Ji-Youn Chang

Influences of hyaluronic acid on the anticandidal activities of lysozyme and the peroxidase system.

OBJECTIVE To investigate the fungistatic and fungicidal activity of hyaluronic acid (HA) and the influences of HA on the anticandidal activities of lysozyme and the peroxidase system. MATERIALS AND METHODS HA, hen egg-white lysozyme, and the bovine lactoperoxidase system were used. Candida albicans ATCC 10231, 18804, and 11006 strains were used in the experiments. The fungistatic activity of HA was determined by measuring the optical densities of the cultures. The candidacidal activity of HA and the influences of HA on the candidacidal activities of lysozyme and the peroxidase system were determined by comparing the numbers of colony-forming units. RESULTS Hyaluronic acid displayed inhibitory effects on the growth of C. albicans, and the inhibitory effects were proportional to HA concentration. HA did not have any measurable candidacidal activity. HA showed inhibitory effects on the candidacidal activities of lysozyme, and the peroxidase system that was proportional to HA concentration. HA at 1.0-2.0 mg ml(-1) almost completely inhibited the candidacidal activities of lysozyme and the peroxidase system. CONCLUSIONS Hyaluronic acid possesses fungistatic activity but no candidacidal activity. HA showed inhibitory effects on the candidacidal activities of lysozyme and the peroxidase system.

MUC1 expression in the oral mucosal epithelial cells of the elderly

OBJECTIVE MUC1 is primarily involved in the protection of epithelial surfaces. Decreases in oral mucosal defence can be a predisposing factor for the development of oral mucosal diseases in the elderly. The aim of this study was to compare MUC1 expression level in oral mucosal epithelial cells of the elderly with that of young adults. DESIGN Thirty elderly (mean age, 71.1±4.6 years) and thirty young (mean age, 26.4±2.4 years) adults (15 men and 15 women in each group) were included. Oral examination, including tooth, periodontal, and oral mucosal status, was performed and whole saliva samples were collected along with flow rate measurements. Precipitates of stimulated whole saliva were used for the evaluation of MUC1 expression using real-time PCR. Clarified supernatants were used for the measurement of pro-inflammatory cytokines, IL-1β, IL-6, and TNF-α. RESULTS There was a significant decrease in the amounts of MUC1 transcripts in elderly subjects compared with those of young subjects, a result seen in both men (0.589-fold) and women (0.547-fold). The MUC1 expression level was not correlated with salivary cytokine level but did show a significant positive correlation with the level of periodontal inflammation (r(s)=0.505, P<0.01) in the elderly group. CONCLUSIONS Oral mucosal defence provided by MUC1 was decreased in the elderly; this decrease may play a role in the development of oral mucosal diseases in the aged population.

MUC1 and toll-like receptor-2 expression in burning mouth syndrome and oral lichen planus

OBJECTIVE Expression levels of MUC1 and TLR-2 were evaluated in burning mouth syndrome (BMS) patients and compared with those of controls and oral lichen planus (OLP) patients. The relationships between the expression levels of MUC1 and TLR-2 and levels of salivary pro-inflammatory cytokines were also investigated. DESIGN Ten female BMS and ten female OLP patients were included. Ten female age-matched volunteers served as controls. RNA was isolated from stimulated whole saliva samples. Real-time PCR was used to quantify MUC1 and TLR-2 mRNA levels relative to β-actin and GAPDH mRNA levels. The clarified supernatants of saliva samples were used to measure IL-1β, IL-6, IL-8, and TNF-α levels. The level of blood contamination in saliva samples was also determined. RESULTS There were significant increases in MUC1 transcripts in BMS patients compared with OLP patients (1.766-fold) as well as controls (1.840-fold). There was no significant difference in TLR-2 expression among the groups. The OLP patients showed significantly higher levels of IL-6 and blood contamination in saliva than other groups. The levels of MUC1 or TLR-2 expression did not correlate significantly with the levels of cytokines or blood contamination in saliva. CONCLUSIONS MUC1 may play a role in the development and/or progression of BMS.

The effects of peroxidase on the enzymatic and candidacidal activities of lysozyme.

OBJECTIVE To investigate the effects of peroxidase or the peroxidase system on the enzymatic and candidacidal activities of lysozyme. DESIGN The effects of peroxidase on lysozyme were examined by incubating hen egg-white lysozyme (HEWL) with bovine lactoperoxidase (bLPO). The influence of the peroxidase system on lysozyme was examined by the subsequent addition of potassium thiocyanate and hydrogen peroxide. Lysozyme activity was determined by the turbidity measurement of a Micrococcus lysodeikticus substrate suspension. Candidacidal activity was determined by comparing the colony forming units of Candida albicans ATCC 10231, ATCC 18804, and ATCC 11006. The Wilcoxon signed rank test was used to analyze the effects of variables. RESULTS bLPO at physiological concentrations enhanced the enzymatic activity of HEWL and its effect was dependent on bLPO concentration. The enhancement of enzymatic activity of HEWL by bLPO was affected by pH and ionic strength. The addition of potassium thiocyanate and hydrogen peroxide did not lead to an additional enhancement of the enzymatic activity of HEWL, as compared with bLPO alone. HEWL displayed candidacidal activity in all 3 strains of C. ablicans. The addition of bLPO alone did not affect the candidacidal activity of HEWL, but the bLPO system enhanced candidacidal activity of HEWL in all 3 strains of C. ablicans. CONCLUSIONS bLPO enhanced the enzymatic activity of HEWL, but the bLPO system did not show additional enhancement of the enzymatic activity of HEWL. The addition of bLPO did not affect the candidacidal activity of HEWL, but the bLPO system did enhance the candidacidal activity of HEWL.

Physical and biological properties of yam as a saliva substitute

OBJECTIVE The purpose of this study was to investigate the viscosity and wettability of a water-soluble extract of yam and its effects on lysozyme and peroxidase activities. DESIGN Human whole saliva, yam tuber, hen egg-white lysozyme, and bovine lactoperoxidase were used. Viscosity was measured with a cone-and-plate digital viscometer, while wettability was determined by measuring the contact angle. Lysozyme activity was determined by the turbidimetric method. Peroxidase activity was determined using the NbsSCN assay. Hydroxyapatite beads were used as a solid-phase. RESULTS The viscosity of the yam solution was proportional to its concentration, with diluted yam solutions at 1:5 and 1:10 in simulated salivary buffer displaying similar viscosity values to unstimulated whole saliva and stimulated whole saliva, respectively. The contact angle of yam solution was not significantly different according to the tested materials or yam concentrations. Contact angles of yam solutions on acrylic resin were higher than those of human saliva. Yam affected lysozyme and peroxidase activities, and those effects were different on the hydroxyapatite surface versus in solution. Hydroxyapatite-adsorbed yam increased subsequent adsorption of lysozyme and peroxidase. CONCLUSION We objectively confirmed the similarity of the viscoelastic properties of yam and human saliva, suggesting a role for yam in the development of effective saliva substitutes.

Interactions between hyaluronic acid, lysozyme, and the glucose oxidase-mediated lactoperoxidase system in enzymatic and candidacidal activities

OBJECTIVE To investigate interactions between hyaluronic acid (HA), lysozyme, and the glucose oxidase-mediated lactoperoxidase (GO-LPO) system in enzymatic and candidacidal activities. DESIGN The influences of HA (0.5, 1.0, and 2.0mg/mL) and lysozyme (30μg/mL hen egg white lysozyme) on the enzymatic activity of GO-LPO system (25μg/mL bovine LPO, 1mM KSCN, 10units/mL GO, and 30μg/mL glucose) were determined by measuring oxidized o-dianisidine production. The influence of the GO-LPO system on lysozyme activity was determined by measuring the turbidity of a Micrococcus lysodeikticus suspension. The effects of interactions between HA, lysozyme, the GO-LPO system on candidacidal activity were examined by pre-incubating various combinations of components. Candidacidal activity was determined by comparing the numbers of colony forming units using Candida albicans ATCC strains 10231, 18804, and 11006. RESULTS HA inhibited the enzymatic activity of the GO-LPO system in a dose-dependent manner. HA inhibited the candidacidal activities of the GO-LPO system. However, the inhibitory activity of HA was not significantly different according to concentration of HA. The GO-LPO system enhanced the enzymatic activity of lysozyme, though lysozyme did not affect the enzymatic activity of the GO-LPO system. The candidacidal activities of the GO-LPO system and lysozyme were not additive. CONCLUSIONS HA inhibited the enzymatic and candidacidal activity of the GO-LPO system. The GO-LPO system enhanced the enzymatic activity of lysozyme, but the candidacidal activities were not additive.

The effects of xylitol and sorbitol on lysozyme- and peroxidase-related enzymatic and candidacidal activities.

OBJECTIVE To investigate whether xylitol and sorbitol affect enzymatic and candidacidal activities of lysozyme, the peroxidase system, and the glucose oxidase-mediated peroxidase system. DESIGN Xylitol and sorbitol were added to hen egg-white lysozyme, bovine lactoperoxidase, glucose oxidase-mediated peroxidase, and whole saliva in solution and on hydroxyapatite surfaces. The enzymatic activities of lysozyme, peroxidase, and glucose oxidase-mediated peroxidase were determined by the turbidimetric method, the NbsSCN assay, and production of oxidized o-dianisidine, respectively. Candidacidal activities were determined by comparing colony forming units using Candida albicans ATCC strains 10231, 11006, and 18804. RESULTS While xylitol and sorbitol did not affect the enzymatic activity of hen egg-white lysozyme both in solution and on hydroxyapatite surfaces, they did inhibit the enzymatic activity of salivary lysozyme significantly in solution, but not on the surfaces. Xylitol and sorbitol enhanced the enzymatic activities of both bovine lactoperoxidase and salivary peroxidase significantly in a dose-dependent manner in solution, but not on the surfaces. Sorbitol, but not xylitol, inhibited the enzymatic activity of glucose oxidase-mediated peroxidase significantly. Both xylitol and sorbitol did not affect candidacidal activities of hen egg-white lysozyme, the bovine lactoperoxidase system, or the glucose oxidase-mediated bovine lactoperoxidase system. CONCLUSIONS Xylitol and sorbitol inhibited salivary lysozyme activity, but enhanced both bovine lactoperoxidase and salivary peroxidase activities significantly in solution. Xylitol and sorbitol did not augment lysozyme- and peroxidase-related candidacidal activities.

Relationships between oral MUC1 expression and salivary hormones in burning mouth syndrome

OBJECTIVES To investigate possible relationships among oral mucosal epithelial MUC1 expression, salivary female gonadal hormones and stress markers, and clinical characteristics in patients with burning mouth syndrome (BMS). DESIGN Thirty post-menopausal female patients with BMS (60.0±5.0 years) were included. Clinical and psychological evaluations were performed and the expression level of oral mucosal epithelial MUC1 was analyzed. The levels of cortisol, dehydroepiandrosterone (DHEA), 17β-estradiol, progesterone, chromogranin A, and blood contamination were determined from unstimulated whole saliva (UWS) and stimulated whole saliva (SWS) samples. RESULTS Salivary progesterone level had significant positive correlations with oral mucosal epithelial MUC1 expression level and with salivary cortisol and DHEA levels. The salivary level of 17β-estradiol showed significant positive correlations with period of symptom duration, severity of effects of oral complaints on daily life, and results from psychological evaluations. Cortisol level in UWS and cortisol/DHEA ratio in UWS and SWS had negative correlations with severity of oral burning sensation significantly. The severity of taste disturbance had positive correlations with results from psychometry significantly. CONCLUSION Dysregulated psychoendocrinological interactions might affect oral mucosal MUC1 expression and severity of oral burning sensation in post-menopausal BMS patients.