Lysophosphatic acid modulates prostaglandin secretion in the bovine uterus

Lysophosphatidic acid (LPA) modulates prostaglandin (PG) synthesis via LPA receptor 3 (LPAR3) in the murine endometrium. The lack of functional LPAR3 in mice may lead to embryo mortality. In the present study, we examined the role of LPA in the bovine uterus. We confirmed that LPA is locally produced and released from the bovine endometrium. Moreover, there are enzymes involved in LPA synthesis (phospholipase (PL) D(2) and PLA2G1B) in the bovine endometrium during estrous cycle and early pregnancy. Expression of the receptor for LPA (LPAR1) was positively correlated with the expression of PGE(2) synthase (PGES) and negatively correlated with the expression of PGF(2alpha) synthase (aldose reductase with 20 alpha-hydroxysteroid dehydrogenase activity - PGFS) during early pregnancy. In vivo LPA induced P4 and PGE(2) secretion was inhibited by LPAR1 antagonist (Ki16425). The overall results indicate that LPA is locally produced and released from the bovine endometrium. Moreover, LPAR1 gene expression in the endometrium during the estrous cycle and early pregnancy indicates that LPA may play autocrine and/or paracrine roles in the bovine uterus. LPAR1 gene expression is positively correlated with the expression of the enzyme responsible for luteotropic PGE(2) production (PGES) in endometrium. In cow, LPA stimulates P4 and PGE(2) secretion. Thus, LPA in the bovine reproductive tract may indirectly (via endometrium) or directly support corpus luteum action via the increase of P4 synthesis and the increase of PGE(2)/PGF(2)(alpha) ratio. It suggests that LPA may serve as an important factor in the maintenance of early pregnancy in cow.     

Identification of oat (<Emphasis Type="Italic">Avena sativa</Emphasis>) and buckwheat (<Emphasis Type="Italic">Fagopyrum esculentum</Emphasis>) proteins and their prolamin fractions using two-dimensional polyacrylamide gel electrophoresis

Total (non-fractionated) kernel proteins and the prolamin fraction (soluble in 75% ethanol) were extracted from oat (Avena sativa) var. Flämingstern kernel and from buckwheat (Fagopyrum esculentum) var. Kora kernel. As for buckwheat, extraction was effective only after kernel dehulling which allowed the removal of tannins and phenolic compounds that form complexes with proteins during extraction. The extracted proteins were analyzed using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE). Gels of the prolamin fractions of oat and buckwheat were used as reference gels in order to detect prolamins on gels of total kernel proteins. The occurrence of 26 and 29 spots corresponding to prolamins was found on gels of total oat proteins and on gels of total buckwheat proteins, respectively. The electrophoretic images of oat and buckwheat prolamins revealed organized subregions containing spots with similar isoelectric points (pI) and various molecular weights (MW), mostly on oat prolamin gels and spots of similar molecular weights with various isoelectric points, mostly on buckwheat prolamin gels. Such organized subregions can be used as identifiers for the occurrence of prolamin fractions in total proteins (particularly as regards buckwheat proteins).     

Development of a nucleic acid lateral flow immunoassay for simultaneous detection of <Emphasis Type="Italic">Listeria</Emphasis> spp. and <Emphasis Type="Italic">Listeria</Emphasis><Emphasis Type="Italic">monocytogenes</Emphasis> in food

We present a new nucleic acid lateral flow immunoassay (NALFIA) for the assessment of listeria contamination. The detection procedure starts with enrichment of sample in Half Fraser broth (24 h). Following isolation of DNA, a duplex PCR is performed with two labelled primer sets, one generic and directed to a specific sequence of the gene encoding 16S rRNA from Listeria spp. and the other specific and directed to a part of the prfA gene encoding the central virulence gene regulator from the food pathogen Listeria monocytogenes (3.5 h). The PCR solution is directly added to the one-step assay device and the appearance of a grey/black line is indicative of the presence of specific amplicons (max 15 min). In all tests performed, the method correctly identified L. monocytogenes and strains of Listeria spp. PCR material of over 20 food samples was tested by NALFIA. The method proved to be useful for the detection of L. monocytogenes in different kinds of food samples.     

Antioxidant capacity and total phenolics of <Emphasis Type="Italic">Cyphostemma digitatum</Emphasis> before and after processing: use of different assays

In the framework of standardisation of new healthy food sources, this paper aimed to study the total phenolics and the antioxidant power of Cyphostemma digitatum (Vitaceae) in water and ethanol extracts, using 96-well micro plates with BMG FLUOstar Optima micro plate reader. Total phenolics by Folin–Ciocalteu method in the water extracts were significantly lower after processing, decreasing from 1.41 ± 0.06 g GAE/100 g in the raw leaves to 0.80 ± 0.08 g GAE/100 g in the processed sample; the ethanol extract revealed the same trend with higher values, decreasing from 1.95 ± 0.03 to 1.56 ± 0.12 g GAE/100 g. The antioxidant capacity was elucidated by four methods: TEAC, DPPH, FRAP and ORAC. No or very weak correlations were found between antioxidant assays and total phenolics; this confirms that the antioxidant capacity could be attributed to other molecules. The ORAC assay proved to be more powerful than the other assays; it showed 103.3 ± 2.5 mmol/100 g Trolox equivalents in the raw leaves ethanol extract and 91.9 ± 3.0 mmol/100 g in the processed sample. ORAC assay showed the opposite for the water extract where the antioxidant capacity increased from 16.7 ± 0.2 to 41.7 ± 2.7 mmol/100 g Trolox equivalents after processing, which could be attributed to new water-soluble compounds generated in the consumed form.     

Purification and characterization of antioxidative peptides derived from rice bran protein hydrolysates

Rice bran protein fraction (RBPF)—albumin, globulin, glutelin and prolamin were hydrolyzed with proteases M, N, P, S and pepsin under their optimal conditions for 24 h. Hydrolysates of various hydrolysis periods were collected and subjected to peptide mapping and the antioxidative activity measured by the 2,2-Azino-bis-3-ethylbenzothiazoline-6-sulfonic Acid (ABTS) method. Protease M hydrolysates showed high degree of hydrolysis (DH), but low antioxidative activity. On the contrary, pepsin hydrolysates showed low DH with high activity. Albumin and globulin hydrolysates had higher DH values, but lower values for glutelin and prolamin. The globulin hydrolysate (Opep2) from 2 h-pepsin hydrolysis was separated by using three consecutive purification steps with RP-HPLC. Nineteen antioxidative peptides were isolated and their amino acid sequences were determined by a gas-phase protein sequencer and MALDI-TOF mass spectrometry. These peptides were composed of 6–30 amino acid residues with molecular masses ranging from 670–3,611 Da. Tyr-Leu-Ala-Gly-Met-Asn had the highest antioxidative activity among them.     

Effects of pretreatments on colour alterations of litchi during drying and storage

The objective of this research was to study the effect of osmotic pretreatment with combined anti-browning agents (acid, glycerol and/or trehalose) on the colour characteristics of dried litchi after drying and during 5 months of storage compared to samples without pretreatment. The pretreated samples showed good inhibition of polyphenol oxidase activity when compared with the control, while the total phenolic contents in the dried products were not reduced. The results demonstrated that water activity, lightness difference, chroma, degree of browning (DB), and 5-hydroxymethylfurfural values of all pretreated samples increased, while hue angle decreased with storage time. Samples pretreated with glycerol showed the best potential for browning retardation, followed by glycerol combined with trehalose, and trehalose, respectively. In addition, the colour parameters were used to calculate the luminescence values, representing the data in grey scale, which were correlated with a non-enzymatic browning index. The results showed grey value could be adequately used to represent the DB of dried litchi with r ² value of 0.92.     

Structural modification of soy protein by 13-hydroperoxyoctadecadienoic acid

To reveal the role of primary products of lipid peroxidation during soy protein oxidation process, oxidative modification of soy protein by 13-hydroperoxyoctadecadienoic acid (13-HPODE) generated by lipoxygenase-catalyzed oxidation of linoleic acid was investigated in this article. Incubation of soy protein with increasing concentration of 13-HPODE resulted in generation of protein carbonyl derivatives and loss of protein sulfhydryl groups. Circular dichroism spectra indicated that exposure of soy protein to 13-HPODE led to loss of α-helix structure. Effect of oxidation on tertiary structure was demonstrated by surface hydrophobicity and tryptophan fluorescence. Surface hydrophobicity gradually decreased, accompanied by loss and burial of some tryptophan residues. The results of surface hydrophobicity and tryptophan fluorescence implied that aggregation was induced by oxidation. Size exclusion chromatogram indicated that the extent of aggregation was increased in a 13-HPODE dose-dependent manner. Sodium dodecyl sulfate polyacrylamide gel electrophoresis indicated that non-disulfide linkages were involved in aggregate formation, and β-conglycinin was more vulnerable to 13-HPODE than glycinin.     

Effects of suni-bug (<Emphasis Type="Italic">Eurygaster</Emphasis> spp.) damage on size distribution of durum wheat (<Emphasis Type="Italic">Triticum durum</Emphasis> L.) proteins

Wholemeal samples were obtained from five durum wheat cultivars at two different bug (Eurygaster spp.) damage levels (medium and high damage). The samples were incubated (60 and 120 min) and used in size exclusion high performance liquid chromatography (SE-HPLC) analyses. The results showed that the amount of larger polymeric protein (TP1) and smaller polymeric protein (TP2) obtained from total (sodium dodecyl sulfate soluble) proteins decreased significantly in the bug-damaged samples, while the amount of total larger monomeric proteins (TP3) increased. The polymeric/monomeric protein ratio of all cultivars decreased at 60 min of incubation with increasing damage level. For all cultivars, the ratio of unextractable polymeric protein (UPP%) significantly decreased at 60 min of incubation except cv. Diyarbakir. The results suggested that bug protease caused depolymerization and/or disaggregation of polymeric proteins to lower their average molecular size. The changes in protein structure as determined using SE-HPLC supported by the decreases in gluten content and gluten index values which decreased with suni-bug damage. Deteriorative effects of bug damage on durum wheat quality were found to be quite similar to those on bread wheats.     

In vitro comparisons between Carica papaya and pancreatic lipases during test meal lipolysis: Potential use of CPL in enzyme replacement therapy

High levels of lipase activity are known to occur in Carica papaya latex, and this activity is being used in some biotechnological applications. The lipolytic activity of C. papaya lipase (CPL) on dietary triacylglycerols (TAG) has not yet been studied. Hence, the aim of this study was to characterise the specific activity of CPL on dietary TAG present in a crude preparation. Also, we have determined its stability during the lipolysis of a test meal at various pH values mimicking those occurring in the gastro-intestinal tract, with or without bile, and have compared these properties with those of porcine pancreatic extract (PPE) and human pancreatic lipase (HPL). CPL showed maximum stability at pH 6.0, both with and without bile. Some residual activity was still observed at pH 2 (20%), whereas the pancreatic lipases tested were immediately completely inactivated at this pH. In the absence of bile, the highest specific activities were measured at pH 6 in the case of CPL, PPE and HPL. Adding bile slightly decreased the CPL activity in the 4–6 pH range, thus shifting the optimum CPL activity to pH 7, where the presence of bile had no effect. Lipolysis levels decreased with the pH, but CPL was still more active than PPE at pH 5 on a relative basis. These results suggest that CPL might be a promising candidate for use as a therapeutic tool on patients with pancreatic exocrine insufficiency.     

Qualitative and quantitative comparison of pollen calendars for plain and mountain areas

A comparison of the quantity and the quality of pollen content in the atmosphere of two regions, one of the plains bordering the Mediterranean sea (altitude 40 m), the other of the mountains of the Pyrenees (altitude 1550 m), was made during the climatological year 1974-1975. The method which was used intercepts the pollen flux of the atmosphere with a vertical filtering unit, which is exposed facing the direction of wind on the filtering door of the weather-vane and collects much larger quantities of pollen than the other techniques of collection. The atmospheric currents displace from one region to another numerous spores and pollens, the trajectories of which are directly influenced by the general circulation of the atmosphere. The density of these fluxes can be very large, reaching 2500 grains/m3 of air at M.T.P.R. in the last week of January; the taxons collected are very numerous (more than 700). The atmospheric transfer of pollen modifies largely the pollen content of the atmosphere of different flowering domains. These interferences manifest themselves in the simplest cases by the presence of two peaks of concentration, the principal corresponding to the local efflorescence, the second to the pollen transferred from other regions. The pollen concentrations in the mountains are one-third of those in the plains. Pollination in the mountains is several weeks late in comparison to the plain during the first semester, whereas during the second semester, it is the plains that show a certain delay. These findings show why some allergic patients who go to the mountains during summer are affected twice by pollination.