Ginsenoside Rb3 inhibits osteoclastogenesis via ERK/NF-κB signaling pathway in vitro and in vivo.

OBJECTIVE: The objective of the study was to determine the anti-osteoclastogenic potential of ginsenoside Rb3 for the treatment of periodontitis. METHODS: The anti-osteoclastogenic effect was determined using RANKL-induced RAW264.7 cells and murine bone marrow-derived macrophages followed by TRAP and phalloidin staining. Expression of osteoclastogenesis-related genes and proteins were examined by qPCR and WB. Activation of signaling pathways was detected by WB and IHC techniques. Experimental periodontitis rat model was built up by gingival injections of P. gingivalis LPS. After 21 days of Rb3 treatment, rats were sacrificed for micro-CT, IHC, H&E, and TRAP staining analyses. RESULTS: Rb3 dramatically inhibits RANKL-induced osteoclastogenesis. Nfatc1, Mmp9, Ctsk, Acp5 mRNA, and MMP9, CTSK proteins were dose-dependently downregulated by Rb3 pretreatment. WB results revealed that Rb3 suppressed activations of p38 MAPK, ERK, and p65 NF-κB, and the inhibition of ERK was most pronounced. Consistently, IHC analysis revealed that p-ERK was highly expressed in alveolar bone surface, blood vessels, odontoblasts, and gingival epithelia, which were notably suppressed by Rb3 treatment. H&E staining and micro-CT analyses showed that Rb3 significantly attenuated gingivitis and alveolar bone resorption in rats. CONCLUSION: Rb3 inhibits RANKL-induced osteoclastogenesis and attenuates P. gingivalis LPS-induced gingivitis and alveolar bone resorption in rats via ERK/NF-κB signaling pathway.

Profiling the oral microbiomes in patients with Alzheimer's disease.

OBJECTIVES: To analyse the characteristics of the oral microbiomes and expected to find biomarkers about Alzheimer's disease (AD). SUBJECTS AND METHODS: AD patients (n = 26) and cognitive intact people (n = 26) were examined for cognition, depression, oral health and collected saliva and gingival crevicular fluid (GCF) in the morning. Full-length 16S rRNA gene was amplified and sequencing was performed using the PacBio platform. RESULTS: The predominant bacterium of salivary microbiome and periodontal microbiome from AD patients was Streptococcus oralis and Porphyromonas gingivalis, respectively. With respect to ß diversity analysis, there was a significance difference in periodontal microbiome between AD patients and cognitively intact subjects. The relative abundance of Veillonella parvula significantly increased in oral microbiomes from AD patients. Interestingly, the dominant species were different between early-onset AD and late-onset AD patients. Moreover, the predominant species were changed as the clinical severity of AD. Furthermore, the correlation analysis revealed that V. parvula was associated with AD in both saliva and GCF and that P. gingivalis was associated with AD only in GCF. CONCLUSIONS: In this study, the microbiome community of oral microbes was altered in AD patients and periodontal microbiome was sensitive to cognition changes. Moreover, V. parvula and P. gingivalis were associated with AD.

Salivary levels of five microorganisms of root caries in nursing home elderly: a preliminary investigation.

BACKGROUND: Streptococcus, Bifidobacteria, Lactobacillus and Actinomyces are acidogenic aciduria that may be associated with root caries (RC). The aim of the study was to analyze Streptococcus mutans (S. mutans), Streptococcus sobrinus (S. sobrinus), Bifidobacterium spp., Lactobacillus spp. and Actinomyces naeslundii (A. naeslundii) in the saliva of nursing home elderly, to assess the correlation between bacterial composition and RC for five putative catiogenic organisms. METHODS: In this study, we collected 43 saliva samples and divided into two groups: the root caries group (RCG, n = 21) and the caries-free group (CFG, n = 22). Bacterial DNA was extracted from the saliva samples. The presence and abundance of the five microorganisms were detected by Quantitative real-time PCR (qPCR). Spearman correlation test was performed to evaluate the relationship between the numbers of root decayed filled surfaces (RDFS) and root caries index (RCI) and salivary levels of the bacteria. RESULTS: The salivary levels of S. mutans, S. sobrinus, Bifidobacterium spp. and Lactobacillus spp. were significantly higher in RCG than in CFG (p < 0.05). RDFS and RCI (RDFS/RCI) were positively associated with salivary levels of S. mutans, S. sobrinus and Bifidobacterium spp. (r = 0.658/0.635, r = 0.465/0.420 and r = 0.407/0.406, respectively). No significant differences in presence and amounts of A. naeslundii was observed between the two groups (p > 0.05). CONCLUSION: S. mutans, S. sobrinus and Bifidobacterium spp. in saliva appear to be associated with RC in the elderly. Taken together, the findings indicate that specific salivary bacteria may be involved in the progression of RC.

Comparison of five single-file systems in the preparation of severely curved root canals: an ex vivo study.

BACKGROUND: The ex vivo study is to compare the root canal preparation outcomes achieved by five nickel-titanium single-file instrumentation systems (M3-L, Reciproc Blue, V-Taper 2H, WaveOne Gold, XP-endo Shaper) in severely curved molar root canals. METHODS: A total of 60 root canals were selected from extracted human molar teeth with curvatures ranging from 25° to 50° and divided into five groups based on the instrumentation system employed (n = 12). Before and after root canal preparation, a Micro-CT scan was taken, and pre- and post-operative data were analyzed to evaluate the following parameters: volume increment of root canals (VI), untouched root canal areas (UTA), and canal transportation (CT). Apically extruded debris (AD) was collected during preparation. After that, all samples were separated into two parts and examined respectively by scanning electron microscope (SEM) to assess cleaning ability. Data were statistically analyzed with ANOVA (UTA, AD, VI) or Kruskal-Wallis test (CT, SEM-score), the level of significance was set at α = 0.05. RESULTS: There were no significant differences between the five systems regarding the AD, VI, and UTA parameters (P > 0.05). In terms of CT, no significant difference was noted at the straight section of canal and apical levels, while XP-endo Shaper showed less canal transportation than M3-L at the level of curved vertex (P < 0.05), and the centering ability of V-Taper 2H was significantly better than WaveOne Gold at the initial point of bending (P < 0.05). Debris and smear layers were present on the canal walls of all specimens, the apical thirds of the canal presented higher SEM scores than the coronal thirds in all groups (P < 0.05). Reciproc Blue and XP-endo Shaper showed fewer smear scores than WaveOne Gold in the apical thirds (P < 0.01 and P < 0.05, respectively), and no statistical difference was found between other groups in the middle and coronal thirds. CONCLUSION: The five single-file systems evaluated performed equally in apically debris extrusion, dentin removal, and untouched root canal areas, while XP-endo Shaper and V-Taper 2H resulted in less canal transportation compared to M3-L and WaveOne Gold. Regarding cleaning ability, Reciproc Blue and XP-endo Shaper were associated with less smear layer than WaveOne Gold in the apical thirds.

Therapeutic effect of curcumin on oral diseases: A literature review.

Curcumin (diferuloylmethane) is a polyphenol compound extracted from the rhizome of the plant Curcuma longa. It has the feature of being a yellow or orange pigment with a variety of biological properties, including anti-inflammation, antioxidation, anti-tumor, anti-bacteria, anti-fungus, and wound healing. Previous studies have reported the role of curcumin in treating different inflammatory diseases and tumors in vitro and in vivo. Recently, it has been demonstrated that curcumin has therapeutic benefits in oral mucosal diseases, periodontal diseases, and mouth neoplasms. In this review, we will focus on the therapeutic effects of curcumin on oral diseases.

Impact of COVID-19 on the oral health of adults in Wuhan and China: results of a nationwide online cross-sectional questionnaire survey.

BACKGROUND: COVID-19 has seriously threatened the health and lives of people. This study aimed to investigate the impact of COVID-19 on the oral health of adults in Wuhan and other places of China amid the epidemic and to evaluate attitudes towards dental care in the post-epidemic period. METHODS: An online cross-sectional survey based on a questionnaire of 22 questions was conducted. RESULTS: A total of 3352 valid questionnaires were collected. Participants from Wuhan tended to be relatively psychologically affected and more concerned about future dental treatment. Toothbrushing frequency did not differ significantly between participants from Wuhan and other places and was associated with the prevalence of oral problems people encountered. Gingival bleeding, bad breath and oral ulcers were the three most common oral problems amid the epidemic, and significantly more participants in Wuhan experienced oral problems than other places in China. CONCLUSION: The three most common oral problems amid the epidemic were gingival bleeding, bad breath and oral ulcers. Adults in Wuhan tended to be more seriously affected and suffered more oral problems than people from other places in China. Maintaining good oral health behaviours plays an important role in preventing dental problems. It is crucial to establish and to follow the standard guidelines for the provision of dental care during and after the epidemic.

The impact of coronavirus lockdown on oral healthcare and its associated issues of pre-schoolers in China: an online cross-sectional survey.

BACKGROUND: The sudden outbreak of coronavirus disease (COVID-19) epidemic influenced people's daily life. During lockdown of Wuhan city, the oral health and its associated issues of preschool children were investigated and guidance for dental clinics when the epidemic were controlled in the future were also provided. METHODS: A national online survey was conducted among preschool children and completed by their caregivers. The questionnaire related to children's oral health status and care behaviour, caregivers' attitudes. The information was statistically analyzed between Wuhan residents and others residents. RESULTS: 4495 valid questionnaires were collected. In oral health status, during Wuhan lockdown, 60.8%, 35.5% and 18.3% children had self-reported dental caries, toothache and halitosis respectively. In oral health attitudes, respondents who would increase attention to oral health was more than that would decrease. In oral hygiene behaviour, compared to non-Wuhan children, the children in Wuhan became more active in brushing their teeth. In utilization of dental services in the future, less Wuhan residents would choose to have dental visit directly, 28.5% Wuhan residents and 34.7% non-Wuhan residents agreed all of procedures could be done if proper protected. CONCLUSIONS: Oral health status and associated issues of preschool children in Wuhan were significantly different from that of others during lockdown of Wuhan city and in the future. Effective measures should be taken as early as possible to protect children's oral health.

Prevalence and associated factors of periodontal conditions among 55- to 74-year-old adults in China: results from the 4th National Oral Health Survey.

OBJECTIVE: The purpose of this study was to assess periodontal health conditions among 55- to 74-year-old Chinese people and to analyze the factors associated with periodontal diseases. MATERIALS AND METHODS: In total, 9054 subjects aged 55-74 years were enrolled from all 31 provinces using a stratified multistage probability sampling method, autonomous regions and municipalities of the Chinese mainland, the response rate was 86.9%. All subjects underwent clinical examinations on the severest site for every tooth and completed a questionnaire that collected information on their sociodemographic characteristics and oral habits. T tests, chi-square tests and binary logistic regression analysis were performed to analyze the data. RESULTS: The percentage of people without bleeding on probing, probing depth ≥ 4 mm and attachment loss > 3 mm was 5.0 and 9.3% in the 55- to 64-year-old and the 65- to 74-year-old age group. The prevalence of bleeding on probing was 88.4% among 55 to 64 years old and 82.6% among 65 to 74 years old. Mean number of teeth with bleeding on probing were 13.87 among 55 to 64 years old and 11.25 among 65 to 74 years old. The prevalence of probing depth ≥ 4 mm and attachment loss > 3 mm were 69.3 and 69.9% in people aged 55-64 years and were 64.6 and 74.2% in people aged 65-74 years. Mean number of teeth with probing depth = 4-5 mm and probing depth ≥ 6 mm were 4.48 and 0.36 in 55-64 age group and 3.70 and 0.33 in 65-74 age group. And mean number of teeth with attachment loss > 3 mm were 5.17 among 55 to 64 years old and 5.63 among 65 to 74 years old. Besides, attachment loss > 3 mm was associated with age, gender, smoking, toothbrushing frequency and toothpick use. CONCLUSIONS: Periodontitis was not highly prevalent among 55- to 74-year-old Chinese adults. Age, gender, smoking, toothbrushing frequency and toothpick use could be risk factors. CLINICAL RELEVANCE: Scientific rationale for the study: The periodontal conditions among 55 to 64 and 65 to 74 years old Chinese population were not highly serious, but prevalence of bleeding on probing, periodontal pockets and attachment loss should be drawn enough attention by relevant public health administrations. PRINCIPAL FINDINGS: The prevalence of periodontal diseases was evaluated in 55- to 64-year-old and 65- to 74-year-old subjects in a nationally representative Chinese sample population. The prevalence of probing depth ≥ 4 mm and AL > 3 mm were high; these values were 69.3% and 69.9%, respectively, in the 55-64 age group and 64.6% and 74.2%, respectively, in the 65-74 age group. In addition, case percentage of AL = 4-5 mm combined with PD < 6 mm were 23.1 and 19.4% among 55- to 64-year-old and 65- to 74-year-old people. And case percentage of AL> 5 mm combined with PD ≥ 6 mm were 11.1% and 12.1% among 55- to 64-year-old and 65- to 74-year-old people, respectively. PRACTICAL IMPLICATIONS: The present study provides a reference for the epidemiological analysis of periodontal diseases. To reduce widespread inadequate treatment of periodontal diseases, clinical management should be performed in dental practices. Furthermore, oral health recommendations should be made at multiple levels.

Ginsenoside Rb3 Inhibits Pro-Inflammatory Cytokines via MAPK/AKT/NF-κB Pathways and Attenuates Rat Alveolar Bone Resorption in Response to Porphyromonas gingivalis LPS.

Conventional treatments for chronic periodontitis are less effective in controlling inflammation and often relapse. Therefore, it is necessary to explore an immunomodulatory medication as an adjuvant. Ginsenoside Rb3 (Rb3), one of the most abundant active components of ginseng, has been found to possess anti-inflammatory and immunomodulatory properties. Here, we detected the anti-inflammatory effect of Rb3 on Porphyromonas gingivalis LPS-stimulated human periodontal ligament cells and experimental periodontitis rats for the first time. We found that the expression of pro-inflammatory mediators, including IL-1ß, IL-6 and IL-8, upregulated by lipopolysaccharide (LPS) stimulation was remarkably downregulated by Rb3 treatment in a dose-dependent manner at both transcriptional and translational levels. Network pharmacological analysis of Rb3 showed that the mitogen-activated protein kinase (MAPK) signaling pathway had the highest richness and that p38, JNK, and ERK molecules were potential targets of Rb3 in humans. Western blot analysis revealed that Rb3 significantly suppressed the phosphorylation of p38 MAPK and p65 NF-κB, as well as decreased the expression of total AKT. In experimental periodontitis rat models, reductions in alveolar bone resorption and osteoclast generation were observed in the Rb3 treatment group. Thus, we can conclude that Rb3 ameliorated Porphyromonas gingivalis LPS-induced inflammation by inhibiting the MAPK/AKT/NF-κB signaling pathways and attenuated alveolar bone resorption in experimental periodontitis rats.

A Meta-Analysis of Oral Health Status of Children with Autism.

Purpose: To present a meta-analysis whether the risks of caries and periodontal problems in autistic children are higher than those in healthy children. Study design: A literature search that included PubMed, Embase, Web of Science, Cochrane, China National Knowledge Infrastructure (CNKI), Wan fang, and Chinese Scientific and Technological Journal (VIP) databases was conducted. The primary outcomes of interest included the DMFT index, Plaque index (PI), Gingival index (GI), and Salivary pH. Quality assessment was performed in accordance with the Newcastle-Ottawa Scale (NOS). Dichotomous variables are presented as relative risk (RR), and continuous variables are presented as weighted mean difference (WMD). Results: Eight studies were included in this meta-analysis. Among these 8 studies, six studies compared the DMFT index, three studies compared PI, three studies compared GI, and three studies compared salivary pH. Meta-analysis showed that the mean DMFT index in autistic children was higher than that in healthy children, and the difference was statistically significant {MD = 0.50, 95% CI [0.04-0.96], P<0.00001}. Similarly, PI and GI in autistic children were higher than those in healthy children, and the difference between PI was statistically significant {MD = 0.59, 95%CI [0.36-0.82], P=0.02}, while the difference between GI was not statistically significant {MD = 0.52, 95%CI [0.30-0.75], P=0.08}. But the salivary pH in autistic children was lower than that in healthy children {MD = -0.28, 95%CI [-0.54--0.02], P = 0.02}, and the difference was statistically significant. Conclusion: The present analysis suggests that children with autism have poorer oral hygiene, higher risk of caries, and a lower salivary pH than healthy children.

Prevalence and relevant factors of halitosis in Chinese subjects: a clinical research.

BACKGROUND: The aim of this study was to investigate the prevalence of halitosis among Chinese subjects and to analyze the associated factors that influence halitosis. METHODS: This study included subjects complaining of halitosis who came to the clinic between 2014 and 2016. Questionnaires were used to obtain general information from patients. An organoleptic test was conducted, and volatile sulfur compounds measurement was obtained to assess halitosis. In conjunction with these tests, the oral health status of each patient was recorded. RESULTS: In total, there were 205 samples entered into data analysis, and the patients' age ranged from 18 to 71 years (mean ± SD: 32.44 ± 10.31). Of these patients, 65.9% had an organoleptic score ≥ 2, and 41% of patients had a volatile sulfur compound level ≥ 110 ppb. The findings indicated that the prevalence of halitosis was higher in males than in females (55.6% vs. 44.4%, respectively, P = 0.018). Several factors including the duration of bad breath, rhinitis, tongue coating and periodontal conditions were found to be associated with the organoleptic score. Tongue coating was also associated with the volatile sulfur compound level. CONCLUSIONS: Among these subjects, 65.9% had halitosis. Oral health status was strongly associated with halitosis, and tongue coating was the most important factor.

Shaping ability of protaper next compared with waveone in late-model three-dimensional printed teeth.

BACKGROUND: Comparison of the shaping ability of advanced nickel-titanium (Ni-Ti) instruments is of great interest to the field of endodontics. However, the models used to study canal preparation still lack uniformity, relevance to reality and complexity. The aim of this study was thus to compare the shaping abilities of the ProTaper Next (PN) and WaveOne (WO) Ni-Ti instruments in three-dimensional (3D)-printed teeth, which may overcome the present defects of most real teeth and model teeth including 3D S-shaped canals. METHODS: Six teeth and their corresponding 3D-printed replicas were prepared using the same kind of Ni-Ti instrument. The pre- and post-preparation volumes, surface areas and transportation of the canals were measured to compare the teeth with their replicas. Twenty 3D-printed teeth with S-shaped canals were used to support the preparation study. The S-shaped canals were then scanned to measure their volumes and surface areas. Next, the two kinds of instruments were used to prepare the 3D-printed canals (n = 10 per group). The volume and surface area of the canals, the transportation along the two curvatures and the percentage of unprepared surface area were measured. Micro-CT and VGstudio2.2 (VG2.2) software were used to perform scans and collect data throughout the research. The paired-samples T test and Kruskal-Wallis H test were used for statistical analysis. RESULTS: There was no significant difference between the real canals and the printed ones post-preparation (P > .05). The printed S-shaped root canals had a unified shape, with a small standard deviation and range. The WO group had higher mean values for the volume and superficial area measurements compared with the PN group (P < .05). No differences in the untouched areas were found between the two systems (P > .05). PN caused less transportation at the apical curve than WO did (P < .05). CONCLUSIONS: In conclusion, 3D-printed teeth are suitable for the study of Ni-Ti rotary instruments. Furthermore, the PN rotary system caused less transportation at the apical curve than the WO system did in complicated root canal procedures.

A Randomized Clinical Trial Investigating the Effect of Particle Size of Calcium Sodium Phosphosilicate (CSPS) on the Efficacy of CSPS-containing Dentifrices for the Relief of Dentin Hypersensitivity.

OBJECTIVES: To investigate the effect of reducing the particle size of calcium sodium phosphosilicate (CSPS) bioactive glass from ~14 µm (NovaMin®) to ~4 µm (Vitryxx®), and of changing the fluoride source in a 5% CSPS dentifrice from sodium monofluorophosphate (SMFP) to sodium fluoride (NaF) on the efficacy of CSPS-containing dentifrices in dentin hypersensitivity (DH) relief. METHODS: A randomized, controlled, examiner-blind, five-treatment arm, parallel group, stratified, exploratory study of NaF dentifrices containing 2.5% or 5% small particle size CSPS (~4 µm), NaF or SMFP dentifrices containing 5% CSPS (~14 µm), and a regular fluoride dentifrice in healthy subjects with DH. Sensitivity to tactile stimulus (Yeaple probe) and evaporative (air) stimulus (Schiff Sensitivity Scale, visual analogue scale) was assessed at baseline and after one, two, four, and eight weeks' twice-daily treatment. The study was not statistically powered to detect significant between-treatment differences. RESULTS: One hundred thirty-three of 134 randomized subjects completed the study. All treatments showed similar, statistically significant (p < 0.007) improvements in DH compared to baseline at Weeks 2, 4, and 8. No trends favoring any specific treatment were observed. Treatments were generally well tolerated. CONCLUSIONS: The apparent absence of a positive treatment effect for the CSPS-containing dentifrices compared to the regular fluoride dentifrice is inconsistent with other previously reported efficacy studies for CSPS dentifrices.

Comparison of immunological and microbiological characteristics in children and the elderly with or without dental caries.

The purpose of this study was to determine the relationships among early childhood caries (ECC), root caries (RC), the quantity of Streptococcus mutans in saliva, and the concentrations of total and specific secretory IgA (sIgA). Saliva samples were collected from 70 children, 3-4 yr of age, with and without ECC, and from 43 adults, ≥60 yr of age, with and without RC. The decayed, missing, and filled teeth (dmft) and decayed, missing, and filled surfaces (dmfs) scores of each child, and the root decayed and filled teeth (RDFT) and root decayed and filled surfaces (RDFS) scores of each elderly subject, were determined. The S. mutans levels, total sIgA, and specific sIgA against two virulence antigens of S. mutans in saliva were analysed using quantitative real-time PCR (qPCR) and ELISAs. The quantity of S. mutans was significantly higher in caries-positive subjects within the two populations than in the caries-free subjects; and a positive correlation was found between the quantity of S. mutans and the dmft, dmfs, RDFT, and RDFS scores. In addition, the salivary total sIgA was significantly higher in children with severe early childhood caries (SECC) and in the elderly subjects with RC. Moreover, although the S. mutans level was significantly higher, the concentrations of specific sIgA against S. mutans antigens were significantly lower in samples from elderly subjects than in samples from children. These results support the concept that S. mutans is positively associated with ECC and RC. Furthermore, the levels of S. mutans-specific antibodies in saliva are too low to prevent infection with cariogenic bacteria and to inhibit development of ECC and RC.

The prevalence and risk indicators of tooth wear in 12- and 15-year-old adolescents in Central China.

BACKGROUND: Tooth wear has been investigated in numerous countries, and the prevalence has varied. However, the data on tooth wear in China are scarce. The aim of this study was to describe the prevalence of tooth wear and to investigate the relative indicators associated with tooth wear in 12- and 15-year-old adolescents in Wuhan City, Hubei Province, Central China. METHODS: A cross-sectional descriptive study was undertaken among 720 adolescents in Hubei Province, Central China. The age groups in this study were 12- and 15-year-old, and each group consisted of 360 participants in which females and males represented 50 % each. A modified version of the Basic Erosive Wear Examination (BEWE) tooth wear index was used for the buccal, cervical, occlusal/incisal and lingual surfaces of all of the teeth in the 720 adolescents. All of the participants were asked to answer a questionnaire consisting of questions about their current and historical dietary habits and oral hygiene. RESULTS: The prevalence of tooth wear was 18.6 and 89.4 % in 12- and 15-year-old adolescents, respectively. The prevalence rates of dentin exposure were 1.9 and 5.6 %, respectively. A significantly higher prevalence of tooth wear and dentin exposure in 15-year-old adolescents was found than in 12-year-old adolescents (p < 0.001 and p = 0.011). Several factors such as drinking soft drinks and fruit juices immediately after sports, taking aspirin, reflux, unilateral chewing, tooth brushing once daily or less often, duration of brushing less than 2 min and swimming in the summer were found to be associated with tooth wear. CONCLUSIONS: Tooth wear in 12- and 15-year-old adolescents in Central China is a significant problem and should receive greater attention. The prevalence of tooth wear increases with age and associated with socio-behavioral risk factors.

Isobavachin attenuates osteoclastogenesis and periodontitis-induced bone loss by inhibiting cellular iron accumulation and mitochondrial biogenesis.

As bone-resorbing cells rich in mitochondria, osteoclasts require high iron uptake to promote mitochondrial biogenesis and maintain a high-energy metabolic state for active bone resorption. Given that abnormal osteoclast formation and activation leads to imbalanced bone remodeling and osteolytic bone loss, osteoclasts may be crucial targets for treating osteolytic diseases such as periodontitis. Isobavachin (IBA), a natural flavonoid compound, has been confirmed to be an inhibitor of receptor activator of nuclear factor κB ligand (RANKL)-induced osteoclast differentiation from bone marrow-derived macrophages (BMMs). However, its effects on periodontitis-induced bone loss and the potential mechanism of its anti-osteoclastogenesis effect remain unclear. Our study demonstrated that IBA suppressed RANKL-induced osteoclastogenesis in BMMs and RAW264.7 cells and inhibited osteoclast-mediated bone resorption in vitro. Transcriptomic analysis indicated that iron homeostasis and reactive oxygen species (ROS) metabolic process were enriched among the differentially expressed genes following IBA treatment. IBA exerted its anti-osteoclastogenesis effect by inhibiting iron accumulation in osteoclasts. Mechanistically, IBA attenuated iron accumulation in RANKL-induced osteoclasts by inhibiting the mitogen-activated protein kinase (MAPK) pathway to upregulate ferroportin1 (Fpn1) expression and promote Fpn1-mediated intracellular iron efflux. We also found that IBA inhibited mitochondrial biogenesis and function, and reduced RANKL-induced ROS generation in osteoclasts. Furthermore, IBA attenuated periodontitis-induced bone loss by reducing osteoclastogenesis in vivo. Overall, these results suggest that IBA may serve as a promising therapeutic strategy for bone diseases characterized by osteoclastic bone resorption.

Eupatilin suppresses osteoclastogenesis and periodontal bone loss by inhibiting the MAPKs/Siglec-15 pathway.

Periodontitis is a widely prevalent oral disease around the world characterized by the disruption of the periodontal ligament and the subsequent development of periodontal pockets, as well as the loss of alveolar bone, and may eventually lead to tooth loss. This research aims to assess the suppressive impact of Eupatilin, a flavone obtained from Artemisia argyi, on osteoclastogenesis in vitro and periodontitis in vivo. We found that Eupatilin can efficiently obstruct the differentiation of Raw264.7 and bone marrow-derived macrophages (BMDMs) induced by RANKL, leading to the formation of mature osteoclasts. Consistently, bone slice resorption assay showed that Eupatilin significantly inhibited osteoclast-mediated bone resorption in a dose-dependent manner. Eupatilin also downregulated the expression of osteoclast-specific genes and proteins in Raw264.7 and BMDMs. RNA sequencing showed that Eupatilin notably downregulated the expression of Siglec-15. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses identified significantly enriched pathways in DEGs, including MAPK signaling pathway. And further mechanistic investigations confirmed that Eupatilin repressed MAPKs/NF-κBsignaling pathways. It was found that Siglec-15 overexpression reversed the inhibitory impact of Eupatilin on the differentiation of osteoclasts. Furthermore, activating MAPK signaling pathway reversed the downregulation of Siglec-15 and the inhibition of osteoclastogenesis by Eupatilin. To sum up, Eupatilin reduced the expression of Siglec-15 by suppressing MAPK signaling pathway, ultimately leading to the inhibition of osteoclastogenesis. Meanwhile, Eupatilin suppressed the alveolar bone resorption caused by experimentalperiodontitis in vivo. Eupatilin exhibits potential therapeutic effects in the treatment of periodontitis, rendering it a promising pharmaceutical agent.

Sitagliptin attenuates Porphyromonas gingivalis virulence and inflammatory response in macrophage on titanium.

BACKGROUND: In peri-implantitis, Porphyromonas gingivalis and macrophage play important roles. The aim of this study was to detect the attenuating effect of an anti-diabetic drug sitagliptin on Porphyromonas gingivalis virulence and inflammatory response in macrophage on titanium discs. MATERIALS AND METHODS: Porphyromonas gingivalis and macrophage were cultured on titanium discs. Antibacterial and antibiofilm activities of sitagliptin were assessed and the morphology of Porphyromonas gingivalis was observed by SEM. Bacterial early adhesion, aggregation, hemolysis and Porphyromonas gingivalis virulence factors mRNA expression were assessed to preliminarily investigate the mechanisms of action. Flow cytometry assay, qRT-PCR assay and ELISA were used to assess the anti-inflammatory effect of sitagliptin on Porphyromonas gingivalis lipopolysaccharide-stimulated macrophage. RESULTS: The present study demonstrated the inhibiting effect of sitagliptin on the growth, biofilm and virulence factors of Porphyromonas gingivalis and the protective effect on the Porphyromonas gingivalis lipopolysaccharide-induced polarization in macrophage. And we also confirmed the anti-inflammatory effect of sitagliptin on the secretion of inflammation-related factors in macrophage. CONCLUSIONS: Sitagliptin possesses the attenuating effect on Porphyromonas gingivalis virulence and inflammatory response in Porphyromonas gingivalis lipopolysaccharide-stimulated macrophage on titanium.

Programmed release of vascular endothelial growth factor and exosome from injectable chitosan nanofibrous microsphere-based PLGA-PEG-PLGA hydrogel for enhanced bone regeneration.

The healing of large bone defects remains a significant challenge in clinical practice. Accelerating both angiogenesis and osteogenesis can promote effective bone healing. In the natural healing process, angiogenesis precedes osteogenesis, providing a blood supply that supports the subsequent progression of osteogenesis. Developing a biomimetic scaffold that mimics the in vivo environment and promotes the proper sequence of vascularization followed by ossification is crucial for successful bone regeneration. In this study, a novel injectable dual-drug programmed releasing chitosan nanofibrous microsphere-based poly(D, l-lactide-co-glycolide)-b-poly(ethylene glycol)-b-poly(D,l-lactide-co-glycolide) (PLGA-PEG-PLGA) hydrogel is fabricated by incorporating vascular endothelial growth factor (VEGF) and microspheres loaded with dental pulp stem cells-derived exosomes (DPSCs-Exo). Rapid release of VEGF promotes the swift initiation of angiogenesis, while DPSCs-Exo release ensures persistent osteogenesis. Our results demonstrate that chitosan microsphere-based PLGA-PEG-PLGA hydrogel significantly promotes angiogenesis in human umbilical vascular endothelial cells and enhances the osteogenic differentiation of pre-osteoblasts. Furthermore, in vivo transplantation of this injectable chitosan microsphere-based PLGA-PEG-PLGA hydrogel into calvarial bone defects markedly promotes bone formation. Overall, our study provides a promising approach for improving bone regeneration by temporally replicating the behavior of angiogenesis and osteogenesis.

Heat Shock Protein Inhibitors Show Synergistic Antibacterial Effects with Photodynamic Therapy on Caries-Related Streptococci In Vitro and In Vivo.

Caries are chronic infections in which the cariogenic biofilm plays a critical role in disease occurrence and progression. Photodynamic therapy (PDT) is a new effective treatment that is receiving wide attention in the antibacterial field, but it can lead to the upregulation of heat shock proteins (HSPs), which enhances bacterial resistance. Herein, we incorporated HSP inhibitors with PDT to evaluate the effect on Streptococcus mutans, Streptococcus sobrinus, and Streptococcus sanguinis under planktonic conditions and on cariogenic biofilms. Additionally, a model of caries was established in 2-week-old rats, and anticaries properties were evaluated by Keyes' scoring. Importantly, the combination of HSP inhibitors and PDT had outstanding efficiency in inhibiting the growth of tested Streptococcus strains and the formation of either monomicrobial or multispecies biofilms in vitro. In addition, the quantity of colonized streptococci and the severity of carious lesions were also distinctly suppressed in vivo. Overall, the synergistic application of HSP inhibitors and PDT has promising potential in the prevention and treatment of dental caries. IMPORTANCE Effective therapies for the prevention and control of caries are urgently needed. Cariogenic streptococci play a key role in the occurrence and progression of caries. Recently, photodynamic therapy has been demonstrated to have good antibacterial efficiency, but it can cause a heat shock response in bacteria, which may weaken its practical effects. We indicate here an effective therapeutic strategy of combining heat shock protein inhibitors and photodynamic therapy, which shows excellent inhibition toward three dominant streptococci related to caries and suppression of carious progression in a rat model. Further development for clinical application is promising.