The Prevalence of Xerostomia in Older Thai Individuals with Type II Diabetes Mellitus and Its Association with Type of Toothpaste and Oral Functions: A Cross-Sectional Study Using Questionnaires.

AIM: To investigate the prevalence of xerostomia in older people with diabetes mellitus and its impacts on oral functions, as well as to determine potential risk factors for xerostomia. METHODS: An analytical cross-sectional study was conducted on 623 older type 2 diabetes mellitus (T2DM) Thai people using valid structural questionnaires. Patients were interviewed, and data were recorded. Xerostomia was assessed using subjective symptom questionnaires. Risk factors for xerostomia were analyzed using bivariate and multiple logistic regression analyses. RESULTS: Among the study participants, 38.4% of the older T2DM people had xerostomia, which is associated with sex, age, type of toothpaste, years of diabetes, hemoglobin A1c level, other systemic diseases, medication, smoking, alcohol consumption, and denture wearing. It was significant that xerostomia was associated with toothpaste containing spicy herbal extracts (OR: 9.32 [3.46 to 15.25]), while toothpaste containing artificial sweeteners tended to lower the risk of xerostomia. In addition, older T2DM adults with xerostomia had greater impaired oral functions, which include difficulties in speaking (OR: 3.31 [1.11 to 9.80]), tasting (OR: 5.12 [3.26 to 8.06]), swallowing (OR: 3.59 [2.32 to 5.53]), and chewing (OR: 3.34 [1.15 to 5.82]). CONCLUSIONS: Xerostomia is prevalent in older Thai people with T2DM. The results suggest that toothpaste containing spicy herbal extracts might increase the risk of xerostomia, resulting in various oral function problems. Therefore, greater awareness of xerostomia in this group should be raised to monitor dental health, and professionals should work in parallel with other aspects of oral health promotion.

Effects of collagen, chitosan and mixture on fibroblast responses and angiogenic activities in 2D and 3D in vitro models.

Despite accumulating evidences have demonstrated the potential of collagen and chitosan on tissue repair, it remains unclear on their combination effects. Here, we examined the regenerative effects of single collagen, chitosan and their mixture on fibroblasts and endothelial cells at cellular levels. The results showed that fibroblast responses, as indicated by high proliferative rate, increased spheroid diameter and migrated area existing from spheroid edge, and decreased wound area, were significantly promoted by either collagen or chitosan stimulation. Similarly, both collagen and chitosan resulted in increased endothelial cell proliferation and migration with accelerated tube-like network formation and upregulated VE-cadherin expression, although collagen strongly provided this effect. While the 1:1 mixture (100:100 µg/mL of chitosan to collagen) treatment caused a reduction in fibroblast viability, the lower ratio of chitosan (1:10 mixture; 10:100 µg/mL) did not produce any impact on both fibroblast and endothelial cell viabilities. The 1:10 mixture also significantly enhanced the additional effects on fibroblast responses and angiogenic activities as shown by higher endothelial growth, proliferation and migration with accelerated capillary-like network formation than those treated with the single substance. Further investigation of signaling proteins found that collagen significantly increased expressions of p-Fak, p-Akt and Cdk5 whereas chitosan upregulated p-Fak and Cdk5 expressions. Comparing to the single treatments, p-Fak, p-Akt and Cdk5 were higher expressed in the 1:10 mixture. These observations indicate that proper collagen-chitosan mixture provides the combination effects on fibroblast responses and angiogenic activities when a high concentration of collagen is used, possibly through Fak/Akt and Cdk5 signaling pathways. Therefore, this study helps to define the clinical use of collagen and chitosan as promising biomaterials for tissue repair.

Cordycepin attenuates migration and invasion of HSC-4 oral squamous carcinoma cells through autophagy-dependent FAK/Akt and MMP2/MMP9 suppression.

Background/purpose: Cordycepin has been proposed anti-cancer effects, however, it is unclear whether and how cordycepin affects oral squamous carcinoma cell (OSCC) migration and invasion. This study aimed to investigate the effect of cordycepin on migration and invasion of OSCC (HSC-4 cells), and its underlying mechanism. Materials and methods: Cell viability was measured with MTT assay. Migrative and invasive abilities were determined by scratch wound healing, agarose spot and transwell invasion assays, respectively. Monodasylcadaverine (MDC) staining, immunofluorescence staining of LC3 and RT-PCR evaluated the gene expression of LC3 and p62 were applied to investigate autophagy. MMP2 and MMP9 gene expression and activity were examined by RT-PCR and gelatin zymography. Expression of caspase 3, cleaved caspase 3, FAK, p-FAK, Akt and p-Akt was determined by Western blot. Results: Cordycepin significantly inhibited HSC-4 cell migration and invasion in a concentration-dependent manner. Cordycepin treatment caused an induction of autophagy, as evidenced by increased MDC fluorescence intensity and MDC positive cells, and upregulated expression level of LC3 gene. In addition, inhibition of autophagy by chloroquine (CQ) significantly abolished cordycepin-inhibited HSC-4 cell migration and invasion, demonstrating that cordycepin-inhibited migration and invasion was mediated by autophagy. Mechanistic studies showed that cordycepin significantly suppressed FAK and Akt phosphorylation, and MMP2 and MMP9 activities. Conversely, CQ pre-incubation significantly restored its expression and activity in cordycepin-treated cells. Conclusion: Cordycepin induces autophagy to suppress FAK and Akt phosphorylation, and MMP2 and MMP9 activity, which responsible for the attenuation of HSC-4 cell migration and invasion.

Collagen-Based Biomaterials in Periodontal Regeneration: Current Applications and Future Perspectives of Plant-Based Collagen.

Collagen is the most widely distributed protein in human body. Within the field of tissue engineering and regenerative medical applications, collagen-based biomaterials have been extensively growing over the past decades. The focus of this review is mainly on periodontal regeneration. Currently, multiple innovations of collagen-based biomaterials have evolved, from hemostatic collagen sponges to bone/tissue regenerative scaffolds and injectable collagen matrices for gene or cell regenerative therapy. Collagen sources also differ from animal to marine and plant-extracted recombinant human type I collagen (rhCOL1). Animal-derived collagen has a number of substantiated concerns such as pathogenic contamination and transmission and immunogenicity, and rhCOL1 is a potential solution to those aforementioned issues. This review presents a brief overview of periodontal regeneration. Also, current applications of collagen-based biomaterials and their mechanisms for periodontal regeneration are provided. Finally, special attention is paid to mechanical, chemical, and biological properties of rhCOL1 in pre-clinical and clinical studies, and its future perspectives in periodontal regeneration are discussed.

Anti-inflammatory activity of soluble chito-oligosaccharides (CHOS) on VitD3-induced human THP-1 monocytes.

Chito-oligosaccharides (CHOS) are oligomers of D-glucosamine and N-acetyl-glucosamine. Anti-inflammatory activities of a wide variety of CHOS mixtures have previously been reported, mainly based on studies with mouse models and murine macrophages. Since the mouse and human immune systems are quite different, gaining insight into the activity of CHOS on human cell lines, using well-characterized CHOS mixtures, is of considerable interest. Bacillus subtilis chitosanase (BsCsn46A) can efficiently convert chitosan to mixtures of water soluble low molecular weight CHOS. Here, the anti-inflammatory activity of a properly characterized CHOS mixture was studied, using human THP-1 cells that were differentiated to mature monocytes using vitamin D3. Addition of CHOS reduced the production of multiple pro-inflammatory cytokines associated with bacterial lipopolyssacharide (LPS)-stimulated inflammation, in a dose-dependent manner and without affecting cell viability. Interestingly, only minimal effects of CHOS were observed in similar experiments with phorbol 12-myristate 13-acetate- (PMA-) differentiated, macrophage-like, THP-1 cells. Altogether, in addition to showing promising biological effects of well-characterized low molecular weight soluble CHOS in a human system, the present study also points at Vitamin D3-stimulated THP-1 cells as a favorable system for assessing the anti-inflammatory activity of bioactive compounds.

The salivary microbiota of Thai adults with metabolic disorders and association with diet.

OBJECTIVE: This study aimed to investigate abundance of specific bacterial taxa in the saliva of 105 Thai adults with different BMI (lean, overweight, and obese) and T2DM subjects using qPCR targeting the 16S rRNA gene of various bacteria taxa. DESIGN: We employed qPCR targeting 16S rRNA genes to explore the bacterial profiles and abundances in the saliva of Thai adult subjects with different BMI and T2DM. Multivariate statistical analyses (multiple factor analysis (MFA) and sparse Partial Least Squares Discriminant Analysis (sPLS-DA) were performed to assess the associations of salivary bacteria with diet, blood profile, gender, age, and use of antibiotics. RESULTS: We found that abundance profiles of the examined salivary bacteria were similar across the four groups. When diet, blood profile, and gender, age, and use of antibiotics were considered, significant differences were noted between subgroups. A positive correlation was also found between consumption of carbonate soft drinks and Bacteroidetes, Gamma-proteobacteria, Veillonella, Fusobacterium and Fusobacterium nucleatum. CONCLUSIONS: This is the first study demonstrating the relative abundance of salivary bacteria in adult Thai subjects with different levels of BMI and T2DM. Regardless of the similar pattern of bacterial profiles across groups, sPLS-DA analysis highlighted the influence of host variables (gender, age, and use of antibiotics) on the abundance of salivary microbiota. Our findings pave the way for further hypothesis testing to gain insight into the association between host factors and salivary microbiome.

Cordycepin-loaded Nanoparticles from Cassava Starch Promote the Proliferation of Submandibular Gland Cells and Inhibit the Growth of Oral Squamous Carcinoma Cells.

This study examined associations between the effect of treatment with nano-cassava starch that contained cordycepin (CS) extract, targeting human submandibular gland cells (HSGs), and human oral squamous carcinoma cells (HSC-4). Cassava starch nanoparticles (CSNPs) were prepared by either physical or acid treatment. These nanoparticles were then loaded with either CS or cordyceps medium and then treated with HSG or HSC-4 cells in different concentrations of CS and nanoparticles. Moreover, the protein secretion, reactive oxygen species (ROS) activity and the expression of salivary-specific genes, antioxidant gene were determined after treatment. CSNPs can enhance the activity of CS at low concentrations. Cordycepin-loaded cassava starch nanoparticles (CCSNPs) increased HSG proliferation, protein secretion, and the expression of salivary-specific genes, AMY and AQP5. Besides, CCSNPs also protected and scavenged of ROS via the stimulation of the antioxidant genes in HSGs, indicating the protective roles of CS to HSGs. On the other hand, CCSNPs inhibited the growth of HSC-4 cells by stimulating ROS generation and reducing protein secretion. This finding suggested that CCSNPs presented the dual actions against HSGs and human oral squamous carcinoma cells, and the encapsulation of CS with cassava nanoparticles enhanced the activity of CS.

Anti-Early Stage of Bacterial Recolonization Effect of Curcuma longa Extract as Photodynamic Adjunctive Treatment.

OBJECTIVE: To evaluate the amount of Fusobacterium nucleatum (F. nucleatum) and Prevotella intermedia (P. intermedia) on subgingival recolonized plaque after mechanical debridement and photodynamic treatment by using blue light-emitting diodes (LEDs) in combination with topical Curcuma longa gel extract. METHODS: A total of 12 subjects with stage III grade B periodontitis were recruited for the study. Maxillary posterior teeth with periodontal pocket >4 mm were selected. These teeth were examined for periodontal clinical data at baseline and at 1, 2, 4, and 6 weeks after treatment. All remaining teeth were treated by scaling and root planing (SRP). Then, the teeth were bilaterally divided using randomized split-mouth design with and without photodynamic adjunctive therapy (PDT). Samples of the subgingival microbiota were obtained in each visit. All samples were analyzed by multicolor TaqMan real-time polymerase chain reaction (PCR) for the presence of target bacteria. RESULTS: Throughout the six-week follow-up, long-term improvement of probing depth and bleeding on probing was revealed on the PDT group. The number of subgingival F. nucleatum and P. intermedia also significantly reduced, compared to the baseline. There was a statistically significant recolonization in F. nucleatum and P. intermedia number after 2 and 4 weeks of conventional SRP, respectively. Our quantitative PCR method showed no significant recolonization of those subgingival bacteria on PDT sites throughout the 6-week study duration. CONCLUSION: The results showed that adjunctive photodynamic treatment by using blue LEDs in combination with topical Curcuma longa gel extract was effective to alter the recolonization patterns of F. nucleatum and P. intermedia after conventional debridement.

Prevalence of self-reported pain-related temporomandibular disorders and association with psychological distress in a dental clinic setting.

OBJECTIVES: To investigate the prevalence of self-reported pain-related temporomandibular disorders (TMDs) and its association with psychological status in a dental clinic setting. METHODS: In this cross-sectional study, patients were asked to complete a TMD pain screener and the Patient Health Questionnaire-4 (PHQ-4). Correlations between symptoms of pain-related TMDs and PHQ-4 scores were analysed using Spearman's correlation test. Symptoms of pain-related TMDs were compared between four groups of participants with different psychological profiles using the Kruskal-Wallis test followed by multiple comparisons. The level of significance was adjusted using the Dunn-Bonferroni test. RESULTS: The prevalence of self-reported pain-related TMDs was 22.2%. TMD pain score was positively correlated with PHQ-4 score. The high anxiety and the comorbidity groups had significantly higher TMD pain scores than the controls. CONCLUSION: There was a high prevalence of self-reported pain-related TMDs, which was correlated with scores on all psychological assessment scales. Symptoms of pain-related TMDs were significantly greater in patients with high anxiety scores, regardless of depression level.

Cordycepin attenuates Salivary Hypofunction through the Prevention of Oxidative Stress in Human Submandibular Gland Cells.

Xerostomia (dry mouth) is a significant age-related condition. Meanwhile, cordycepin, the natural therapeutic agent, has demonstrated an anti-aging effect. Therefore, the present study aimed to investigate the preventive effects of cordycepin on secretory function in an in vitro model of hydrogen peroxide (H2O2)-induced salivary hypofunction. After being exposed to H2O2, human submandibular gland (HSG) cells were treated with various concentrations of cordycepin (6.25-50 µM) for 24, 48, and 72h. To evaluate cell proliferation and reactive oxygen species (ROS) generation, 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide and 2, 7'-dichlorodihydrofluorescein diacetate assays were performed. The amylase activity was kinetically measured by 2-chloro-p-nitrophenol linked with maltotrioside. The expression of salivary, antioxidant and apoptotic markers at mRNA and protein levels were performed by reverse transcriptase polymerase chain reaction (RT-PCR) and immunofluorescence analysis, respectively. We demonstrated that cordycepin (6.25-25 µM) contributed to significant increases in expression of the salivary marker genes, alpha-amylase 1 (AMY1A) and aquaporin-5 (AQP5), and in amylase secretion without changes in cell viability. Under oxidative stress, HSG cells showed remarkable dysfunction. Cordycepin rescued the protective effects partially by decreasing ROS generation and restoring the expression of the salivary proteins, AMY and AQP5 via anti-oxidant and anti-apoptotic activity. In addition, the amount of amylase that was secreted from HSG cells cultured in cordycepin was increased. In conclusion, cordycepin demonstrated a protective effect on H2O2 -induced HSG cells by decreasing ROS generation and upregulating the salivary function markers, AMY1A and AQP5, at both the transcriptional and translational levels.

Treatment of periodontitis reduces systemic inflammation in type 2 diabetes.

AIMS: To assess the impact of periodontal treatment on systemic inflammation in type 2 diabetes. MATERIALS AND METHODS: Adults with type 2 diabetes (n = 83) and without diabetes (controls, n = 75) were recruited, and participants with periodontitis received periodontal treatment and 12 months' follow-up. Biomarkers for periodontal inflammation (gingival crevicular fluid interleukin-6, tumour necrosis factor-α, interleukin-1ß, interferon-γ, matrix metalloproteinase-8, matrix metalloproteinase-9, adiponectin) and serum markers of inflammation and diabetes control (glycated haemoglobin, high sensitivity C-reactive protein, interleukin-6, tumour necrosis factor-α, interleukin-1ß, interferon-γ, leptin, adiponectin) were measured. Structural equation modelling was used to evaluate periodontal treatment effects on oral and systemic inflammation. RESULTS: Periodontal treatment resulted in significant improvements in clinical status and reductions in gingival crevicular fluid biomarkers from baseline to month 12. Structural equation modelling identified that, at baseline, individuals with diabetes and periodontitis had significantly higher systemic inflammation than non-diabetic controls with periodontitis (Δ = 0.20, p = .002), with no significant differences between groups for oral inflammation. There was a greater reduction in systemic inflammation following periodontal treatment in individuals with diabetes and periodontitis compared to those with periodontitis but not diabetes (Δ = -0.25, p = .01). CONCLUSIONS: Diabetes and periodontitis together appear to increase systemic inflammation, with evidence of reductions following periodontal treatment.

Photodynamic therapy of Curcuma longa extract stimulated with blue light against Aggregatibacter actinomycetemcomitans.

BACKGROUND AND OBJECTIVE: Curcumin, one of an established curcuminoid substances extracted from Curcuma longa, has been used as a photosensitizer (PS) in photodynamic therapy (PDT). Curcuminoid substances has been reported to have benefits in treating dental chronic infection and inflammation diseases, such as chronic periodontitis. The purpose of this study was to find the optimum concentration of Curcuma longa (CL) extract, containing all curcuminoid substances, and the power density of blue light (BL) in photodynamic therapy against periodontally pathogenic bacteria, A. actinomycetemcomitans. METHODS: Antibacterial activity of various concentrations of CL extract against A. actinomycetemcomitans was determined. Exponentially growing bacteria were combined with 2-fold dilution of CL extract solution ranging from 25 to 0.098 µg/ml. Co-culture bacteria treated with 0.12% chlorhexidine (CHX) served as the positive control. The effect of photostimulation with light emitting diode (LED) 420-480 nm at 16.8 J/cm2 for 1 min on the selected concentration of CL extract was examined. Bacteria viability was determined by plate counting technique. In addition, production of free radicals was tested by electron spin resonance spectroscope (ESR) with 5,5-dimethyl-1-pyrroline N-oxide (DMPO). RESULTS: The antibacterial activity of CL extract was dose dependent. Without BL, 25 µg/ml CL extract showed 6.03 ±â€¯0.39 log10A. actinomycetemcomitans. Interestingly, the combination of BL and 0.78 µg/ml CL extract solution showed complete absence of A. actinomycetemcomitans. Peak signal intensity of hydroxyl radical production was also detected with the combination of BL and CL. CONCLUSIONS: CL extract not only had antimicrobial activity but also could be used as an effective PS when stimulated with BL in PDT. The optimal antibacterial effect of CL extract with BL was equal to the standard oral disinfectant, 0.12% CHX.

Leptin enhances the secretion of interleukin (IL)-18, but not IL-1ß, from human monocytes via activation of caspase-1.

Circulating levels of leptin are elevated in type-2 diabetes mellitus (T2DM) and leptin plays a role in immune responses. Elevated circulating IL-18 levels are associated with clinical complications of T2DM. IL-18 regulates cytokine secretion and the function of a number of immune cells including T-cells, neutrophils and macrophages and as such has a key role in immunity and inflammation. Pro-inflammatory monocytes exhibiting elevated cytokine secretion are closely associated with inflammation in T2DM, however, little is known about the role of leptin in modifying monocyte IL-18 secretion. We therefore aimed to investigate the effect of leptin on IL-18 secretion by monocytes. We report herein that leptin increases IL-18 secretion in THP-1 and primary human monocytes but has no effect on IL-18mRNA. Leptin and LPS signalling in monocytes occurs by overlapping but distinct pathways. Thus, in contrast to a strong stimulation by LPS, leptin has no effect on IL-1ßmRNA levels or IL-1ß secretion. In addition, LPS stimulates the secretion of IL-6 but leptin did not whereas both treatments up regulate IL-8 secretion from the same cells. Although leptin (and LPS) has a synergistic effect with exogenous ATP on IL-18 secretion in both THP-1 and primary monocytes, experiments involving ATP assays and pharmacological inhibition of ATP signalling failed to provide any evidence that endogenous ATP secreted by leptin-stimulated monocytes was responsible for enhancement of monocyte IL-18 secretion by leptin. Analysis of the action of caspase-1 revealed that leptin up regulates caspase-1 activity and the effect of leptin on IL-18 release is prevented by caspase-1 inhibitor (Ac-YVAD-cmk). These data suggest that leptin activates IL-18 processing rather than IL-18 transcription. In conclusion, leptin enhances IL-18 secretion via modulation of the caspase-1 inflammasome function and acts synergistically with ATP in this regard. This process may contribute to aberrant immune responses in T2DM and other conditions of hyperleptinemia.

Expression and regulation of interleukin-33 in human monocytes.

Interleukin-33 (IL-33) is an IL-1 family cytokine that has a role in regulating T helper type 2 cytokines and mast cell development. Expression of IL-33 is also associated with chronic inflammatory conditions such as rheumatoid arthritis. However, there is little information regarding IL-33 in myeloid cell immune responses, which are important in immunity and inflammation. We therefore investigated the expression, intracellular location and regulation of myeloid cell IL-33 by lipopolysaccharide (LPS) from Escherichia coli and the periodontal pathogen Porphyromonas gingivalis. We detected IL-33 messenger RNA in the human promonocytic cell line THP-1, in monocytes derived from these cells and in primary human monocytes. However, IL-33 was not expressed in primary monocyte-derived dendritic cells. Stimulation of monocytes with E. coli LPS (Toll-like receptor 4 agonist) and LPS from P. gingivalis (Toll-like receptor 2 agonist) up-regulated IL-33 at both the messenger RNA and protein levels but IL-1beta and tumour necrosis factor-alpha had no effect. The IL-33 protein was mainly found in the cytoplasm of monocytes with no evidence of nuclear translocation in stimulated cells. Furthermore, no IL-33 secretion was detected after stimulation with LPS and/or ATP. These data indicate that the function, if any, of IL-33 in activated monocytes is primarily intracellular. Interestingly, immunofluorescence analysis indicated that IL-33 was sequestered in the nucleus of monocytes undergoing apoptosis but released into the extracellular milieu by LPS-stimulated cells in which necrosis had been induced by freeze-thawing. Therefore, this endorses the view that IL-33 may function as an 'alarmin' and have a role in signalling cellular damage and inflammatory disease pathogenesis through release from damaged or necrotic cells.