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The astringency of green tea is an integrated result of the synergic and antagonistic effects of individual tea components, whose mechanism is highly complex and not completely understood. Herein, we used an epigallocatechin gallate (EGCG)/caffeine (CAF)/saliva model to simulate the oral conditions during tea drinking. The effect of CAF on the interaction between EGCG and salivary proteins was first investigated using molecular docking and isothermal titration calorimetry (ITC). Then, the rheological properties and the micro-network structure of saliva were studied to relate the molecular interactions and perceived astringency. The results revealed that CAF partially occupied the binding sites of EGCG to salivary proteins, inhibiting their interaction and causing changes in the elastic network structure of the salivary film, thereby reducing astringency., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Long-term intake of procyanidins has been suggested to reduce the risk of cardiovascular disease, dementia, and sensory function decline associated with aging. However, most of the ingested procyanidins are not absorbed and are excreted in the feces, so the mechanism of their beneficial impact is unknown. Procyanidins are the components of astringency in plant foods and their stimulation appears to be directly transmitted to the central nervous system via sensory nerves. Recent attention has been focused on the taste receptors expressed in the extra-oral gastrointestinal tract may regulate homeostasis via the neuroendocrine system. In this paper, we have reviewed recent findings on the relationship between the astringency of procyanidins and their bioregulatory effects., (© The Author(s) 2023. Published by Oxford University Press on behalf of Japan Society for Bioscience, Biotechnology, and Agrochemistry.)

Recent studies have demonstrated that the interaction of dietary constituents with taste and olfactory receptors and nociceptors expressed in the oral cavity, nasal cavity and gastrointestinal tract regulate homeostasis through activation of the neuroendocrine system. Polyphenols, of which 8000 have been identified to date, represent the greatest diversity of secondary metabolites in plants, most of which are bitter and some of them astringent. Epidemiological studies have shown that polyphenol intake contributes to maintaining and improving cardiovascular, cognitive and sensory health. However, because polyphenols have very low bioavailability, the mechanisms of their beneficial effects are unknown. In this review, we focused on the taste of polyphenols from the perspective of sensory nutrition, summarized the results of previous studies on their relationship with bioregulation and discussed their future potential.

Astringency, commonly described as a drying, roughening, and/or puckering sensation associated with polyphenol-rich foods affects their palatability. While the compounds eliciting astringency are known, its mechanism of action is debated. This study investigated the role of transient receptor potential (TRP) channels A1 and V1 in astringency perception. If TRP A1 or V1 have a functional role in astringency perception, then desensitizing these receptors should decrease perceived astringency. Thirty-seven panelists underwent unilateral lingual desensitization of TRP A1 and V1 channels using mustard oil and capsaicin, respectively. Panelists then evaluated four astringent stimuli: epicatechin (EC), epigallocatechin gallate (EGCG), tannic acid (TA), and potassium alum (Alum), via 2-AFC and intensity ratings. When TRPA1 receptors were desensitized on one half of the tongue via mustard oil, no significant differences were observed between the treated and untreated sides for both 2-AFC and intensity ratings. Similarly, when TRPV1 receptors were desensitized on one half of the tongue via capsaicin, no significant differences were observed between the treated and untreated sides for both 2-AFC and intensity ratings. These findings challenge the notion that TRP channels play a pivotal role in astringency perception., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Phenolic compounds are responsible for food unpleasant taste properties, including astringency, due to their ability to interact with salivary proteins and oral constituents. Astringency is a crucial attribute for consumer's acceptability. To fulfill the demand for both healthy and tasty food, polysaccharides raise as a good alternative to modulate astringency. In this work, a cell-based quaternary system was developed to evaluate the ability of polysaccharides to reduce the interaction between two classes of hydrolysable tannins - gallotannins (tannic acid) and ellagitannins (punicalagin) - and oral constituents (cells, salivary proteins and mucosal pellicle). So, pectic polysaccharide fractions isolated from grape skins, imidazole soluble polysaccharides (ISP) and carbonate soluble polysaccharides (CSP), as well as a commercial pectin, were tested. Results showed that the polysaccharide's effect depends on the structural features of the molecules involved. CSP fraction and pectin were the most effective, reducing the interactions between both tannins and the oral constituents, mainly in the complete oral model. The highest uronic acid content and the presence of methyl esterified groups could explain their high reduction ability. For tannic acid, the reduction effect increased along with the galloylation degree, while the interaction of β-punicalagin with the oral constituents was practically inhibited at 3.0 mg.mL -1 ., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Astringency is an important mouthfeel attribute that influences the sensory experiences of many food and beverage products. While salivary lubricity loss and increased oral friction were previously believed to be the only astringency mechanisms, recent research has demonstrated that nontactile oral receptors can trigger astringency by responding to astringents without mechanical stimulation. Various human factors have also been identified that affect individual responses to astringents. This article presents a critical review of the key research milestones contributing to the current understanding of astringency mechanisms and the instrumental approaches used to quantify perceived astringency intensity. Although various chemical assays or physical measures mimic in-mouth processes involved in astringent mouthfeel, this review highlights how one chemical or physical approach can only provide a single measure of astringency determined by a specific mechanism. Subsequently, using a single measurement to predict astringency perception is overly idealistic. Astringency has not been quantified beyond the loss of saliva lubrication; therefore, nontactile receptor-based responses must also be explored. An important question remains about whether astringency is a single perception or involves distinct sub-qualities such as pucker, drying, and roughness. Although these sub-quality lexicons have been frequently cited, most studies currently view astringency as a single perception rather than dividing it into sub-qualities and investigating the potentially independent mechanisms of each. Addressing these knowledge gaps should be an important priority for future research., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Astringency as the complex sensory of drying or shrinking can be perceived from natural foods, including abundant phenolic compounds. Up to now, there have been two possible astringency perception mechanisms of phenolic compounds. The first possible mechanism involved chemosensors and mechanosensors and took salivary binding proteins as the premise. Although piecemeal reports about chemosensors, friction mechanosensor's perception mechanisms were absent. There might be another perception way because a part of astringent phenolic compounds also triggered astringency although they could not bind with salivary proteins, however, the specific mechanism was unclear. Structures caused the differences in astringency perception mechanisms and intensities. Except for structures, other influencing factors also changed astringency perception intensity and aimed to decrease it, which probably ignored the health-promoting effects of phenolic compounds. Therefore, we roundly summarized the chemosensor's perception processes of the first mechanism. Meanwhile, we speculated that friction mechanosensor's probably activated Piezo2 ion channel on cell membranes. Phenolic compounds directly binds with oral epithelial cells, activating Piezo2 ion channel probably the another astringency perception mechanism. Except for structure, the increase of pH values, ethanol concentrations, and viscosity not only lowered astringency perception but were beneficial to improve the bioaccessibility and bioavailability of astringent phenolic compounds, which contributed to stronger antioxidant, anti-inflammatory, antiaging and anticancer effects., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Taste perception plays a crucial role in determining food choices. It has been described in literature a relationship between diet composition and taste perception. Nowadays, with the rising concern in climate change and animal welfare, the number of people following a vegan diet is increasing to become a real trend. Research about differences in taste perception between vegan and omnivore is lacking. The aim of the study was to compare detection threshold for bitter, sour, umami and astringency stimuli (quinine monohydrochloride dihydrate, citric acid anhydrous, monosodium glutamate and tannic acid, respectively) participants following a vegan diet (n=24) and participants following an omnivore diet (n=30). Participants reported their consumption frequency for main food categories. The mean detection thresholds between the two groups narrowly missed significance with p-values of 0.07, 0.08, 0.06, for bitter, umami and astringency perception, respectively. No differences were found for sour taste (p-value=0.33). Further research is required to validate such findings and to understand the origin of the relationship between diet style and taste sensitivity., Competing Interests: Declaration of Competing Interest None, (Copyright © 2023 Elsevier Inc. All rights reserved.)

Roles of polysaccharides on modulating wine astringency from the perspective of polyphenol-proteins interaction has received increasing attention in last decade. In this work, proanthocyanidins extracts from three wines with different polyphenolic profiles and organoleptic properties were prepared to establish polyphenol-proteins interaction model wines. The effect of three wine polysaccharides including mannoproteins (MP), arabinogalactan protein (AGP) and rhamnogalacturonan II (RG-II) as well as their pairwise combinations on the interaction model wines were evaluated. Results showed that the structure and concentration of proanthocyanidins and polysaccharides had great influence on astringency. Proanthocyanidins with high mean degree of polymerization generated stronger astringency than others. Combining the results of fluorescence quenching and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, RG-II and other two polysaccharides (MP and AGP) modulated astringency through forming a ternary complex and competing reaction, respectively. Owing to synergetic effects, pairwise combinations of three polysaccharides (especially AGP + RG-II) reduced astringency more significantly than individual polysaccharides. Lower concentration (0.2 g/L-0.6 g/L) polysaccharides showed great contribution in modulating astringency. Sensory evaluation also verified the above-mentioned results. These findings were supposed to help better understand changes of astringency perception owing to the interaction of macromolecular substances in wine., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Green tea is popularly known for its pleasant flavor and health-care functions. Bitterness and astringency are the two important quality attributes of green tea that enrich tea flavor. Although many research works have focused on the flavor formation of green tea, the review articles about bitterness and astringency is limited. This review article summarizes the major components of bitter and astringent substances in green tea, their sensory perception mechanism, factors influencing the formation of these substances, and the evaluation methods of bitterness and astringency. This review will shed light on the subsequent studies in tea flavor, and provide deeper insight for the research of bitterness and astringency in other foods., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Astringency is an important sensory characteristic of food and beverages containing polyphenols. However, astringency perception in elderly people has not been previously documented. The aim of the present work was to evaluate sensitivity to astringency as a function of age, salivary flow and protein amount. Fifty-four panellists, including 30 elderly people (age = 75 ± 4.2 years) and 24 young people (age = 29.4 ± 3.8 years), participated in this study. Astringency sensitivity was evaluated by the 2-alternative forced choice (2-AFC) procedure using tannic acid solutions. Whole saliva was collected for 5 min before and after the sensory tests. The results showed that the astringency threshold was significantly higher in the elderly group than the young group. No correlation was observed between the salivary protein amount and threshold value. However, a negative correlation between salivary flow and threshold was observed in the young group only. These results showed a difference in oral astringency perception as a function of age. This difference can be linked to salivary properties that differ as a function of age.

Deficits in olfaction are associated with neurodegenerative disorders such as Alzheimer's disease. A recent study reported that intranasal zinc sulfate (ZnSO 4 )-treated mice show olfaction and memory deficits. However, it remains unknown whether olfaction deficit-induced learning and memory impairment is associated with the cholinergic system in the brain. In this study, we evaluated olfactory function by the buried food find test, and learning and memory function by the Y-maze and passive avoidance tests in ZnSO 4 -treated mice. The expression of choline acetyltransferase (ChAT) protein in the olfactory bulb (OB), prefrontal cortex, hippocampus, and amygdala was assessed by western blotting. Moreover, we observed the effect of the acetylcholinesterase inhibitor physostigmine on ZnSO 4 -induced learning and memory deficits. We found that intranasal ZnSO 4 -treated mice exhibited olfactory dysfunction, while this change was recovered on day 14 after treatment. Both short-term and long-term learning and memory were impaired on days 4 and 7 after treatment with ZnSO 4 , whereas the former, but not the latter, was recovered on day 14 after treatment. A significant correlation was observed between olfactory function and short-term memory, but not long-term memory. Treatment with ZnSO 4 decreased the ChAT level in the OB on day 4, and increased and decreased the ChAT levels in the OB and hippocampus on day 7, respectively. Physostigmine improved the ZnSO 4 -induced deficit in short-term, but not long-term, memory. Taken together, the present results suggest that short-term memory may be closely associated with olfactory function via the cholinergic system., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Introduction: Illicium verum commonly known as star anise has been widely used in many Asian countries for pharmaceutical treatment for many diseases. The aim of the present study was to investigate the anti-inflammatory, astringent, and antimicrobial properties of an Illicium verum mouthwash., Methods: The present double blinded randomized clinical trial was conducted on fifty subjects, divided into groups A and B. Illicium verum mouthwash (group A) and placebo (group B) were provided to subjects for 21 days; after 14 days, washout period mouthwashes were switched as per crossover design between groups for 21 days. The gingival index (GI), papillary bleeding index (PBI), and oral microbial count were recorded at each stage of study., Results: The significant intragroup difference was observed, before crossover in group A and after crossover in group B for GI, PBI, and oral microbial count at different stages of study. On comparing both group A and group B at the first and second follow-up for GI, PBI, and oral microbial count, a statistically significant difference ( p < 0.05) was observed. A statistically highly significant mean intergroup and intragroup difference was seen for all the clinical parameters at different stages of study., Conclusion: The study revealed that the Illicium verum/star anise has potent antibacterial, anti-inflammatory, and astringent properties., Competing Interests: The authors explicitly state that they have no conflict of interest with any organization or institution., (Copyright © 2021 Ali A. Assiry et al.)

The food industry is focused on developing plant-based foods that incorporate pea protein isolates. However, these ingredients are often described as having persistent beany, bitter, and astringent notes, which can decrease the desirability of the resulting foods. These perceptions are rooted in the complex composition of volatile and non-volatile compounds in foods. The aim of our study was to better understand how the volatile and non-volatile fractions of pea protein isolates influence the perception of pea-protein-based foods. To this end, a mixture design was used. First, we obtained three fractions (the pellet, permeate, and retentate) from two pea protein isolates, resulting in a total of six fractions. Second, we used various combinations of the six fractions to create a set of 46 pea-protein-based solutions via various processes (solubilization, centrifugation, filtration, and mixing). Each fraction was specifically representative of the following constituent groups: insoluble proteins (the pellet); soluble compounds, such as volatiles, peptides, and phenolics (the permeate); and soluble proteins interacting with volatiles (the retentate). Factor levels were chosen with two aims: to explore the widest possible range of combinations and to realistically represent protein concentrations so as to build optimal mixture models. Third, 17 trained panelists were asked to score the attributes of the solutions using sensory profiling. Model performance was assessed using analysis of variance; results were significant for 18/18 attributes, and there was no significant lack-of-fit for 17/18 attributes. It was also assessed using the results of trials conducted with six supplementary solutions. These results clarified the origin of the perceived beany, bitter, and astringent notes. Beaniness was mainly influenced by the retentate and permeate fractions and was strongly affected by hexanal levels. Bitterness was mainly influenced by the retentate fraction, whereas astringency was influenced by the retentate and pellet fractions. Additionally, perception of these latter two attributes was affected by caffeic acid levels. This study has increased understanding of the relationship between pea protein fractions and the undesirable sensory attributes of pea protein isolates. It has also revealed how fraction-based formulation could be used to reduce the beaniness, bitterness, and astringency of pea-protein-based foods., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The effects of epigallocatechin gallate (EGCG), epigallocatechin (EGC) and epicatechin gallate (ECG) on the chemical and cell-based antioxidant activity, sensory properties, and cytotoxicity of a catechin-free model beverage were modeled using response surface methodology. Results showed that ECG presented the highest reducing capacity while EGCG presented the highest Cu 2+ chelating ability. Binary interactions (EGCG/EGC and EGCG/ECG) had an additive effect on CUPRAC, DPPH and Cu 2+ chelating ability. The mixture containing 67.4% ECG and 32.6% EGCG was the optimal combination of flavanols (OPC). In a beverage model - chrysanthemum tea - OPC enhanced the anti-proliferative activity in relation to OVCAR-3, HEK293 and HFL1 cells and decreased the intracellular generation of reactive oxygen species. OPC enhanced the bitterness and astringency of the beverage models impacting in a decrease in overall acceptance. The pasteurization process did not decrease the antioxidant activity and the flavanol concentration of the beverages., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Background: Seasonal persimmon (Diospyros kaki L.) crops have steadily increased in Spain; this has been linked to a significant increase in the postharvest production waste. Therefore, development of valorized products is of great interest. In this study, a hot air-drying technique was used to obtain persimmon snacks. Slices from astringent and non-astringent persimmons (submitted to de-astringency treatment) at three different ripening stages were dried at 40 and 60 °C to reach 15 ± 3% water content., Results: After the drying treatment, dehydrated samples were harder, turned into a more orange hue angle, and had a reduced soluble tannin content. Dehydrated samples obtained from the astringent fruit at the most advanced ripening stage had similar soluble tannin content as the samples obtained from non-astringent fruit, especially at 60 °C. Besides, a high correlation was observed between the level of astringency perceived by consumers and the decrease of soluble tannin content. Although, in the first ripening stage, consumers preferred the snacks obtained from non-astringent fruits; in the last ripening stage, snacks produced from astringent fruits were equally accepted than the non-astringent ones., Conclusion: Therefore, well-accepted persimmon snacks are obtained from both astringent and non-astringent fruits when advanced ripening stages of persimmon are used. © 2020 Society of Chemical Industry., (© 2020 Society of Chemical Industry.)

The volatile profile of 'Rama Forte' persimmon fruit treated with high concentration of CO 2 or ethanol, as well as the association of specific volatile organic compounds (VOC) to the loss of astringency given by sensory and chemical evaluation were investigated in our study. Fruit were harvested at the maturity stage showing crisp texture and commercial color, and exposed to different astringency removal treatments: 70% CO 2 for 18 h or 1.70 mL kg -1 ethanol for 6 h. Fruit were daily assessed for VOC, astringency, and soluble tannins content throughout eight days at room temperature. The HS-SPME/GC-MS analysis allowed to tentatively identify 31 volatile compounds and two fatty acids. A clear separation of the persimmon fruit from the beginning to the end of the post-treatment period was showed by PCA results, mainly from the fifth day for CO 2 -treated and the seventh day for ethanol-treated persimmon. The loadings from CO 2 treatment highlighted the increase in the concentrations of a great number of compounds with the progression of the days. The compounds 2,4-di-tert-butylphenol and 1-pentadecanal were tentatively identified on fruit from both treatments after the longest periods and were absent on astringent non-treated fruit. These compounds are reported for the first time on persimmon fruit. Astringency tending to absent was noticed from the fifth and the seventh day after the fruit exposition to CO 2 and ethanol vapor, respectively, when flesh soluble tannins concentrations close to 0.1% FW were found. Our study indicates a strong relationship between the astringency removal and the compounds 2,4-di-tert-butylphenol and 1-pentadecanal, supporting them as potential marker compounds for artificial deastringency in 'Rama Forte' persimmon fruit., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Ethnopharmacological Relevance: The botanical identity of the ancient vernacular cynomorium does not correspond to the modern scientific genus while it is not clear how many species of hipocistis (Cytinus sp.) were differentiated by the ancient physicians and whether Cynomorium coccineum was subsumed. The early history of therapeutic uses related to the herbal drugs derived from these parasitic taxa is therefore not easily accessible. Cynomorium coccineum became an important pharmaceutical commodity after the Siege of Malta but its importance decreased in the 18th century and now is considered obsolete., Material and Methods: We compare the morphological, ecological and therapeutic information of Cynomorium and other parasitizing plant taxa across the past 2000 years and contextualize their uses with the pharmacological properties of their principal metabolites focusing on the raise and fall of C. coccineum as a medicine., Results: The therapeutic uses of C. coccineum, the Maltese mushroom, seem to become clearly traceable since the Canon of Medicine by Avicenna. Styptic and astringent drugs such as Cynomorium, Cytinus but also gall apples and many others have been selected for their protein-linking capacity leading to the formation of a protective layer on the mucous membranes, which can be used to reduce the secretion of water and electrolytes in case of diarrhoea, dysentery and external bleedings. Whether C. coccineum is effective as a systemically applied anti-haemorrhagic drug is questionable., Conclusion: It appears that the vernacular cynomorium of the ancients corresponds to an edible Orobanche sp. while it remains doubtful whether the vernacular hipocistis was next to Cytinus sp. also applied to C. coccineum as evidence of C. coccineum parasitizing Cistus sp. is scarce. The isolation of gallic acid used as a styptic and the increasing availability of chemical styptics in the 18th century together with the availability of effective alternative anti-diarrhoeic drugs with a more reliable supply very probably led to the decline of the importance of the Maltese mushroom in pharmacy during the 18th century. The effectiveness of gallic acid as a systemic anti-haemorrhagic remains uncertain., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Wine astringency is important for quality and consumer acceptance. Perception of this mouthfeel is temporal and can be separated further into unique textural sub-qualities. Quantitative data on these astringent sub-qualities in wine however are poorly understood. The aim of this study was to characterize the dynamic astringency profiles of 13 Australian commercial red wines and 2 rosés made from 11 grape varieties using modified progressive profiling by a trained sensory panel (n = 8). Seven attributes generated and defined by the panel (overall astringent intensity and 6 sub-qualities: pucker, mouth coat, dry, grippy, adhesive and graininess) were scored at six time periods (each lasting 10 s), with 20 s gap between each time period. Attributes were rated on 15 cm scales with anchors at 10 and 90% and samples were evaluated in duplicate. The wine composition as well as phenolic profiles were determined. Intensities of astringent sub-qualities were correlated with overall intensity, but the sub-quality profiles at a specific evaluation period and the progression of an attribute varied differently depending on the wine. The discrimination of wines at each time interval was dependent on attribute, and the relative importance of each astringent sub-quality varied at different evaluation periods. Correlations between mouthfeel attributes and chemical measures were established. This study demonstrated the utilisation of modified progressive profiling for wine astringency evaluation, providing a tool to capture quantitative data on astringent sub-qualities in wine., (Crown Copyright © 2019. Published by Elsevier Ltd. All rights reserved.)

The proteinaceous pellicle layer, which develops upon contact with saliva on the surface of teeth, is important for the formation of oral biofilms and for the protection of teeth from abrasion and chemically induced erosion. Astringent food ingredients comprising polyphenols, cationic macromolecules, and multivalent metal salts are known to interact with the pellicle. However, astringent-induced changes in the physicochemical properties of the tooth-saliva interphase are not yet completely understood. Here we provide comprehensive insights into interfacial charging, ultrastructure, thickness, and surface roughness of the pellicles formed on the model substrates silicon oxide (SiO 2 ), Teflon ® AF, and hydroxyapatite, as well as on bovine enamel before and after incubation with the astringents epigallocatechin gallate, tannic acid, iron(III) salt, lysozyme, and chitosan. Quartz crystal microbalance with dissipation monitoring demonstrated viscous behavior of untreated pellicles formed in vitro on the different materials. Electrokinetic (streaming current) measurements revealed that cationic astringents reverse the charge of native pellicles, whereas polyphenols did not change the charge under physiological pH condition. In addition, transmission electron microscopy and atomic force microscopy showed a concentration-dependent increase in average film thickness and pellicle surface roughness as induced by astringents. These multifaceted alterations of the salivary pellicle may come along with an increase in roughness perceived on the teeth, which is part of the complex sensations of oral astringency., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Cosmeceuticals are cosmetics that promise to deliver physiologically relevant benefits without the incorporation of prescription drugs. To entice consumers to purchase these premium priced products, a story must be told of how the cosmeceutical delivers on these appearance improvement promises. The backbone of any cosmeceutical skin care regimen is facial cleansing and moisturizing. This article reviews the novel ingredients and technologies used to achieve these benefits examining what is real and what is not., (Copyright © 2018 Elsevier Inc. All rights reserved.)

It has been suggested that the addition of flavonols (i.e. white grape skins) improves and stabilizes the color of red wines. However, it has been shown that flavonol glycosides produce a mouth-drying and mouth-coating sensation at very low threshold concentrations. Moreover, the addition of polysaccharides to wines is a practice addressed to improve the smoothness and roundness and correct excessive astringency, so we have studied the effect of the addition of yeast mannoproteins (MP) on the interaction between quercetin 3-glucoside and human salivary peptides. Sensory analysis showed the first evidence of the mannoprotein smoothing effect when the flavonol is added to wine. Additionally, MP/SP/polyphenol interactions were studied using fluorescence spectroscopy, dynamic light scattering and isothermal titration calorimetry. Results obtained indicate not only the existence of interactions between mannoproteins and flavonols but also between mannoproteins and salivary proteins (SP), suggesting a possible formation of protein/polyphenol/polysaccharide ternary complex., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The interaction of tannins with salivary proteins is involved in astringency. This paper focussed on saliva lining oral mucosae, the mucosal pellicle. Using a cell-based model, the impact of two dietary tannins (EgC and EgCG) on the mucosal pellicle structure and properties was investigated by microscopic techniques. The role of basic Proline-Rich-Proteins (bPRPs) in protecting the mucosal pellicle was also evaluated. At low (0.05 mM) tannin concentration, below the sensory detection threshold, the distribution of salivary mucins MUC5B on cells remained unaffected. At 0.5 and 1 mM, MUC5B-tannin aggregates were observed and their size increased with tannin concentration and with galloylation. In addition, 3 mM EgCG resulted in higher friction forces measured by AFM. In presence of bPRPs, the size distribution of aggregates was greatly modified and tended to resemble that of the "no tannin" condition, highlighting that bPRPs have a protective effect against the structural alteration induced by dietary tannins., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Ethnopharmacological Relevance: The World Health Organization (WHO) recognizes the potential of plants used in secular traditional medicine and considers this an important source of evidence to assess their effectiveness and safety. Brazil is rich in biodiversity and traditional uses based on the Amerindian culture. However, many processes started with the arrival of the Portuguese in the year 1500. The successive economic cycles, for example, led to destruction of native vegetation and an intense cultural erosion. As a consequence, the information about the use of plants in the past centuries are dispersed and without interpretation. In this study a methodology to evidence the traditionality of Brazilian plants was demonstrated using data about barbatimão barks (Stryphnodendron adstringens (Mart.) Coville - Fabaceae) and Copaiba oleoresin (Copaifera spp. - Fabaceae) in wound healing, was established., Material and Methods: Data about use of the plants were recovered from bibliography published between 1576 and 2011. The books (101) were classified using weights, considering the date of publication and the source of Information. Older books that describe primary information received weight 10, while books written more recently and with secondary information received weight 0.4. A score for each category of medicinal use was calculated based on the books weights and the frequency of citation. A review about the current use of both plants was also performed from ethnobotanical studies published in journals., Results and Discussion: The traditional secular use of barks of barbatimão and oleoresin of copaiba to treat wounds was confirmed based on the historic bibliographic research. The most frequent use of barbatimão in a timeline of 500 years of Brazil's history, was as astringent, whereas for copaíba was as healing of skin and mucosal lesions. The continuous and current use of these plants to treat wounds, confirmed by recent ethnobotanical studies, is an indicative of the resilience of these remedies and their effectiveness., Conclusion: The use of preparations containing barbatimão barks and copaiba oleoresin can be considered effective in the treatment of wounds. Nonetheless, it is necessary to improve the quality of the formulas as established by WHO., (Copyright © 2018 Elsevier B.V. All rights reserved.)

This study examined the effect of zinc supplementation on the sleep quality (SQ) of intensive care unit (ICU) nurses. In a double-blind, randomized controlled trial, 54 ICU nurses were randomly assigned to the intervention group ( n = 27) that received 220 mg zinc sulfate capsules every 72 hours for 1 month and the control group ( n = 26) that received placebo. Sleep quality of ICU nurses was measured by calculating the total quality sleep score using the Pittsburgh Sleep Quality Index (PSQI). The serum zinc level was a secondary outcome. All measurements were calculated at both baseline and 1 month after intervention. The total PSQI, subjective SQ, and sleep latency scores for the intervention group were significantly lower than the control group, which means that the SQ of ICU nurses in the intervention group improved from baseline. The serum zinc level of the intervention group at the end of the study was significantly higher than the control group, which means that zinc supplementation improved participants' serum zinc level. Based on these findings, the researcher suggested that zinc supplementation could be associated with better SQ, subjective SQ, and sleep latency in this group of workers.

Purpose: The compatibility of chemical gingival margin displacement agents with polyether impression materials has not been determined. The aim of this study was to evaluate the setting time of polyether impression elastomers after contact with conventional and experimental gingival displacement agents., Materials and Methods: The study compared the setting time of two polyether impression materials: medium body (Impregum Penta Soft) and light body (Impregum Garant L DuoSoft) after contact with 10 gingival displacement agents, including 5 conventional astringents (10%, 20%, and 25% aluminum chloride, 25% aluminum sulfate, and 15.5% ferric sulfate) and 5 experimental adrenergics (0.1% and 0.01% HCl-epinephrine, 0.05% HCl-tetrahydrozoline, 0.05% HCl-oxymetazoline, and 10% HCl-phenylephrine). As many as 120 specimens (60 light body and 60 medium body) were mixed with 20 μl of each of 10 gingival displacement agents, and the time to achieve maximum viscosity was measured with a viscometer. The setting times of these specimens were compared with the control group of 12 specimens, which were polymerized without contact with the displacement agents. The experiments were performed in two environments: 23°C and 37°C (± 0.1°C). Individual and average polymerization time compatibility indices (PTCI) were calculated. Data were analyzed by 2-way ANOVA (α = 0.05)., Results: The evaluated chemical displacement agents from both groups changed the setting time of light- and medium-body PE. The negative individual PTCI values achieved astringent (20% aluminum chloride) with two PE in both temperature environments. The average PTCI values of the experimental displacement agents at laboratory and intraoral temperatures were significantly higher than the conventional agents., Conclusions: The present findings suggest that experimental retraction agents can be recommended clinically as gingival margin displacement agents with minimal effects on the setting time of medium- and light-body polyether impression materials; however, direct contact of chemical displacement agents and polyether impression materials can be avoided., (© 2016 by the American College of Prosthodontists.)

We explored use of the suction-blister wound model in the assessment of not only epidermal regeneration but also pain, the microvascular response and bacteriology. The effects of topical zinc sulfate were studied to articulate the methodologies in this double-blind trial. One epidermal suction blister (10 mm) was induced on each buttock in 30 healthy volunteers (15 females:15 males) and deroofed on day 0. The wounds were randomized to daily treatment with 1.4% zinc sulfate shower gel (n = 20), placebo (n = 20) or control (n = 20). Digital photography coupled with planimetry, transepidermal water loss (TEWL) measurement and optical coherence tomography (OCT) was benchmarked to the gold standard of histology of 60 full-thickness wound biopsies on day 4. Pain increased after application of the shower gels. Microvessel density, determined from OCT images, increased from day 0 to day 2 in the three groups but increased more with the placebo than with the zinc shower gel (p = 0.003) or the control treatment (p = 0.002) and correlated (r S  = 0.313, p = 0.015) with the inflammatory response on day 4, as determined by histology. Coagulase-negative staphylococci were more common in wounds compared with skin (p = 0.002) and was reduced (p = 0.030) with zinc sulfate treatment. Planimetric analysis of digital wound images was not biased (p = 0.234) compared with histology, and TEWL measurements showed no correlation (r S  = 0.052, p = 0.691) with epithelialization. Neoepidermal formation, determined by histology, did not differ (p = 0.290) among the groups. Zinc sulfate reduced (p = 0.031) the release of lactate dehydrogenase from cultured gel-treated keratinocytes isolated from the blister roofs. Therefore, combination of the standardized suction-blister wound model with noninvasive planimetry and OCT is a useful tool for assessing wound therapies. Zinc sulfate transiently dampened inflammation and reduced bacterial growth., (© 2018 by the Wound Healing Society.)

Many of scientific evidences suggest that regular consumption of fruits and vegetables can prevent chronic diseases. In Northern Thailand, there are many vegetables that are usually consumed by local people. In this study, 17 local vegetables were selected and extracted with 95% ethanol. The extracts were screened for 5α-reductase inhibitory activity, total tannin and flavonoid contents, astringent and antioxidant activities. The results showed that Spondias pinnata and Ocimum americanum had the highest tannin and flavonoid content, respectively. Neptunia oleracea was the most potent 5α-reductase inhibitor. For antioxidant activities, S pinnata was the most potent ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) radical scavenger and the most potent ferric reducer. Polygonatum odoratum was the most potent hydrogen peroxide scavenger and Leucaena leucocephala was the most potent DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenger among the tested samples. This suggests that local vegetables in Northern Thailand have a health promotion potential, which can be further developed as nutritional supplements, preventive medicines, and topical products for cosmetic purposes.

Texture contributes to food acceptance, but oral texture perception is incompletely understood. Presently, we quantified individual sensitivities to lingual tactile roughness and assessed the impact of age, salivary flow (SF), and fungiform papillae density (FPD) on threshold and suprathreshold perception. Additionally, we tested the hypothesis that individuals highly sensitive to tactile roughness exhibit sensitivity to astringent stimuli. Detection thresholds (DTs) were determined using the staircase method for surface roughness from stainless steel coupons (Ra; 0.177-0.465 µm) and astringency elicited by epigallocatechin gallate (EGCG; 0-1.64 mM) and tannic acid (TA; 0-0.71 mM) from 30 individuals. Suprathreshold sensitivity was assessed from intensity ratings of electroforming comparator surfaces with roughnesses ranging from 0.51 to 22.8 µm and astringent stimuli ranging from 0 to 5.2 mM (EGCG) and from 0 to 1.9 mM (TA). SF, FPD, and astringent food pleasantness scores were collected. Variability in threshold roughness sensitivity enabled dividing subjects into high (RHi; n = 16) and low (RLo; n = 14) sensitivity groups; however, no significant differences in age, FPD, or SF were observed across these cohorts. Interestingly, compared with RLo, the RHi group exhibited greater sensitivity to EGCG but not TA astringency and indicated greater pleasantness from astringent foods (e.g., unripe bananas and dark chocolate). When participants were allocated into high (SalivaHi; n = 15) or low SF (SalivaLo; n = 15) groups, TA-evoked astringency thresholds were significantly lower in SalivaHi whom also indicated greater pleasantness from astringent red wines. For suprathreshold assessments of surface roughness or astringency, no significant associations were identified with age, FPD, or SF. Suprathreshold roughness sensitivity was, however, associated with suprathreshold sensitivity to EGCG but not TA astringency., (© The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objectives: This electron microscopic study aimed at investigating effects of oral astringent stimuli on the enamel pellicle's morphology., Methods: Pellicles were formed in situ within 30min on bovine enamel slabs, fixed to individuals' upper jaw splints. The pellicle-coated specimens were immersed in vitro in seven diverse astringent solutions and subsequently analyzed by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, as well as transmission electron microscopy (TEM). Four biocompatible astringents, namely the polyphenol epigallocatechin gallate, the metal salt iron(III) sulfate, the basic protein lysozyme, and the aminopolysaccharide chitosan, were additionally applied in situ. After rinsing the oral cavity with these compounds, the pellicle's ultrastructure was imaged by SEM and TEM, respectively. Untreated pellicle samples served as controls., Results: Exposure to polyphenols and lysozyme induced particularly thicker and electron-denser pellicles in comparison to the control pellicle with similar characteristics in vitro and in situ. In contrast, acidic chitosan and metal salt solutions, respectively, revealed minor pellicle alterations. The incorporation of Fe and Al into the pellicles treated with the corresponding inorganic salts was verified by EDX analysis., Conclusions: Astringent-induced pellicle modifications were for the first time visualized by TEM. The ultrastructural alterations of the dental pellicle may partly explain the tooth-roughening effect caused by oral astringent stimuli., Clinical Significance: Astringents might modify the pellicle's protective properties against dental erosion, attrition, as well as bacterial adhesion, and by this means may influence tooth health. The findings may thus be particularly relevant for preventive dentistry., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Aim: The purpose of study was to assess the effect of zinc sulfate (ZS) supplementation on premenstrual syndrome (PMS) and health-related quality of life (QoL)., Methods: This was a double-blind randomized and placebo-controlled trial using the parallel technique conducted between June 2013 and May 2014. A total of 142 women (age, 20-35 years) with PMS were allocated to either the ZS or placebo group. The women in the intervention group received ZS 220-mg capsules (containing 50 mg elemental zinc) from the 16th day of the menstrual cycle to the second day of the next cycle. Data were collected using the Premenstrual Symptoms Screening Tool (PSST) and 12-item Short-Form Health Survey Questionnaire., Result: The prevalence of moderate to severe PMS in the ZS group significantly decreased throughout the study period (9.5% in the first, 6% in the second and 2.6% in the third month of the study, P < 0.001), but in the control placebo group this reduction was seen only in the first month of the study (14.2% in the first, 13.7% in the second and 13.5% in the third month, P = 0.08). Also, ZS improved the PSST component scores throughout the study period. The mean scores of QoL in physical and mental components were significantly improved in the ZS intervention group. However, the differences were statistically significant only 3 months after the intervention., Conclusion: Zinc sulfate, as a simple and inexpensive treatment, was associated with improvement of PMS symptoms and health-related QoL. Additional studies are warranted to confirm these findings., (© 2017 Japan Society of Obstetrics and Gynecology.)

Individual differences in astringency perception are poorly understood. Astringency from tannins stimulates the release of specific classes of salivary proteins. These proteins form complexes with tannins, altering their perceived astringency and reducing their bioavailability. We studied the bitter compound, 6-n-propylthioural (PROP), as a phenotypic marker for variation in astringency perception and salivary protein responses. Seventy-nine subjects classified by PROP taster status rated cranberry juice cocktail (CJC; with added sugar) supplemented with 0, 1.5 or 2.0g/L tannic acid (TA). Saliva for protein analyses was collected at rest, or after stimulation with TA or cranberry juice (CJ; without added sugar). CJC with 1.5g/L tannic acid was found to be less astringent, and was liked more by PROP non-taster males than PROP taster males, consistent with the expectation that non-tasters are less sensitive to astringency. Levels of acidic Proline Rich Proteins (aPRPs) and basic Proline Rich Proteins (bPRPs) decreased after TA, while levels of aPRPs, bPRPs and Cystatins unexpectedly rose after CJ. Increases in bPRPs and Cystatins were only observed in PROP tasters. The PROP phenotype plays a gender-specific, but somewhat limited role in the perceived astringency of tannic-acid supplemented, cranberry juice cocktail. The PROP phenotype (regardless of gender) may also be involved in the release of salivary proteins previously implicated in oral health., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Bone morphogenetic protein-2 (BMP-2)/Smad signaling pathway plays an important role in regulating osteoblast (OB) differentiation. OB differentiation is a key process of bone formation. Aluminum (Al) exposure inhibits bone formation and causes Al-induced bone disease. However, the mechanism is not fully understood. To investigate whether BMP-2/Smad signaling pathway is associated with OB differentiation in aluminum trichloride (AlCl 3 )-treated OBs, the primary rat OBs were cultured and exposed to 0 (control group, CG), 1/40 IC 50 (low-dose group, LG), 1/20 IC 50 (mid-dose group, MG), and 1/10 IC 50 (high-dose group, HG) of AlCl 3 for 24 h, respectively. We found that the expressions of OB differentiation markers (Runx-2, Osterix and ALP) and BMP-2/Smad signaling pathway components (BMP-2, BMPR-IA, p-BMPR-IA, BMPR-II, p-Smad1/5/8 and p-Smad1/5/8/4) were all decreased in AlCl 3 -treated OBs compared with the CG. These results indicated that inhibition of OB differentiation by AlCl 3 was associated with inhibition of BMP-2/Smad pathway component expression. Our findings provide a novel insight into the mechanism of AlCl 3 -induced bone disease., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Astringents (alum, malic acid, tannic acid) representing 3 broad classes (multivalent salts, organic acids, and polyphenols) were characterized alone, and as 2- and 3-component mixtures using isoboles. In experiment 1, participants rated 7 attributes ("astringency," the sub-qualities "drying," "roughing," and "puckering," and the side tastes "bitterness," "sourness," and "sweetness") using direct scaling. Quality specific power functions were calculated for each stimulus. In experiment 2, the same participants characterized 2- and 3-component mixtures. Multiple factor analysis (MFA) and hierarchical clustering on attribute ratings across stimuli indicate "astringency" is highly related to "bitterness" as well as "puckering," and the subqualities "drying" and "roughing" are somewhat redundant. Moreover, power functions were used to calculate indices of interaction (I) for each attribute/mixture combination. For "astringency," there was evidence of antagonism, regardless of the type of mixture. Conversely, for subqualities, the pattern of interaction depended on the mixture type. Alum/tannic acid and tannic acid/malic acid mixtures showed evidence of synergy for "drying" and "roughing"; alum/malic acid mixtures showed evidence of antagonism for "drying," "roughing," and "puckering." Collectively, these data clarify some semantic ambiguity regarding astringency and its subqualities, as well as the nature of interactions of among different types of astringents. Present data are not inconsistent with the idea that astringency arises from multiple mechanisms, although it remains to be determined whether the synergy observed here might reflect simultaneous activation of these multiple mechanisms., (© The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The purpose of this study was to evaluate the antibacterial activity against polymicrobial (PM) biofilms of a condensed tannin extracted from astringent persimmon (PS-M), which is contained in refreshing beverages commercially available in Japan. Salivary PM biofilms were formed anaerobically on glass coverslips for 24 and 72 h and were treated for 5 min with sterilized deionized water (DW), 0.05 and 0.2 wt% chlorhexidine digluconate (CHX), and 0.5-4.0 wt% PS-M solution. The colony forming units (CFU/mL) were determined and morphological changes of the biofilms were observed by scanning electron microscopy (SEM). The CFUs were lower in all PS-M and CHX groups compared to the DW group. PS-M exerted a dose-dependent effect. PS-M (1.53 × 10(7)) at a dose of 4.0 wt% had the same effect as 0.2 wt% CHX (2.03 × 10(7)), regardless of the culture period. SEM revealed the biofilm structures were considerably destroyed in the 4.0 wt% PS-M and 0.2 wt% CHX. These findings indicate that the antibacterial effects of PS-M, a naturally derived substance, are comparable to those of CHX. PS-M may keep the oral cavity clean and prevent dental caries and periodontal disease related to dental plaque, as well as systemic disease such as aspiration pneumonitis.

Social interaction enables animals to transmit various types of sensory information that can modulate learned avoidance behavior and fear responses, which are important to survival. We previously reported that, under a passive avoidance paradigm, avoidance behavior is facilitated when a rat observes another rat (demonstrator) receiving a shock when performing a specific behavior. However, the sensory mechanisms underlying this 'social facilitation of avoidance' are not well understood. The present study examined the role of sensory pathways for social transmission of avoidance, focusing on the olfactory and visual systems. The olfactory ability of observer rats was blocked by an intranasal application of ZnSO4, and their visual ability was blocked by an opaque partition placed between observer and demonstrator rats. We found that blocking either olfactory or visual input drastically diminished the social transmission of avoidance. Interestingly the social transmission of fear responses remained intact even when olfactory or visual information was blocked. These results indicate that the social transmission of avoidance is mediated not by any single sensory modality but by multisensory interaction in rats, suggesting a distinct sensory mechanism from that underlying the social transmission of fear., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Yarrow (Achillea millefolium L.) is an important medicinal plant with different pharmaceutical uses. A. millefolium has been used for centuries to treat various diseases including malaria, hepatitis and jaundice. A. millefolium is commonly prescribed to treat liver disorders. It is also used as an anti-inflammatory agent and is a hepatoprotective herb. A. millefolium is considered safe for supplemental use. It has antihepatotoxic effects also. It is prescribed as an astringent agent. It is prescribed in hemorrhoids, headache, bleeding disorders, bruises, cough, influenza, pneumonia, kidney stones, high blood pressure, menstrual disorders, fever, rheumatoid arthritis, gout, osteoarthritis, hemorrhagic disorders, chicken pox, cystitis, diabetes mellitus, indigestion, dyspepsia, eczema, psoriasis and boils.

The aim of this study was to investigate the effect of norepinephrine (NE) on spleen lymphocytes exposed to aluminum trichloride (AlCl3). In this experiment, lymphocytes were isolated from spleens of healthy Wistar rats weighing about 130 g and cultured with RPMI-1640 medium containing the final concentration of 0.552 mmol/L AlCl3. NE was added to the cultured cells at the final concentrations of 0 (control group), 0.1 (low-dose group), 1 (mid-dose group), and 10 (high-dose group) nmol/L. No addition of both AlCl3 and NE serviced as blank (BG). The T lymphocyte proliferation; the contents of IL-2, TNF-α, and T lymphocyte subsets; immunoglobulin G (IgG) and intracellular cyclic adenosine monophosphate (cAMP) concentrations; and β2-adrenergic receptor (β2-AR) density were measured at the end of the culture. The result showed that NE decreased T lymphocyte proliferation and the contents of IL-2, TNF-α, and T lymphocyte subsets whereas increased the concentrations of IgG and intracellular cAMP and β2-AR density of the lymphocyte exposed to AlCl3. AlCl3 exposure without adding NE showed the similar impacts on these measures compared with BG. The results suggested that NE aggravated AlCl3 immunotoxicity on the lymphocytes and disordered the immune functions of the lymphocyte through the β2-AR-cAMP signal pathway.

Unlabelled: Astringency, a tactile sensation felt in the mouth after exposure to various foods, is poorly understood. Our objective was to investigate the mechanism of astringency by determining if it was related to a loss of saliva's ability to lubricate mouth surfaces. We used 2 complementary approaches: (1) instrumentally determining if astringents decrease salivary lubricity and (2) determining if human subjects could perceive these changes. Instrumentally measured friction of saliva-tannin mixtures was greater than that of saliva-water mixtures, but these differences were not detectable by human subjects. Adding alum or acid to saliva did not increase friction measured either instrumentally or by human subjects rubbing the mixture between their thumb and fingers. Thus a loss of salivary lubricity is likely not a central mechanism of astringency., Practical Applications: If astringency's mechanism can be elucidated, food producers will gain knowledge that will enable them to manufacture, alter, or treat the food in a way to retain its healthful attributes while minimizing the astringency. This knowledge will also benefit sensory scientists interested in the intensity perceptions of the sensations and will allow them to devise improved methods for the assessment of the attribute., (© 2012 Institute of Food Technologists®)

Whey protein beverages have been shown to be astringent, which means that they are not appealing to consumers. The exact mechanism of astringency in whey protein beverages is yet to be fully elucidated. In this preliminary study, the binding between β-lactoglobulin (β-LG), lactoferrin (LF) and human oral epithelial cells (HSC-2 and NO-1-N-1 cells) at pH 3.5 and pH 7.4 was assayed as a function of protein concentration using an enzyme-linked immunosorbent assay. The binding of β-LG and LF to HSC-2 and NO-1-N-1 cells was dependent on protein type, protein concentration, pH and time. The intensity of the binding to HSC-2 and NO-1-N-1 cells was much greater for LF than for β-LG and was protein concentration dependent, which was consistent with the in vivo astringency perception of LF and β-LG. The findings demonstrated that the binding interaction between whey proteins and human oral epithelial cells may play an important role in the perception of astringency in whey protein beverages., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Unlabelled: Astringency is a complex sensation mainly caused by the precipitation of salivary proteins with polyphenols. In wine it can be enhanced or reduced depending on the composition of the medium. In order to investigate the effect of ethanol, tartaric acid, fructose, and commercial mannoproteins (MPs) addition on the precipitation of salivary proteins, the saliva precipitation index (SPI) was determined by means of the sodium dodecyl sulphate polyacrylamide gel electrophoresis of human saliva after the reaction with Merlot wines and model solutions. Gelatin index, ethanol index, and Folin-Ciocalteu index were also determined. As resulted by Pearson's correlation, data on SPI were well correlated with the sensory analysis performed on the same samples. In a second experiment, increasing the ethanol (11%-13%-17%), MPs (0-2-8 g/L), fructose (0-2-6 g/L) level, and pH values (2.9-3.0-3.6), a decrease in the precipitation of salivary proteins was observed. A difference in the SPI between model solution and red wine stated that an influence of wine matrix on the precipitation of salivary proteins occurred., Practical Application: Results provide interesting suggestions for enologists, which could modulate the astringency of red wine by: (i) leaving some residual reducing sugars (such as fructose) in red wine during winemaking of grapes rich in tannins; (ii) avoiding the lowering of pH; (iii) adding commercial mannoproteins or promoting a "sur lie" aging; and (iv) harvesting grapes at high technological maturity in order to obtain wines with a satisfactory alcoholic content when possible., (© 2012 Institute of Food Technologists®)

Understanding astringency has focused on the interaction of tannins with the salivary proline-rich proteins (PRPs), although it remains unclear if other astringents precipitate the PRPs or how this interaction relates to sensory perceptions of astringency. We used 2 approaches to compare how distinct classes of astringent compounds interacted with the salivary PRPs and mucins. Using sodium dodecyl sulfate polyacrylamide gel electrophoresis, we evaluated protein patterns and characterized the salivary proteins present in the supernatants and pellets of pooled saliva assayed with tannin, alum, and hydrochloric acid solutions. Tannins and alum precipitated many of the PRPs, but acid did not. Mucins were precipitated by both the acid and alum, but not by the tannins. From our research, it appears that the precipitation of salivary proteins may be involved in the mechanism of astringency, but the precipitation of PRPs is not requisite for the development of astringency. We also measured mucin and deoxyribonucleic acid content of expectorated solutions of astringents that panelists swished in their mouths to determine if astringency was associated with a loss of oral lubricating films., (© 2012 Institute of Food Technologists®)

Astringency has been defined as a group of sensations involving dryness, tightening, and shrinking of the oral surface. It has been accepted that astringency is due to the tannin-induced interaction and/or precipitation of the salivary proline-rich proteins (PRPs) in the oral cavity, as a result of the ingestion of food products rich in tannins, for example, red wine. The sensory evaluation of astringency is difficult, and the existence of fast and reliable methods to its study in vitro is scarce. So, in this work, the astringency of red wine supplemented with oligomeric procyanidins (condensed tannins), and the salivary proteins (SP) involved in its development were evaluated by high-performance liquid chromatography analysis of human saliva after its interaction with red wine and by sensorial evaluation. The results show that for low concentration of tannins, the decrease of acidic PRPs and statherin is correlated with astringency intensity, with these families having a high relative complexation and precipitation toward condensed tannins comparatively to the other SP. However, for higher concentrations of tannins, the relative astringency between wines seems to correlate's to the glycosylated PRPs changes. This work shows for the first time that the several families of SP could be involved in different stages of the astringency development.

The aim of this in vitro study was to evaluate the cytotoxic effects of the vasoconstrictor experimental gingival retraction agents (VEGRAs) in a dynamic setting. The strong cytotoxic effects of the astringent-based conventional gingival retraction agents (ACGRAs) on human gingival fibroblasts (HGFs) in vitro was our motivation to evaluate the biocompatibility of the vasoconstrictor-based experimental gingival retraction agents (VEGRAs) for the selected minimally invasive chemical agent. These agents were used to create three self-made retraction gels. Human gingival fibroblasts (HGFs) were treated with two groups of retraction agents: 1) three α- and β-adrenergic agents (VEGRA-αβ-s) based on 0.1%, 0.01% and 0.05% HCl-epinephrine, and 2) seven α-adrenergic agents (VEGRA-α-s), including two commercially available 0.05% HCl-tetrahydrozoline solutions, one 0.05% HCl-oxymetazoline solution, 10% HCl-phenylephrine solution, and three new self-made experimental 0.05% HCl-tetrahydro zoline-based gels. The methyl thiazolyl tetrazolium (MTT) colorimetric assay was performed to determine the oxidoreductive mitochondrial function after 3, 5, 10 min and 24 h of incubation. The cytotoxic effect, measured by cell viability lower than the 50% threshold, was not observed at any time period, even 24 h after application of 0.05% HCl-tetrahydrozolinebased self-manufactured retraction gels. High cell viability values of human gingival fibroblasts after the treatment with the three self-made 0.05% HCl-tetrahydrozoline- based gels may serve as a basis for further studies aimed at selecting the best retraction agents biocompatible with gingival margin tissues.

Astringency, an orosensory sensation associated with dietary tannins, contributes to food appetitiveness/aversiveness. However, astringency perception varies greatly among individuals. This study examined whether genetically homogeneous naïve mice display appetitiveness/aversiveness when provided with tannin-containing drink solutions. Ingestion of serial dilutions of tannic acid (TA) by inbred mice (A/Snell) was assessed by a one-bottle preference test. Drink intake was far predominant at night (circadian rhythm). TA concentration-dependently inhibited daily drink consumption. Overnight consumption of TA solutions (range = 0.5-8 g/L) decreased linearly to zero during the first night and was recovered significantly during subsequent nights. TA also inhibited drink consumption in another two inbred mouse strains. The protein fraction of saliva collected from naive mice was markedly reactive with TA at the concentrations shown to affect drink consumption. Thus, testing for drink ingestion in inbred mice during short-term (overnight) exposure to tannin-containing liquid foods represents an advantageous animal model for assessing astringency.

Aluminium (Al) stress is an important factor limiting crop yields in acid soils. Despite this, very little is known about the mechanisms of resistance to this stress in woody plants. To understand the mechanisms of Al-toxicity and response in blueberries, we compared the impact of Al-stress in Al-resistant and Al-sensitive genotypes using Vaccinium corymbosum L. (Ericaceae) as a plant model. We investigated the effect of Al-stress on the physiological performance, oxidative metabolism and expression of genes that encode antioxidant enzymes in two V. corymbosum cultivars maintained hydroponically with AlCl(3) (0 and 100 μM). Microscopic analyses of Al-treated root tips suggested a higher degree of Al-induced morphological injury in Bluegold (sensitive genotype) compared to Brigitta (resistant genotype). Furthermore, the results indicated that Brigitta had a greater ability to control oxidative stress under Al-toxicity, as reflected by enhancement of several antioxidative and physiological properties (radical scavenging activity: RSA, superoxide dismutase: SOD and catalase: CAT; maximum quantum yield: Fv/Fm, effective quantum yield: ФPSII, electron transport rate: ETR and non-photochemical quenching: NPQ). Finally, we analyzed the expression of genes homologous to GST and ALDH, which were identified in a global expression analysis. In the resistant genotype, the expression of these genes in response to Al-stress was greater in leaves than in roots., (Copyright © 2011 Elsevier Masson SAS. All rights reserved.)

This study aims to examine the effect of zinc administration on liver glycogen levels of rats in which diabetes was induced with streptozotocin and which were subjected to acute swimming exercise. The study was conducted on 80 adult Sprague-Dawley male rats, which were equally allocated to eight groups: group 1, general control; group 2, zinc-administrated control; group 3, zinc-administrated diabetic control; group 4, swimming control; group 5, zinc-administrated swimming; group 6, zinc-administrated diabetic swimming; group 7, diabetic swimming; group 8, diabetic control group. In order to induce diabetes, animals were injected with 40 mg/kg intraperitoneal (ip) streptozotocin. The injections were repeated in the same dose after 24 h. Animals which had blood glucose at or above 300 mg/dl 6 days after the last injections were accepted as diabetic. Zinc was administrated ip for 4 weeks as 6 mg/kg/day per rat. Hepatic tissue samples taken from the animals at the end of the study were fixed in 95% ethyl alcohol. Cross sections of 5 µm thickness, taken by the help of a microtome from the tissue samples buried in paraffin, were placed on a microscope slide and stained with periodic acid-Schiff and evaluated by light microscope. All microscopic images were transferred to a PC and assessed with the help of Clemex PE3.5 image analysis software. The lowest liver glycogen levels in the study were obtained in groups 3, 4, 6, 7, and 8. Liver glycogen levels in group 5 were higher than groups 3, 4, 6, 7, and 8, but lower than groups 1 and 2 (p < 0.05). Groups 1 and 2 had the highest liver glycogen levels. The results obtained from the study indicate that liver glycogen levels which dropped in acute swimming exercise were restored by zinc administration and that diabetes induced in rats prevented the protective effect of zinc.

Objective: The aim of the present study was to assess the null hypothesis that the astringency and loss of lubrication in the oral cavity are not related to the properties of the epigallocatechin-3-gallate (EGCG) adlayer, the affinity and the entropy-drive of EGCG binding to saliva., Methods: The mass, thickness, and viscoelasticity of the EGCG adlayer and the temperature dependence of EGCG adsorption onto saliva surfaces were determined by quartz crystal microbalance with dissipation (QCM-D). The affinities of EGCG to human whole saliva (WS) and to parotid saliva (PS) were carried out by QCM-D monitoring and fluorescence quenching., Results: The stiffer and more compact EGCG adlayers were formed on saliva surfaces at various concentrations of EGCG. The affinity for EGCG binding to WS was higher than that to PS. The precipitation of EGCG/saliva was temperature-dependent. The driving force of EGCG binding to saliva is dominated by the hydrogen bond, the hydrophobic reaction, and the entropy-drive, which were confirmed by the FTIR spectra and the measurement of temperature- dependence, respectively., Conclusion: The viscoelasticity of the EGCG adlayer, the affinity of EGCG to saliva, and the priority of EGCG binding to hydrophobic proteins on the mucosa may account for the oral astringency and loss of lubrication.

The extent of the change in salivary protein characteristics after repeated stimulations was shown to be correlated to differences in perceived astringency. Salivary characteristics of 77 subjects were compared after masticatory (S1) and taste/masticatory (S2) stimulations. The variations (S2 minus S1) of protein concentration and saliva haze-forming capacity (HFC) were used to define 3 subject groups: low responding (LR, n = 20), medium responding (MR, n = 37), and high responding (HR, n = 20). Salivary protein concentration did not change in LR subjects; decreased a little, but significantly, in MR subjects; and strongly decreased in HR subjects. After S2, HFC increased in LR subjects, slightly decreased in MR subjects, and strongly decreased in HR subjects. Salivary protein electrophoresis patterns for HR and LR subjects were analyzed. No significant modifications of glycosylated proline-rich proteins (PRPs), PRPs, and amylases and a slight decrease in cystatins and histatins were found when S2 and S1 samples were compared in LR subjects, whereas HR subjects showed a strong decrease in all the above proteins after S2. Significant modifications of mucins were not found. Tannic acid (TA, 3 g/L) astringency ratings after S1 from HR subjects were significantly higher than those from the other 2 groups, whereas no differences were found comparing LR and MR ratings. The "carryover" effect due to 4 sequential exposures to TA samples (1.4 g/L) was observed in both HR and MR groups, whereas no significant astringency rating variation was found in the LR group. The results support the inhibiting role of proteins with strong phenol-binding activity on astringency elicitation. Individual physiological variations of parotid gland functionality might account for differences in sensitivity to astringent phenolic stimuli.

Ethyl pyruvate (EP), a simple aliphatic ester of pyruvic acid, has been shown to act as an anti-inflammatory molecule in various pathological conditions, which include sepsis or hemorrhagic shock. Recently, we showed that ethyl pyruvate has a neuroprotective effect in the postischemic brain and also in KA-induced pathogenesis in the brain. In this study, we examined whether aspirin augments neuroprotective effect of ethyl pyruvate in transient focal ischemia model by complementing the neuroprotective effects of ethyl pyruvate. Although, most of neuroprotective effect of aspirin has been attributed to the anti-platelet action, aspirin also has direct neuroprotective effects, including NF-kappaB inhibition. Ethyl pyruvate dose-dependently suppressed infarct formation in the postischemic brain, wherein intravenous administration of 5 mg/kg ethyl pyruvate 30 min after the occlusion reduced infarct volume to 34.5 +/- 15.5% (n = 6, P < 0.01) of that of the untreated control. In combination with aspirin (5 mg/kg, i.v.), the neuroprotective effect was enhanced, resulting in 16.0 +/- 5.9% (n = 6, P < 0.01) infarct volume. The time window for synergistic neuroprotection by ethyl pyruvate and aspirin extended to 9 h post-MCAO. The synergistic reduction in infarct volume was accompanied by suppression of the clinical manifestations associated with cerebral ischemia including motor impairment and neurological deficits. Inflammatory processes including microglial activation and proinflammatory cytokine expression were notably suppressed by the combination treatment in the postischemic brain and in primary microglia cultures, wherein ethyl pyruvate and aspirin modulate NF-kappaB signaling differentially. Aspirin interferes with IkappaB phosphorylation and degradation in the cytoplasm, possibly by specifically inhibiting IkappaB kinase-beta, whereas, the effect of ethyl pyruvate seems to occur in the nucleus, where it may interfere with the binding of NF-kappaB to responsive promoter elements in the target genes. Similar enhancement in neuroprotective effect was also observed in primary cortical cultures after NMDA or Zn(2+) treatment or oxygen-glucose deprivation. Together, these results indicate that combination treatment of ethyl pyruvate and aspirin affords synergistic neuroprotection in the postischemic brain with a wide therapeutic window, in part via differential modulation of the NF-kappaB signaling pathway.