Nanocochleates containing N-Octylglicoside extracted Vibrio cholerae antigens elicited high vibriocidal antibodies titers after intragastric immunization in a mice model.

Biological detergents are used in research laboratories, to extract or solubilize proteins from cell membranes. In order to evaluate the ability to extract antigens from the bacterial cell surface of the wild Vibrio cholerae strain C7258 and study their immunogenic potential by forming proteoliposomes and cochleate and preserving their immunogenicity, the non-ionic detergent, n-Octylglucoside (n-OG), and the Zwitterionic detergent (3-cholamidopropyl dimethylammonio 1-propanesulfonate; CHAPS) were tested in concentrations between 5 and 15%. The anionic detergent sodium deoxycholate (DOC) was used as a reference. Electrophoretic, immunochemical and electron microscopy techniques have characterized the extracts and their chromatographic fractions. With CHAPS and n-OG detergents in concentrations between 5 and 15%, a higher yield was obtained in the extraction of proteins and lipopolysaccharides (LPS) and other components from the bacterial surface compared to 10% DOC. When using 10% DOC, 15% CHAPS and n-OG between 5 and 15%, stable proteoliposomes were formed, of average size between 82 and 93 nm in diameter, with known proportions of proteins, LPS and other components. In some of the concentrations, liposomes were formed with almost pure proteins. Some cholera outer membrane proteins like the 17 kDa protein, which corresponds to the mannose-sensitive hemagglutinin (MSHA), which mediates the adhesion to the brush border of the small intestine and the outer membrane protein U (OMPU) were identified with monoclonal antibodies (mAbs) and purified. The fundamental components of liposomes, proteins and LPS, retained their molecular weights, when compared with known standards and by processing programs of electrophoretic profiles and their antigenicity, without alterations due to the extraction procedure, as could be verified by immune identification techniques with monoclonal antibodies in the case of LPS, significant antigens in this pathogen. The main purpose of the present work was to show that a new anticholera vaccine formulation based on cochleates, containing selected protein and LPS fraction extracted by detergents, is able to elicit protective high titers of bactericidal antibodies after intragastric immunization in the mice model. The objective was achieved.

Polyphenol composition and antioxidant capacity from different extracts of Aster scaber.

Phenolic contents and antioxidant capacities from different solvent extracts (petroleum ether, ethyl acetate, methanol, butanol and water) of Aster scaber leaf were investigated. Antioxidant activity was evaluated by three different methods, namely DPPH radical scavenging activity, reducing power assay and phosphomolybdenum activity. A total of twenty-three polyphenolic compounds were identified and quantified from A. scaber leaf extracts, including hydroxybenzoic acids, hydroxycinnamic acids, flavonols and other groups of phenolic compounds. Ultra high performance liquid chromatography (UHPLC) analysis of the leaf extract revealed that myricetin (4850.45 µg/g) was the most dominant flavonols, compared to quercetin and kaempferol. Caffeic acid was the dominant phenolic compound in A. scaber leaf extracts, it constituted about 104.20 µg/g, followed by gentisic acid (84.50 µg/g), gallic acid (61.05 µg/g) and homogentisic acid (55.65 µg/g). The total phenolic and flavonoid content was the highest in ethyl acetate extract (322.43 and 6.51 mg/g). The decreasing order of antioxidant activity among the A. scaber leaf extracts assayed through all the three methods was found to be ethyl acetate > butanol > methanol > petroleum ether > water extract.

Optimization of factors influencing in vitro flowering of gherkin (Cucumis anguria L.).

This study investigated the factors influencing in vitro flowering of gherkin (Cucumis anguria L.). Multiple shoots were efficiently regenerated from cotyledonary node and axillary bud explants of C. anguria within 15 days on MSB5 medium containing 3% sucrose and supplemented with 1.5 mg l-1 6-benzyladinine (BA). The elongated shoots were excised and transferred to MSB5 medium containing 4% sucrose supplemented with 0.5 mg l(-1) gibberellic acid (GA(3)) and 1.0 mg l(-1) indole-3-butyric acid (IBA) induced maximum number of flowers (9.5 flowers/plant) and root induction (16.5 roots/plant). Factors that influence the in vitro flowering were optimizing pH, photoperiod and temperature. In vitro flowering was significantly early and higher number of flowers produced at pH (5.8), photoperiod (12/12 h) and room temperature (28 °C). In vitro developed flowers were less viable (80 ± 1.0%) compared to control plants (90 ± 2.0%). Our in vitro flower induction procedures provide an extremely effective method for further research on flowering regulation mechanisms in C. anguria. These plantlets were successfully transferred to the soil where they grew well for 3 to 5 weeks with 90% survivability. Plants grew normally and produced flowers with viable pollen and fertile seeds.