Synergistic antimicrobial potential of EGCG and fosfomycin against biofilms associated with endodontic infections.

OBJECTIVE: This study aimed to evaluate the cytotoxicity and synergistic effect of epigallocatechin gallate (EGCG) and fosfomycin (FOSFO) on biofilms of oral bacteria associated with endodontic infections. METHODOLOGY: This study determined minimum inhibitory and bactericidal concentration (MIC/MBC) and fractionated inhibitory concentration (FIC) of EGCG and FOSFO against Enterococcus faecalis, Actinomyces israelii, Streptococcus mutans, and Fusobacterium nucleatum. Monospecies and multispecies biofilms with those bacteria formed in polystyrene microplates and in radicular dentin blocks of bovine teeth were treated with the compounds and control chlorhexidine (CHX) and evaluated by bacterial counts and microscopy analysis. Toxicity effect of the compounds was determined on fibroblasts culture by methyl tetrazolium assays. RESULTS: The combination of EGCG + FOSFO demonstrated synergism against all bacterial species, with an FIC index ranging from 0.35 to 0.5. At the MIC/FIC concentrations, EGCG, FOSFO, and EGCG+FOSFO were not toxic to fibroblasts. EGCG+FOSFO significantly reduced monospecies biofilms of E. faecalis and A. israelli, whereas S. mutans and F. nucleatum biofilms were eliminated by all compounds. Scanning electron microscopy of multispecies biofilms treated with EGCG, EGCG+FOSFO, and CHX at 100x MIC showed evident biofilm disorganization and substantial reduction of extracellular matrix. Confocal microscopy observed a significant reduction of multispecies biofilms formed in dentin tubules with 84.85%, 78.49%, and 50.6% of dead cells for EGCG+FOSFO, EGCG, and CHX at 100x MIC, respectively. CONCLUSION: EGCG and fosfomycin showed a synergistic effect against biofilms of oral pathogens related to root canal infections without causing cytotoxicity.

Cytotoxicity and Biomineralization Potential of Flavonoids Incorporated into PNVCL Hydrogels.

This study aimed to evaluate the effects of flavonoids incorporated into poly(N-vinylcaprolactam) (PNVCL) hydrogel on cell viability and mineralization markers of odontoblast-like cells. MDPC-23 cells were exposed to ampelopsin (AMP), isoquercitrin (ISO), rutin (RUT) and control calcium hydroxide (CH) for evaluation of cell viability, total protein (TP) production, alkaline phosphatase (ALP) activity and mineralized nodule deposition by colorimetric assays. Based on an initial screening, AMP and CH were loaded into PNVCL hydrogels and had their cytotoxicity and effect on mineralization markers determined. Cell viability was above 70% when MDPC-23 cells were treated with AMP, ISO and RUT. AMP showed the highest ALP activity and mineralized nodule deposition. Extracts of PNVCL+AMP and PNVCL+CH in culture medium (at the dilutions of 1/16 and 1/32) did not affect cell viability and stimulated ALP activity and mineralized nodules' deposition, which were statistically higher than the control in osteogenic medium. In conclusion, AMP and AMP-loaded PNVCL hydrogels were cytocompatible and able to induce bio-mineralization markers in odontoblast-cells.

Synergistic antimicrobial potential of EGCG and fosfomycin against biofilms associated with endodontic infections

Abstract Objective This study aimed to evaluate the cytotoxicity and synergistic effect of epigallocatechin gallate (EGCG) and fosfomycin (FOSFO) on biofilms of oral bacteria associated with endodontic infections. Methodology This study determined minimum inhibitory and bactericidal concentration (MIC/MBC) and fractionated inhibitory concentration (FIC) of EGCG and FOSFO against Enterococcus faecalis, Actinomyces israelii, Streptococcus mutans, and Fusobacterium nucleatum. Monospecies and multispecies biofilms with those bacteria formed in polystyrene microplates and in radicular dentin blocks of bovine teeth were treated with the compounds and control chlorhexidine (CHX) and evaluated by bacterial counts and microscopy analysis. Toxicity effect of the compounds was determined on fibroblasts culture by methyl tetrazolium assays. Results The combination of EGCG + FOSFO demonstrated synergism against all bacterial species, with an FIC index ranging from 0.35 to 0.5. At the MIC/FIC concentrations, EGCG, FOSFO, and EGCG+FOSFO were not toxic to fibroblasts. EGCG+FOSFO significantly reduced monospecies biofilms of E. faecalis and A. israelli, whereas S. mutans and F. nucleatum biofilms were eliminated by all compounds. Scanning electron microscopy of multispecies biofilms treated with EGCG, EGCG+FOSFO, and CHX at 100x MIC showed evident biofilm disorganization and substantial reduction of extracellular matrix. Confocal microscopy observed a significant reduction of multispecies biofilms formed in dentin tubules with 84.85%, 78.49%, and 50.6% of dead cells for EGCG+FOSFO, EGCG, and CHX at 100x MIC, respectively. Conclusion EGCG and fosfomycin showed a synergistic effect against biofilms of oral pathogens related to root canal infections without causing cytotoxicity.

Microbiological Properties and Cytotoxicity of PNVCL Hydrogels Containing Flavonoids as Intracanal Medication for Endodontic Therapy.

This study aimed to evaluate the cytotoxicity and microbiological properties of poly (N-vinylcaprolactam)-PNVCL hydrogels containing flavonoids as intracanal medication for endodontic therapy. Antimicrobial activity of ampelopsin (AMP), isoquercitrin and rutin was determined against Enterococcus faecalis, Actinomyces israelii, Lactobacillus casei, Streptococcus mutans, and Fusobacterium nucleatum by the microdilution method. After synthesis and characterization by rheology, PNVCL hydrogels were loaded with AMP and controls calcium hydroxide (CH) and chlorhexidine (CHX), and determined the compounds release profile. PNVCL+AMP, PNVCL+CH, PNVCL+CHX were evaluated on multi-species biofilms and analyzed by Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM). Cytotoxicity was determined after fibroblasts exposure to serial dilutions of AMP and PNVCL hydrogel extracts. AMP was effective against all of the bacteria tested, especially against S. mutans, A. israelli and F. nucleatum. SEM and CLSM analysis showed that PNVCL + AMP caused a significant decrease and disorganization of multi-species biofilms and reduction of intracanal viable cells, superior to the other groups. AMP affected fibroblast viability at concentrations above 0.125 mg/mL, and extracts of PNVCL+AMP showed low cytotoxicity. In conclusion, PNVCL containing AMP demonstrated cytocompatibility and potent effect against multi-species biofilms and could be potential intracanal medication for endodontic purposes.

Antibacterial Activity of Isobavachalcone (IBC) Is Associated with Membrane Disruption.

Isobavachalcone (IBC) is a natural prenylated chalcone with a broad spectrum of pharmacological properties. In this work, we newly synthesized and investigated the antibacterial activity of IBC against Gram-positive, Gram-negative and mycobacterial species. IBC was active against Gram-positive bacteria, mainly against Methicillin-Susceptible Staphylococcus aureus (MSSA) and Methicillin-Resistant Staphylococcus aureus (MRSA), with minimum inhibitory concentration (MIC) values of 1.56 and 3.12 µg/mL, respectively. On the other hand, IBC was not able to act against Gram-negative species (MIC > 400 µg/mL). IBC displayed activity against mycobacterial species (MIC = 64 µg/mL), including Mycobacterium tuberculosis, Mycobacterium avium and Mycobacterium kansasii. IBC was able to inhibit more than 50% of MSSA and MRSA biofilm formation at 0.78 µg/mL. Its antibiofilm activity was similar to vancomycin, which was active at 0.74 µg/mL. In order to study the mechanism of the action by fluorescence microscopy, the propidium iodide (PI) and SYTO9 fluorophores indicated that IBC disrupted the membrane of Bacillus subtilis. Toxicity assays using human keratinocytes (HaCaT cell line) showed that IBC did not have the capacity to reduce the cell viability. These results suggested that IBC is a promising antibacterial agent with an elucidated mode of action and potential applications as an antibacterial drug and a medical device coating.

Efeito antimicrobiano e anti-inflamatório de ácidos fenólicos isolados, combinados e incorporados em hidrogéis de quitosana para aplicação endodôntica / Antimicrobial and anti-inflammatory effect of phenolic acids, alone, combined and incorporated in chitosan hydrogels for endodontic application

O objetivo do tratamento endodôntico é manter a integridade da raiz, bem como, prevenir ou resolver doenças periapicais, pela erradicação dos microrganismos e de suas fontes de nutrientes provenientes do sistema de canais radiculares. A complexidade da anatomia dos canais radiculares e dos biofilmes multiespécies aumenta a dificuldade em eliminar os microrganismos e controlar a inflamação por procedimentos químico-mecânicos convencionais, o que justifica o uso de medicações intracanais. Novos compostos com amplo efeito antimicrobiano e potencial antiinflamatório, como os ácidos fenólicos, poderiam ser explorados como princípios ativos de medicamentos intracanais. Entretanto, para aumentar a solubilidade, controlar a liberação e estender os efeitos biológicos dos ácidos fenólicos, seria interessante incorporá-los em carreadores de medicamentos como os hidrogéis de quitosana. Este estudo foi dividido em dois capítulos que apresentaram como objetivos: 1) avaliar as atividades antimicrobiana, antibiofilme e antiinflamatória e a citotoxicidade do ácido cinâmico e seus derivados; 2) sintetizar e caracterizar as propriedades químicas e físico-mecânicas de hidrogéis termossensíveis de quitosana e poloxamer contendo ácidos fenólicos, e avaliar o efeito desses hidrogéis sobre biofilmes multiespécies e na viabilidade de macrófagos e fibroblastos. No capítulo 1, a atividade antimicrobiana do ácido cinâmico (CI) e seus derivados ácido cumárico (CO), ácido cafeico (CA), ácido ferúlico (FE) e ácido sinápico (SI) foi avaliada pela determinação da concentração inibitória e bactericida mínima (CIM/CBM) e Concentração Inibitória Fracionada (CIF) sobre Enterococcus faecalis, Streptococcus mutans, Lactobacillus casei, Actinomyces israelii e Fusobacterium nucleatum. Os ácidos fenólicos foram selecionados e seu efeito em biofilmes dual-espécies e multiespécies com as mesmas cepas padrão ou cepas clínicas foram avaliados por contagem bacteriana, microscopia eletrônica de varredura e microscopia confocal. A viabilidade de fibroblastos L929 e macrófagos RAW 264.7 na presença desses ácidos fenólicos foi avaliada por ensaios de resazurina. Além disso, os níveis de mRNA dos marcadores pró-inflamatórios TNF-α, IL-1ß, iNOS e COX-2 foram determinados por PCR quantitativo TaqMan após exposição de macrófagos aos ácidos fenólicos e ao lipopolissacarídeo (LPS). No capítulo 2, foi realizada a síntese e caracterização físicomecânica de hidrogéis de quitosana-poloxamer (CPH) contendo ácidos fenólicos e avaliado seus efeitos no biofilme multiespécies e na viabilidade de macrófagos e fibroblastos. Os dados foram analisados estatisticamente considerando p< 0,05. O ácido cinâmico e o ácido cafeico apresentaram efeito inibitório e bactericida contra todas as espécies bacterianas testadas, com os menores valores de CIM e CBM. Entretanto, não houve efeito sinérgico entre eles (FICI> 0,5). Ambos os compostos (5x a CIM mais alta) foram eficazes na eliminação de biofilmes dual-espécies e na redução significativa de biofilmes multiespécies, especialmente o ácido cinâmico. O ácido cinâmico causou toxicidade mínima para ambas as culturas celulares nas concentrações de CIM e o ácido cafeico não foi citotóxico em concentrações abaixo de 0,125 mg/mL. Ambos os compostos reduziram significativamente TNF-α, IL-1ß, iNOS e COX-2, de maneira dose-dependente. Os CPH foram caracterizados como termorreversíveis e com propriedades mecânicas e bioadesivas desejáveis. O efeito dos hidrogéis CPH+CA (77,8%) e CPH+CI (73,2%) em reduzir os biofilmes multiespécies foi superior ao CPH+ hidroxido de cálcio (CH) (53,6%) e CPH+ clorexidina (CHX) (39,9%). Em geral, CPH + CI causou menor citotoxicidade quando comparado a CPH + CA, para ambas as linhagens celulares. Conclui-se que o ácido cinâmico e ácido cafeico apresentaram efeito bactericida e contra biofilmes formados por bactérias associadas com infecções endodônticas, causando baixa citotoxicidade. Ambos os compostos apresentaram efeito antiinflamatório, inibindo a expressão de marcadores próinflamatórios em macrófagos estimulados por LPS. Os hidrogéis de quitosana-poloxamer foram termorreversíveis e apresentaram adequadas propriedades mecânicas e adesivas para aplicação clínica, e quando combinados principalmente com ácido cinâmico, promoveram a redução de biofilmes multiespécies formados nos túbulos dentinários, causando baixa toxicidade em fibroblastos e macrófagos(AU)

The objective of endodontic treatment is to maintain the integrity of the root, as well as to prevent or resolve periapical diseases, by eradicating microorganisms and their sources of nutrients from the root canal system. The complexity of root canal anatomy and multispecies biofilms increases the difficulty in eliminating microorganisms and controlling inflammation by conventional chemical-mechanical procedures, which justifies the use of intracanal medications. New compounds with broad antimicrobial effect and anti-inflammatory potential, such as phenolic acids, could be explored as active principles of intracanal medications. However, to increase the solubility, control the release and extend the biological effects of phenolic acids, it would be interesting to incorporate them into drug carriers such as chitosan hydrogels. This study was divided into two chapters with the following objectives: 1) to evaluate the antimicrobial, antibiofilm and anti-inflammatory activities and the cytotoxicity of cinnamic acid and its derivatives; 2) synthesize and characterize chemical and physicomecanical properties of thermosensitive chitosan and poloxamer hydrogels containing phenolic acids and evaluate the effect of these hydrogels on multispecies biofilms and on the viability of macrophages and fibroblasts. In chapter 1, the antimicrobial activity of cinnamic acid (CI) and its derivatives coumaric acid (CO), caffeic acid (CA), ferulic acid (FE) and sinapic acid (SI) was evaluated by determining the minimum inhibitory and bactericidal concentration (MIC/MBC) and Fractional Inhibitory Concentration (FIC) on Enterococcus faecalis, Streptococcus mutans, Lactobacillus casei, Actinomyces israelii and Fusobacterium nucleatum. Phenolic acids were selected and their effect on bispecies and multispecies biofilms with the same standard or clinical strains were evaluated by bacterial counts, scanning electron microscopy and confocal microscopy. The viability of L929 fibroblasts and RAW 264.7 macrophages in the presence of these phenolic acids was evaluated by resazurin assays. In addition, mRNA levels of the proinflammatory markers TNF-α, IL-1ß, iNOS and COX-2 were determined by quantitative TaqMan PCR after macrophage exposure to phenolic acids and lipopolysaccharide (LPS). In chapter 2, the synthesis and physical-mechanical characterization of chitosanpoloxamer (CPH) hydrogels containing phenolic acids were performed and their effects on multispecies biofilm and on the viability of macrophages and fibroblasts were evaluated. Data were statistically analyzed considering p< 0.05. Cinnamic acid and caffeic acid showed an inhibitory and bactericidal effect against all bacterial species tested, with the lowest MIC and MBC values. However, no synergistic effect was observed between the compounds (FICI> 0.5). Both compounds (at 5x the highest MIC) were effective in eliminating dual-species biofilms and significantly decreasing multispecies biofilms, especially cinnamic acid. Cinnamic acid caused minimal toxicity to both cell cultures at MIC concentrations and caffeic acid was not cytotoxic at concentrations below 0.125 mg/mL. Both compounds significantly reduced TNF-α, IL1ß, iNOS and COX-2, in a dose-dependent manner. CPH were characterized as thermoreversible and with adequate mechanical and bioadhesive properties. The effect of CPH+CA (77.8%) and CPH+CI (73.2%) hydrogels against multispecies biofilms was superior to CPH + calcium hydroxide (CH) (53.6%) and CPH + chlorhexidine (CHX) (39.9%). In general, CPH + CI caused less cytotoxicity when compared to CPH + CA, for both cell lines. In conclusion, cinnamic acid and caffeic acid showed bactericidal effect and against biofilms of bacteria associated with endodontic infections, causing minimal cytotoxicity. In addition, both compounds showed an anti-inflammatory effect, inhibiting the expression of pro-inflammatory markers in LPS-stimulated macrophages. The chitosan-poloxamer hydrogels were thermoreversible and presented adequate mechanical and bioadhesive properties for clinical application, and when combined specially with cinnamic acid, they promoted the reduction of multispecies biofilms formed in the dentinal tubules, causing low toxicity to fibroblasts and macrophages(AU)

Effect of S. mutans combinations with bifidobacteria/lactobacilli on biofilm and enamel demineralization.

The present study evaluated the ability of Bifidobacterium and Lactobacillus species associated with streptococci to increase insoluble extracellular polysaccharide (EPS) production and initial caries lesion progression. Bovine enamel blocks (n = 190; 4 mm x 4 mm) were prepared, selected according to initial surface hardness (SH), and divided into two groups: a) double combinations: S. mutans with Bifidobacterium or Lactobacillus, and b) triple combinations: S. mutans and S. sobrinus with Bifidobacterium or Lactobacillus species. The blocks were exposed to the bacterial associations for 7 days. Subsequently, quantity of EPS from biofilms and caries lesion depth were determined by means of colorimetric and cross-sectional enamel hardness (ΔKHN) analysis. The data were submitted to one-way analysis of variance, followed by the Bonferroni test (p < 0.05). S. mutans with B. animalis or B. dentium produced a higher quantity of EPS; S. mutans + B. animalis led to the highest ∆KHN. S. mutans + S. sobrinus + B. longum induced greater EPS and ∆KHN values. In conclusion, associations of B. animalis and B. longum with streptococci promoted EPS production and caries lesion progression.

Effect of S. mutans combinations with bifidobacteria/lactobacilli on biofilm and enamel demineralization

Abstract The present study evaluated the ability of Bifidobacterium and Lactobacillus species associated with streptococci to increase insoluble extracellular polysaccharide (EPS) production and initial caries lesion progression. Bovine enamel blocks (n = 190; 4 mm x 4 mm) were prepared, selected according to initial surface hardness (SH), and divided into two groups: a) double combinations: S. mutans with Bifidobacterium or Lactobacillus, and b) triple combinations: S. mutans and S. sobrinus with Bifidobacterium or Lactobacillus species. The blocks were exposed to the bacterial associations for 7 days. Subsequently, quantity of EPS from biofilms and caries lesion depth were determined by means of colorimetric and cross-sectional enamel hardness (ΔKHN) analysis. The data were submitted to one-way analysis of variance, followed by the Bonferroni test (p < 0.05). S. mutans with B. animalis or B. dentium produced a higher quantity of EPS; S. mutans + B. animalis led to the highest ∆KHN. S. mutans + S. sobrinus + B. longum induced greater EPS and ∆KHN values. In conclusion, associations of B. animalis and B. longum with streptococci promoted EPS production and caries lesion progression.

Efeito citotóxico e ação antimicrobiana/antibiofilme de híbridos de curcumina e cinamaldeído sobre microrganismos de interesse endodôntico / Cytotoxic effect and antimicrobial action / antibiofilm of hybrids of curcumin and cinnamaldehyde on microorganisms of endodontic interest

Embora o tratamento endodôntico convencional reduza significativamente a microbiota presente no interior dos canais radiculares, a permanência de microrganismos devido à complexidade anatômica do sistema de canais radiculares e a resistência destes ao tratamento químico-mecânico pode ocasionar infecções persistentes ou secundárias. Muitos estudos têm explorado o uso de fitoquímicos, buscando obter novos compostos que apresentem propriedades farmacológicas. A curcumina, pigmento amarelo isolado dos rizomas da Curcuma longa (Zingiberaceae), e o cinamaldeido, substância volátil responsável pelo odor e sabor das cascas dos caules de plantas do gênero Cinnamomum (Lauraceae) são possíveis substâncias promissoras. O objetivo do estudo foi avaliar o efeito citotóxico e ação antimicrobiana/antibiofilme de compostos híbridos de curcumina e cinamaldeído sobre microrganismos de interesse endodôntico. Foram realizados ensaios para determinação da Concentração Inibitória Mínima (CIM) e Concentração Bactericida Mínima (CBM) do cinamaldeído, da curcumina e dos 23 híbridos sobre Enterococcus faecalis, Streptococcus mutans, Lactobacillus casei, Actinomyces israelii e Fusobacterium nucleatum. Os melhores compostos foram avaliados em ensaios de biofilme simples (cada cepa bacteriana isoladamente) e dualespécies (E. faecalis + L. casei, E. faecalis + S. mutans, E. faecalis + A. israelii, E. faecalis + F. nucleatum) em placas de poliestireno objetivando-se determinar o efeito sobre o metabolismo bacteriano utilizando o ensaio de XTT e sua viabilidade através da contagem das Unidades Formadoras de Colônias (UFCs), após 24 ou 48 horas de exposição ao composto. A toxicidade também foi avaliada sobre fibroblastos (linhagem L-929) utilizando o ensaio de methyltetrazolium (MTT). Além disso, biofilmes mistos com as mesmas espécies bacterianas selecionadas e multiespécies com amostras de biofilme humano foram formados em dentina radicular de dentes bovinos e após tratamento de 48 horas com o composto/controle, foram avaliados por microscopia confocal. Os dados apresentaram distribuição normal e as diferenças entre grupos (antimicrobianos e tempos de crescimento ­ 1 ou 2 semanas) foi analisada por ANOVA (One-way ou Two-way) seguido pelo teste de Tukey. Dos 25 compostos testados, 9 deles apresentaram efeito inibitório para, no mínimo, uma das espécies bacterianas testadas com valores de MIC/MBC variando entre 0,009 a 0,625 mg/mL. O composto LA11 e o controle clorexidina (CHX) apresentaram o melhor efeito inibitório para todas as espécies bacterianas testadas e, por este motivo, foram selecionados para os ensaios subsequentes. LA11 apresentou compatibilidade em fibroblastos em concentração superior à da Clorexidina (CHX) e teve efeito superior ou semelhante à CHX, reduzindo estatisticamente o metabolismo e viabilidade bacteriana nos biofilmes simples e dual-espécies, sendo que biofilmes de S. mutans foram os mais afetados. Para os biofilmes formados em dentina radicular, LA11 teve efeito significante sobre os biofilmes mistos com redução de 85,93%, enquanto que nos biofilmes multiespécies, a redução microbiana foi de 33,76%. Conclui-se que o composto híbrido LA11 apresentou citocompatibilidade e efeito antimicrobiano e contra biofilme de espécies bacterianas relacionadas às infecções radiculares e poderia ser uma opção de agente antimicrobiano para aplicação no tratamento endodôntico(AU)

Although conventional endodontic treatment significantly reduces the microbiota present inside the root canals, the permanence of microorganisms due to the anatomical complexity of the root canal system and their resistance to chemical-mechanical treatment can lead to persistent or secondary infections. Many studies have explored the use of phytochemicals, seeking to obtain new compounds that present pharmacological properties. Curcumin, a yellow pigment isolated from Curcuma longa rhizomes (Zingiberaceae), and cinnamaldehyde, the volatile substance responsible for the odor and taste of plant stems of the genus Cinnamomum (Lauraceae) are possible promising substances. The objective of the study was to evaluate the cytotoxic effect and antimicrobial action / antibiofilm of hybrid compounds of curcumin and cinnamaldehyde on microorganisms of endodontic interest. The minimum inhibitory concentration (MIC) and minimum bacterial concentration (MBM) of cinnamaldehyde, curcumin and 23 hybrids on Enterococcus faecalis, Streptococcus mutans, Lactobacillus casei, Actinomyces israelii and Fusobacterium nucleatum were determined. The best compounds were evaluated on single biofilms (single bacterial strain) and dual-species biofilms (E. faecalis + L. casei, E. faecalis + S. mutans, E. faecalis + A. israelii, E. faecalis + F. nucleatum) in polystyrene plates to determine the effect on bacterial metabolism using the XTT assay and its viability by counting Colony Forming Units (CFUs) after 24 or 48 hours of exposure to the compound. Toxicity was also evaluated on fibroblasts (L929 cell line) using the methyltetrazolium (MTT) assay. In addition, mixed biofilms with the same bacterial species selected and multispecies with human biofilm samples were formed in the dentinal root of bovine teeth and after 48 hours treatment with the compound / control, they were evaluated by confocal microscopy. The data presented normal distribution and the differences between groups (antimicrobials and growth times - 1 or 2 weeks) were analyzed by ANOVA (One-way or Two-way) followed by the Tukey test. Of the 25 compounds tested, 9 of them had inhibitory effect for at least one of the bacterial species tested with MIC / MBC values ranging from 0.009 to 0.625 mg / mL. The LA11 compound and the chlorhexidine control (CHX) had the best inhibitory effect for all bacterial species tested and were therefore selected for subsequent assays. LA11 showed a higher concentration of chlorhexidine (CHX) in the fibroblasts and had a CHX-like or higher effect, reducing bacterial metabolism and viability in single and dualspecies biofilms, with S. mutans biofilms being the most affected. For biofilms formed in root dentin, LA11 had a significant effect on mixed biofilms with a reduction of 85.93%, whereas in the multispecies biofilms, the microbial reduction was 33.76%. It is concluded that the hybrid compound LA11 presented cytocompatibility and antimicrobial effect and against biofilm of bacterial species related to root infections and could be an option of antimicrobial agent for application in endodontic treatment(AU)