Effects of Coffee Intake on Oxidative Stress During Aging-related Alterations in Periodontal Tissue.

BACKGROUND/AIM: The purpose of this study was to determine the anti-aging effects of coffee intake on oxidative stress in rat periodontal tissue and alveolar bone loss. MATERIALS AND METHODS: Male Fischer 344 rats (8 weeks old) were randomized to four groups; the baseline group immediately sacrificed, the control group fed with normal powdered food for 8 weeks, and the experimental groups fed with powdered food containing 0.62% or 1.36% coffee components for 8 weeks. RESULTS: Alveolar bone loss and gingival level of 8-hydroxydeoxyguanosine were significantly lower in the 1.36% coffee group than in the control group. Nuclear factor erythroid 2-related factor 2 translocation to the nucleus was significantly higher in the 1.36% coffee group than in the control group. CONCLUSION: Continuous intake of 1.36% coffee could prevent age-related oxidative stress in the periodontal tissue and alveolar bone loss, possibly by up-regulating the Nrf2 signaling pathway.

Detection of Serum miRNAs Affecting Liver Apoptosis in a Periodontitis Rat Model.

BACKGROUND/AIM: miRNA molecules have been attracting attention as genetic modifiers between organs. We examined the relationship between serum miRNA and targeted liver mRNA profiles in a periodontitis rat model, and the influence of periodontitis on the liver. MATERIALS AND METHODS: Male Wistar rats (n=16, 8 weeks old) were randomly divided into two groups (8 rats each): control and periodontitis (ligature placement for 4 weeks). Serum miRNA and liver mRNA profiles were compared. RESULTS: Periodontal destruction and hepatocyte apoptosis were induced in the periodontitis group. Microarray analysis indicated that 52 serum miRNAs and 33 liver mRNAs were expressed with a >1.5-fold change (FC) and a >2.0-FC (p<0.05), respectively, between the two groups. From the miRNA target genes, 12 genes equivalented to liver mRNAs with a >2.0-FC, among which, Hyou1, Chac1, and Bloc1s3 have apoptotic functions in our model. miRNAs upstream of these 3 mRNAs are miR-3591, miR-181a-2-3p and miR-6321. CONCLUSION: miR-3591, miR-181a-2-3p and miR-6321 induced hepatocyte apoptosis in our periodontitis rat model.

The level of salivary lactate dehydrogenase as an indicator of the association between gingivitis and related factors in Japanese university students.

The aim of this study was to investigate the association between the presence of gingivitis estimated using the salivary level of lactate dehydrogenase (LD) and related factors in young Japanese adults. Data from 1,915 participants (21.4 ± 2.5 years) were analyzed. Unstimulated saliva was collected from each participant and the salivary LD level was evaluated using a commercially available test kit with an integer scale ranging from 1 to 10. Gingivitis was defined as the LD level of ≥8. The number of permanent teeth, the simplified oral hygiene index (OHI-S), the presence of partially erupted molars and body mass index were recorded. Additionally, participants answered a questionnaire. The percentage of male participants, the number of permanent teeth, the OHI-S and the presence of partially erupted molars were higher, whereas the proportion receiving dental check-ups was lower in the gingivitis group (n = 88, 4.6%) than in the healthy group. Logistic regression analysis showed that gingivitis was significantly associated with OHI-S (OR: 2.68, 95% CI: 1.94-3.69) and receiving dental checkups (OR: 0.31, 95% CI: 0.10-0.99). The present findings indicated that the OHI-S and receiving dental checkups were significantly associated with gingivitis, as assessed by the salivary LD level, in this cohort.

Relationship Between Renal Dysfunction and Oral Mucositis in Patients Undergoing Concurrent Chemoradiotherapy for Pharyngeal Cancer: A Retrospective Cohort Study.

BACKGROUND/AIM: The aim of this retrospective cohort study was to investigate the association between renal dysfunction (RD) and the development of oral mucositis (OM) in patients undergoing concurrent chemoradiotherapy (CCRT) for pharyngeal cancer including radiation to the oral cavity. PATIENTS AND METHODS: Of 130 patients diagnosed as having pharyngeal cancer who received CCRT at the Okayama University Hospital Head and Neck Cancer Center, 44 were finally selected. RESULTS: During the observation period, 24 (54.5%) patients experienced severe OM (grade 3). The Cox proportional hazards regression model demonstrated that RD (hazard ratio(HR)=2.45, 95% confidence interval(CI)=1.067-6.116, p=0.035) and nasopharynx/oropharynx as center of the irradiated area (HR=2.56, 95% CI=1.072-5.604, p=0.034) were significantly associated with the incidence of severe OM (grade 3). CONCLUSION: In patients with pharyngeal cancer treated with CCRT including radiation to the oral cavity, RD at baseline can be a risk factor for developing severe OM.

Does Instruction of Oral Health Behavior for Workers Improve Work Performance?-Quasi-Randomized Trial.

Oral disease can cause economic loss due to impaired work performance. Therefore, improvement of oral health status and prevention of oral disease is essential among workers. The purpose of this study was to investigate whether oral health-related behavioral modification intervention influences work performance or improves oral health behavior and oral health status among Japanese workers. We quasi-randomly separated participants into the intervention group or the control group at baseline. The intervention group received intensive oral health instruction at baseline and a self-assessment every three months. Both groups received oral examinations and answered the self-questionnaire at baseline and at one-year follow-up. At follow-up, the prevalence of subjects who use fluoride toothpastes and interdental brushes/dental floss were significantly higher in the intervention group than in the control group. Three variables (tooth brushing in workplace, using fluoride toothpaste, and experience of receiving tooth brushing instruction in a dental clinic) showed significant improvement only in the intervention group. On the other hand, work performance and oral status did not significantly change in either group. Our intensive oral health-related behavioral modification intervention improved oral health behavior, but neither work performance nor oral status, among Japanese workers.

Topical application of ointment containing 0.5% green tea catechins suppresses tongue oxidative stress in 5-fluorouracil administered rats.

OBJECTIVE: The purpose of this study was to investigate the preventive effects of topical application of green tea catechins on tongue oxidative stress induced by 5-fluorouracil (5-FU) administration in rats. DESIGN: Male Wistar rats (n=28, 8 weeks old) were divided into four groups of seven rats each: a negative control group (saline administration and application of ointment without green tea catechins), a positive control group (5-FU administration and application of ointment without green tea catechins), and two experimental groups (5-FU administration and application of ointment containing 0.1% or 0.5% green tea catechins). Topical application of each ointment to the ventral surface of the tongue was performed once a day for 5days. The level of 8-hydroxydeoxyguanosine (8-OHdG) was determined to evaluate oxidative stress. Fluorescence staining was also performed to confirm nuclear factor erythroid 2-related factor 2 (Nrf2) translocation to the nucleus. RESULTS: After the experimental period, the ratios of 8-OHdG-positive cells in the ventral tongue tissue were higher in the positive control group than in the negative control group (P<0.05). On the other hand, those in the 0.5% green tea catechin group, but not in the 0.1% green tea catechin group, were lower than the positive control group (P<0.05). In addition, Nrf2 translocation to the nucleus was greater in the 0.5% green tea catechin group than in the positive control group (P<0.05). CONCLUSIONS: Topical application of ointment containing 0.5% green tea catechins could prevent tongue oxidative stress in 5-FU administered rats, via up-regulation of the Nrf2 signaling pathway.

Association between periodontitis and prognosis of pancreatobiliary tract cancer: A pilot study.

Several studies have indicated that periodontitis is a risk factor for cancer. However, the association between periodontitis and the prognosis of pancreatobiliary tract cancer remains unclear. The aim of this pilot study was to investigate the association between periodontitis and prognosis of pancreatobiliary tract cancer. A total of 22 patients diagnosed with pancreatobiliary tract cancer were analyzed. Oral health status, including severity of periodontitis, general health status and biochemical serum markers were evaluated. The Kaplan-Meier method and Cox proportional hazards model were used to assess factors affecting the prognosis of pancreatobiliary tract cancer. The Kaplan-Meier analysis demonstrated that low body mass index, high concentration of serum C-reactive protein (CRP) and severe periodontitis were significant prognostic factors for survival rate. The Cox proportional hazards model revealed that serum carbohydrate antigen 19-9 concentration [hazard ratio (HR)=1.002; 95% confidence interval (CI): 1.000-1.004] and serum CRP concentration (HR=2.57; 95% CI: 1.15-5.74) were significantly associated with the prognosis of pancreatobiliary tract cancer. In addition, cancer patients with severe periodontitis had higher serum CRP concentrations compared with those without severe periodontitis. Therefore, severe periodontitis indirectly affected the prognosis of pancreatobiliary tract cancer through promoting systemic inflammation.

Validity of a New Kit Measuring Salivary Lactate Dehydrogenase Level for Screening Gingivitis.

Aim. The aim of this study was to determine the usefulness of a new kit that can evaluate salivary lactate dehydrogenase (LD) level in real time for screening gingivitis. Materials and Methods. The study included 70 systemic healthy volunteers [29 males and 41 females; mean age ± SD: 24.1 ± 2.6 years]. Resting saliva was collected from each participant and LD level was evaluated in real time using the kit (a color-changing sheet with an integer scale ranging from 1 to 10). A dentist measured probing pocket depth, clinical attachment level, and the proportion of sites with bleeding on probing (% BOP) at six sites on all teeth. Gingivitis was diagnosed when the BOP value was ≥20%. Results. Salivary LD level was positively correlated with mean % BOP (odds ratio: 1.47, 95% confidence interval: 1.132-1.916, and P < 0.001) in a logistic regression model. The sensitivity and specificity of the kit were 0.89 and 0.98, respectively, at a cut-off value of 8.0 for LD level. Conclusions. The new kit for measurement of salivary LD level may be a useful tool to screen for gingivitis in young adults, which contributes to early detection of future periodontitis.

Preventive Effects of Drinking Hydrogen-Rich Water on Gingival Oxidative Stress and Alveolar Bone Resorption in Rats Fed a High-Fat Diet.

Obesity induces gingival oxidative stress, which is involved in the progression of alveolar bone resorption. The antioxidant effect of hydrogen-rich water may attenuate gingival oxidative stress and prevent alveolar bone resorption in cases of obesity. We examined whether hydrogen-rich water could suppress gingival oxidative stress and alveolar bone resorption in obese rats fed a high-fat diet. Male Fischer 344 rats (n = 18) were divided into three groups of six rats each: a control group (fed a regular diet and drinking distilled water) and two experimental groups (fed a high-fat diet and drinking distilled water or hydrogen-rich water). The level of 8-hydroxydeoxyguanosine was determined to evaluate oxidative stress. The bone mineral density of the alveolar bone was analyzed by micro-computerized tomography. Obese rats, induced by a high-fat diet, showed a higher gingival level of 8-hydroxydeoxyguanosine and a lower level of alveolar bone density compared to the control group. Drinking hydrogen-rich water suppressed body weight gain, lowered gingival level of 8-hydroxydeoxyguanosine, and reduced alveolar bone resorption in rats on a high-fat diet. The results indicate that hydrogen-rich water could suppress gingival oxidative stress and alveolar bone resorption by limiting obesity.

miR­1246 and miR­4644 in salivary exosome as potential biomarkers for pancreatobiliary tract cancer.

Pancreatobiliary tract cancer is a highly fatal cancer. Detection of pancreatobiliary tract cancer is difficult because it lacks typical clinical symptoms and because of its anatomical location. Biomarker discovery is therefore important to detect pancreatobiliary tract cancer in its early stage. A study demonstrated that expression levels of miR­1246, miR­3976, miR­4306, and miR­4644 in serum exosomes were higher in pancreatic cancer patients than these levels in healthy control participants. Supposing that microRNA (miRNA) expression profiles in saliva are similar to those in serum, four miRNAs (miR­1246, miR­3976, miR­4306, and miR­4644) in salivary exosomes may also be useful for detection of pancreatobiliary tract cancer. In this study, it was examined whether these miRNAs could be used as biomarkers for pancreatobiliary tract cancer. Twelve pancreatobiliary tract cancer patients and 13 healthy control participants were analyzed as a cancer and a control group, respectively. Unstimulated whole saliva was collected, salivary exosomes were isolated, and total RNA was extracted. Using quantitative real­time PCR (RT­qPCR), the relative expression ratios of miR­1246 and miR­4644 were significantly higher in the cancer group than these ratios in the control group. Receiver operating characteristic (ROC) curves were constructed to analyze the discrimination power of these miRNAs. For miR­1246, the results yielded an area under the curve (AUC) of 0.814 (P=0.008). For miR­4644, the results yielded an AUC of 0.763 (P=0.026). For the combination of miR­1246 and miR­4644, the results yielded an increased AUC of 0.833 (P=0.005). This pilot study suggests that miR­1246 and miR­4644 in salivary exosomes could be candidate biomarkers for pancreatobiliary tract cancer.

Association between Knowledge about Comprehensive Food Education and Increase in Dental Caries in Japanese University Students: A Prospective Cohort Study.

In Japan, comprehensive food education (shokuiku) programs are carried out with the aim of improving dietary practices and thereby reducing the incidence of lifestyle-related diseases, including dental caries. The purpose of this prospective cohort study was to investigate the association between knowledge about shokuiku and the increase in dental caries among Japanese university students who had attended a shokuiku program while in junior/senior high school. A total of 562 students volunteered to undergo oral examinations over a three-year follow-up period, during which the number of cases of dental caries were recorded. Additional information was collected using a questionnaire survey regarding knowledge about shokuiku, dietary habits, and oral health behaviors. In logistic regression analysis, males who lacked knowledge about shokuiku had significantly higher odds for dental caries than those who did not (odds ratio (OR), 2.00; 95% confidence interval (CI), 1.12-3.58; p = 0.019). On the other hand, among females, those who frequently consumed sugar-sweetened soft drinks had significantly higher odds for dental caries than those who did not (OR, 1.89; 95% CI, 1.05-3.42; p = 0.035). These results suggest that having no knowledge about shokuiku is associated with a risk of increase in dental caries in Japanese male university students.

Relationship Between Prehypertension/Hypertension and Periodontal Disease: A Prospective Cohort Study.

BACKGROUND: Most cross-sectional studies have found a significant positive relationship between periodontal disease and prehypertension/hypertension. However, these studies had limitations and there are few prospective cohort studies in young adults. The purpose of this prospective cohort study was to investigate whether periodontal disease was related to prehypertension/hypertension in Japanese university students. METHODS: Students (n = 2,588), who underwent health examinations before entering university and before graduation, were included in the analysis. The association between periodontal disease such as the percentage of bleeding on probing (BOP) and community periodontal index (CPI) scores, and change in blood pressure status was determined. RESULTS: At the reexamination, the numbers of participants with prehypertension (systolic blood pressure 120-139mm Hg or diastolic blood pressure 80-89mm Hg) and hypertension (≥140/90mm Hg) were 882 (34.1%) and 109 (4.2%), respectively. In a logistic regression model, the risk of hypertension was significantly associated with male (odds ratio (OR): 6.31; 95% confidence interval (CI): 2.63-15.13; P < 0.001), no habitual physical activity at baseline (OR: 2.90; 95% CI: 1.56-5.38; P < 0.01) and periodontal disease defined as the presence of both probing pocket depth (PPD) ≥ 4mm and BOP ≥ 30% at baseline (OR: 2.74; 95% CI: 1.19-6.29; P = 0.02) in participants with prehypertension at baseline. On the other hand, the risk of prehypertension was not associated with presence of periodontal disease (OR: 0.93; 95% CI: 0.51-1.70; P = 0.82). CONCLUSION: In the short-term prospective cohort study, a significant association between presence of periodontal disease and hypertension was observed in Japanese university students.

MicroRNAs in Salivary Exosome as Potential Biomarkers of Aging.

The aim of this study was to examine whether salivary exosomal miRNAs could be identified as aging biomarkers. Fifteen young healthy volunteers (median age, 21.0 years) and 13 old individuals (median age, 66.0 years) were recruited. Unstimulated whole saliva was collected, salivary exosomes were isolated, and total RNA was extracted. In a microarray, 242 miRNAs were commonly detected in these two mixed samples. Based on the cut-off values of 2- or 0.5-fold changes (FC) and regulatory power for aging process, six candidate miRNAs (miR-24-3p, miR-371a-5p, miR-3175, miR-3162-5p, miR-671-5p, and miR-4667-5p) were selected. After comparing each total RNA obtained by the 15 young and 13 old individuals to validate the FC values using quantitative real-time PCR, miR-24-3p was identified as a novel candidate aging biomarker. This pilot study suggested that salivary exosomal miRNAs could be identified as candidate aging biomarkers. To confirm whether miR-24-3p in salivary exosomes are suitable biomarkers of aging, further validation research is required.