Does smoking influence tryptophan metabolism in periodontal inflammation? A cross-sectional study.

OBJECTIVES: The aim of this study was to identify the effects of smoking and periodontal inflammation on tryptophan-kynurenine metabolism as well as the correlation between these findings and clinical periodontal parameters. BACKGROUND: It has been shown that the tryptophan amino acid's primary catabolic pathway, the kynurenine pathway (KP), may serve as a key biomarker for periodontal disease. Although there are studies investigating the effect of smoking on KYN-TRP metabolism, the effect of smoking on periodontal disease through KP has not been revealed so far. METHODS: The salivary and serum samples were gathered from 24 nonsmoker (NS-P) stage III, grade B generalized periodontitis and 22 smoker (S-P) stage III, grade C generalized periodontitis patients, in addition to 24 nonsmoker (NS-C) and 24 smoker (S-C) periodontally healthy control individuals. Saliva and serum IL-6, kynurenine (KYN), and tryptophan (TRP) values, and KYN/TRP ratio were analyzed by liquid chromatography-mass spectrometry. Clinical periodontal measurements were recorded. RESULTS: Salivary TRP values were significantly higher in both periodontitis groups than control groups (p < .05). Salivary KYN values were highest in NS-P group (p < .05). Salivary KYN values did not differ significantly between periodontitis groups (p = .84). Salivary KYN/TRP ratio was significantly lower in NS-P group compared to other groups (p < .001). Serum TRP value is higher in S-P group than other groups; however, significant difference was found in S-C group (p < .05). Serum KYN values were significantly lower in smokers than nonsmokers. Serum KYN/TRP ratio is higher in NS-P group. NS-P group has the highest salivary IL-6 levels, NS-C group has the lowest values (p < .05). CONCLUSIONS: Our results point out that smoking exacerbates inflammation in the periodontium and increases TRP destruction and decreases IDO activity by suppressing KP in serum. As a result, kynurenine and its metabolites may be significant biomarkers in the link between smoking and periodontal disease.

The effect of game-based learning on basic life support skills training for undergraduate dental students.

OBJECTIVES: The aim of this study was to investigate the impact of serious game training on the performance of undergraduate dental students during basic life support (BLS) training. METHODS: Students at the Ankara University Faculty of Dentistry were divided into two groups at random: Serious Game (SG) (n = 46) and Traditional (Tr) (n = 45). Students completed the BLS pre-test following their lecture-based training. The SG set of students practiced until they achieved an 85 on the BLS Platform, after which they completed the BLS post-test. All students practiced cardiopulmonary resuscitation (CPR) on a manikin with the instructor's guidance, and then they independently applied CPR by using the model training component. The module evaluation scale was then used to determine each student's grade. Finally, the students provided input on surveys regarding technology perceptions of SG training, serious gaming, and hands-on training. RESULTS: In the SG group, the BLS post-test scores were significantly higher than the pre-test results (p = 0.00). In the SG and Tr groups, there was no statistically significant difference in the overall hands-on training scores (p = 0.11). Students in both groups evaluated the hands-on training on the manikin favorably and with high levels of participation. CONCLUSIONS: The SG-based training platform for BLS training has enhanced the BLS performance of undergraduate dental students in terms of knowledge and skill. It has been shown that digital learners have a beneficial impact on game-based learning outcomes; it is advised to use SGs and develop new games for various learning objectives.

Influence of periodontal inflammation on tryptophan-kynurenine metabolism: a cross-sectional study.

OBJECTIVES: Kynurenine pathway (KP) is the primary way of degrading tryptophan (TRP) and generates several bioactive metabolites (such as kynurenine (KYN), kynurenic acid (KYNA), 3-hydroxykynurenine (3OHKYN)) to regulate biological processes that include host-microbiome signaling and immune cell response. This study is aimed to determine the relationship between periodontal inflammation and tryptophan-kynurenine metabolism and identify their association with periodontal clinical parameters. MATERIALS AND METHODS: Saliva and serum samples were collected from 20 stage III, grade B generalized periodontitis patients, and 20 periodontally healthy control individuals. Samples were analyzed for IL-6, KYN, TRP, KYN/TRP ratio, KYNA, 3OHKYN, picolinic acid (PA), and quinolinic acid (QA) by liquid chromatography-mass spectrometry. Clinical periodontal parameters (plaque index (PI), probing pocket depth (PPD), gingival recession (GR), clinical attachment loss (CAL), and bleeding on probing (BOP)) were recorded. RESULTS: Clinical parameters were significantly higher in the periodontitis group (p < 0.001). Salivary IL-6, TRP, KYN, KYNA, PA, and QA levels were significantly higher and KYN/TRP ratio was significantly lower in periodontitis group than control group (p < 0.05). Serum KYN, KYN/TRP ratio and PA levels were significantly higher in periodontitis group than control group (p < 0.05). PPD, BOP, PI, and CAL had significantly positive correlations with salivary IL-6, TRP, PA, QA, and serum KYN and significantly negative correlations with salivary KYN/TRP ratio. CONCLUSIONS: Our results suggest that periodontal inflammation plays a role in local and systemic tryptophan-kynurenine metabolism. CLINICAL RELEVANCE: Due to their effects on the immune and inflammatory systems, kynurenines may be potential agents for diagnosis and treatment of periodontal diseases.

Astaxanthin Enhances Gingival Wound Healing following High Glucose-Induced Oxidative Stress.

Fibroblasts of the gingiva play a key role in oral wound healing in diabetes. In this study, effects of astaxanthin (ASTX), a xanthophyll carotenoid, were tested on gingival fibroblasts in a wound healing assay in vitro. The aim of this study was to determine whether ASTX can recover delayed wound healing or not when oxidative stress is elevated by high glucose exposure. For this purpose, human gingival fibroblasts were incubated with or without ASTX following exposure to systemic doses of low glucose (LG) and high glucose (HG) in culture media (5- and 25-, 50 mM D-glucose in DMEM Ham's F12) following 24 hours of incubation. Levels of ROS (Reactive oxygen species) were determined for each experimental group by confocal microscopy. Cell proliferation and viability were assessed by an automated cell counter with trypan blue assay. Wound healing assay was designed in 60 mm petri dishes. Cells were exposed to 5-, 25-, and 50 mM glucose for 24 hours, and a straight line free of cells was created upon full confluency. 100 µM ASTX was added to the recovery group, simultaneously. Cells were monitored with JuLIⓇ-Br Cell History Recorder. ROS levels were significantly increased with increasing glucose levels, while cell proliferation and viability demonstrated a negative correlation with increasing oxidative stress. ROS levels significantly decreased in the 100 µM ASTX-treated group compared to the gingival fibroblasts treated with 50 mM HG medium-only, as well as growth rate and viability. Wound healing was delayed in a dose-dependent manner following high glucose exposure, while ASTX treatment recovered wounded area by 1.16-fold in the 50 mM HG group. Our results demonstrated that ASTX enhances gingival wound healing through its antioxidative properties following high glucose induced oxidative stress. Therefore, ASTX can be suggested as a promising candidate to maintain oral health in chronic wounds of the oral tissues related to diabetes.