In Vitro Evaluation of Sodium Hypochlorite, Chlorhexidine, Propolis, and Calcium Hydroxide Effect on Lipoteichoic-Acid-Induced Proinflammatory Cytokines Production.

This study aimed to evaluate the effects of sodium hypochlorite (NaOCl), chlorhexidine (CHX), and the glycolic extract of propolis (GEP) as endodontic irrigants and of calcium hydroxide [Ca(OH)2], CHX, or Ca(OH)2 + CHX as intracanal medications on the capacity of the lipoteichoic acid (LTA) of Enterococcus faecalis in macrophages' proinflammatory cytokines production. Freshly extracted 108 human single-rooted teeth were used in this study. The LTA of E. faecalis was standardized in double-distilled pyrogen-free water (250 µg/mL) and inoculated into the specimens subdivided into nine subgroups (n = 12). Cultures of murine macrophages (RAW 264.7) were treated with 30 µL of each sample collected from root canals and incubated (37 °C, 5% CO2) for 24 h. Lastly, anti-TNF-α, anti-IL-6, anti-IP-10, anti-MIP-1α, anti-G-CSF, and anti-IL-1ß DuoSet kits were used to perform an ELISA assay. Data were analyzed using one-way ANOVA and Tukey test (p ≥ 0.05). It was found that 1% NaOCl was the most effective irrigant in reducing the capacity of LTA in cytokines production, followed by 12% GEP and 2% CHX, respectively. Ca(OH)2 + CHX presented the best results when associated with NaOCl or GEP. Thus, NaOCl or GEP associated with Ca(OH)2 + CHX were effective in reducing the capacity of LTA in different macrophages pro-inflammatory cytokines production.

α-IRAK-4 Suppresses the Activation of RANK/RANKL Pathway on Macrophages Exposed to Endodontic Microorganisms.

Periapical lesions are common pathologies affecting the alveolar bone, often initiated by intraradicular lesions resulting from microbial exposure to dental pulp. These microorganisms trigger inflammatory and immune responses. When endodontic treatment fails to eliminate the infection, periapical lesions persist, leading to bone loss. The RANK/RANKL/OPG pathway plays a crucial role in both the formation and the destruction of the bone. In this study, the objective was to inhibit the RANK/RANKL pathway in vitro within exposed Thp-1 macrophages to endodontic microorganisms, specifically Enterococcus faecalis, which was isolated from root canals of 20 patients with endodontic secondary/persistent infection, symptomatic and asymptomatic, and utilizing an α-IRAK-4 inhibitor, we introduced endodontic microorganisms and/or lipoteichoic acid from Streptococcus spp. to cellular cultures in a culture plate, containing thp-1 cells and/or PBMC from patients with apical periodontitis. Subsequently, we assessed the percentages of RANK+, RANKL+, and OPG+ cells through flow cytometry and measured the levels of several inflammatory cytokines (IL-1ß, TNF-α, IL-6, IL-8, IL-10, and IL-12p70) in the cellular culture supernatant through a CBA kit and performed analysis by flow cytometry. A significant difference was observed in the percentages of RANK+RANKL+, OPG+ RANKL+ cells in thp-1 cells and PBMCs from patients with apical periodontitis. The findings revealed significant differences in the percentages of the evaluated cells, highlighting the novel role of the IRAK-4 inhibitor in addressing this oral pathology, apical periodontitis, where bone destruction is observed.

Clinical evaluation of culturable bacteria, endotoxins and lipoteichoic acid in teeth with vital normal pulp tissues.

The objective of this study was to investigate the presence of culturable bacteria, endotoxins (LPS) and lipoteichoic acid (LTA) levels in teeth with normal vital pulp (NVP) with intact crowns (IC) and those with coronal restoration (CR) limited to the enamel level. A total of 20 teeth indicated for endodontic treatment due to prosthetic reasons were selected. Samples were collected from the root canals. The levels of cultivable bacteria, LPS and LTA were assessed. Statistical analyses were performed at significance level set at 5%. None of the teeth presented microbial growth. In the IC group, the LPS levels were limited to the lowest concentration of LPS. On the contrary, higher LPS and LTA levels were detected in teeth with CR. It was concluded that teeth with NVP and IC were negative for bacteria, LPS and LTA; while teeth with CR were positive for bacterial virulence factors.

Detoxification of LTA by intracanal medication: analysis by macrophages proinflammatory cytokines production

Abstract The aim of this study was to evaluate in vitro the effect of calcium hydroxide [Ca(OH)2], 2% chlorhexidine gel (CHX) on macrophages (RAW 264.7) to produce pro-inflammatory cytokines and nitric oxide after pretreatment with lipoteichoic acid (LTA) of Enterococcus faecalis. Forty-eight human single-rooted teeth were instrumented with R25.08 (RECIPROC) and sterilized by gamma irradiation. LTA was inoculated in the root canal of each specimen for 96 hours. Specimens were instrumented with 40.06 and 50.05 (RECIPROC) and medicated with: I) Pyrogen-free saline solution (SS); II) 2% CHX gel; III) Ca(OH)2 + SS; or IV) Ca(OH)2 + CHX for 14 days. Three samples (S) were performed of the root canal of each specimen at: S1) immediately after instrumentation; S2) after Ethylenediaminetetraacetic acid (EDTA); S3) after intracanal medication removal. Subsequent quantification of cytokines (IL-1β, TNF-α, MIP-1α, IP-10, G-CSF and IL-6) by immunosorbent assay (ELISA) and nitric oxide by the Griess method was carried-out. Data were submitted to a normality test and then analyzed with one-way ANOVA and Tukey test with a significance level of 5% using GraphPad Prism 6. Ca(OH)2 + SS and Ca(OH)2 + CHX presented lower levels of TNF-α, TNF-α, IL-6, G-CSF and nitric oxide. Ca(OH)2 + SS was the most effective in reducing MIP-1α. CHX was effective in reducing IL-6 and G-CSF. Therefore, the combined intracanal medication of calcium hydroxide and chlorhexidine is effective in reducing the cytokines TNF-α, IL-1β, IL-6, G-CSF and nitric oxide.

Resumo O objetivo deste estudo foi avaliar in vitro o efeito do hidróxido de cálcio [Ca(OH)2], clorexidina gel a 2% (CHX) em macrófagos (RAW 264.7) na produção de citocinas pró-inflamatórias e óxido nítrico após pré-tratamento com ácido lipoteicóico (LTA) de Enterococcus faecalis. Quarenta e oito dentes humanos uniradiculares foram instrumentados com R25.08 (RECIPROC) e esterilizados por irradiação gama. LTA foi inoculado no canal radicular de cada espécime por 96 horas. Os espécimes foram instrumentados com 40.06 e 50.05 (RECIPROC) e medicados com: I) solução salina apirogênica (SS); II) CHX 2%; III) Ca(OH)2 + SS; ou IV) Ca(OH)2 + CHX durante 14 dias. Três amostras (S) foram realizadas do canal radicular de cada espécime em: S1) imediatamente após a instrumentação; S2) após ácido etilenodiaminotetracético (EDTA); S3) após a retirada da medicação intracanal. Foi realizada a quantificação subsequente de citocinas (IL-1β, TNF-α, MIP-1α, IP-10, G-CSF e IL-6) por imunoensaio (ELISA) e de óxido nítrico pelo método de Griess. Os dados foram submetidos a um teste de normalidade e então analisados com ANOVA one-way e teste de Tukey com nível de significância de 5% usando GraphPad Prism 6. Ca(OH)2 + SS e Ca(OH)2 + CHX apresentaram níveis mais baixos de TNF -α, TNF-α, IL-6, G-CSF e óxido nítrico. Ca(OH)2 + SS foi o mais eficaz na redução de MIP-1α. CHX foi eficaz na redução de IL-6 e G-CSF. Sendo assim a associação de hidróxido de cálcio e clorexidina é eficaz na redução das citocinas TNF-α, IL-1β, IL-6, G-CSF e óxido nítrico.

Efficacy of 6% Sodium Hypochlorite on Infectious Content of Teeth with Symptomatic Irreversible Pulpitis.

INTRODUCTION: The objective of this study was to monitor the effects of chemomechanical preparation (CMP) performed with 6% sodium hypochlorite and calcium hydroxide-based intracanal medication (ICM) on the levels and diversity of bacteria, endotoxins (lipopolysaccharides [LPS]), and lipoteichoic acid (LTA) in root canals of teeth with symptomatic irreversible pulpitis. METHODS: Samples were collected from 10 teeth with symptomatic irreversible pulpitis before CMP (S1), after CMP (S2), and after ICM (S3). The levels of bacteria, LPS, and LTA were assessed by using checkerboard DNA-DNA hybridization, LAL Pyrogent 5000, and enzyme-linked immunosorbent assay, respectively. Wilcoxon test, repeated-measures analysis of variance, and Tukey post hoc test were used for statistical analysis at a significance level of 5%. RESULTS: Forty species were detected at S1. Two species were eliminated after CMP and 5 after ICM. Resistant and pain-related species were detected in the root canals. Higher levels of culturable bacteria were detected at S1. However, CMP and ICM effectively reduced the microbial load in the root canals. Higher levels of LPS and LTA were detected at S1. CMP was effective in reducing both LPS and LTA (P < .05). ICM produced additional reduction in the levels of LPS (P > .05) and LTA (P < .05). CONCLUSIONS: Chemomechanical preparation using 6% sodium hypochlorite and calcium hydroxide-based intracanal medication were effective in reducing the levels of bacteria, LPS, and LTA in teeth with vital pulp and irreversibly inflamed pulp.

Effectiveness of 1-Visit and 2-Visit Endodontic Retreatment of Teeth with Persistent/Secondary Endodontic Infection: A Randomized Clinical Trial with 18 Months of Follow-up.

INTRODUCTION: This randomized clinical trial aimed to compare the effectiveness of endodontic retreatment of teeth with posttreatment apical periodontitis (PTAP) performed in 1 visit versus 2 visits on the reduction of cultivable bacteria (colony-forming units [CFUs]), lipopolysaccharides (LPSs), lipoteichoic acid (LTA), and the periapical lesion volume (mm3) after 18 months of follow-up. METHODS: Forty patients diagnosed with PTAP were selected and randomly divided into the following 2 groups: 1-visit retreatment and 2-visit retreatment with the placement of calcium hydroxide medication for 14 days. Cone-beam computed tomographic scans were performed at 2 stages: preoperatively and after 18 months of follow-up. Samples were collected before and after root canal procedures. A chromogenic limulus amebocyte lysate assay test was used to quantify endotoxins (EU/mL). LTA levels were measured using the enzyme-linked immunosorbent assay (pg/mL). Culture techniques were used to determine cultivable bacteria by counting the CFU (CFU/mL). The volume of the periapical lesions at the onset of the trial and at the 18-month posttreatment follow-up was obtained by the ITK-SNAP program (Cognitica, Philadelphia, PA). RESULTS: All samples showed baseline values greater than those collected after the retreatment protocol for all investigated parameters. A higher bacterial load and lower LTA level were found in the 2-visit group after the retreatment protocol (P < .05), with no statistical differences between the groups regarding endotoxin levels and periapical lesion volume (mm³) at the 18-month follow-up analyzed by cone-beam computed tomographic imaging (P > .05). CONCLUSIONS: Endodontic retreatment in 1 or 2 visits exhibited equally favorable periapical healing at 18 months, with no statistically significant differences between groups.

Chemomechanical preparation influences the microbial community and the levels of LPS, LTA and cytokines in combined endodontic-periodontal lesions: A clinical study.

BACKGROUND: This study was conducted to compare the microbiomes, the levels of lipopolysaccharides (LPS), lipoteichoic acid (LTA), and cytokines (interleukin [IL]-1ß and tumor necrosis factor-alpha [TNF-α]), before and after chemomechanical preparation (CMP) of the root canals (RC) and their associated periodontal pockets (PP) in teeth with combined EPL. MATERIALS: Samples were taken from 10 RC and PP, before and after CMP. The microbiomes (next-generation sequencing, V3-V4 hypervariable region of the 16S rRNA gene), microbiome diversity (bioinformatics analyses), LPS (limulus amebocyte lysate), LTA, IL-1ß, and TNF-α (ELISA) were evaluated. A statistical analysis was performed with significance level set at 5%. RESULTS: The most abundant phyla in both sites were Firmicutes and Proteobacteria. Comparative studies of bacterial genera species revealed that some increased and others decreased after CMP at both sites. A 3% reduction in Gram-negative bacteria (RC) and a 4% increase in Gram-positive bacteria (PP) were detected. LPS levels were 4.4 times higher in PP than in the RC. LTA was detected in all samples investigated. Higher levels of IL-1ß and TNF-α were detected in both sites at baseline. After CMP, LPS, LTA, IL-1ß and TNF-α were reduced in both sites. CONCLUSION: The microbial community in the RC and PP in teeth with combined EPL indicated a similarity between both sites. CMP effectively reduced the microbial load and the LPS levels from teeth with EPL, and consequently diminished the cytokine levels. The reduction in LTA levels in the RC and PP proved challenging.

Investigation of microbial profile, levels of endotoxin and lipoteichoic acid in teeth with symptomatic irreversible pulpitis: a clinical study.

AIM: To investigate the microbial profile, and levels of endotoxin (LPS) and lipoteichoic acid (LTA), in infected dentine (ID) and root canals (RC) at different phases of root canal treatment in teeth with symptomatic irreversible pulpitis. METHODOLOGY: Ten volunteers were included, and samples were collected from infected dentine (ID) and the root canal lumen (RC) using sterile excavators and paper points, respectively. RC samples were taken before (S1) and after (S2) chemo-mechanical canal preparation (CMP), and after intracanal medication (ICM; S3). Checkerboard DNA-DNA hybridization was used for microbial analysis. The levels of LPS and LTA were evaluated using the limulus amebocyte lysate assay and ELISA, respectively. Shapiro-Wilk's test was used to verify data normality. Friedman's test was used to evaluate statistical differences using checkerboard DNA-DNA hybridization in the ID and RC at the different phases of the RC treatment. Post hoc Dunn's multiple comparison test was used to verify significant differences recorded at the different time-points. The levels of LPS and LTA were analysed statistically by using repeated measures anova and Tukey's post hoc test to evaluate differences in both sites. The significance level was set at 5% (P < 0.05). RESULTS: A total of 40 DNA probes were used for microbial investigation of ID and RC samples using checkerboard DNA-DNA hybridization. The levels and complexity of bacteria were similar in the ID and initial RC samples. The levels of LPS and LTA in ID were significantly higher than the initial RC samples (S1; P < 0.05). Canal preparation was effective in significantly decreasing the levels of bacteria, LPS and LTA (P < 0.05). ICM did not provide additional reduction in the levels of bacteria and LPS (P > 0.05). However, a significant reduction in the levels of LTA was observed after ICM (P < 0.05). CONCLUSION: The microbial profile of infected dentine and root canals of teeth with irreversible pulpitis was complex, harbouring different species including Gram-positive and Gram-negative, cocci and bacilli, and facultative and strict anaerobes. Root canal preparation was effective in reducing the levels of bacteria, LPS and LTA from the root canals of teeth with pulpitis.

Bacteria and virulence factors in periapical lesions associated with teeth following primary and secondary root canal treatment.

AIM: This cross-sectional study aimed to investigate the microbial profile and to quantify the levels of endotoxins (LPS) and lipoteichoic acid (LTA) present in periapical lesions associated with root filled teeth and those that had received root canal retreatment. It also aimed to investigate the association between microorganisms and their virulence factors with clinical and radiographic features. METHODOLOGY: Patients with periapical lesions in teeth with post-treatment endodontic disease following primary root canal treatment (n = 19) and unsuccessful root canal retreatment (n = 13) were treatment planned for endodontic microsurgery, where the periapical lesions were collected. Clinical and radiographic data were also collected. For microbiological analysis, nested polymerase chain reaction was used to detect 17 bacterial species. Levels of LPS and LTA were determined using limulus amebocyte lysate and enzyme-linked immunosorbent assays, respectively. The Student t-test or Wilcoxon-Mann-Whitney tests were applied to compare the data on LPS and LTA with clinical and radiographic features. The associations between the clinical and radiographic features and the bacterial species were analysed using the Fisher's exact test. A significance level of 5% was adopted. RESULTS: Bacterial DNA, LPS and LTA were detected in all samples. Parvimonas micra was the most commonly detected species in all groups, followed by Enterococcus faecalis, Fusobacterium nucleatum and Porphyromonas endodontalis. The type of endodontic treatment, whether a primary root canal treatment or retreatment, was not associated with the presence of any bacterial species in periapical lesions. The levels of LPS and LTA in periapical lesions of root filled teeth were not significantly different from those that had been retreated. Associations between the levels of LPS and LTA with clinical signs and symptoms were found. No association was found between specific bacteria and clinical features. CONCLUSION: Periapical lesions associated with teeth after primary root canal treatment and retreatment had similar polymicrobial composition. The levels of LPS and LTA in periapical lesions associated with teeth after primary root canal treatment and retreatment were similar, and both were associated with the same symptomatology.

Rutin Prevents LTA Induced Oxidative Changes in H9c2 Cells.

Lipoteichoic acid (LTA), a component of Gram-positive bacteria cell walls is involved in infective endocarditis (IE), a life-threatening disease. We evaluated for the first time, whether flavonoid rutin (quercetin-3-rutinoside) can block LTA-induced pro-inflammatory response and reactive oxygen species (ROS) production, and reduction of antioxidant enzymes. We found that rutin suppresses LTA effects on the antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase, as well as the pro-inflammatory enzyme cyclooxygenase-2, preventing phosphorylation of the mitogen-activated protein kinases (MAPKs), p38, and c-Jun N-terminal kinase, and the increase of ROS production induced by LTA. Taken together, these findings suggest that rutin prevents oxidative damage, inflammation, and MAPKs activation induced by LTA. Rutin may exert a protective effect in IE. These data provide novel insights for future use of rutin to prevent the mechanisms of LTA-related pathogenesis, inflammatory processes, and antioxidant enzyme levels in diseases such as IE.

Clinical Investigation of Microbial Profile and Levels of Endotoxins and Lipoteichoic Acid at Different Phases of the Endodontic Treatment in Teeth with Vital Pulp and Associated Periodontal Disease.

INTRODUCTION: The aim of this in vivo study was to investigate the microbial profile as well as the levels of lipopolysaccharide (LPS) and lipoteichoic acid (LTA) at different phases of endodontic treatment in teeth with vital pulp and associated periodontal disease. METHODS: Ten patients were selected for this clinical study. Samples were taken from periodontal pockets (PPs) and root canals (RCs) using sterile paper points before and after chemomechanical preparation and after intracanal medication. For microbiological analysis, nested polymerase chain reaction and checkerboard DNA-DNA hybridization were used. Levels of LPS and LTA were assessed using limulus amebocyte lysate and enzyme-linked immunosorbent assays, respectively. Data were statistically analyzed at a significance level of 5%. RESULTS: Bacterial DNA from 17 of the 17 species investigated was detected in samples of PPs, whereas 6 of the 17 species were not present in the initial samples of RCs using nested polymerase chain reaction. In the initial samples, 38 of 40 probes were detected in PPs, whereas 12 of 40 probes were detected in RCs using checkerboard DNA-DNA hybridization. Overall, endodontic procedures were efficient in modifying the microbiota of PPs and RCs. Levels of LPS and LTA were reduced after the endodontic procedures, although higher concentrations of both had been found in PPs compared with RCs. CONCLUSIONS: The microbiota of PPs and RCs in teeth with vital pulp and associated periodontal disease is polymicrobial, with the presence of gram-negative, gram-positive, facultative, and strict anaerobes. Chemomechanical preparation and calcium hydroxide-based intracanal medication allowed the reduction of infectious content in both sites.

Primary versus post-treatment apical periodontitis: microbial composition, lipopolysaccharides and lipoteichoic acid levels, signs and symptoms.

OBJECTIVES: To compare the microbial load and composition and to determine the lipopolysaccharides (LPS) and lipoteichoic acid (LTA) concentrations found in primary apical periodontitis (PAP) and post-treatment apical periodontitis (PTAP), correlating these findings with clinical/tomographic features. MATERIAL AND METHODS: Sixty patients with PAP (31) and PTAP (29) were submitted to clinical and tomographic assessment. Samples were collected from each root canal using paper points for microbiological assessment (culture technique and Checkerboard DNA-DNA hybridization) and determination of LPS and LTA levels (limulus amebocyte lysate and enzyme-linked immunosorbent assays, respectively). Data were correlated with clinical/tomographic findings and statistically analyzed using the Mann-Whitney and Pearson correlation tests (α = 5%). RESULTS: A higher number of cultivable bacteria and LPS were found in PAP (p < 0.05). The median number of species per root canal found in PAP and PTAP was 9 and 22, respectively (p < 0.05). LPS was positively correlated with a larger periapical lesion volume (p < .05). LTA levels were similar in both infections and had no correlation with signs and symptoms. In PAP, gram-positive bacteria were correlated with spontaneous pain (p < .05) and exudate (p < .05). Tenderness to percussion and pain on palpation were correlated to the presence of both gram-positive and negative bacteria. In PTAP, a positive correlation was observed between both gram-positive and gram-negative bacteria with exudate and periapical lesion volume (p < .05). CONCLUSIONS: PAP had higher contents of microbial load and LPS compared with PTAP. However, PTAP presented a more diverse microbiota compared with PAP. Higher content of LPS was positively correlated with larger periapical bone destruction, whereas signs and symptoms with specific microorganisms. CLINICAL RELEVANCE: It was verified that PAP and PTAP are polymicrobial infections with predominance of gram-negative bacteria and a more diverse bacterial population found in PTAP. A wide interaction of specific microbial species resulted in different clinical features in both infections.

Photodynamic and peptide-based strategy to inhibit Gram-positive bacterial biofilm formation.

The self-produced extracellular polymeric matrix of biofilms renders them difficult to eliminate once they are established. This makes the inhibition of biofilm formation key to successful treatment of biofilm infection. Antimicrobial photodynamic therapy (aPDT) and antimicrobial peptides offer a new approach as antibiofilm strategies. In this study sub-lethal doses of aPDT (with chlorin-e6 (Ce6-PDT) or methylene blue (MB-PDT)) and the peptides AU (aurein 1.2 monomer) or (AU)2K (aurein 1.2 C-terminal dimer) were combined to evaluate their ability to prevent biofilm development by Enterococcus faecalis. Biofilm formation was assessed by resazurin reduction, confocal microscopy, and infrared spectroscopy. All treatments successfully prevented biofilm development. The (AU)2K dimer had a stronger effect, both alone and combined with aPDT, while the monomer AU had significant activity when combined with Ce6-PDT. Additionally, it is shown that the peptides bind to the lipoteichoic acid of the E. faecalis cell wall, pointing to a possible key mechanism of biofilm inhibition.

Apigenin reduce lipoteichoic acid-induced inflammatory response in rat cardiomyoblast cells.

Infective endocarditis is caused by Streptococcus sanguinis present in dental plaque, which can induce inflammatory responses in the endocardium. The present study depicts research on the properties of apigenin in embryonic mouse heart cells (H9c2) treated with lipoteichoic acid (LTA) obtained from S. sanguinis. Interleukin-1ß and cyclooxygenase (COX)-2 expression were detected by reverse transcriptase polymerase chain reaction. In addition, western blot assays and immuno-fluorescence staining were used to assess translocation of nuclear factor kappa beta (NF-κB), degradation of IκB, as well as activity of the mitogen activated protein kinases: extracellular signal-regulated kinase (ERK)1/2, p38, and c-Jun N-terminal kinase (JNK). Effect of apigenin on cell viability was equally assessed in other experimental series. Our results showed that apigenin blocked activation of ERK, JNK, and p38 in cardiomyocytes treated with LTA in a dose-dependent fashion. Moreover, apigenin showed no cytotoxic effects; it blocked NF-κB translocation and IκB degradation. Our findings suggested that apigenin possessed potential value in the treatment of infectious endocarditis.

Efecto del ácido lipoteicoico sobre la expresión de genes en cardiomiocitos de ratón (H9c2) / Effect of lipoteichoic acid on gene expression in mice (H9c2) cardiomyocite

La mayoría de las enfermedades de la pulpa dental y de los tejidos perirradiculares guardan relación con microorganismos. Los peptidoglucanos y el ácido lipoteicoico son dos de los principales componentes de las bacterias Gram positivas que tienen actividades relacionadas con el desarrollo de sepsis. Tras la invasión microbiana de estos tejidos, el huésped responde con defensas tanto inflamatorias inespecíficas como inmunológicas específicas. El tratamiento endodóncico quirúrgico y no quirúrgico son en esencia, procedimientos de desbridamiento destinados a destruir y eliminar el ecosistema microbiano, asociado con el proceso patológico. Es importante que los clínicos comprendan la íntima relación entre presencia de microorganismos y enfermedad endodóncica, con el fin de diseñar un tratamiento racional y efectivo; sobre todo en aquellos individuos susceptibles a Endocarditis Infecciosa. En el presente estudio se investigó la expresión de TNFα, IL-1 y COX-2 por efecto del ácido lipoteicoico (ALT) de Streptococcus sanguinis caracterizando las señales intracelulares involucradas en cardiomiocitos H9c2. La línea celular fue tratada con ALT a diferentes concentraciones durante 30 minutos. Comparadas con los controles, las respuestas al tratamiento con ALT fueron dependientes de la dosis y mediante un análisis de One Step RT-PCR (Invitrogen) se evaluó dicha expresión; la cual se asemeja a la respuesta fisiológica del organismo durante un episodio de Endocarditis infecciosa y a la agudización durante un procedimiento endodóncico.

Most dental pulp diseases and diseases of tissues surrounding the root are somehow related to micro-organisms. Peptidoglycans and lipoteichoic acid are two of the main Gram-positive bacteria components with activities related to sepsis development. When tissues sustain microbial invasion the host responds with both unspecific inflammatory defenses and specific immunological reactions. Surgical and non surgical endodontic treatments are essentially debridement procedures intended to destroy and eliminate the microbial eco-system associated to the pathological process. It is essential for clinicians to understand the intimate relationship existing between micro-organisms and endodontic disease, so as to be able to tailor a rational and effective treatment especially in subjects susceptible to infective endocarditis processes. In the present study research was conducted on TNFα, IL-1 COX-2 expression through the effect of lipoteichoic acid (LTA) of Streptococcus sanguinis by characterizing intra-cellular signals involved in H9c'' cardiomyocytes. The cell line was treated with LTA at different concentrations during 30 minutes. When compared to control group, responses to LTA treatment were dependent on dosage. That expression was assessed by means of a One Step RT-PCR (Invitrogen) analysis. It was noted that the aforementioned expression resembled the organisms's physiological response during an infective endocarditis episode and to exacerbation observed during an endodontic procedure.

Myricetin suppresses lipoteichoic acid-induced interleukin-1ß and cyclooxygenase-2 expression in human gingival fibroblasts.

Periodontitis is an inflammatory disease affecting the connective tissue and supporting bone surrounding the teeth. In periodontitis, human gingival fibroblasts (HGFs) synthesize IL-1ß, causing a progressive inflammatory response. Flavones demonstrate a variety of biological activity: among others, they possess anti-inflammatory properties. Myricetin is a flavone with a strong anti-inflammatory activity. The objective of this study was to evaluate the effect of the flavonoid myricetin on HGFs under inflammatory conditions induced by lipoteichoic acid (LTA). the effect of myricetin on HGFs was assessed by measuring cell viability, signaling pathways and IL-1ß expression and synthesis. It was found that, over time, myricetin did not affect cell viability. However, it inhibited activation of p38 and extracellular-signal-regulated kinase-1/2 in LTA-treated HGFs and also blocked IκB degradation and cyclooxygenase-2 and prostaglandin E2 synthesis and expression. These findings suggest that myricetin has therapeutic effects in the form of controlling LTA-induced inflammatory responses.

The reaction of dental pulp to Escherichia coli lipopolysaccharide and Enterococcus faecalis lipoteichoic acid

This research evaluates the effects of the lipopolysaccharides (LPS) from Escherichia coli and lipoteichoic acid (LTA) from Enterococcus faecalis on dental pulp. These molecules are components of the Gram-negative and Gram-positive bacteria cell wall, respectively. Ten dogs were used in the experiment. Inoculation in surgically opened pulp and coronal restoration with glass ionomer was the method chosen. The evaluation times were 1, 7, 15, 30 and 60 days. The results showed that the LPS and LTA, at 150 µg/ml, produced a negative interference in the pulp leading to destruction. LTA caused less damage than LPS.

O presente trabalho avaliou os efeitos do ácido lipoteicóico (LTA) e do lipopolissacarídeo (LPS) no tecido pulpar. Essas moléculas estão presentes nas paredes das bactérias Gram-positivas e Gram-negativas, respectivamente. Utilizaram-se dez cães para inoculação das substâncias em polpas expostas cirurgicamente. Os períodos de avaliação foram de 1, 7, 15, 30 e 60 dias. Os resultados demonstraram que 150 µg/ml de LPS e LTA interferem negativamente na polpa promovendo destruição tecidual. O LTA estabeleceu um padrão citotóxico menos agressivo que o LPS.