to growing season's climate scenarios. Moreover, the second MANOVA revealed significant differences between abandoned and modern cultivars' CD-related peptide amounts. Although we could not conclude that there was an augment of allergens in newly selected durum wheat lines compared to abandoned ones, we demonstrated that modern genotype peptides were less sensitive to climate variation, which is a useful indicator for wheat breeders.

Plants are a source of bioactive compounds such as antioxidants and enzyme inhibitors. In this work, effect of the Eucalyptus globulus and Mentha viridis extraction by different solvents on phenolics content, flavonoids content, condensed tannins content, antioxidant activity and inhibitory effect against two lipases from Aspergillus niger and olive was studied. Methanolic (MeOH) extract showed the strongest antioxidant and anti-lipase activities. High correlation between total phenolics content, total flavonoids content, antioxidant activity and lipases inhibitory action was observed. Kinetic analysis of lipases inhibition was performed with Linweaver-Burk, Dixon and Cornish-Bowden plots. These results revealed competitive inhibition mode by E. globulus and non competitive mixed inhibition mode by M. viridis against the two lipases. Inhibition constant (KI) values calculated with E. globulus MeOH extract were 0.271 and 0.188 mg/mL for Aspergillus niger and olive lipases respectively. With M. viridis MeOH extract KI values were 0.303 and 0.421 mg/mL for the fungal and the plant lipases respectively. The inhibitory concentration 50% (IC50) values determined with E. globulus MeOH extract were 0.69 mg/mL for Aspergillus niger lipase and 1.29 mg/mL for olive lipase. With M. viridis MeOH extract IC50 were 0.43 and 1.44 mg/mL for Aspergillus niger and olive lipases respectively.

The olive tree historically provided economic benefits to the countries in Mediterranean basin as a source of products contributing to health promotion. Some of the health benefits attributed to olive tree leaves are related to phenolic composition. In this study, a 10-point augmented simplex-centroid design was used to formulate a three-component mixture system using water, ethanol, and methanol, adequate for the extraction of phenolics from olive leaves. Phenolic and flavonoid content, antioxidant activity with 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), oleuropein, and luteolin7-O-glucoside concentrations were selected as responses. The optimal extraction mixture was: 12.7% water, 14.8% ethanol, and 72.5% methanol. The yields of total phenolic and flavonoid compounds, oleuropein, and luteolin-7-O-glucoside were 163.69 ± 6.35 mg gallic acid g−1, 114.69 ± 3.56 mg rutin g−1, 858.29 µg g−1, and 21.04 µg g−1 dry weight of olive leaves. The antioxidant capacity was 238.71 ± 4.35 mM equiva...

The present work had a dual objective: to assess if the evolution of durum wheat from landraces to modern genotypes as function of breeding programs impacted proteins and starch fractions, as well as starch properties. Flours and starches isolated from Tunisian durum wheat landraces, old and modern lines were thoroughly characterized for their compositional, morphological, and gel properties. Statistical results showed significant (p ≤ 0.05) differences among the studied set. Protein and starch fractions assessment revealed that modern genotypes had the highest total starch and albumin contents, old genotypes had the highest amylose and glutenin contents, and landraces had the highest protein and gliadin contents. Starch properties screening allowed several findings: no significant (p > 0.05) differences were found among starch granules morphology, significant (p ≤ 0.05) differences were recorded in terms of technological properties, and old genotypes had the highest starch gel hardness. Overall, these results indicated that the influence of genotype on flour and starch properties was more relevant than breeding history.

Leishmaniasis represents a serious threat to the health as one of the most important neglected tropical diseases as designated by the World Health Organization. The disease is endemic in 82 countries, among them Tunisia is an indigenous area for cutaneous Leishmaniasis. In a previous work, two tritepenic acids namely oleanolic and maslinic acids have been isolated from olive leaf extract. In the present paper, the in vitro activity against amastigotes stage of Leishmania (L.) infantum and Leishmania (L.) amazonensis was investigated. Maslinic acid showed the highest activity, against L. amazonensis, with an IC50 of 1.417 ± 0.401 µg/mL and a selectivity index of 9.405. Although, the oleanolic acid exhibit a better activity against L. infantum with an IC50 of 0.999 ± 0.089 µg/mL and selectivity index of 8.111.

Baker's asthma is a serious airway disease triggered by wheat protein CM3 α-amylase/trypsin inhibitor. The purpose of the present study was to investigate the impact of genotype and crop year on allergen CM3 α-amylase/trypsin inhibitor associated with baker's asthma. A historical series of Tunisian durum wheat (100 accessions), derived from three crop years, was used to compare the amount of CM3 from landraces to advanced cultivars. CM3 protein quantification was assessed after an enzymatic cleavage of the soluble protein extracts on a UPLC/ESI-MS system, using a marker peptide for its quantification. Combined data analysis of variance revealed an important effect of genotype, crop year, and their interaction. The CM3 allergenic proteins were found to significantly vary among studied genotypes, as confirmed by genetic variability, coefficient of variance, heritability, and genetic advance.

Because of the continuous increase in the prevalence of gluten-related disorders, selection of wheat with a low content of immunogenic gluten epitopes could be an innovative alternative for prevention. In this review, the focus is on literature data concerning the deallergenization tools of wheat, which are mainly related to breeding approaches (classic and advanced) and processing operations (germination and fermentation). Until now, no safe wheat genotype has been identified, whereas decreasing wheat allergenicity is possible. On the other hand, the decrease of gluten or some of its epitopes can strongly affect technological properties. Thus, obtaining celiac-safe gluten without affecting the technological properties of wheat could be considered as a new challenge that scientists will be facing. Celiac-safe wheat-based product development could be a great revolution in the market of foods for special medical purposes. The present paper is aiming to: (a) review the strategies and the approaches used, or that can be used, for developing low allergenic wheat: their utilities and limits were also discussed and (b) screen the impact of gluten reduction or removal on the quality of wheat end-use products.

International audience; Increased levels of 7-ketocholesterol (7KC), which results mainly from cholesterol auto-oxidation, are often found in the plasma and/or cerebrospinal fluid of patients with neurodegenerative diseases and might contribute to activation of microglial cells involved in neurodegeneration. As major cellular dysfunctions are induced by 7KC, it is important to identify molecules able to impair its side effects. Since consumption of olive and argan oils, and fish is important in the Mediterranean diet, the aim of the study was to determine the ability of oleic acid (OA), a major compound of olive and argan oil, and docosahexaenoic acid (DHA) present in fatty fishes, such as sardines, to attenuate 7KC-induced cytotoxic effects. Since elaidic acid (EA), the trans isomer of OA, can be found in hydrogenated cooking oils and fried foods, its effects on 7KC-induced cytotoxicity were also determined. In murine microglial BV-2 cells, 7KC induces cell growth inhibition, mitochondrial dysfunctions, reactive oxygen species overproduction and lipid peroxidation, increased plasma membrane permeability and fluidity, nuclei condensation and/or fragmentation and caspase-3 activation, which are apoptotic characteristics, and an increased LC3-II/LC3-I ratio, which is a criterion of autophagy. 7KC is therefore a potent inducer of oxiapoptophagy (OXIdation + APOPTOsis + autoPHAGY) on BV-2 cells. OA and EA, but not DHA, also favor the accumulation of lipid droplets revealed with Masson's trichrome, Oil Red O, and Nile Red staining. The cytotoxicity of 7KC was strongly attenuated by OA and DHA. Protective effects were also observed with EA. However, 7KC-induced caspase-3 activation was less attenuated with EA. Different effects of OA and EA on autophagy were also observed. In addition, EA (but not OA) increased plasma membrane fluidity, and only OA (but not EA) was able to prevent the 7KC-induced increase in plasma membrane fluidity. Thus, in BV-2 microglial cells, the principal fatty acids of the Mediterranean diet (OA, DHA) were able to attenuate the major toxic effects of 7KC, thus reinforcing the interest of natural compounds present in the Mediterranean diet to prevent the development of neurodegenerative diseases.

The aim of this work is to study the use of Ruta chalepensis essential oil as a bioactive substance in order to propose ways of valuation and rational exploitation of the plant. In this context, the extraction of essential oil was carried out using hydrodistillation process. 23 compounds were identified in the aerial part of Ruta chalepensis essential oil. The major compound is undecan-2-one (77.7 %). In addition, the phytotoxic activity of Ruta chalepensis essential oil was investigated. An important toxicity on the germination of the hard wheat was observed. Indeed, the rate of hard wheat germination passes from 65.55 % at 0.5 μ1.ml−1 essential oil concentration to 31.11% at 1 μ1.ml−1.

To evaluate the effects of hydrodistillation parameters and the vegetative cycle of the plant (Ruta chalepensis L.) on the global essential oil yield the response surface methodology was used. The parameters tested are the volume of water in the suspension to be distilled and the time of distillation. The third parameter is the vegetative cycle of the plant. The responses were the global extraction yield and the extraction yield of following essential oil compounds: 2-undecanone, 2-decanone, 2-dodecanone and 2-tridecanone. The optimal conditions selected for the total output of the extraction obtained from the analysis of the response surfaces are: time of distillation: 120 minutes; volume of water in the suspension to be distilled: 500 ml; stage of vegetation: January (young growths). The results show that the time of distillation and the stage of vegetation are the parameters more meaning on the global essential oil yield.

The extraction of essential oil was carried out using two processes: hydrodistillation and supercritical CO2 extraction. The chemical composition of extracted essential oil was determined. The yield of extraction by supercritical CO2 was about 7.8 %. This yield is more important than that obtained by hydrodistillation process (5.51 %). The chemical composition of the supercritical CO2 extract indicates the presence of only two compounds. The major one is undecan-2-one (100 %). The second one is limonene which is present as trace. However, 23 compounds were identified in the essential oil of the aerial part of Ruta chalepensis extracted by hydrodistillation process. The major compound is also undecan-2-one (77.7 %).

In this study, milk thistle seeds growing in different areas in Tunisia were cold pressed and the extracted oils were examined for their chemical and antioxidant properties. The major fatty acids were linoleic acid (C18:2) (57.0%, 60.0%, and 60.3% for the milk thistle seed oils native to Bizerte, Zaghouan and Sousse, respectively) and oleic acid (C18:1) (15.5%, 21.5%, and 22.4% for the milk thistle seed oils originating from Bizerte, Zaghouan and Sousse, respectively). High performance liquid chromatography (HPLC) analysis showed the richness of the milk thistle seed oils (MTSO) in α-tocopherol. The highest content was recorded for that of the region of Zaghouan (286.22 mg/kg). The total phenolic contents (TPC) of Zaghouan, Bizerte, and Sousse were 1.59, 8.12, and 4.73 Gallic Acid Equivalent (GAE) mg/g, respectively. Three phenolic acids were also identified (vanillic, p-coumaric, and silybine), with a predominance of the vanillic acid. The highest value was recorded for the Zaghouan milk thistle seed oil (83 mg/100 g). Differences in outcomes between regions may be due to climatic differences in areas. Zaghouan’s cold-pressed milk thistle seed oil had a better quality than those of Bizerte and Sousse, and can be considered as a valuable source for new multi-purpose products or by-products for industrial, cosmetic, and pharmaceutical utilization.

The aim of this work was to select strains with proteolytic activity on wheat gliadin, among lactic acid bacteria, previously isolated from Tunisian fermented wheat dough. Hydrolysis of gliadin, as sole nitrogen source, in an agar medium was visualized by a clear zone surrounding colonies. The increase in absorbance due to gliadin breakdown was measured spectrophotometrically using O-phthaldialdehyde (OPA) on Gliadin Glucose Broth medium. Fermented liquid dough inoculated with individual selected Enterococcus faecalis, showed a decrease of the gliadin concentration from 45 g/kg to 18 g/kg determined by sandwich ELISA test (R-7001). Only the enterococci strains show an hydrolysis of gliadin proteins. Strains showing proteolytic activity are gaining more and more importance in cereal based fermented foods and may help to reduce gliadin involved in coeliac disease.

6cfu/g of mesophilic aerobic bacteria (MAB). Lactic acid bacteria (LAB) and yeasts dominated the microflora of these samples. They varied from 10 5 to 10 8 cfu/g. The LAB/yeasts ratio arising from microbial counts were varied between 1/1 and 200/1. More than 50% of the analysed samples were deprived of Enterococcus. The content of contaminating microflora like coliforms and mesophilic Bacillus ranged from 10 2 to 10 4 cfu/g. The ratio

Therapy against Acanthamoeba infections such as Granulomatous Amoebic Encephalitis (GAE) and Acanthamoeba Keratitis (AK), remains as an issue to be solved due to the existence of a cyst stage which is highly resistant to most chemical and physical agents. Recently, the activity of Olive Leaf Extracts (OLE) was demonstrated against Acanthamoeba species. However, the molecules involved in this activity were not identified and/or evaluated. Therefore, the aim of this study was to evaluate the activity of the main molecules which are present in OLE and secondly to study their mechanism of action in Acanthamoeba. Among the tested molecules, the observed activities ranged from an IC50 of 6.59 in the case of apigenine to an IC50 > 100 μg/ml for other molecules. After that, elucidation of the mechanism of action of these molecules was evaluated by the detection of changes in the phosphatidylserine (PS) exposure, the permeability of the plasma membrane, the mitochondrial membrane potential and the ATP levels in the treated cells. Vanillic, syringic and ursolic acids induced the higher permeabilization of the plasma membrane. Nevertheless, the mitochondrial membrane was altered by all tested molecules which were also able to decrease the ATP levels to less than 50% in IC90 treated cells after 24 h. Therefore, all the molecules tested in this study could be considered as a future therapeutic alternative against Acanthamoeba spp. Further studies are needed in order to establish the true potential of these molecules against these emerging opportunistic pathogenic protozoa.

Background Thymus algeriensis Boiss. et Reut. (Lamiaceae), popularly known as “mougecha” or “mazoukcha” is prolific in Mediterranean regions, mostly in North Africa, and is used in folk medicine to treat of stomach diseases. Methods In this study, animals were induced with gastric ulcers using HCl/ethanol (0.3 M HCl/60% ethanol) and treated orally with essential oil of Thymus algeriensis (EOTa) in various doses ranging from 54 mg/kg body weight to 180 mg/kg body weight. Result The dose found to be effective was 180 mg/kg body weight, since this dose brought about a maximum reduction in lesion index in female rats. In gastric tissues, levels of total glutathiones (GSH, GST and GPx) and thiobarbituric acid reactive substances (TBARS) were evaluated. The activities of the antioxidant enzymes, catalase (CAT) and superoxide dismutase (SOD) were measured. Histopathological changes were observed using a cross section of gastric tissue. Chemical analysis revealed the presence of 13 components accounting for 77.7% of the essential oil from dried leaves. Oral administration of EOTa (54, 117 and 180 ml/kg) inhibited HCl/ethanol-induced ulcers. Lesion index was significantly reduced in ulcer induced animals treated with EOTa (HCl/ethanol + EOTa) compared to those ulcerated with HCl/ethanol but with no treatment given. Females showed a greater resistance to ulcers and gastric lesions occurred less often than in males. GSH, pH, enzymic antioxidants, and adherent mucus content were all significantly increased. Conclusion From the data presented in this study, it can be concluded that male rats are more sensitive to gastric ulcers induced by HCl/ethanol than females.

Protozoan diseases, such as leishmaniasis, are a cause of considerable morbidity throughout the world, affecting millions every year. In this study, two triterpenic acids (maslinic and oleanolic acids) were isolated from Tunisian olive leaf extracts and their in vitro activity against the promastigotes stage of Leishmania ( L .) infantum and Leishmania ( L .) amazonensis was investigated. Maslinic acid showed the highest activity with an IC 50 of 9.32 ± 1.654 and 12.460 ± 1.25 μg/ml against L. infantum and L. amazonensis , respectively. The mechanism of action of these drugs was investigated by detecting changes in the phosphatidylserine (PS) exposure, the plasma membrane permeability, the mitochondrial membrane potential and the ATP level production in the treated parasites. By using the fluorescent probe SYTOX® Green, both triterpenic acids showed that they produce a time-dependent plasma membrane permeabilization in the treated Leishmania species. In addition, spectrofluorimeteric data revealed the surface exposure of PS in promastigotes. Both molecules reduced the mitochondrial membrane potential and decreased the ATP levels to 15% in parasites treated with IC 90 for 24 h. We conclude that the triterpenic acids tested in this study, show potential as future therapeutic alternative against leishmaniasis. Further studies are needed to confirm this.

The essential oils of the dried aerial parts of Ruta chalepensis collected from the north of Tunisia were recovered by hydro-distillation with approximately 5.51% yield on a dry weight basis. The effects of drying and hydro-distillation duration on the chemical composition of the essential oils were studied. The obtained essential oils of the different parts of the herb were analyzed by GC–MS and 13 major compounds were identified. The main ones are 2-undecanone (77.18%), 2-decanone (8.96%) and 2-dodecanone (2.37%). 2-Undecanone was shown to be the unique component (100%) of the essential oil obtained from R. chalepensis flowers. Pulegone was identified only in the essential oil of the stems (about 32.11%) and camphor was identified exclusively in the essential oil of leaves (2.46%). The identification of the components of R. chalepensis essential oil should contribute to the understanding of the pharmacological activities of the herb.

The chemical composition, antioxidant and antimicrobial activities, and the preservative effect ofThymus capitataessential oil againstListeria monocytogenesinoculated in minced beef meat were evaluated. The essential oil extracted was chemically analyzed by gas chromatography-mass spectrometry. Nineteen components were identified, of which carvacrol represented (88.89%) of the oil. The antioxidant activity was assessedin vitroby using both the DPPH and the ABTS assays. The findings showed that the essential oil exhibited high antioxidant activity, which was comparable to the reference standards (BHT and ascorbic acid) with IC50values of 44.16 and 0.463μg/mL determined by the free-radical scavenging DPPH and ABTS assays, respectively. Furthermore, the essential oil was evaluated for its antimicrobial activity using disc agar diffusion and microdilution methods. The results demonstrated that the zone of inhibition varied from moderate to strong (15–80 mm) and the minimum inhibition concentration values ranged from 0.32 to 20 mg/mL. In addition, essential oil evaluatedin vivoagainstListeria monocytogenesshowed clear and strong inhibitory effect. The application of 0.25 or 1% (v/w) essential oil ofT. capitatato minced beef significantly reduced theL. monocytogenespopulation when compared to those of control samples (P-value <0.01).

The catalytic activity of thermolysin during the hydrolysis of n -(3-[2-furyl]acryloyl)-Gly-Leu amide is noticeably enhanced in the presence of sugars and polyols. A series of polyhydroxylic additives were tested and the degree of activation was found to depend on both the concentration and nature of the additive. Sucrose and trehalose were found to yield the higher activation effect whereas glycerol was found to yield an inhibition of thermolysin in a large domain of concentration. A mechanism of activation based on the lowering of the energy barrier for the enzymatic reaction is proposed. This free energy barrier lowering is very likely due to water structure modification by the additives.

Leishmaniasis is one of the neglected tropical diseases in terms of drug discovery and development. Furthermore, the chemotherapy used to treat this disease has been proved to be highly toxic and to present resistance issues. As consequent, the need for novel leishmanicidal molecules has notably increased in the recent years. In the present work an attempt was made to evaluate the antioxidant and leishmanicidal activities besides presence of compounds in leaf extracts of 5 different Tunisian olive tree varieties, used as traditional medicine in this country. The concentration of extracts needed to inhibit 50% of the parasitic growth (IC50) was estimated using different Leishmania strains. All tested extracts showed an inhibitory effect on the parasite growth with IC50 ranging from 2.130±0.023 to 71.570±4.324μg/ml, respectively for the methanolic extracts of Limouni and Zarrazi against Leishmania donovani. In fact, this activity was significantly affected by the olive cultivar and the tested Leishmania strain. Furthermore, the activities against both Leishmania tropica and major species were correlated to the total phenolic compounds. These results could suggest that olive leaf extract could carry potential new compounds for the development of novel drugs against Leishmaniasis.

The olive tree (Olea europaea, Oleaceae) has historically provided huge economic and nutritional benefits to the Mediterranean basin. In fact, olive leaf extracts have also been used by native people of this area in folk medicine to treat fever and other diseases such as malaria. Recently, several studies have focused on the extraction of high-added-value compounds from olive leaves. However, no previous studies have been developed in order to evaluate the activity of these extracts against Acanthamoeba. In the present work, olive leaf extracts from five different Tunisian varieties of olive trees (Chemlali Tataouine, Zarrazi, Toffehi, Dhokkar, and Limouni) were obtained by using three different solvents, and their activity against the trophozoite stage of Acanthamoeba castellanii Neff was screened. The IC50/96 h (50 % parasite growth inhibition) was chosen as the appropriate and comparable data to give as previously described. It could be observed that the amoebicidal activity was dose dependent. Trophozoite growth was inhibited by all the tested extracts with IC50 ranging from 8.234 ± 1.703 μg/ml for the alcoholic mixture of the Dhokkar extract to 33.661 ± 1.398 μg/ml for the methanolic extract of the Toffehi variety. The activity in fact was affected especially by the tested variety and not by the solvent extraction, the Dhokkar variety being the most active one as mentioned above.

International audience; The UV-spectra of pure caffeine were measured and two quite differentiated hyper- or hypo-chromic effects were observed as concentration was increased. The first one was explained as due to caffeine-water molecule interaction and the second as originating from dimer formation and staking of caffeine molecules. The effects of sucrose and beta-cyclodextrin on the hydration and the self-association of caffeine were also examined by UV spectroscopy. Sucrose was found to enhance the self-association of caffeine molecules by attracting and structuring water molecules around itself. The caffeine-caffeine hydrophobic interactions were promoted in such hydrophilic environment and so was the stacking. The molecular aggregation leads to reducing the electronic mobility and so is the case for the mesomeric effect in the heterogeneous cycle. This could explain the hypo-chromic phenomenon observed when sucrose concentration was increased. beta-Cyclodextrin shows a distinct behaviour because of its ability to form inclusion complexes with various hydrophobic guest molecules. This ability enhances the solubility of caffeine molecules throughout the inclusion interactions and prevents the caffeine self-association.

International audience; The effects of KCl, NaCl and cysteine on the solubility in water of partially hydrolyzed gluten were studied at different pH values. As expected, solubility was shown to depend on solution pH. It decreased to reach a minimal value at the isoelectric pH (pH 6) and then it increased. In the presence of additives, the same behaviour was observed with an increase in solubilities values. In fact, an improvement of solubility of 28–30% was observed in the case of KCl and cysteine, while NaCl was much less efficient. The solubilisation effect of such additives was found to decrease with the initial concentration of wheat gluten. The structural investigation, by analysis of the amide I region of the infrared spectra of gluten samples, solubilised in the presence of additives, showed an increase in the proportion of β-turns and extended structures, accompanied by a decrease in the α-helix proportion. Such results confirm and explain the improvement of wheat gluten solubility by enhancing water–protein bonding and reducing protein–protein interactions. Structural changes result in a better accessibility of more water molecules to the protein and in greater hydration and solubilisation effects.