Antioxidant polysaccharide-enriched fractions obtained from olive leaves by ultrasound-assisted extraction with α-amylase inhibition, and antiproliferative activities.

Polysaccharide-rich materials were extracted from the alcohol-insoluble solids of Olea europaea l. **leaves. Structural characteristics were determined by colorimetric techniques, FT-IR, GC-MS, SEC/MALS/VD/DRI, and NMR (1H,13C). The extract and its main macromolecular components were characterized to assess their ability toward antioxidant, α-amylase inhibition, and antiproliferative activities. Results revealed that the ultrasound olive leave extract comprises polysaccharides with uronic acid, galactose, arabinose, and glucose in molar percentages of 11.7%, 11.3%, 7.5%, and 4.9% respectively, constituting 41% of the total mass. In addition, polyphenols (21%) and proteins (9%) are associated with these polysaccharides. Further, the extract showed noticeable ORAC and free radical scavenging abilities, in addition to high in vitro antiproliferative activity against Caco-2 colon carcinoma cell lines. Similarly, the extract exhibited a strong, uncompetitive inhibition of α-amylase by 75% in the presence of the extract with 0.75 µg/mL of concentration. This research concludes that ultrasound extraction method can be used for the extraction of polysaccharide-polyphenol-protein complexes. These conjugates exhibit the potential for combined biological activities resulting from a synergistic effect of its compounds, making them promising ingredients for the development of functional food.

A Bioinformatic Study on the Potential Anti-Vitiligo Activity of a Carpobrotus edulis Compound.

The plant Carpobrotus edulis has traditionally been known for its wide applications in diseases, especially vitiligo, which is characterized by patches and white macules caused by the loss of melanocytes. One of the chemical treatments for vitiligo consists mainly of skin repigmentation and usually leads to a non-durable effect by inhibiting the Janus kinase (JAK) signal transduction (STAT pathway). JAK inhibitors generally block multiple JAK tyrosine kinases, which leads to secondary effects. In this study, natural molecules from Carpobrotus edulis were extracted and tested using a structure-based drug-design approach and pharmacophore modeling. The best-fit candidate from the extracted molecules was compared to the chemical molecules used. The results indicated a similarity between the chemical and natural ligands which suggested the potential use of the natural product against vitiligo. The main finding of this research work was the discovery of a new molecule extracted from a natural plant and the detection of its anti-vitiligo activity using an in-silico approach. This method can significantly reduce the cost of searching for potential medicinal molecules.

Use of Insect-Derived Chitosan for the Removal of Methylene Blue Dye from Wastewater: Process Optimization Using a Central Composite Design.

Insects are a readily available source of chitosan due to their high reproductive rates, ease of breeding, and resistance to changes in their ecosystem. This study aimed to extract chitosan from several widespread insects: Blaps lethifera (CS-BL), Pimelia fernandezlopezi (CS-PF), and Musca domestica (CS-MD). The study was also extended to using the obtained chitosans in removing methylene blue dye (MB) from wastewater. The source of the chitosan, the initial concentration of MB dye, and the reaction time were chosen as the working parameters. The experiments were designed using a central composite design (CCD) based on the dye removal efficiency as the response variable. The experimental work and statistical calculation of the CCD showed that the dye removal efficiency ranged from 35.9% to 88.7% for CS-BL, from 18.8% to 47.1% for CS-PF, and from 10.3% to 29.0% for CS-MD at an initial MB concentration of 12.79 mg/L. The highest methylene blue dye removal efficiency was 88.7% for CS-BL at a reaction time of 120 min. This indicates that the extraction of chitosan from insects (Blaps lethifera) and its application in dye removal is a promising, environmentally friendly, economical, biodegradable, and cost-effective process. Furthermore, the CCD is a statistical experimental design technique that can be used to optimize process variables for removing other organic pollutants using chitosan.

Design and use of chimeric peptides in a new non-destructive ecological process applied to the extraction of all trans/9-cis ß-carotene isomers from Dunaliella salina.

Recently, ß-carotene has gained tremendous importance as a bioactive molecule due to the growing awareness of the harmful effects of synthetic products. ß-carotene is a high-value natural pigment that has the highest demand in the global carotenoid market owing to its proven antioxidant properties relevant for several diseases. To date, Dunaliella salina is the most important producer of natural ß-carotene and is the subject of important industrial efforts. However, the extraction of ß-carotene remains challenging since all the proposed techniques present a risk of product contamination or loss of quality due to solvent residuals and low yields. The purpose of this study was to set up a green, ecological, and innovative process of extraction of the two major ß-carotene isomers from the halophilic microalgae Dunaliella salina. Based on molecular modeling, docking, and drug design, we conceived and synthesized two chimeric peptides (PP2, PP3) targeting specifically the two major isomers: all-trans or 9-cis ß-carotene. The experimental protocol used in this study demonstrated the ability and the efficacy of those two peptides to cross the cell membrane and bind with high affinity to ß-carotene isomers and exclude them toward the extracellular medium while preserving the integrity of living cells. Interestingly, the tested peptides (PP2, PP3) exhibit significant ß-carotene extraction yields 58% and 34%, respectively, from the total of the ß-carotene in microalgae cells. In addition to its simplicity, this process is fast, independent of the source of the ß-carotene, and selective. These results would allow us to set up a green, ecological, and very profitable process of extraction from microalgae containing high amounts of ß-carotene. Our innovative approach is highly promising for the extraction of Dunaliella salina biomass on an industrial scale.

Potential Use of Probiotic Consortium Isolated from Kefir for Textile Azo Dye Decolorization.

Azo dyes are recalcitrant pollutants, which are toxic, carcinogenic, mutagenic and teratogenic, that constitute a significant burden to the environment. The decolorization and the mineralization efficiency of Remazol Brillant Orange 3R (RBO 3R) was studied using a probiotic consortium (Lactobacillus acidophilus and Lactobacillus plantarum). Biodegradation of RBO 3R (750 ppm) was investigated under shaking condition in Mineral Salt Medium (MSM) solution at pH 11.5 and temperature 25°C. The bio-decolorization process was further confirmed by FTIR and UV-Vis analysis. Under optimal conditions, the bacterial consortium was able to decolorize the dye completely (>99%) within 12 h. The color removal was 99.37% at 750 ppm. Muliplex PCR technique was used to detect the Lactobacillus genes. Using phytotoxicity, cytotoxicity, mutagenicity and biototoxicity endpoints, toxicological studies of RBO 3R before and after biodegradation were examined. A toxicity assay signaled that biodegradation led to detoxification of RBO 3R dye.

Evaluation of Antioxidant, Anticholinesterase, and Antidiabetic Potential of Dry Leaves and Stems in Tamarix aphylla Growing Wild in Tunisia.

Tamarix aphylla (L.) Karst. has a wide geographic distribution and was employed in traditional medicine as astringent, anti-rheumatic and to treat fever. T. aphylla leaves and stems extracts were studied from both chemical and biological points of view to assess the antidiabetic, anticholinesterase and antioxidant potential of this species. The HPLC/Diode Array Detector (DAD) analysis showed the presence of 14 phenolic compounds (gallic, caffeic, p-coumaric, ferulic and ellagic acids, kaempferol, quercetin, quercetin 3-O-galactoside and six flavonol derivatives). This is the first study reporting a comparative study of the biological activities of different extracts from T. aphylla. High activities were obtained against DPPH radical, superoxide anion radical (O2∙-) and nitric oxide radical (• NO) in a concentration-dependent manner, the most active extracts being the polar ones. T. aphylla also showed moderate protective effects against acetylcholinesterase, but no effects were observed against butyrylcholinesterase. Against α-glucosidase the MeOH extracts displayed IC50 values from 8.41 to 24.81 µg/ml.

Assessment of the individual and mixture toxicity of cadmium, copper and oxytetracycline, on the embryo-larval development of the sea urchin Paracentrotus lividus.

Multiple pollutions by trace metals and pharmaceuticals have become one of the most important problems in marine coastal areas because of its excessive toxicity on organisms living in this area. This study aimed to assess the individual and mixture toxicity of Cu, Cd, and oxytetracycline frequently existing in the contaminated marine areas and the embryo-larval development of the sea urchin Paracentrotus lividus. The individual contamination of the spermatozoid for 1 h with the increasing concentrations of Cd, Cu, and OTC decreases the fertility rate and increases larvae anomalies in the order Cu > Cd > OTC. Moreover, the normal larva frequency and the length of spicules were more sensitive than the fertilization rate and normal gastrula frequency endpoints. The mixture toxicity assessed by multiple experimental designs showed clearly that concentrations of Cd, Cu, and OTC superior to 338 µg/L, 0.56 µg/L, and 0.83 mg/L, respectively, cause significant larva malformations.

Improvement of biomass production and glucoamylase activity by Candida famata using factorial design.

To improve biomass production and glucoamylase activity (GA) by Candida famata, culture conditions were optimized. A 2(3) full factorial design (FFD) with a response surface model was used to evaluate the effects and interactions of pH (X1 ), time of cultivation (X2 ), and starch concentration (X3 ) on the biomass production and enzyme activity. A total of 16 experiments were conducted toward the construction of an empiric model and a first-order equation. It was found that all factors (X1 , X2 , and X3 ) and their interactions were significant at a certain confidence level (P < 0.05). Using this methodology, the optimum values of the three tested parameters were obtained as follows: pH 6; time of cultivation 24 H and starch concentration 7 g/L, respectively. Our results showed that the starch concentration (X3) has significantly influenced both dependent variables, biomass production and GA of C. famata. Under this optimized medium, the experimental biomass production and GA obtained were 1.8 ± 0.54 g/L and 0.078 ± 0.012 µmol/L/Min, about 1.5- and 1.8-fold, respectively, higher than those in basal medium. The (R(2) ) coefficients obtained were 0.997 and 0.990, indicating an adequate degree of reliability in the model. Approximately 99% of validity of the predicted value was achieved.

Bacteriocins active against multi-resistant gram negative bacteria implicated in nosocomial infections.

Multiresistant Gram-negative bacteria are the prime mover of nosocomial infections. Some are naturally resistant to antibiotics, their genetic makes them insensitive to certain families of antibiotics and they transmit these resistors to their offspring. Moreover, when bacteria are subjected to antibiotics, they eventually develop resistance against drugs to which they were previously sensitive. In recent years, many bacteriocins active against gram-negative bacteria have been identified proving their efficacy in treating infections. While further investigation remains necessary before the possibilities for bacteriocins in clinical practice can be described more fully, this review provides an overview of bacteriocins acting on the most common infectious gram negative bacteria (Klebsiella, Acinetobacter, Pseudomonas aeruginosa and E. coli).

Concentration of antioxidant polyphenols from Thymus capitatus extracts by membrane process technology.

Thymus capitatus is a Mediterranean plant characterized by its antioxidant polyphenols of which the most known are the carnosic and rosmarinic acids. In this way, this study aims to concentrate these acids by membrane processes. The thyme essential oil composition was established by capillary GC-MS and 27 components were identified representing 98.93%± 1.97% of total oils. The antioxidant test for permeate and retentate of methanolic and aqueous extract were determined using 3 types of membranes. The results showed that the synthetic NF membrane is able to trap and concentrate phenolic compounds in the retentate much better than the NF commercial and UF synthetic membrane. The results of the total phenolic content (TPC) showed a significant value of the polyphenol content present in the aqueous extract with 175.53 mg Gallic Acid Equivalents (GAE)/g of extract. The spectrum of the aqueous extract of Thymus capitatus showed the presence of 3 visible peaks, the 1st one at 217 nm corresponding to the carnosic acid, the 2nd one at 277 nm for essential oils, and the last one at 326 nm attributed to the rosmarinic acid. The commercial membrane NF-DK succeeded to concentrate rosmarinic acid and can be considered as a stage towards the concentration of this product with a high added value.

Application of the mixture design to optimise the formulation of active consortia to decolorize azo-dye methyl red.

With the aid of analysis software (Minitab 14.0), the formulation of pure culture in Mineral Salts Medium (MSM) can be optimized for several responses and the best formulation can be obtained. The influence of the different mixtures of three strains in the pure culture in MSM on the flavor components in decolorization of Methyl Red (with initial total cell density fixed at OD600 = 1 and in addition of 750 ppm of dye) was studied using equilateral triangle diagram and mixture experimental design to assess color and COD removal during species evolution. The regression model on microorganism composition and main metabolites was established. The results suggested that the highest predictable specific decolorization rate and Chemical Oxygen Demand (COD) were 77.97 and 93.77%. Based on these, the response values that satisfied all expectations were optimized, and the optimal composition of the mixed consortium for the dedolorization and COD removal were (Sphingomonas paucimobilis 45.20%, Bacillus sp 61.94% and Staphylococcus epidermidis 80.00%) and (Sphingomonas paucimobilis 77.03%, Bacillus sp 86.42% and Staphylococcus epidermidis 71.74%) respectively. Very high regression coefficient between the variables and the responses: decolorization and COD removal were respectively R(2)=0.96 and 0.81 indicated excellent evaluation of experimental data by polynomial regression model.