Evaluation of Aglianico grape skin and seed polyphenols astringency by SDS-PAGE electrophoresis of salivary proteins after the binding reaction

SDS–PAGE electrophoresis and densitometry analysis were carried out to evaluate the reactivity of Aglianico red grape skin and seed polyphenols with human salivary proteins in order to find a method able to assess their astringency. Analysis of the supernatant obtained after a tannin/human salivary protein binding assay and sensorial analysis showed that four proteins, lactoferrin, PRPbg1, PRPbg2 and a-amylase, were the proteins best able to distinguish tannin solutions characterised by different levels of astringency. A correlation between densitometric data and tannin concentration was plotted in order to give an indirect measure of astringency. The two sources of Aglianico grape polyphenols differed from each other in astringency power; the seed extract solution was about two-fold more tannic than the skin one. The difference in astringency was also perceived by sensorial analysis. The results from this study show that SDS–PAGE electrophoresis of human salivary proteins after the binding reaction with grape polyphenol extracts, coupled with densitometric analysis and the use of a calibration curve, looks extremely promising as a new approach to evaluate polyphenol astringency

Anopheline salivary protein genes and gene families: an evolutionary overview after the whole genome sequence of sixteen Anopheles species

Background: Mosquito saliva is a complex cocktail whose pharmacological properties play an essential role in blood feeding by counteracting host physiological response to tissue injury. Moreover, vector borne pathogens are transmitted to vertebrates and exposed to their immune system in the context of mosquito saliva which, in virtue of its immunomodulatory properties, can modify the local environment at the feeding site and eventually affect pathogen transmission. In addition, the host antibody response to salivary proteins may be used to assess human exposure to mosquito vectors. Even though the role of quite a few mosquito salivary proteins has been clarified in the last decade, we still completely ignore the physiological role of many of them as well as the extent of their involvement in the complex interactions taking place between the mosquito vectors, the pathogens they transmit and the vertebrate host. The recent release of the genomes of 16 Anopheles species offered the opportunity to get insights into function and evolution of salivary protein families in anopheline mosquitoes. Results: Orthologues of fifty three Anopheles gambiae salivary proteins were retrieved and annotated from 18 additional anopheline species belonging to the three subgenera Cellia, Anopheles, and Nyssorhynchus. Our analysis included 824 full-length salivary proteins from 24 different families and allowed the identification of 79 novel salivary genes and re-annotation of 379 wrong predictions. The comparative, structural and phylogenetic analyses yielded an unprecedented view of the anopheline salivary repertoires and of their evolution over 100 million years of anopheline radiation shedding light on mechanisms and evolutionary forces that contributed shaping the anopheline sialomes. Conclusions: We provide here a comprehensive description, classification and evolutionary overview of the main anopheline salivary protein families and identify two novel candidate markers of human exposure to malaria vectors worldwide. This anopheline sialome catalogue, which is easily accessible as hyperlinked spreadsheet, is expected to be useful to the vector biology community and to improve the capacity to gain a deeper understanding of mosquito salivary proteins facilitating their possible exploitation for epidemiological and/or pathogen-vector-host interaction studies

Rheological Behavior of Food Emulsions Mixed with Saliva: Effect of Oil Content, Salivary Protein Content, and Saliva Type

In this paper, we studied the effect of saliva on the rheological properties of ß-lactoglobulin- and lysozyme-stabilized emulsions, prepared at pH¿=¿6.7 in relation to variation of emulsions- and saliva-related parameters. The effect of oil¿volume fraction (2.5% w/w to 10% w/w), salivary protein concentration (0.1 to 0.8 mg ml¿1), and the use of both stimulated and unstimulated saliva was investigated. Viscosity and storage modulus were measured before (¿ emul and G¿emul, respectively) and after addition of saliva (¿ mix and G¿mix). To better estimate the changes due to saliva-induced flocculation of the emulsions, the ratios ¿ mix/¿ emul, G¿mix/G¿emul were calculated. In addition, tan ¿ (=the ratio of the loss and storage moduli) was investigated to evaluate the viscoelastic behavior of the emulsion/saliva mixtures. Increasing the oil¿volume fraction and salivary protein concentration resulted in an increase in ¿ mix/¿ emul and G¿mix/G¿emul, while a decrease in tan ¿ of the emulsion/saliva mixtures is occurring. When compared with unstimulated saliva, mixing ß-lactoglobulin-stabilized emulsions with stimulated saliva led to a reduction in ¿ mix/¿ emul and G¿mix/G¿emul, and an augment of tan ¿ at all measured deformations. In case of lysozyme-stabilized emulsions, the use of stimulated saliva increased G¿mix/G¿emul for ¿

Histochemical studies of the secretory processes in bovine salivary glands : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science at Massey University /

Salivary glands from 12 bovine animals were dissected, weighed and sampled for histological examination. The total salivary gland weight was positively correlated with body weight but there were not normally consistent differences between the weights of left and right glands. However, in animals that had chronic re-entrant cannulations of the left parotid and mandibular ducts, the ipsilateral glands were always lighter. The histological features of salivary glands and the histochemical reactivity of their secretory and duct cells were examined. Parotid gland secretory endpieces were elongated and their individual cells contained PAS+ve granules. These cells were shown by immunohistochemistry to be the site of protein secretion and thus were classified as proteoserous cells. Chronic parotid duct cannulation in association with duct obstruction caused dilation of the secretory endpiece lumens and degenerative changes within the endpiece cells. Intralobular duct cells contained PAS+ve granules which may be the secretory component that is associated with secretory IgA. Variable numbers of intrastriated duct cells occured in the parotid glands of different animals and in retrospect, this was found to correlate positively with the animals known susceptibility to bloat. The parotid excretory duct contained many goblet cells which contribute a small amount of mucosubstance to the proteoserous secretion. Secretory endpieces of the mandibular gland were composed of mucous cells which were PAS, AY and weakly AB+ve and demilune cells which were PAS and AB+ve as well as acidophilic and pyroninophilic. Clumps of plasma cells were observed in the intralobular connective tissue. The effect of obstruction of chronic duct cannulation on the mandibular gland was to dilate endpiece and intralobular duct lumens, cause degenerative changes in mucous and demilune cells and increase the numbers of small lymphocytes, PMN neutrophils and mast cells in the connective tissues of the gland. By contrast with the excretory duct of the parotid, that of the mandibular contained no goblet cells but simply a stratified columnar epithelium. Mucous cells of the sublingual gland were PAS+ve, AY+ve and weakly AB+ve and arranged into long tubular endpieces. The demilune cells contained abundant PAS+ve, AB+ve, AY-ve granules. Many plasma cells were present in the connective tissue between the secretory endpieces and around the intralobular and interlobular ducts. In animals with chronic cannulations of parotid and mandibular glands the ispilateral sublingual gland weighed less than the contralateral gland. The posterior tongue, soft palate, pharynx and the lingual aspect of the epiglottis contained extensive areas of glandular tissue. The secretory endpieces consisted of a high proportion of mucous cells and a few scattered proteoserous demilune cells. The glandular tissue of the epiglottis contained abundant plasma cells in the intralobular connective tissue. Based on their histochemical reactivity the demilune cells of the intermediate buccal glands produced a purely serous secretion. In addition, the intermediate and dorsal buccal glands contained many AB, AY and PAS+ve mucous producing cells. The labial glands were small, scattered lobules of secretory tissue found at the labial commisures. The glandular lobules were composed of tubular secretory endpieces capped with large proteoserous demilune cells which were AY-ve, PAS+ve, strongly acidophilic and pyroninophilic. Large numbers of plasma cells were found in the connective tissues within and around the secretory tissue

Impact of Physical Stress on Salivary Buffering Capacity

Background: Saliva has many properties and the buffering capacity is important for the neutralization of oral fluids. It is unclear whether stressful conditions directly affect salivary buffering capacity, and we investigated the impact of physical stress on salivary buffering capacity. Methods: Twelve participants were subjected to the physical stress of jogging and running. The salivary buffering capacity and flow rate of the participants were measured before and after exposure to stressful conditions. Salivary α-amylase activity was measured as a quantitative index of stress. Results: No change in buffering capacity was detected among each time point during the whole course under physically stressful conditions. Next, we examined the change in buffering capacity after jogging compared to baseline. Six participants showed an increase in buffering capacity (Group A), while the other six participants showed a decrease or no change (Group B) after jogging. Group B showed a decrease in flow rate and increases in α-amylase activity and protein level after jogging, whereas Group A showed no changes in these properties. Conclusions: The results suggest that salivary buffering capacity changes following exposure to physically stressful conditions, and that the changes are dependent on the stress susceptibility of individuals

Role of amylase, mucin, IgA and albumin on salivary protein buffering capacity: A pilot study

It has been suggested that proteins serve as major salivary buffers below pH 5. It remains unclear, however, which salivary proteins are responsible for these buffering properties. The aim of this pilot study was to evaluate the correlation between salivary concentration of total protein, amylase, mucin, immunoglobulin A (IgA), albumin and total salivary protein buffering capacity at a pH range of 4-5. In addition, the buffering capacity and the number of carboxylic acid moieties of single proteins were assessed. Stimulated saliva samples were collected at 9:00, 13:00 and 17:00 from 4 healthy volunteers on 3 successive days. The buffering capacities were measured for total salivary protein or for specific proteins. Also, the concentration of total protein, amylase, mucin, IgA and albumin were analysed. Within the limits of the current study, it was found that salivary protein buffering capacity was highly positively correlated with total protein, amylase and IgA concentrations. A weak correlation was observed for both albumin and mucin individually. Furthermore, the results suggest that amylase contributed to 35% of the salivary protein buffering capacity in the pH range of 4-

The Influence of oral environment on diet choices in goats: a focus on saliva protein composition

There is ample evidence that ruminants are capable of making choices between different foods that provide a more balanced diet that would be obtained by eating at random. In the particular case of goats, they occupy a diversity of habitats and different breeds present variability of feeding behaviors resultant from adaptations to the existent plant species. In their food search activity, individuals are faced with variable amounts of plant secondary metabolites (PSMs), which may present some toxic and anti-nutritional effects depending on the individual’s ability to deal with it. The oral cavity has a key role in the recognition and decision processes of ingestion or rejection. In this chapter we will first consider how goats identify foods and behave according to the food items available. Focus will be done on the importance of taste sense in this process and the information available on the main structures involved in taste detection and perception in goats will be reviewed. In a second section we will focus on the characteristics of goat’s saliva, particularly in terms of their protein composition, presenting results obtained by our research team

Salivary immunity and lower respiratory tract infections in non-elite marathon runners

Peer ReviewedPostprint (published version

Adsorption of aminefluorides on human enamel

Changes in surface characteristics of ground and polished human enamel after adsorption of two types of aminefluorides (AmF 297 and AmF 335) have been studied. After adsorption of aminefluorides from solutions with concentrations up to 10 mM for 2 min followed by rinsing of the surface with distilled water, contact angle measurements were carried out to yield surface free energies and ellipsometry was performed to yield the adsorbed layer thickness. In a separate experiment on powdered enamel, set up in an analogous way, zeta potential changes after adsorption of aminefluorides were determined in a 10 mM potassium phosphate buffer at pH 7·0. Surface free energies decreased from 88 erg·cm−2 to 52 erg·cm−2 and 35 erg·cm−1 after adsorption of AmF 297 and AmF 335 respectively at c = 1 mM. Increasing the aminefluoride concentration in solution did not affect the values obtained. Zeta potentials, originally −36 mV, became positive after adsorption, while ellipsometry indicated the buildup of adsorbed layers with a thickness between 3 run and 12 nm. All three types of experiments indicated that both AmF 297 and AmF 335 form an adsorbed monolayer on ground and polished enamel at a concentration of 1 mM. Negligible additional adsorption takes place at higher concentrations under the present experimental circumstances. In vivo, adsorbed aminefluoride layers will be rapidly covered by adsorbed protein layers, shielding both the adsorbed aminefluoride layer as well as its physicochemical characteristics. This effect has been studied in vivo by measuring surface free energy changes of ground and polished enamel, with AmF 297 and AmF 335 adsorbed at c = 2·5 mM as a function of the time, these samples were carried by test persons in partial dentures. On both types of AmF-coated enamel the surface free energies increased within 30 min to values approaching the one obtained previously for pellicle-coated ground and polished enamel (110 ± 9 erg·cm−2)

Marked increase in PROP taste responsiveness following oral supplementation with selected salivary proteins or their related free amino acids

The genetic predisposition to taste 6-n-propylthiouracil (PROP) varies among individuals and is associated with salivary levels of Ps-1 and II-2 peptides, belonging to the basic proline-rich protein family (bPRP). We evaluated the role of these proteins and free amino acids that selectively interact with the PROP molecule, in modulating bitter taste responsiveness. Subjects were classified by their PROP taster status based on ratings of perceived taste intensity for PROP and NaCl solutions. Quantitative and qualitative determinations of Ps-1 and II-2 proteins in unstimulated saliva were performed by HPLC-ESI-MS analysis. Subjects rated PROP bitterness after supplementation with Ps-1 and II-2, and two amino acids (L-Arg and L-Lys) whose interaction with PROP was demonstrated by (1)H-NMR spectroscopy. ANOVA showed that salivary levels of II-2 and Ps-1 proteins were higher in unstimulated saliva of PROP super-tasters and medium tasters than in non-tasters. Supplementation of Ps-1 protein in individuals lacking it in saliva enhanced their PROP bitter taste responsiveness, and this effect was specific to the non-taster group.(1)H-NMR results showed that the interaction between PROP and L-Arg is stronger than that involving L-Lys, and taste experiments confirmed that oral supplementation with these two amino acids increased PROP bitterness intensity, more for L-Arg than for L-Lys. These data suggest that Ps-1 protein facilitates PROP bitter taste perception and identifies a role for free L-Arg and L-Lys in PROP tasting