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.

The Dynamics of Subcutaneous Tissue Response to Microorganisms Associated with the Extract of Araçá (Psidium cattleianum): An Edemogenic and Microscopic Analysis / A Dinâmica da Resposta do Tecido Subcutâneo para Associação de Microorganismos com o Extrato de Araçá (Psidium cattleianum): Uma Análise Microscópica e Edemogênica

Objective: To evaluate in vivo tissue reaction to the extract of araçá (Psidium cattleianum) associated with inactivated microorganisms. Material and Methods: A 0.1 mL suspension was used containing Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, Enterococcus faecalis, Peptostreptococcus micros, and Porphyromonas endodontalis, which were inactivated by heat and mixed into a 1.0 mL saline (control group), an aqueous solution, or a hydroalcoholic extract of araçá. Eighteen male rats (Rattus norvegiccus) under general anesthesia received 0.2 mL of 1% intravenous Evans blue. Thirty minutes later, 0.1 mL of one of the associations was injected into the animals' dorsal region. The animals were euthanized after 3 and 6 hours, and the materials obtained were placed in formamide for 72 hours then analyzed in a spectrophotometer (λ=630 ηm). For the morphological analysis, 30 rats received polyethylene tubes implants with the extracts or the saline with the associations in the dorsal region and euthanized after 7 and 30 days to be analyzed according to an inflammation cell score. Results: No significant difference (p>0.05) was observed in the edema among groups. The optical microscopy results showed a repair in the 30-day-period, which was higher when compared to the 7-day-period (p< 0.0001). Nevertheless, in the 7-day-period, the hydroalcoholic extract presented a significant response compared to the aqueous extract (p=0.05) and a trend for better results than the control group. Conclusion: The aqueous and hydroalcoholic araçá extracts associated with inactivated microorganisms showed similar responses to control, indicating no interference on the toxic effects of the bacterial components in tissue repair. (AU)

Objetivo: Avaliar in vivo a reação tecidual do extrato de araçá (Psidium cattleianum) associado com microorganismos inativados. Material e Métodos: Uma suspensão de 0.1mL foi usada contendo Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, Enterococcus faecalis, Peptostreptococcus micros e Porphyromonas endodontalis dos quais foram inativos por aquecimento e misturados a 1,0 mL de soro fisiológico (grupo controle), uma solução aquosa ou hidroalcoólica de araçá. Dezoito ratos machos (Rattus norvegiccus) sob anestesia geral receberam 0,2mL de Azul de Evans a 1% intravenoso. Após trinta minutos, 0,1mL de um dos extratos (associado com microorganismos inativos) foi injetado nos animais na região dorsal. Os animais foram eutanasiados após 3 e 6 horas, e os materiais obtidos colocados em formamida por 72 horas para análise em espectrofotômetro (λ=630 ηm). Para análise morfológica, 30 ratos receberam implante subcutâneo de tubo de polietileno com as associações na região dorsal, eutanasiados após 7 e 30 dias para serem analisados de acordo com um escore de células inflamatórias. Resultados: Não houve diferença significativa (p>0,05) no edema entre os grupos. Os resultados obtidos em microscópio óptico apontaram reparo em 30 dias superior ao de 7 dias (p< 0,0001). No período de 7 dias a solução hidroalcoólica apresentou resposta superior a solução aquosa (p=0,05) e uma tendência de melhor resultado que o controle. Conclusão: A solução aquosa e hidroalcoólica de extrato de araçá associadas a microrganismos inativados apresentaram respostas biológicas semelhantes ao controle, indicando que não há interferência sobre os efeitos tóxicos advindos dos componentes bacterianos, no sentido de favorecer o reparo(AU)