Saliva: An all-rounder of our body

Investigation of Hydrocolloid Plant Polysaccharides as Potential Candidates to Mimic the Functions of MUC5B in Saliva

The successful substitution of complex physiological fluids, such as human saliva, remains a major challenge in drug development. Although there are a large number of saliva substitutes on the market, their efficacy is often inadequate due to short residence time in the mouth, unpleasant mouthfeel, or insufficient protection of the teeth. Therefore, systems need to be identified that mimic the functions of saliva, in particular the salivary mucin MUC5B and the unique physiological properties of saliva. To this end, plant extracts known to contain hydrocolloid polysaccharides and to have mucus-forming properties were studied to evaluate their suitability as saliva substitutes. The aqueous plant extracts of Calendula officinalis, Fucus sp. thalli, and lichenan from Lichen islandicus were examined for composition using a range of techniques, including GC-MS, NMR, SEC, assessment of pH, osmolality, buffering capacity, viscoelasticity, viscoelastic interactions with human saliva, hydrocolloid network formation, and in vitro cell adhesion. For this purpose, a physiologically adapted adhesive test was developed using human buccal epithelial cells. The results show that lichenan is the most promising candidate to mimic the properties of MUC5B. By adjusting the pH, osmolality, and buffering capacity with K2HPO4, it was shown that lichenan exhibited high cell adhesion, with a maximum detachment force that was comparable to that of unstimulated whole mouth saliva.

The Association between Salivary Metabolites and Gingival Bleeding Score in Healthy Subjects: A Pilot Study

Periodontal diseases, including gingivitis and periodontitis, are among the most prevalent diseases in humans. Gingivitis is the mildest form of periodontal disease, characterized by inflammation of the gingiva caused by the accumulation of dental plaque. Salivary diagnostics are becoming increasingly popular due to the variation in saliva composition in response to pathological processes. We used a metabolomics approach to investigate whether a specific saliva metabolic composition could indicate preclinical stage of gingivitis. 1H-NMR spectroscopy was used to obtain the salivary metabolite profiles of 20 healthy subjects. Univariate/multivariate statistical analysis evaluated the whole saliva metabolite composition, and the Full-Mouth Bleeding Score (FMBS) was employed as a classification parameter. Identifying a signature of specific salivary metabolites could distinguish the subjects with high FMBS scores but still within the normal range. This set of metabolites may be due to the enzymatic activities of oral bacteria and be associated with the early stages of gingival inflammation. Although this analysis is to be considered exploratory, it seems feasible to establish an FMBS threshold that distinguishes between the absence and presence of early inflammatory alterations at the salivary level.

A cross-sectional study on activity impairment in primary Sjogren's syndrome

OBJECTIVE

The aim of this cross-sectional study was to show relations between activity impairment and salivary gland involvement for patient empowerment in primary Sjogren's syndrome (pSS).

METHODS

In the study, 86 patients with pSS were included. The data were collected through clinical examinations and a questionnaire regarding Work Productivity and Activity Impairment (WPAI), EULAR Sjogren's syndrome patient-reported index (ESSPRI) and Oral Health Impact Profile-14 (OHIP-14). Relations were analysed by using mediation and moderation analyses. In simple mediation analysis, an independent variable (X) influences outcome variable (Y) through a mediator variable (M) whereas a moderator variable (W) affects the direction of the relationship between the dependent (Y) and independent variables (X).

RESULTS

Increases in ESSPRI-Dryness score (X) (p = 0.0189) and OHIP-14 score (M) (p = 0.0004) were associated with the poor WPAI activity impairment score (Y) in the first mediation analysis. The WPAI activity impairment score was mediated by the elevated ESSPRI-Fatigue score (X) (p = 0.03641) and low U-SFR (M) (p = 0.0000) in the second mediation analysis. In addition, ESSPRI-Pain score (W) was the significant moderator for WPAI activity impairment (Y) in patients without hyposalivation in the moderation analysis (p = 0.0010).

CONCLUSION

WPAI activity impairment was affected by both ESSPRI-Dryness with OHRQoL and ESSPRI-Fatigue with SFR in glandular involvement.

Advances in Research on Pig Salivary Analytes: A Window to Reveal Pig Health and Physiological Status

Saliva is an important exocrine fluid that is easy to collect and is a complex mixture of proteins and other molecules from multiple sources from which considerable biological information can be mined. Pig saliva, as an easily available biological liquid rich in bioactive ingredients, is rich in nucleic acid analytes, such as eggs, enzymes, amino acids, sugars, etc. The expression levels of these components in different diseases have received extensive attention, and the analysis of specific proteins, metabolites, and biological compositions in pig saliva has become a new direction for disease diagnosis and treatment. The study of the changes in analytes in pig saliva can provide a new strategy for early diagnosis, prognosis assessment, and treatment of diseases. In this paper, the detection methods and research progress of porcine salivary analytes are reviewed, the application and research progress of porcine salivary analytes in diseases are discussed, and the future application prospect is presented.

Dental care professionals' awareness of oral dryness and its clinical management: a questionnaire-based study

BACKGROUND

Despite the high prevalence of oral dryness and awareness of its complications, there is limited research on the clinical management of patients with oral dryness in general dental care.

PURPOSE

To (1) describe and compare awareness among dental care professionals regarding saliva functions, potential causes and complications of oral dryness, and patient management (2) Investigate if the length of professional experience influences these aspects.

METHODS

A digital self-administrated survey was sent to 2668 dental care professionals working in the general dental care, Public Dental Service, in Sweden. Twelve dental care professionals reviewed the questionnaire prior to its distribution. The questionnaire comprised 32 questions about patient management, awareness of saliva functions, causes and complications of oral dryness, and self-assessment queries.

RESULTS

The response rate was 18.6% (241 dentists and 257 dental hygienists). Older adults (65+) were asked more often about dry mouth (93.0%) compared to those aged 18-23 years (50.0%) and those under 18 years (24.9%). Dental hygienists encountered individuals with oral dryness more frequently (61.1%) than dentists (48.5%) (p < 0.01), and more often asked individuals in the age groups 18-23 years (p = 0.003), 24-40 years (p = 0.045), and 41-65 years (p = 0.031) about dry mouth. A higher proportion of dental hygienists (88.3%) than dentists (51.0%) had measured salivary secretion rate, (p < 0.001) and more often suggested preventive dental care 3-4 times a year, (42.5% vs. 30.5%) (p < 0.007). Dentists had a higher awareness of saliva functions, while dental hygienists had a higher awareness about causes and complications of oral dryness. Higher proportions of dentists and dental hygienists with over 10 years of professional experience had measured salivary secretion rate (69.1% vs. 95.7%) compared to their counterparts with less than 10 years of professional experience (35.9% vs. 79.5%) (p < 0.001 for both).

CONCLUSION

Compared to dentists, dental hygienists were more attentive to patients with oral dryness as they encountered these individuals more often, asked more age-groups, suggested frequent preventive measures, and had higher awareness of the causes and complications of oral dryness. Length of professional experience could improve both the management of patients with oral dryness and awareness of its causes, particularly for dental hygienists.

Effect of the Teeth Whitening Procedure on the Mineral Composition of Oral Fluid

The basis of modern tooth whitening systems is the use of a whitening gel, which usually contains hydrogen peroxide or carbamide peroxide. The study included 81 patients aged 22 to 35 years with a tooth color A2 and a darker color on the Vita Classic scale. The purpose of our research was to identify a new approach to whitening teeth to improve safety and gentleness. To perform this, we assessed the effect of the tooth whitening procedure on the mineral composition of the oral fluid. A new approach to the teeth whitening procedure was to use a mouth retractor and a tool for aspirating the whitening gel, which we developed. Before the procedure, a protective film-forming aerosol, which included sodium ascorbate, was applied. After the tooth whitening procedure, the enamel was remineralized with a sealing liquid for 14 days. The concentrations of calcium and phosphorus in the oral fluid were determined using a spectrophotometer with a set of reagents (Human). The results obtained indicate that the new approach to the teeth whitening procedure contributed to less pronounced changes in the concentrations of calcium (+29.07, p < 0.001) and phosphorus (-14%, p < 0.001) in the oral fluid immediately after the procedure and in combination with the standard procedure for teeth whitening; immediately after this procedure, the calcium concentration increased by 74.4% (p < 0.001), and the phosphorus concentration decreased by 23.07% (p < 0.001). The use of remineralizing agents led to a faster recovery of the initial levels of calcium and phosphorus in the oral fluid.

Cytocompatibility, Antimicrobial and Antioxidant Activity of a Mucoadhesive Biopolymeric Hydrogel Embedding Selenium Nanoparticles Phytosynthesized by Sea Buckthorn Leaf Extract

Phytosynthesized selenium nanoparticles (SeNPs) are less toxic than the inorganic salts of selenium and show high antioxidant and antibacterial activity. Chitosan prevents microbial biofilm formation and can also determine microbial biofilm dispersal. Never-dried bacterial nanocellulose (NDBNC) is an efficient carrier of bioactive compounds and a flexible nanofibrillar hydrophilic biopolymer. This study aimed to develop a selenium-enriched hydrogel nanoformulation (Se-HNF) based on NDBNC from kombucha fermentation and fungal chitosan with embedded biogenic SeNPs phytosynthesized by an aqueous extract of sea buckthorn leaves (SbLEx)-SeNPsSb-in order to both disperse gingival dysbiotic biofilm and prevent its development. We determined the total phenolic content and antioxidant activity of SbLEx. Liquid chromatography-mass spectrometry (LC-MS) and high-performance liquid chromatography (HPLC) were used for the identification of polyphenols from SbLEx. SeNPsSb were characterized by transmission electron microscopy-energy-dispersive X-ray spectroscopy (TEM-EDX), dynamic light scattering (DLS), zeta potential, Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) in small- and wide-angle X-ray scattering (SAXS and WAXS). The hydrogel nanoformulation with embedded SeNPsSb was characterized by SEM, FTIR, XRD, rheology, mucin binding efficiency, contact angle and interfacial tension measurements. We also assessed the in vitro biocompatibility, antioxidant activity and antimicrobial and antibiofilm potential of SeNPsSb and Se-HNF. TEM, DLS and SAXS evidenced polydisperse SeNPsSb, whereas FTIR highlighted a heterogeneous biocorona with various biocompounds. The contact angle on the polar surface was smaller (52.82 ± 1.23°) than that obtained on the non-polar surface (73.85 ± 0.39°). The interfacial tension was 97.6 ± 0.47 mN/m. The mucin binding efficiency of Se-HNF decreased as the amount of hydrogel decreased, and the SEM analysis showed a relatively compact structure upon mucin contact. FTIR and XRD analyses of Se-HNF evidenced an interaction between BNC and CS through characteristic peak shifting, and the rheological measurements highlighted a pseudoplastic behavior, 0.186 N adhesion force and 0.386 adhesion energy. The results showed a high degree of cytocompatibility and the significant antioxidant and antimicrobial efficiency of SeNPsSb and Se-HNF.

Saliva Analysis Based on Microfluidics: Focusing the Wide Spectrum of Target Analyte

Saliva is one of the most critical human body fluids that can reflect the state of the human body. The detection of saliva is of great significance for disease diagnosis and health monitoring. Microfluidics, characterized by microscale size and high integration, is an ideal platform for the development of rapid and low-cost disease diagnostic techniques and devices. Microfluidic-based saliva testing methods have aroused considerable interest due to the increasing need for noninvasive testing and frequent or long-term testing. This review briefly described the significance of saliva analysis and generally classified the targets in saliva detection into pathogenic microorganisms, inorganic substances, and organic substances. By using this classification as a benchmark, the state-of-the-art research results on microfluidic detection of various substances in saliva were summarized. This work also put forward the challenges and future development directions of microfluidic detection methods for saliva.

Supernatant of activated platelet-rich plasma rejuvenated aging-induced hyposalivation in mouse

Hyposalivation is a common complaint among the elderly, but no established treatment prevents age-induced hyposalivation. Platelet derivatives such as platelet-rich plasma (PRP), platelet-rich fibrin (PRF), and plasma rich in growth factor (PRGF), are used widely in different areas of regenerative medicine to enhance the wound healing processes. This study examined whether the local injection of the supernatant of activated PRP (saPRP) into the salivary gland (SG) could help prevent aging-induced SG dysfunction and explored the mechanisms responsible for the protective effects on the SG hypofunction. The platelets were separated from the blood of male SD rats (220 ± 20 g). saPRP was manufactured by removing the fibrin clot after activating platelet with calcium ionophore 10 μM (A23187). The total protein and TGF-β1 levels were significantly higher in saPRP than in PRP. Human salivary gland epithelial cell(hSGEC) was treated with saPRP or PRP after senescence through irradiation. The significant proliferation of hSGEC was observed in saPRP treated group compared to irradiation only group and irradiation + PRP group. Cellular senescence, apoptosis, and inflammation significantly reduced in saPRP group. The SG function and structural tissue remodeling by the saPRP were investigated with naturally aged mice. The mice were divided into three groups: 3 months old (3 M), 22 months old (22 M), and 22 months old treated with saPRP (22 M + saPRP). Salivary flow rate and lag time were significantly improved in 22 M + saPRP group compared to 22 M group. The histologic examinations showed the significant proliferation of acinar cell in 22 M + saPRP group. The decrease of senescence, apoptosis, and inflammation observed by western blot in 22 M + saPRP group. The saPRP induced the proliferation of hSGECs, leading to a significant decrease in cellular senescence via decrease inflammation and apoptosis, in vitro. Moreover, the acini cells of the salivary gland were regenerated, and the salivary function increased in aged mice. These results showed that saPRP could be a treatment agent against aging-induced SG dysfunction.

Sialagogic Effects Through Olfactory Stimulation with Mastic Resin and α-pinene Volatiles in vivo

BACKGROUND

Xerostomia, often associated with decreased saliva quality, poses challenges due to limited treatment efficacy. This study aimed to investigate alternative approaches to enhance saliva secretion through olfactory volatile stimulation with mastic resin and its main compound α-pinene, known for inhibiting acetylcholinesterase in vitro.

METHODS

The inhibitory effects of freshly prepared mastic resin extract oil and α-pinene oil on acetylcholinesterase (AChE) activity were measured in vitro. Eighty healthy participants were recruited and divided into two groups: exposed to mastic resin volatiles (n = 40) or α-pinene volatiles (n = 40). Saliva samples were collected pre, during and post exposure to analyze saliva flow rate, spinnbarkeit, ion composition and MUC5B levels.

RESULTS

Mastic resin extract oil and α-pinene oil inhibited AChE activity by 207 % and 22 %, respectively. Olfactory stimulation with these volatiles significantly increased saliva secretion rate without altering spinnbarkeit and ion composition. Salivary MUC5B concentration rose after exposure to mastic resin volatiles.

CONCLUSIONS

Olfactory stimulation with mastic resin and α-pinene volatiles demonstrated a bona fide in vivo effect on saliva secretion, confirming their sialagogic capability, potentially as a result of local glandular AChE inhibition. These findings highlight the therapeutic potential of both volatile compounds in treating patients with xerostomia and hyposalivation through olfactory exposure.

Human Serum and Salivary Metabolomes: Diversity and Closeness

Saliva, which contains molecular information that may reflect an individual's health status, has become a valuable tool for discovering biomarkers of oral and general diseases. Due to the high vascularization of the salivary glands, there is a molecular exchange between blood and saliva. However, the composition of saliva is complex and influenced by multiple factors. This study aimed to investigate the possible relationships between the salivary and serum metabolomes to gain a comprehensive view of the metabolic phenotype under physiological conditions. Using 1H-NMR spectroscopy, we obtained the serum metabolite profiles of 20 healthy young individuals and compared them with the metabolomes of parotid, submandibular/sublingual, and whole-saliva samples collected concurrently from the same individuals using multivariate and univariate statistical analysis. Our results show that serum is more concentrated and less variable for most of the shared metabolites than the three saliva types. While we found moderate to strong correlations between serum and saliva concentrations of specific metabolites, saliva is not simply an ultrafiltrate of blood. The intense oral metabolism prevents very strong correlations between serum and salivary concentrations. This study contributes to a better understanding of salivary metabolic composition, which is crucial for utilizing saliva in laboratory diagnostics.

Allergen Stability in Food Allergy: A Clinician's Perspective

PURPOSE OF REVIEW

The globally rising food allergy prevalence is associated with the urgent need for new disease prevention methods, efficient treatment, and reliable risk assessment methods for characterization of food allergens. Due to inter-individual variations in the digestive system, food allergens are degraded to a different extent in each person. Food processing also influences allergen digestion.

RECENT FINDINGS

In this review, we provide an overview of the digestive system with focus on relevance for food allergy. Main food proteins causing allergic reactions are evaluated, and the combined role of food processing and digestion for allergen stability is highlighted. Finally, clinical implications of this knowledge are discussed. Recent literature shows that allergen digestibility is dependent on food processing, digestive conditions, and food matrix. Digestion affects proteins allergenicity. It is currently not possible to predict the immunogenicity of allergens solely based on protein stability.

Antibacterial, antibiofilm and anticaries effect of BioXtra® mouthrinse for head and neck cancer (HNC) patients under a microcosm biofilm model

BACKGROUND AND PURPOSE

Considering the lack of studies investigating salivary substitutes to control post-radiation caries for patients with head and neck cancer (HNC), this study aimed to evaluate the antibacterial, antibiofilm, and anticaries effects of BioXtra® on the microcosm biofilm formed on different enamel types (non-irradiated and irradiated) and from distinct saliva sources (control and HNC patients).

MATERIALS AND METHODS

Non-irradiated and irradiated enamel specimens were treated with BioXtra®, phosphate-buffered-saline (PBS; negative control), or 0.12% chlorhexidine (CHX; positive control) for 1 min. Biofilm was produced from human saliva (healthy participants with normal salivary flow for the control group or irradiated HNC patients with hyposalivation for the HNC group), mixed with McBain saliva, under 0.2% sucrose exposure, daily submitted to the treatments (1 min), for 5 days. Bacterial metabolic activity, biofilm viability, CFU counting, and enamel demineralization were determined.

RESULTS

BioXtra® significantly reduced the bacterial metabolic activity for both enamel types and the inoculum sources, being more effective for the irradiated enamel or for the saliva from the control group. Similarly, BioXtra® significantly reduced the biofilm viability, the CFU for total microorganisms, mutans streptococci, and lactobacilli, and was able to significantly reduce the mineral loss and the lesion depth compared to PBS. CHX was an effective treatment to significantly reduce all parameters, performing better than BioXtra® and reinforcing its reliable efficiency as a positive control.

CONCLUSION

Regardless of the enamel type and the inoculum source, BioXtra® presented antibacterial, antibiofilm, and anticaries effects under this experimental model, which should be confirmed in further clinical studies.

Salivary pellicle modulates biofilm formation on titanium surfaces

OBJECTIVES

The present study aimed to evaluate the potential of the salivary pellicle (SP) formed on titanium (Ti) surfaces to modulate the formation of a biofilm composed of Streptococcus gordonii, Actinomyces naeslundii, Fusobacterium nucleatum, and Porphyromonas gingivalis.

MATERIALS AND METHODS

Ti substrates were incubated for 2 h with a pool of saliva samples obtained from 10 systemically and periodontally healthy subjects. Enamel substrates were included as a biological reference. Scanning electron microscopy (SEM) and Raman spectroscopy analysis were used to analyze the formation of the salivary pellicle. After the SP formation, the surfaces were incubated for 12 h with a mix of Streptococcus gordonii, Actinomyces naeslundii, Fusobacterium nucleatum, and Porphyromonas gingivalis. The number of bacterial cells attached to each surface was determined by the XTT assay while bacterial viability was analyzed by fluorescence microscopy using the LIVE/DEAD® BacLightTM kit.

RESULTS

The SEM and Raman spectroscopy analysis confirmed the presence of a salivary pellicle formed on the tested surfaces. Regarding the biofilm formation, the presence of the SP decreases the number of the bacterial cells detected in the test surfaces, compared with the uncover substrates. Even more, the SP-covered substrates showed similar bacterial counts in both Ti and enamel surfaces, meaning that the physicochemical differences of the substrates were less determinant than the presence of the SP. While on the SP-uncover substrates, differences in the bacterial adhesion patterns were directly related to the physicochemical nature of the substrates.

CONCLUSIONS

The salivary pellicle was the main modulator in the development of the biofilm consisting of representative oral bacteria on the Ti substrates.

CLINICAL RELEVANCE

The results of this study provide valuable information on the modulatory effect of the salivary pellicle on biofilm formation; such information allows us to understand better the events involved in the formation of oral biofilms on Ti dental implants.

Use and efficacy of dry-mouth interventions in Sjögren's disease patients and possible association with perceived oral dryness and patients' discomfort

OBJECTIVES

Sjögren's disease (SjD) patients use various interventions to relief their oral dryness. However, the use and efficacy of these interventions have only partially been evaluated. The present study aims to investigate whether there is an association between the perceived oral dryness and discomfort of SjD patients and their use of specific interventions.

MATERIALS AND METHODS

A cross-sectional study was performed among SjD patients, who completed several questionnaires to assess the severity of their oral dryness and an inventory of dry-mouth interventions. The perceived efficacy of each intervention was reported on a 5-point Likert-scale.

RESULTS

The questionnaires were returned by 92 SjD patients. For relief of oral dryness, they mostly used "eating fruit", "drinking tea", "moistening the lips", "drinking water, and "drinking small volumes" (> 50%). Three interventions had a frequency of use ranging from 2-6 times/day, whereas, "drinking water" and "drinking small volumes" showed higher frequencies (> 14). The highest overall efficacy (≥ 3.5) was reported for "chewing gum" and "using a mouth gel". Furthermore, various dry-mouth interventions showed significant associations with oral dryness scores and/or patients' discomfort. For example, "drinking small volumes" and "using XyliMelts" were associated with the Bother Index score.

CONCLUSION

Great variation was found in the use of dry-mouth interventions by the participants and the severity of the oral dryness and/or patients' discomfort seemed to affect their choice of intervention. Notably, the mostly used interventions did not show the highest reported efficacy.

CLINICAL RELEVANCE

These findings might help SjD patients and clinicians in their choice of effective dry-mouth interventions.

Identification of potential salivary biomarkers for Sjögren's syndrome with an untargeted metabolomic approach

INTRODUCTION

Despite the rise of metabolomics over the past years, and particularly salivary metabolomics, little research on Sjögren's syndrome (SS) biomarkers has focused on the salivary metabolome.

OBJECTIVES

This study aims to identify metabolites that could be used as biomarkers for SS.

METHODS

Using the software called XCMS online, the salivary metabolic profiles obtained with liquid chromatography coupled to high-resolution mass spectrometry for 18 female SS patients were compared to those obtained for 22 age-matched female healthy controls.

RESULTS AND CONCLUSION

A total of 91 metabolites showed differential expression in SS patients. A putative identification was proposed with the use of a database for 37 of these metabolites and, of these, 16 identifications were confirmed. Given the identified metabolites, some important metabolic pathways, such as amino acid metabolism, purine metabolism, or even the citric acid cycle seem to be affected. Through the analyses of the ROC (receiver operating characteristic) curves, three metabolites, namely alanine, isovaleric acid, and succinic acid, showed both good sensitivity (respectively 1.000, 1.000, and 0.750) and specificity (respectively 0.692, 0.615, and 0.692) for identifying SS and could then be interesting biomarkers for a potential salivary diagnosis test.

Diagnostic Value of Salivary Amino Acid Levels in Cancer

This review analyzed 21 scientific papers on the determination of amino acids in various types of cancer in saliva. Most of the studies are on oral cancer (8/21), breast cancer (4/21), gastric cancer (3/21), lung cancer (2/21), glioblastoma (2/21) and one study on colorectal, pancreatic, thyroid and liver cancer. The amino acids alanine, valine, phenylalanine, leucine and isoleucine play a leading role in the diagnosis of cancer via the saliva. In an independent version, amino acids are rarely used; the authors combine either amino acids with each other or with other metabolites, which makes it possible to obtain high values of sensitivity and specificity. Nevertheless, a logical and complete substantiation of the changes in saliva occurring in cancer, including changes in salivary amino acid levels, has not yet been formed, which makes it important to continue research in this direction.

Monitoring Salivary Concentrations of Tedizolid and Linezolid Using Rats

BACKGROUND AND OBJECTIVE

Therapeutic drug monitoring (TDM) is an effective tool for the management of patients who are administered linezolid. The use of saliva for TDM has potential advantages over the use of plasma; however, only a few reports have compared drug concentrations in the saliva and plasma. Moreover, there are no reports on the salivary concentration of tedizolid, an oxazolidinone antibiotic similar to linezolid. In the present study, the concentrations of tedizolid and linezolid in rat submandibular saliva were compared with those measured in the plasma.

METHODS

Tedizolid (10 mg/kg, n = 6) and linezolid (12 mg/kg, n = 5) were administered via the rat tail vein. Submandibular saliva and plasma samples were collected for up to 8 h after the initiation of drug administration, and assayed for the concentrations of tedizolid and linezolid.

RESULTS

A strong correlation was found between the saliva and plasma concentrations of tedizolid (r = 0.964, p < 0.001) and linezolid (r = 0.936, p < 0.001). The value of tedizolid maximum concentration of drug (C_max) was 0.99 ± 0.08 µg/mL in the saliva and 14.46 ± 1.71 µg/mL in the plasma. Meanwhile, the C_max of linezolid was 8.01 ± 1.42 µg/mL in the saliva and 13.00 ± 1.90 µg/mL in the plasma. According to these results, the saliva/plasma concentration ratios of tedizolid and linezolid in rats were 0.0513 ± 0.0080 and 0.6341 ± 0.0339, respectively.

CONCLUSIONS

Considering the correlation between saliva and plasma concentrations of tedizolid and linezolid, as well as the characteristics of saliva, the results of this study suggest that saliva is a useful matrix for TDM.

Potential Diagnostic Value of Salivary Tumor Markers in Breast, Lung and Ovarian Cancer: A Preliminary Study

The aim of the study was to determine the content of tumor markers for breast, lung and ovarian cancer in saliva, as well as for benign diseases of the corresponding organs and in the control group, and to evaluate their diagnostic significance. Strictly before the start of treatment, saliva samples were obtained and the concentrations of tumor markers (AFP, NSE, HE4, CA15-3, CA72-4, CA125 and CEA) were determined using an enzyme immunoassay (ELISA). CA125 and HE4 were simultaneously determined to be in the blood serum of patients with ovarian cancer. The concentrations of salivary CEA, NSE, CA15-3, CA72-4 and CA125 of the control group were significantly lower than in oncological diseases; however, these tumor markers also increased in saliva with benign diseases. The content of tumor markers depends on the stage of cancer, and the presence of lymph node metastasis; however, the identified patterns are statistically unreliable. The determination of HE4 and AFP in saliva was not informative. In general, the area of potential use of tumor markers in saliva is extremely narrow. Thus, CEA may be diagnostic for breast and lung cancer, but not for ovarian cancer. CA72-4 is most informative for ovarian mucinous carcinoma. None of the markers showed significant differences between malignant and non-malignant pathologies.

Sensory, structural breakdown, microstructure, salt release properties, and shelf life of salt-coated air-dried yellow alkaline noodles

Salt reduction in food has been employed to improve public health. The effects of salt coatings on sodium content, sensory properties, structural breakdown, microstructure, salt release properties, and shelf life of yellow alkaline noodles (YAN) were evaluated. 15 g/dL resistant starch HYLON™ VII (HC) or 5% (v/v) Semperfresh™ (SC) with 10, 20, and 30 g/dL sodium chloride (NaCl) were used. HC-Na30 and SC-Na30 had the highest sodium content and came closest to commercial YAN in taste and saltiness perception. Structural improvement was demonstrated with HC-Na10 and SC-Na10 as both noodles required maximum work to be broken down. Moreover, SEM micrographs of these noodles showed a more compact and dense appearance with increased continuity of the matrix and fewer voids and hollows. However, ruptured surfaces were observed in noodles coated with 20 and 30% salt. The enhanced salt release from the coatings was demonstrated in an in vivo analysis, with the released salt occurring rapidly from HC and SC coatings. HC-Na10 and SC-Na10 noodles had a shelf life of more than 8 days when stored at 4 °C, which is longer than HC-Na0 and SC-Na0 noodles. Storage at 4 °C decelerated the microbiological growth, changes in pH and CIE L* values in salt-coated noodles than storage at 25 °. Thus, HC-Na10 and SC-Na10 could be suitable formulations to replace commercial YAN.

Circulating Biomarkers for Cancer Detection: Could Salivary microRNAs Be an Opportunity for Ovarian Cancer Diagnostics?

MicroRNAs (miRNAs) are small non-coding RNAs with the crucial regulatory functions of gene expression at post-transcriptional level, detectable in cell and tissue extracts, and body fluids. For their stability in body fluids and accessibility to sampling, circulating miRNAs and changes of their concentration may represent suitable disease biomarkers, with diagnostic and prognostic relevance. A solid literature now describes the profiling of circulating miRNA signatures for several tumor types. Among body fluids, saliva accurately reflects systemic pathophysiological conditions, representing a promising diagnostic resource for the future of low-cost screening procedures for systemic diseases, including cancer. Here, we provide a review of literature about miRNAs as potential disease biomarkers with regard to ovarian cancer (OC), with an excursus about liquid biopsies, and saliva in particular. We also report on salivary miRNAs as biomarkers in oncological conditions other than OC, as well as on OC biomarkers other than miRNAs. While the clinical need for an effective tool for OC screening remains unmet, it would be advisable to combine within a single diagnostic platform, the tools for detecting patterns of both protein and miRNA biomarkers to provide the screening robustness that single molecular species separately were not able to provide so far.

Cell-Free Therapies: The Use of Cell Extracts to Mitigate Irradiation-Injured Salivary Glands

Radiotherapy is a standard treatment for head and neck cancer patients worldwide. However, millions of patients who received radiotherapy consequently suffer from xerostomia because of irreversible damage to salivary glands (SGs) caused by irradiation (IR). Current treatments for IR-induced SG hypofunction only provide temporary symptom alleviation but do not repair the damaged SG, thus resulting in limited treatment efficacy. Therefore, there has recently been a growing interest in regenerative treatments, such as cell-free therapies. This review aims to summarize cell-free therapies for IR-induced SG, with a particular emphasis on utilizing diverse cell extract (CE) administrations. Cell extract is a group of heterogeneous mixtures containing multifunctional inter-cellular molecules. This review discusses the current knowledge of CE's components and efficacy. We propose optimal approaches to improve cell extract treatment from multiple perspectives (e.g., delivery routes, preparation methods, and other details regarding CE administration). In addition, the advantages and limitations of CE treatment are systematically discussed by comparing it to other cell-free (such as conditioned media and exosomes) and cell-based therapies. Although a comprehensive identification of the bioactive factors within CEs and their mechanisms of action have yet to be fully understood, we propose cell extract therapy as an effective, practical, user-friendly, and safe option to conventional therapies in IR-induced SG.

Association Between Salivary Cytokines, Chemokines and Growth Factors and Salivary Gland Function in Children with Chronic Kidney Disease

Introduction

Chronic kidney disease (CKD) is a systemic inflammatory disease that leads to multiple organ complications not only in the kidneys and the cardiovascular system, but also in the oral cavity. CKD children experience reduced saliva secretion (hyposalivation), which leads to increased incidence of dental caries and significant impairment of patients' quality of life. However, the causes of salivary gland dysfunction in children with CKD are unknown. The present study is the first to evaluate the inflammatory and anti-inflammatory profile in the saliva of children with CKD at different stages of renal failure with normal and reduced salivary gland function.

Methods

Thirty children with CKD (age 9-16) and thirty age- and gender-matched healthy children were classified for the study. Salivary inflammatory and anti-inflammatory profile were assayed using the multiplex ELISA assay.

Results

We demonstrated statistically significant changes in salivary pro-inflammatory (↑TNF-α, ↓IL-7), anti-inflammatory (↑IL-10), Th1 (↑INF-γ, ↑IL-15), Th2 (↑IL-4, ↑IL-5, ↑IL-6, ↑IL-9) and Th17 (IL-17) cytokines as well as chemokines (↑MCP-1/CCL-2, ↑MIP-1α/CCL3, ↓MIP-1β/CCL4, ↓EOTAXIN/CCL11) and growth factors (↑G-CSF, ↑FGF) in unstimulated saliva of children with CKD compared to the controls. Although the evaluation of the salivary inflammatory profile does not indicate a particular dominance of any of the branches of the immune system, we observed a statistically significant increase in the concentration of all Th2 cytokines assayed. The multivariate regression analysis showed that the content of salivary cytokines, chemokines and growth factors depends on the secretory function of the salivary glands, ie, salivary flow, total protein concentration and amylase activity in the saliva. Salivary MIP-1α/CCL3 was the most effective to differentiate children with CKD and hyposalivation from patients with normal saliva secretion.

Discussion

Inflammation is involved in salivary gland dysfunction in children with CKD, although further studies on in vitro and in vivo models are necessary to confirm this hypothesis.

Progress in salivary glands: Endocrine glands with immune functions

The production and secretion of saliva is an essential function of the salivary glands. Saliva is a complicated liquid with different functions, including moistening, digestion, mineralization, lubrication, and mucosal protection. This review focuses on the mechanism and neural regulation of salivary secretion, and saliva is secreted in response to various stimuli, including odor, taste, vision, and mastication. The chemical and physical properties of saliva change dynamically during physiological and pathophysiological processes. Moreover, the central nervous system modulates salivary secretion and function via various neurotransmitters and neuroreceptors. Smell, vision, and taste have been investigated for the connection between salivation and brain function. The immune and endocrine functions of the salivary glands have been explored recently. Salivary glands play an essential role in innate and adaptive immunity and protection. Various immune cells such as B cells, T cells, macrophages, and dendritic cells, as well as immunoglobins like IgA and IgG have been found in salivary glands. Evidence supports the synthesis of corticosterone, testosterone, and melatonin in salivary glands. Saliva contains many potential biomarkers derived from epithelial cells, gingival crevicular fluid, and serum. High level of matrix metalloproteinases and cytokines are potential markers for oral carcinoma, infectious disease in the oral cavity, and systemic disease. Further research is required to monitor and predict potential salivary biomarkers for health and disease in clinical practice and precision medicine.

A systematic review of the biological mediators of fat taste and smell

Taste and smell play a key role in our ability to perceive foods. Overconsumption of highly palatable energy-dense foods can lead to increased caloric intake and obesity. Thus there is growing interest in the study of the biological mediators of fat taste and associated olfaction as potential targets for pharmacologic and nutritional interventions in the context of obesity and health. The number of studies examining mechanisms underlying fat taste and smell has grown rapidly in the last 5 years. Therefore, the purpose of this systematic review is to summarize emerging evidence examining the biological mechanisms of fat taste and smell. A literature search was conducted of studies published in English between 2014 and 2021 in adult humans and animal models. Database searches were conducted using PubMed, EMBASE, Scopus, and Web of Science for key terms including fat/lipid, taste, and olfaction. Initially, 4,062 articles were identified through database searches, and a total of 84 relevant articles met inclusion and exclusion criteria and are included in this review. Existing literature suggests that there are several proteins integral to fat chemosensation, including cluster of differentiation 36 (CD36) and G protein-coupled receptor 120 (GPR120). This systematic review will discuss these proteins and the signal transduction pathways involved in fat detection. We also review neural circuits, key brain regions, ingestive cues, postingestive signals, and genetic polymorphism that play a role in fat perception and consumption. Finally, we discuss the role of fat taste and smell in the context of eating behavior and obesity.

Untargeted Metabolomic Approach to Study the Impact of Aging on Salivary Metabolome in Women

Despite the growing interest in salivary metabolomics, few studies have investigated the impact of aging on the salivary metabolome. The alterations in metabolic pathways that occur with aging are likely to be observed in pathologies affecting older people and may interfere with the search for salivary biomarkers. It is therefore important to investigate the age-related changes occurring in the salivary metabolome. Using reversed phase liquid chromatography and hydrophilic interaction chromatography coupled to mass spectrometry used in positive and negative ionization modes, the salivary metabolic profiles of young (22 to 45 years old) and older people (55 to 92 years old) were obtained. Those profiles were compared with the use of XCMS online to highlight the under or overexpression of some metabolites with aging. A total of 60 metabolites showed differential expression with age. The identification of 26 of them was proposed by the METLIN database and, among them, 17 were validated by standard injections. Aging seemed to affect most of the main metabolic pathways (amino acid metabolism, Krebs cycle, fatty acid synthesis, and nucleic acid synthesis). Moreover, most of the metabolites that were over- or under-expressed with age in this study have already been identified as being potential biomarkers of diseases affecting older people, such as in Alzheimer's disease. Special attention should be paid in the search for biomarkers of pathologies affecting the elderly to differentiate age-related changes from disease-related changes.

Grape Polyphenols in the Treatment of Human Skeletal Muscle Damage Due to Inflammation and Oxidative Stress during Obesity and Aging: Early Outcomes and Promises

Today, inactivity and high-calorie diets contribute to the development of obesity and premature aging. In addition, the population of elderly people is growing due to improvements in healthcare management. Obesity and aging are together key risk factors for non-communicable diseases associated with several co-morbidities and increased mortality, with a major impact on skeletal muscle defect and/or poor muscle mass quality. Skeletal muscles contribute to multiple body functions and play a vital role throughout the day, in all our activities. In our society, limiting skeletal muscle deterioration, frailty and dependence is not only a major public health challenge but also a major socio-economic issue. Specific diet supplementation with natural chemical compounds such as grape polyphenols had shown to play a relevant and direct role in regulating metabolic and molecular pathways involved in the prevention and treatment of obesity and aging and their related muscle comorbidities in cell culture and animal studies. However, clinical studies aiming to restore skeletal muscle mass and function with nutritional grape polyphenols supplementation are still very scarce. There is an urgent need for clinical studies to validate the very encouraging results observed in animal models.

Impacts of Pesticides on Oral Cavity Health and Ecosystems: A Review

Pesticides are chemical substances used to control, prevent, or destroy agricultural, domestic, and livestock pests. These compounds produce adverse changes in health, and they have been associated with the development of multiple chronic diseases. This study aimed to present a detailed review of the effect of pesticides on the oral cavity and the oral microbiome. In the oral cavity, pesticides alter and/or modify tissues and the microbiome, thereby triggering imbalance in the ecosystem, generating an inflammatory response, and activating hydrolytic enzymes. In particular, the imbalance in the oral microbiome creates a dysbiosis that modifies the number, composition, and/or functions of the constituent microorganisms and the local response of the host. Pesticide exposure alters epithelial cells, and oral microbiota, and disrupts the homeostasis of the oral environment. The presence of pesticides in the oral cavity predisposes the appearance of pathologies such as caries, periodontal diseases, oral cancer, and odontogenic infections. In this study, we analyzed the effect of organochlorines, organophosphates, pyrethroids, carbamates, bipyridyls, and triazineson oral cavity health and ecosystems.

Low rate of asymptomatic carriage and salivary immunoglobulin A response to Group A Streptococci in the healthy adult population in Finland

Streptococcus pyogenes, also called group A streptococcus (GAS), is a human pathogen causing a wide range of infections ranging from mild tonsillitis to severe, life threatening conditions such as bacteraemia, necrotizing fasciitis, and streptococcal toxic shock syndrome. GAS may also colonise the oropharynx without causing any signs of disease which is known as asymptomatic carriage. This study aims to investigate IgA responses against GAS and oral streptococci from saliva samples collected from healthy Finnish adults. In addition, asymptomatic throat GAS carriage was studied. The study participants consisted of healthy adult volunteers who provided one saliva sample, a throat swab, and a background questionnaire. Total salivary IgA, and GAS specific IgA were analysed from the saliva samples using enzyme-linked immunosorbent assays (ELISA) and the results were compared to oral streptococci specific IgA levels. Asymptomatic GAS throat carriers were identified by bacterial culture, and the isolates were emm typed. Samples from a total of 182 individuals were analysed. The median salivary IgA concentration was 62.9 µg/ml (range 17.3–649.9 µg/ml), and median GAS and oral streptococcal specific IgA concentrations 2.7 and 3.3 arbitrary units (AU, range 1.4–7.4 AU and 1.6–12.0 AU), respectively. Three individuals with asymptomatic GAS throat carriage were identified.

Diagnosis, Prevention, and Treatment of Radiotherapy-Induced Xerostomia: A Review

In patients with head and neck cancer, irradiation (IR)-sensitive salivary gland (SG) tissue is highly prone to damage during radiotherapy (RT). This leads to SG hypofunction and xerostomia. Xerostomia is defined as the subjective complaint of dry mouth, which can cause other symptoms and adversely affect the quality of life. In recent years, diagnostic techniques have constantly improved with the emergence of more reliable and valid questionnaires as well as more accurate equipment for saliva flow rate measurement and imaging methods. Preventive measures such as the antioxidant MitoTEMPO, botulinum toxin (BoNT), and growth factors have been successfully applied in animal experiments, resulting in positive outcomes. Interventions, such as the new delivery methods of pilocarpine, edible saliva substitutes, acupuncture and electrical stimulation, gene transfer, and stem cell transplantation, have shown potential to alleviate or restore xerostomia in patients. The review summarizes the existing and new diagnostic methods for xerostomia, along with current and potential strategies for reducing IR-induced damage to SG function. We also aim to provide guidance on the advantages and disadvantages of the diagnostic methods. Additionally, most prevention and treatment methods remain in the stage of animal experiments, suggesting a need for further clinical research, among which we believe that antioxidants, gene transfer, and stem cell transplantation have broad prospects.

Development of analytical methods to study the salivary metabolome: impact of the sampling

Advances in metabolomics have allowed the identification and characterization of saliva metabolites that can be used as biomarkers. However, discrepancies can be noted with the content of the same biomarker being increased or decreased for a given disease. Differences in the way saliva is collected, stored, and/or treated could cause these discrepancies. Indeed, there is no standardized method for saliva sampling and analysis. In this work, two chromatographic modes were used, i.e., RP-LC and HILIC both coupled to MS used in positive and negative ionization modes. The analytical conditions were optimized with a mixture of 90 compounds naturally present in saliva, representative of the wide range of molecular mass and polarity of salivary metabolites and being described as having a differential expression in various pathologies. These four methods were applied to the analysis of saliva samples collected by spitting, aspiration, or Salivette® with or without prior rinsing of the mouth. Rinsing had an effect on some metabolite concentrations. As it can induce an additional parameter of variability to the sampling, it seems therefore preferable to use methods without rinsing while effects of these parameters on the metabolites are investigated. Saliva obtained by spitting and aspiration gave statistically equivalent results for 84% of the metabolites studied. Conversely, Salivette® gave different results since the majority of the metabolites chosen for the study were not quantified in the samples. The Salivette® does not seem therefore to be a suitable sampling method for an untargeted analysis of the salivary metabolome, unlike aspiration and spitting.

Prognostic significance of oral fluid fluoride measurement in acute pericoronitis

Oral fluid is a valuable substrate for assessing dental health and other aspects of physical status. New methods for early diagnosis and prognosis of dental diseases on the basis of oral fluid composition are in constant demand. Excessive fluoride concentrations, often oversighted by dental therapists, negatively affect organs and tissues of the oral cavity. This study aimed at development and approbation of a method for reliable measurement of fluoride ions in oral fluid by capillary electrophoresis to be used in patients with dental diseases. The fluoride ion concentrations were measured in health (2.16 ± 0.48 mg/L), in isolated acute pericoronitis (15.2 ± 2.7 mg/L) and in acute pericoronitis combined to multiple caries (18.9 ± 4.2 mg/L). By post-operative day 3, fluoride levels in the group with isolated acute pericoronitis dropped to normal values (2.28 ± 0.52 mg/L), whereas in the group with acute pericoronitis combined to multiple caries fluoride levels remained high (8.7 ± 1.9 mg/L; р < 0.0001). The developed protocol is efficient for studying fluoride ion concentrations in isolated and combined dental diseases.

«Salivaomics» of Different Molecular Biological Subtypes of Breast Cancer

The aim of the study was to determine the metabolic characteristics of saliva depending on the molecular biological subtype of breast cancer, as well as depending on the expression levels of HER2, estrogen receptors (ER), and progesterone receptors (PR). The study included 487 patients with morphologically verified breast cancer and 298 volunteers without breast pathologies. Saliva samples were obtained from all patients strictly before the start of treatment and the values of 42 biochemical indicators were determined. It has been established that the saliva of healthy volunteers and patients with various molecular biological subtypes of breast cancer differs in 12 biochemical indicators: concentrations of protein, urea, nitric oxide, malondialdehyde, total amino acid content, and activity of lactate dehydrogenase, alkaline phosphatase, gamma-glutamyltransferase, catalase, amylase, superoxide dismutase, and peroxidases. The saliva composition of patients with basal-like breast cancer differs from other subtypes in terms of the maximum number of indicators. Changes in biochemical indicators indicated an increase in the processes of lipid peroxidation and endogenous intoxication and a weakening of antioxidant protection, which correlates with the severity of the disease and the least favorable prognosis for this subtype of breast cancer. An analysis was made of the individual contribution of the expression level of HER2, estrogen, and progesterone receptors to changes in the biochemical composition of saliva. The HER2 (−)/HER2 (+) group, which should be considered as a single group, as well as ER-positive breast cancer, differ statistically significantly from the control group. For ER/PR-positive breast cancer, a more favorable ratio of saliva biochemical indicators was also noted compared to ER/PR-negative breast cancer.

Investigation of Cellular Interactions of Lipid-Structured Nanoparticles With Oral Mucosal Epithelial Cells

Lipid-based nanosystems enable intracellular delivery of drugs in the oral cavity for the treatment of local diseases. To rationally design such systems, suitable matrix compositions and particle properties need to be identified, and manufacturing technologies that allow reproducible production have to be applied. This is a prerequisite for the reliable and predictable performance of in-vitro biological studies. Here, we showed that solid lipid nanoparticles (SLN, palmitic acid) and nanostructured lipid carriers (NLC, palmitic acid and oleic acid in different ratios) with a size of 250 nm, a negative zeta potential, and a polydispersity index (PdI) of less than 0.3 can be reproducibly prepared by high-pressure homogenization using quality by design and a predictive model. SLN and NLC were colloidally stable after contact with physiological fluid and did not form agglomerates. The in-vitro studies clearly showed that besides particle size, surface charge and hydrophobicity, matrix composition had a significant effect. More specifically, the addition of the liquid lipid oleic acid increased the cellular uptake capacity without changing the underlying uptake mechanism. Regardless of the matrix composition, caveolin-mediated endocytosis was the major route of uptake, which was confirmed by particle localization in the endoplasmic reticulum. Thus, this work provides useful insights into the optimal composition of lipid carrier systems to enhance the intracellular uptake capacity of drugs into the oral mucosa.

Effects of Various Drying Times on the Properties of 3D Printed Orodispersible Films

Orodispersible films are an innovative dosage form. Their main advantages are the application comfort and the possibility of personalization. This work aimed to evaluate the influence of different drying times on the properties of orodispersible films of various thicknesses, prepared in two different semisolid extrusion 3D printing setups. In the first experiment, drying times were dependent on the overall print time of each batch. In the second setup, the drying time was set equal according to the longest one. The evaluated parameters were films’ weight uniformity, thickness, moisture content, surface pH, disintegration time, hardness, and tensile strength. Upon statistical comparison, significant differences in the moisture content were found, subsequently affecting the disintegration time. Moreover, statistically significant differences in films’ mechanical properties (hardness, tensile strength) were also described, proving that moisture content simultaneously affects film plasticity and related properties. In conclusion, a mutual comparison of the manufactured orodispersible films showed that the drying time affects their physical and mechanical properties. The in-process drying setup was proved to be sufficient while allowing quicker manufacturing.

The relationship between the severity of oral dryness and the use of dry-mouth interventions by various subgroups of dry-mouth patients

OBJECTIVE

Dry-mouth patients use different interventions to relieve their oral dryness. As recent studies showed that various subgroups of dry-mouth patients perceived different intra-oral regions as most dry, the present study investigated whether the use of dry-mouth interventions by various subgroups of dry-mouth patients was related to the perceived oral dryness as well as salivary flow rate.

MATERIALS AND METHODS

Xerostomia Inventory (XI) scores, Regional Oral Dryness Score (RODI) scores and used dry-mouth interventions were extracted from the medical records of 528 patients visiting a saliva clinic. Based on their medical history, they were allocated into 6 subgroups.

RESULTS

The subgroups of dry-mouth patients used a wide range of interventions to relieve their oral dryness. Sjögren's syndrome patients used most interventions more frequently than patients with oral dryness due to use of a limited number of medications and controls. Patients using medications showed associations between the total XI score and dry-mouth interventions aimed at the entire mouth. In medication using patients and controls, the locally applied intervention "using mouth gel" was associated with RODI scores of the anterior tongue.

CONCLUSION

The use of dry-mouth interventions was associated with dry-mouth feelings. Use of interventions aimed to relieve dryness of the entire mouth was significantly associated with total XI score, while locally applied interventions were significantly associated with the severity of dryness at specific intra-oral regions, the anterior tongue in particular.

CLINICAL RELEVANCE

The results will help clinicians to advise dry-mouth patients about the most suitable interventions for relief of oral dryness complaints.

Preferences of Sjögren's syndrome patients regarding potential new saliva substitutes

OBJECTIVES

Sjögren's syndrome (SS) patients should be involved in the development of new saliva substitutes at an early stage. The purpose of the current study was to explore the preferences of these patients regarding various product characteristics of potential new saliva substitutes.

MATERIAL AND METHOD

A questionnaire was distributed among SS patients. They could anonymously indicate their preferences for saliva substitute characteristics using 5-point Likert scales.

RESULTS

Fifty-nine SS patients filled in the questionnaire. According to their opinion, the most ideal saliva substitute has a thin-watery consistency with a neutral flavour that should be applied as a spray. Patients demand a prolonged alleviation of dry mouth complaints and neutralization of harmful bacteria. The patients mainly object against the presence of artificial sweeteners and alcohol in saliva substitutes, but have limited objections against the presence of vegetable-based ingredients and natural enzymes. Major objections were against the potential side effects "bitter taste" and "discoloration of teeth". Age and severity of xerostomia affected desire of flavours. Younger patients preferred menthol flavour, while respondents with severe xerostomia preferred the use of "neutral flavours" significantly more.

CONCLUSION

The most ideal saliva substitute has thin-watery consistency in spray form with a neutral flavour and providing long alleviation of dry mouth complaints. Besides, it should not contain artificial sweeteners or alcohol, and should not have a bitter taste or cause discoloration of the teeth.

CLINICAL RELEVANCE

Investigating the opinion of SS patients provides tailoured insights into their preference, which may contribute to the development of more effective saliva substitutes.

Stabilization of Salivary Biomarkers

The use of saliva as a diagnostic biofluid has been increasing in recent years, thanks to the identification and validation of new biomarkers and improvements in test accuracy, sensitivity, and precision that enable the development of new noninvasive and cost-effective devices. However, the lack of standardized methods for sample collection, treatment, and storage contribute to the overall variability and lack of reproducibility across analytical evaluations. Furthermore, the instability of salivary biomarkers after sample collection hinders their translation into commercially available technologies for noninvasive monitoring of saliva in home settings. The present review aims to highlight the status of research on the challenges of collecting and using diagnostic salivary samples, emphasizing the methodologies used to preserve relevant proteins, hormones, genomic, and transcriptomic biomarkers during sample handling and analysis.

Envisaging Antifungal Potential of Histatin 5: A Physiological Salivary Peptide

Fungi are reported to cause a range of superficial to invasive human infections. These often result in high morbidity and at times mortality. Conventional antifungal agents though effective invariably exhibit drug interactions, treatment-related toxicity, and fail to elicit significant effect, thus indicating a need to look for suitable alternatives. Fungi thrive in humid, nutrient-enriched areas. Such an environment is well-supported by the oral cavity. Despite this, there is a relatively low incidence of severe oral and periodontal fungal infections, attributed to the presence of antimicrobial peptides hosted by saliva, viz. histatin 5 (Hstn 5). It displays fungicidal activity against a variety of fungi including Candida albicans, Candida glabrata, Candida krusei, Cryptococcus neoformans, and unicellular yeast-like Saccharomyces cerevisiae. Candida albicans alone accounts for about 70% of all global fungal infections including periodontal disease. This review intends to discuss the scope of Hstn 5 as a novel recourse for the control of fungal infections.

Functional outcomes after submandibular gland-sparing neck dissection in patients with oral squamous cell carcinoma

The feasibility of submandibular gland (SMG) preservation during neck dissection has been described. The aim of this study was to analyse the functional outcomes in patients undergoing SMG preservation during neck dissection for cT1-2N0 oral squamous cell carcinoma. Consecutive patients were divided into two groups based on the management of the SMG, and underwent a saliva flow test before surgery, 7 days after surgery, and at 3, 6, 9, and 12 months after surgery. All enrolled patients completed the fourth version of the University of Washington Quality of Life (UWQOL) questionnaire at 12 months after surgery. In patients who underwent SMG preservation during neck dissection, the flow rate at 7 days after surgery was significantly lower than that preoperative; however, it gradually returned to baseline at 9 months after surgery. The saliva flow rate at 9 months after surgery was similar to that at 12 months after surgery. Further, patients with SMG preservation had higher scores for the activity, swallowing, chewing, and saliva domains than patients without SMG preservation. The results of the study suggest that saliva secretion ability can be preserved following SMG-sparing neck dissection, and that SMG preservation improves postoperative quality of life.

Influence of Electronic Cigarettes on Antioxidant Capacity and Nucleotide Metabolites in Saliva

The balance between reactive oxygen species production and the activity of antioxidant systems present in saliva is an important element in maintaining oral environment homeostasis. E-cigarettes adversely affect the oral cavity and their cytotoxic effect is related to oxidative stress. The aim of this study was to assess the influence of using electronic cigarettes on antioxidant capacity of saliva. The study involved 110 subjects (35 e-cigarettes users, 33 traditional cigarettes smokers and 42 non-smokers). Laboratory analysis involved quantitation of uric acid, hypoxanthine, xanthine, TAOS (total antioxidant status) and TEAC (Trolox equivalent antioxidant capacity) in saliva. Lower values for TAOS and TEAC were observed among e-cigarettes users and traditional cigarettes smokers in comparison to non-smokers. Uric acid concentration tended to be higher among e-cigarettes users while no differences in hypoxanthine and xanthine saliva concentrations were observed. Electronic cigarettes usage affects antioxidant capacity of saliva to the same extent as traditional cigarettes, when comparing smokers to non-smokers. Further longitudinal studies on a larger study group are needed to assess the effect of changes in antioxidant status on oral health.

Acylated anthocyanins: A review on their bioavailability and effects on postprandial carbohydrate metabolism and inflammation

Anthocyanins, the natural red and purple colorants of berries, fruits, vegetables, and tubers, improve carbohydrate metabolism and decrease the risk factors of metabolic disorders, but their industrial use is limited by their chemical instability. Acylation of the glycosyl moieties of anthocyanins, however, changes the chemical properties of anthocyanins and provides enhanced stability. Thus, acylated anthocyanins are more usable as natural colorants and bioactive components of innovative functional foods. Acylated anthocyanins are common in pigmented vegetables and tubers, the consumption of which has the potential to increase the intake of health-promoting anthocyanins as part of the daily diet. For the first time, this review presents the current findings on bioavailability, absorption, metabolism, and health effects of acylated anthocyanins with comparison to more extensively investigated nonacylated anthocyanins. The structural differences between nonacylated and acylated anthocyanins lead to enhanced color stability, altered absorption, bioavailability, in vivo stability, and colonic degradation. The impact of phenolic metabolites and their potential health effects regardless of the low bioavailability of the parent anthocyanins as such is discussed. Here, purple-fleshed potatoes are presented as a globally available, eco-friendly model food rich in acylated anthocyanins, which further highlights the industrial possibilities and nutritional relevance of acylated anthocyanins. This work supports the academic community and industry in food research and development by reviewing the current literature and highlighting gaps of knowledge.

Salivary cytokine profile in patients with ischemic stroke

Inflammation plays a crucial role in stroke pathogenesis. Thus, it is not surprising that cytokines, chemokines, and growth factors have been advocated in stroke diagnostics. Our study is the first to evaluate the salivary cytokine profile in patients with ischemic stroke. Twenty-five patients with subacute ischemic stroke and an age-, sex-, and oral hygiene status-matched control group were enrolled in the study. The number of patients was set a priori based on our previous experiment (α = 0.05, test power = 0.9). Salivary concentrations of tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), and interleukin 10 (IL-10) were assessed using an ELISA method. We showed that salivary TNF-α and IL-6 were significantly higher, whereas IL-10 content was statistically lower in both non-stimulated (NWS) and stimulated (SWS) whole saliva of ischemic stroke patients. However, evaluation of cytokines in NWS rather than in SWS may be of greater diagnostic value. Of particular note is salivary TNF-α, which may indicate cognitive/physical impairment in post-stroke individuals. This parameter distinguishes stroke patients from healthy controls and correlates with cognitive decline and severity of functional impairment. It also differentiates (with high sensitivity and specificity) stroke patients with normal cognition from mild to moderate cognitive impairment. Saliva may be an alternative to blood for assessing cytokines in stroke patients, although further studies on a larger patient population are needed.

The association between oral dryness and use of dry-mouth interventions in Sjögren's syndrome patients

Objective

Sjögren’s syndrome patients use different dry-mouth interventions for the relieve of their oral dryness. Recently, it was shown that patients with dry-mouth complaints have regional differences in perceived intra-oral dryness. Therefore, the aim of the present study was to investigate whether the use of dry-mouth interventions is related to the perceived regional oral dryness.

Materials and methods

A cross-sectional study was performed among Sjögren’s patients. Volunteers could anonymously administer various questionnaires, including the Regional Oral Dryness Inventory (RODI), Xerostomia Inventory (XI), Bother Index (BI) and a list of dry-mouth interventions.

Results

Sjögren’s syndrome patients use a wide variety for the relieve of oral dryness. “Drinking water’’ and “moistening the lips’’ were used most frequently. Dry-mouth interventions, “drinking water’’, “rinsing of the mouth”, and “drinking small volumes” had significant associations with the RODI-scores of the posterior palate, and anterior and posterior tongue, respectively. On the other hand, “using mouth gel’’ had a significant association with the RODI-scores of the inside cheeks.

Conclusion

Sjögren’s syndrome patients are more likely to use mouth gels when their inside cheeks were experienced as most dry, while they drank water, rinsed their mouth or drank small volumes if the posterior palate, and anterior and posterior tongue were considered as dry. It can be concluded that intra-oral dryness affects dry-mouth perception and thereby also the use of the various dry-mouth interventions.

Clinical relevance

The therapeutic choice of dry-mouth interventions by Sjögren’s syndrome patients seems to some extent to be related to dryness at specific intra-oral regions.

Influence of saliva interaction on surface properties manufactured for rapid osseointegration in dental implants

Surface treatments are designed to promote modified implant surfaces with positive interactions with the surrounding living tissues. However, the inadvertent early contact of these surfaces with oral fluids during surgery may lead to undesired conditions affecting osseointegration. This study aimed to investigate the possible alterations in the physico-chemical properties of modified-surfaces caused by early saliva exposure. Titanium (Ti) surfaces were exposed to three different samples of human saliva and later analyzed for protein adhesion, physico-chemical surface alterations, and osteogenic cell-viability. The results indicated that surface roughness was the most significant factor influencing saliva protein adsorption; moreover, hydrophilic surfaces had critically lost their characteristics after contact with saliva. Decreased cell viability was observed in cultures after contact with saliva. Early contact with saliva might negatively influence modified surface properties and local cell viability. Careful surgical insertion of implants with hydrophilic surfaces is recommended, particularly in sites where saliva interaction is prone to occur.

Integrated analysis of lncRNA and mRNA expression profiles in the submandibular glands of DIO mice

OBJECTIVE

Obesity contributes to the dysfunction of salivary gland. To explore the specific underlying mechanism for obesity-induced hyposalivation, a model for high-fat diet-induced obese (DIO) mice were constructed to analyze long non-coding RNAs (lncRNAs) and messenger RNAs (mRNAs) expression profiles.

METHODS

The DIO group and control group were fed a diet containing 60 kcal% fat and a normal chow diet for 16 weeks respectively. Microarray analyses were performed to detect the expression profiles of lncRNA and mRNA in submandibular gland tissues from control group mice and DIO mice. Gene ontology, kyoto encyclopedia of genes and genomes, protein-protein interaction, coding-non-coding gene co-expression, transcription factors and competing endogenous RNA analyses were performed to examine the function of differentially expressed genes.

RESULTS

Microarray analyses identified that 624 lncRNAs, along with 297 mRNAs were differentially expressed. Bioinformatic analyses revealed that "complement and coagulation cascades," "glutathione metabolism," "cysteine and methionine metabolism," and "estrogen signaling pathway" were significantly associated with candidate lncRNAs. Transcription factors analysis on candidate lncRNAs revealed several genes such as tribbles pseudokinase 3 may play regulatory roles.

CONCLUSIONS

Our results revealed the expression profiles of lncRNAs and mRNAs and provided new insights into the mechanism of obesity-induced hyposalivation using bioinformatic analyses.

SP, N. M, Barik AK, Pai KM, Unnikrishnan VK, George SD, Kartha VB, Chidangil S. Photonics of human saliva: potential optical methods for the screening of abnormal health conditions and infections

Human saliva can be treated as a pool of biological markers able to reflect on the state of personal health. Recent years have witnessed an increase in the use of optical devices for the analysis of body fluids. Several groups have carried out studies investigating the potential of saliva as a non-invasive and reliable clinical specimen for use in medical diagnostics. This brief review aims to highlight the optical technologies, mainly surface plasmon resonance (SPR), Raman, and Fourier transform infrared (FTIR) spectroscopy, which are being used for the probing of saliva for diverse biomedical applications. Advances in bio photonics offer the promise of unambiguous, objective and fast detection of abnormal health conditions and viral infections (such as COVID-19) from the analysis of saliva.

The cAMP-phosphodiesterase 4 (PDE4) controls β-adrenoceptor- and CFTR-dependent saliva secretion in mice

Saliva, while often taken for granted, is indispensable for oral health and overall well-being, as inferred from the significant impairments suffered by patients with salivary gland dysfunction. Here, we show that treatment with several structurally distinct PAN-PDE4 inhibitors, but not a PDE3 inhibitor, induces saliva secretion in mice, indicating it is a class-effect of PDE4 inhibitors. In anesthetized mice, while neuronal regulations are suppressed, PDE4 inhibition potentiates a β-adrenoceptor-induced salivation, that is ablated by the β-blocker Propranolol and is absent from homozygous ΔF508-CFTR mice lacking functional CFTR. These data suggest that PDE4 acts within salivary glands to gate saliva secretion that is contingent upon the cAMP/PKA-dependent activation of CFTR. Indeed, PDE4 contributes the majority of total cAMP-hydrolytic capacity in submandibular-, sublingual-, and parotid glands, the three major salivary glands of the mouse. In awake mice, PDE4 inhibitor-induced salivation is reduced by CFTR deficiency or β-blockers, but also by the muscarinic blocker Atropine, suggesting an additional, central/neuronal mechanism of PDE4 inhibitor action. The PDE4 family comprises four subtypes, PDE4A-D. Ablation of PDE4D, but not PDE4A-C, produced a minor effect on saliva secretion, implying that while PDE4D may play a predominant role, PDE4 inhibitor-induced salivation results from the concurrent inactivation of multiple (at least two) PDE4 subtypes. Taken together, our data reveal a critical role for PDE4/PDE4D in controlling CFTR function in an in vivo model and in inducing salivation, hinting at a therapeutic potential of PDE4 inhibition for cystic fibrosis and conditions associated with xerostomia.