Preventing Pseudomonas aeruginosa and Chromobacterium violaceum infections by anti-adhesion-active components of edible seeds

<p>Abstract</p> <p>Background</p> <p><it>Pseudomonas aeruginosa </it>adhesion to animal/human cells for infection establishment involves adhesive proteins, including its galactose- and fucose-binding lectins PA-IL (LecA) and PA-IIL (LecB). The lectin binding to the target-cell receptors may be blocked by compatible glycans that compete with those of the receptors, functioning as anti-adhesion glycodecoys. The anti-adhesion treatment is of the utmost importance for abrogating devastating antibiotic-resistant <it>P. aeruginosa </it>infections in immunodeficient and cystic fibrosis (CF) patients. This strategy functions in nature in protecting embryos and neonates. We have shown that PA-IL, PA-IIL, and also CV-IIL (a PA-IIL homolog produced in the related pathogen <it>Chromobacterium violaceum</it>) are highly useful for revealing natural glycodecoys that surround embryos in diverse avian eggs and are supplied to neonates in milks and royal jelly. In the present study, these lectins were used as probes to search for seed embryo-protecting glycodecoys.</p> <p>Methods</p> <p>The lectin-blocking glycodecoy activities were shown by the hemagglutination-inhibition test. Lectin-binding glycoproteins were detected by Western blotting with peroxidase-labeled lectins.</p> <p>Results</p> <p>The present work reports the finding - by using PA-IL, PA-IIL, and CV-IIL - of rich glycodecoy activities of low (< 10 KDa) and high MW (> 10 kDa) compounds (including glycoproteins) in extracts of cashew, cocoa, coffee, pumpkin, and tomato seeds, resembling those of avian egg whites, mammal milks, and royal jelly.</p> <p>Conclusions</p> <p>Edible seed extracts possess lectin-blocking glycodecoys that might protect their embryos from infections and also might be useful for hampering human and animal infections.</p

Are the major antioxidants derived from soy protein and fructo-oligosaccharides model systems colored aqueous soluble or insoluble compounds?

9 páginas, 6 figuras, 1 tabla.The present research aimed to determine the overall antioxidant capacity of solid model glycation systems based on either defatted soy flour or soy protein isolate as protein sources and fructo-oligosaccharides (FOS). In addition, we try to gain insight into the physicochemical characteristic of the major neo-antioxidants generated during heating of the model systems. These compounds may be formed in thermally processed foods containing as ingredients both components soy proteins and FOS. Samples constituted by protein source and FOS alone were employed as controls. The Maillard reaction was induced by heating at 150 °C for 1 h. Formation of colored compounds was detected by measuring the absorbance at 420 nm wavelength. The overall antioxidant capacity of the samples was either directly measured by the QUENCHER (quick, easy, new, cheap and reproducible) approach concept adapted to the ORACFL assay or indirectly by summing the ORAC values obtained by analysis under ORACFL standard conditions of aqueous and ethanol fractions of the samples. The sets of data were compared. The relationship between browning and antioxidant capacity was investigated. All samples excepting unheated FOS showed antioxidant capacity. Data seem to indicate that the QUENCHER approach allowed to determine in a single step, the overall antioxidant capacity of FOS caramels and thermally processed glycation mixtures leading to significant compositional changes as results of the simultaneous occurrence of reactions, such as Maillard, caramelization and thermoxidation. Our results also suggested a major formation of aqueous-soluble colored antioxidants from caramelization and Maillard reactions.This research was funded by the COST Action 927 ‘‘Thermally Processed Foods: possible health implications’’, Ministerio de Ciencia e Innovación (projects AGL2008-2541/ALI, AGL2007- 63462/ALI) and CONSOLIDER INGENIO 2010 program (FUN-CFOOD CSD 2007-063).Peer reviewe