Inhibitory activity of Varronia curassavica and Mikania laevigatafractions against pathogens associated with persistent dental infections

Herbal medicines have been studied as potential antimicrobial agents, emerging as treatments against oral diseases. The current study evaluated the antimicrobial activity of the crude extract and fractions of Mikania laevigata SchultzBip. ex Baker (ML) and Varronia curassavicaJacq (VC) against oral pathogens associated with persistent dental root infections, under planktonic and biofilm conditions. Minimal inhibitory concentrations and minimal bactericidal/fungicidal concentrations were determined for the ML and VC fractions/extracts against Enterococcus faecalis, Actinomyces israelii, Pseudomonas aeruginosa, and Candida albicans using the microdilution method. The best results were chosen for subsequent biofilm assays. All tested ML and VC extracts/fractions demonstrated inhibitory activity against E. faecalis and A. israelii. The ML ethyl acetate fraction affected the growth of all microorganisms tested. C. albicans and P. aeruginosawere not affected by any VC extract/fractions. The ML ethyl acetate fraction eliminated E. faecalis, A.israelii, and P. aeruginosa biofilms after 24h. A similar result was observed for ML crude hydroethanolic extract and its hexane fraction for A. israelii. The VC hexane fraction was able to eliminate A. israelli biofilms. None of the tested extracts or fractions eliminated C. albicans biofilm. The Mikania laevigata ethyl acetate fraction is an efficient antimicrobial agent against oral pathogens and could be indicated for the treatment of persistent dental infections.

Cytotoxicity and antimicrobial effects of citronella oil (Cymbopogon nardus) and commercial mouthwashes on S. aureus and C. albicans biofilms in prosthetic materials.

Although the effectiveness of some mouthwashes has been proven, phytotherapy is still a field to be explored as an alternative to commercial products. OBJECTIVE: To evaluate, in vitro, the cytotoxicity and efficacy of two solutions based on citronella oil (CN), on S. aureus and C. albicans biofilms (in formation-adhesion phase and 24 h-biofilm formation) on acrylic resin and nickel-chromium alloy samples (one trademark of each material), compared to two alcohol-free commercial mouthwashes. MATERIAL AND METHODS: Two solutions containing CN at concentrations of 5x and 10x the minimum bactericidal/fungicidal concentration (MBC/MFC) were prepared by microdilution. After contamination of the samples surfaces with these microorganisms, the mouthwashes (CN - 5x and 10x; CHX - 0,12% alcohol-free chlorhexidine and LT - alcohol-free essential oils) were evaluated. Mouthwash simulation was performed for 1 min at two moments, the first simulation after 4 h of microbial adhesion and 24 h-biofilm formation, and the second simulation, 6 h after the first simulation. For biofilm quantification, the number of cultured cells was evaluated by CFUs. The cytotoxicity assay was performed on HaCat epithelial cells and quantified by the MTT method. RESULTS: Tested solutions completely inhibited the growth of both microorganisms in the adhesion phase. All solutions showed inhibitory activity against 24 h-biofilm formation. However, CN led to greater microbial reduction, regardless of the surface of the sample. All solutions demonstrated a toxic effect. However, after serial dilution, CN presented the lowest cytotoxic effect. CONCLUSION: Citronella had a lower cytotoxic effect and a higher action compared to commercial solutions.

Development and characterization of p1025-loaded bioadhesive liquid-crystalline system for the prevention of Streptococcus mutans biofilms.

Formation of a dental biofilm by Streptococcus mutans can cause dental caries, and remains a costly health problem worldwide. Recently, there has been a growing interest in the use of peptidic drugs, such as peptide p1025, analogous to the fragments 1025-1044 of S. mutans cellular adhesin, responsible for the adhesion and formation of dental biofilm. However, peptides have physicochemical characteristics that may affect their biological action, limiting their clinical performance. Therefore, drug-delivery systems, such as a bioadhesive liquid-crystalline system (LCS), may be attractive strategies for peptide delivery. Potentiation of the action of LCS can be achieved with the use of bioadhesive polymers to prolong their residence on the teeth. In line with this, three formulations - polyoxypropylene-(5)-polyoxyethylene-(20)-cetyl alcohol, oleic acid, and Carbopol C974P in different combinations (F1C, F2C, and F3C) were developed to observe the influence of water in the LCS, with the aim of achieving in situ gelling in the oral environment. These formulations were assessed by polarized light microscopy, small-angle X-ray scattering, rheological analysis, and in vitro bioadhesion analysis. Then, p1025 and a control (chlorhexidine) were incorporated into the aqueous phase of the formulation (F + p1025 and F + chlorhexidine), to determine their antibiofilm effect and toxicity on epithelial cells. Polarized light microscopy and small-angle X-ray scattering showed that F1C and F2C were LCS, whereas F3C was a microemulsion. F1C and F2C showed pseudoplastic behavior and F3C Newtonian behavior. F1C showed the highest elastic and bioadhesive characteristics compared to other formulations. Antibiofilm effects were observed for F + p1025 when applied in the surface-bound salivary phase. The p1025-loaded nanostructured LCS presented limited cytotoxicity and effectively reduced S. mutans biofilm formation, and could be a promising p1025-delivery strategy to prevent the formation of S. mutans dental biofilm.

Antimicrobial Activity and Biocompatibility of the Psidium cattleianum Extracts for Endodontic Purposes

Abstract Psidium cattleianum (PC) has been displaying inhibitory effect against a variety of microorganisms, but this effect has not yet been tested against endodontic pathogens. The aim of this study was to evaluate the antimicrobial activity and biocompatibility of the aqueous (PCAE) and hydroethanolic (PCHE) extracts from Psidium cattleianum (PC) leaves. Minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) were determined using the microdilution broth method in order to analyze the antimicrobial effect against Enterococcus faecalis, Pseudomonas aeruginosa, Actinomyces israelii and Candida albicans in planktonic conditions. Biofilm assays were conducted only with the extracts that were able to determine the MLC for microorganisms in planktonic conditions. Immediate and late tissue reactions against PC extracts were evaluated using edemogenic test and histological analysis of subcutaneous implants in Wistar rats. The results showed that the MIC and MLC values ranged between 0.25 and 4 mg/mL. The MLC obtained for PCHE inhibited 100% growth of all the tested strains, except for C. albicans. PCAE had the same effect for E. faecalis and P. aeruginosa. Both PC extracts were able to eliminate E. faecalis biofilms and only the PCHE eliminated P. aeruginosa biofilms. The positive controls inhibited the growth of all tested strains in MIC and MLC essays, but no CHX tested concentrations were able to eliminate A. israelii biofilm. PCAE caused a discrete increase in the edema over time, while PCHE caused a higher initial edema, which decreased progressively. Both PCAE and PCHE extracts were biocompatible, but PCHE showed better results with slight levels of inflammation at 28 days. In conclusion, PCHE was biocompatible and presented better antimicrobial effect against important pathogens associated with persistent endodontic infections

Resumo Psidium cattleianum (PC) tem apresentado atividade inibitória frente diversos microrganismos, entretanto esse efeito ainda não foi testado contra microrganismos de interesse endodôntico. O objetivo desse estudo foi avaliar a atividade antimicrobiana e a biocompatibilidade dos extratos aquoso (EAPC) e hidroetanólico (EHPC) das folhas de Psidium cattleianum. As concentrações inibitória mínima (CIM) e letal mínima (CLM) foram determinadas pelo método de microdiluição em caldo, com o objetivo de analisar o efeito antimicrobiano frente Enterococcus faecalis, Pseudomonas aeruginosa, Actinomyces israelii e Candida albicans em condições planctônicas. Os ensaios de biofilme foram realizados somente com os extratos em que se determinou a CLM frente os microrganismos em condições planctônicas. Respostas teciduais imediata e tardia frente aos extratos de Psidium cattleianum foram avaliadas por teste edemogênico e análise histológica de implantes subcutâneos em ratos Wistar. Os resultados mostraram que CIM e CLM variaram entre 0,25 e 4 mg/mL. As CLMs determinadas pelo EHPC inibiram 100% do crescimento de todas as cepas testadas, exceto Candida albicans. EAPC apresentou o mesmo efeito para E. faecalis e P. aeruginosa. Ambos os extratos de PC conseguiram eliminar o biofilme de E. faecalis, e somente o EHPC eliminou o biofilme de P. aeruginosa. Os controles positivos inibiram o crescimento de todos os microrganismos testados nos ensaios de CIM e CLM, mas nenhuma das concentrações de clorexidina testadas foi capaz de eliminar o biofilme de A. israelii. O EAPC provocou um discreto aumento de edema com o tempo, enquanto EHPC provocou um edema inicial severo, que diminuiu progressivamente. Ambos os extratos EAPC e EHPC foram biocompatíveis, entretanto, EHPC apresentou melhores resultados com baixos níveis de inflamação em 28 dias. Pode-se concluir que EHPC foi biocompatível e apresentou melhor efeito antimicrobiano frente importantes patógenos associados a infecções endodônticas persistentes.

Antimicrobial Activity and Biocompatibility of the Psidium cattleianum Extracts for Endodontic Purposes.

Psidium cattleianum (PC) has been displaying inhibitory effect against a variety of microorganisms, but this effect has not yet been tested against endodontic pathogens. The aim of this study was to evaluate the antimicrobial activity and biocompatibility of the aqueous (PCAE) and hydroethanolic (PCHE) extracts from Psidium cattleianum (PC) leaves. Minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) were determined using the microdilution broth method in order to analyze the antimicrobial effect against Enterococcus faecalis, Pseudomonas aeruginosa, Actinomyces israelii and Candida albicans in planktonic conditions. Biofilm assays were conducted only with the extracts that were able to determine the MLC for microorganisms in planktonic conditions. Immediate and late tissue reactions against PC extracts were evaluated using edemogenic test and histological analysis of subcutaneous implants in Wistar rats. The results showed that the MIC and MLC values ranged between 0.25 and 4 mg/mL. The MLC obtained for PCHE inhibited 100% growth of all the tested strains, except for C. albicans. PCAE had the same effect for E. faecalis and P. aeruginosa. Both PC extracts were able to eliminate E. faecalis biofilms and only the PCHE eliminated P. aeruginosa biofilms. The positive controls inhibited the growth of all tested strains in MIC and MLC essays, but no CHX tested concentrations were able to eliminate A. israelii biofilm. PCAE caused a discrete increase in the edema over time, while PCHE caused a higher initial edema, which decreased progressively. Both PCAE and PCHE extracts were biocompatible, but PCHE showed better results with slight levels of inflammation at 28 days. In conclusion, PCHE was biocompatible and presented better antimicrobial effect against important pathogens associated with persistent endodontic infections.

Análise da atividade antimicrobiana dos extratos de Cordia verbenacea DC, Mikania laevigata Sch. Bip. ex Baker e Psidium Cattleianum frente a microrganismos endodônticos / Antimicrobial analysis of the Cordia verbenacea DC, Mikania laevigata Sch. Bip. ex Baker e Psidium Cattleianum plant extracts against endodontic microorganisms

Na busca por fontes alternativas de antimicrobianos, diversos autores tem explorado o uso de plantas medicinais para o tratamento de várias doenças. A atividade antimicrobiana de várias espécies de plantas como, Cordia verbenacea DC, Mikania laevigata Schultz Bip. Ex Baker e Psidium cattleianum, popularmente chamadas de erva-baleeira, guaco e de araçá, respectivamente, tem sido relatada contra diversos microrganismos orais. O objetivo do presente estudo foi avaliar o efeito antimicrobiano dos extratos hidroetanólico bruto e as suas respectivas frações aquosa, butanol, hexano e acetato de etila de Cordia verbenacea (CV) e Mikania laevigata (ML) e extratos aquoso e hidroetanólico de Psidium cattleianum (PC) contra Enterococcus faecalis, Pseudomonas aeruginosa, Actinomyces israelii e Candida albicans, sob condições planctônicas e de biofilme. Os microrganismos foram analisados em condições planctônicas por meio de ensaios para a determinação da concentração inibitória mínima (CIM) e concentração letal mínima (CLM), pelo método de microdiluição em caldo. Posteriormente, foram selecionados somente os extratos capazes de eliminar completamente cada microrganismo (CLM 100%), para a análise da atividade antimicrobiana em ensaios de biofilme. Os resultados mostraram que os valores de CIM e CLM variaram de 250 à 4000μg/ml. O biofilme formado por E. faecalis foi eliminado frente à ação dos extratos aquoso e hidroetanólico de PC e à fração acetato de etila de ML. A mesma fração de ML e o extrato hidroetanólico de PC também foram capazes de eliminar biofilme de P. aeruginosa. O mesmo ocorreu com as frações hexânicas de CV e ML e o extrato hidroetanólico de ML frente ao biofilme de A. israelii. Nenhum extrato/fração foi capaz de eliminar biofilme de C. albicans. Este estudo demonstrou o potencial antimicrobiano de extratos ou frações de Cordia verbenacea, Mikania laevigata e Psidium cattleianum, sugerindo seu emprego com finalidade endodôntica devido à sua efetividade...

Seeking for alternative sources of the antimicrobials, several authors have explored the use of herbal medicines for the treatment of diseases. The antimicrobial activity of various species of plants, such as Cordia verbenacea DC, Mikania laevigata Schultz Bip. Ex Baker and Psidium cattleianum, known as erva-baleeira, guaco and araçá, respectively, has been reported against several oral microorganisms. The present study aimed to evaluate the antimicrobial effect of Cordia verbenacea (CV) and Mikania laevigata (ML) hydroethanolic crude extracts and their fractions aqueous, butanol, hexane and ethyl acetate and aqueous and hydroethanolic extracts of Psidium cattleianum (PC) against Enterococcus faecalis, Pseudomonas aeruginosa, Actinomyces israelii and Candida albicans, under planktonic and biofilm conditions. The microorganisms in planktonic conditions were analyzed by determination of minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) assays using the microdilution broth method. Posteriorly, only the extracts that were able to totally eliminate each microorganism (MLC 100%) were selected for the antimicrobial activity analysis in the biofilm assay. The results showed that the MIC and MLC values ranged between 250 and 4000μg/ml. E. faecalis biofilm was eliminated by PC aqueous and hydroethanolic extracts and the ML ethyl acetate fraction. The same ML fraction and PC hydroethanolic extract were also able to eliminate the P. aeruginosa biofilm. The same occurred with the CV and ML hexane fractions and ML hydroethanolic extract against the A. israelii biofilm. None of the extracts/fractions were able to eliminate the C. albicans biofilm. This study confirmed the antimicrobial activity potential of Cordia verbenacea, Mikania laevigata and Psidium cattleianum, suggesting their use for endodontic purposes due to their effectiveness against pathogens associated with persistent or secondary endodontic infections...

Análise da atividade antimicrobiana dos extratos de Cordia verbenacea DC, Mikania laevigata Sch. Bip. ex Baker e Psidium Cattleianum frente a microrganismos endodônticos / Antimicrobial analysis of the Cordia verbenacea DC, Mikania laevigata Sch. Bip. ex Baker e Psidium Cattleianum plant extracts against endodontic microorganisms

Na busca por fontes alternativas de antimicrobianos, diversos autores tem explorado o uso de plantas medicinais para o tratamento de várias doenças. A atividade antimicrobiana de várias espécies de plantas como, Cordia verbenacea DC, Mikania laevigata Schultz Bip. Ex Baker e Psidium cattleianum, popularmente chamadas de erva-baleeira, guaco e de araçá, respectivamente, tem sido relatada contra diversos microrganismos orais. O objetivo do presente estudo foi avaliar o efeito antimicrobiano dos extratos hidroetanólico bruto e as suas respectivas frações aquosa, butanol, hexano e acetato de etila de Cordia verbenacea (CV) e Mikania laevigata (ML) e extratos aquoso e hidroetanólico de Psidium cattleianum (PC) contra Enterococcus faecalis, Pseudomonas aeruginosa, Actinomyces israelii e Candida albicans, sob condições planctônicas e de biofilme. Os microrganismos foram analisados em condições planctônicas por meio de ensaios para a determinação da concentração inibitória mínima (CIM) e concentração letal mínima (CLM), pelo método de microdiluição em caldo. Posteriormente, foram selecionados somente os extratos capazes de eliminar completamente cada microrganismo (CLM 100%), para a análise da atividade antimicrobiana em ensaios de biofilme. Os resultados mostraram que os valores de CIM e CLM variaram de 250 à 4000μg/ml. O biofilme formado por E. faecalis foi eliminado frente à ação dos extratos aquoso e hidroetanólico de PC e à fração acetato de etila de ML. A mesma fração de ML e o extrato hidroetanólico de PC também foram capazes de eliminar biofilme de P. aeruginosa. O mesmo ocorreu com as frações hexânicas de CV e ML e o extrato hidroetanólico de ML frente ao biofilme de A. israelii. Nenhum extrato/fração foi capaz de eliminar biofilme de C. albicans. Este estudo demonstrou o potencial antimicrobiano de extratos ou frações de Cordia verbenacea, Mikania laevigata e Psidium cattleianum, sugerindo seu emprego com finalidade endodôntica devido à sua efetividade...

Seeking for alternative sources of the antimicrobials, several authors have explored the use of herbal medicines for the treatment of diseases. The antimicrobial activity of various species of plants, such as Cordia verbenacea DC, Mikania laevigata Schultz Bip. Ex Baker and Psidium cattleianum, known as erva-baleeira, guaco and araçá, respectively, has been reported against several oral microorganisms. The present study aimed to evaluate the antimicrobial effect of Cordia verbenacea (CV) and Mikania laevigata (ML) hydroethanolic crude extracts and their fractions aqueous, butanol, hexane and ethyl acetate and aqueous and hydroethanolic extracts of Psidium cattleianum (PC) against Enterococcus faecalis, Pseudomonas aeruginosa, Actinomyces israelii and Candida albicans, under planktonic and biofilm conditions. The microorganisms in planktonic conditions were analyzed by determination of minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) assays using the microdilution broth method. Posteriorly, only the extracts that were able to totally eliminate each microorganism (MLC 100%) were selected for the antimicrobial activity analysis in the biofilm assay. The results showed that the MIC and MLC values ranged between 250 and 4000μg/ml. E. faecalis biofilm was eliminated by PC aqueous and hydroethanolic extracts and the ML ethyl acetate fraction. The same ML fraction and PC hydroethanolic extract were also able to eliminate the P. aeruginosa biofilm. The same occurred with the CV and ML hexane fractions and ML hydroethanolic extract against the A. israelii biofilm. None of the extracts/fractions were able to eliminate the C. albicans biofilm. This study confirmed the antimicrobial activity potential of Cordia verbenacea, Mikania laevigata and Psidium cattleianum, suggesting their use for endodontic purposes due to their effectiveness against pathogens associated with persistent or secondary endodontic infections