ABSTRACT
Background: Green tea, obtained from the Camellia sinensis, is one of the most popular drinks worldwide and has recently been in the focus of scientific research due to its beneficial effects on general health. Several studies suggest that, among the polyphenols found on green tea, epigallocatechin-3-gallate (EGCG) is the most bioactive compound and is responsible for its antibacterial activity. Purpose: To conduct a qualitative systematic review of literature evaluating the antibacterial efficacy of EGCG against Streptococcus mutans (S. mutans). Methods: Relevant published studies included in the Pubmed (1966- June 2015), Scopus (1960- June 2015), Web of Science (1900- June 2015), and Google Scholar databases were identified. Publications of in vitro studies, which studied EGCG antibacterial efficacy against S. mutans, were extracted and pooled in a table. The evaluation included inhibition zone measures, reduction of the number of microorganisms, and biofilm formation. Results: Twelve studies were selected to compose this systematic review. Eleven of them showed that EGCG has antibacterial efficacy against S. mutans. Conclusions : In vitro evidence available confirms the antibacterial activity of EGCG against S. mutans.
Antecedentes: El té verde, obtenido de la Camellia sinensis, es una de las bebidas más populares en el mundo y ha estado recientemente en el foco de atención de la investigación científica por sus efectos benéficos en la salud general. Varios estudios sugieren que, entre los polifenoles encontrados en el té verde, la epigalocatequina-3-galato (EGCG) es el compuesto más bioactivo y es el responsable de su actividad antimicrobiana. Objetivo: Realizar una revisión sistemática cualitativa de la literatura donde se evalúe la actividad antibacteriana de la EGCG contra el Streptococcus mutans (S. mutans). Métodos: Se identificaron estudios relevantes incluidos en las bases de datos bibliográficas Pubmed (1966-junio del 2015), Scopus (1960-junio del 2015), Web of Science (1900- junio del 2015) y Google Académico. Los datos de estudios in vitro que investigaron la eficacia antibacterial de la EGCG contra el S. mutans se seleccionaron y organizaron en una tabla. La evaluación de los estudios incluyó los criterios: medidas de las zonas de inhibición, reducción del número de microorganismos y formación de biopelícula. Resultados: Se seleccionaron 12 estudios para la revisión sistemática. Once de ellos comprobaron la eficacia antibacteriana de la EGCG contra el S. mutans. Conclusiones: La evidencia in vitro disponible confirma que la EGCG tiene un efecto antibacteriano contra el S. mutans.
Subject(s)
Humans , Camellia sinensis , Dental Caries , Anti-Infective AgentsABSTRACT
A Dietilnitrosamina (DEN), uma substância reconhecidamente hepatotóxica e carcinogênica, foiutilizada na indução da necrose hepática centrolobular em ratos isogênicos Lewis divididos em 5 grupos de 5 animais. O objetivo deste estudo foi avaliar o efeito quimiopreventivo da epigalocatequina-3-galato (EGCG), de Camellia sinensis (chá verde) no tratamento da hepatotoxicidade celular induzida pela DEN. Foi mensurada a concentração sérica da alanina aminotransferase (ALT) e aspartato aminotransferase(AST) dos diferentes grupos experimentais. No ensaio bioquímico para AST e ALT, houve diferença significativa entre os valores médios do grupo controle (163±70,32) comparado ao grupo DEN (1631±1039,44), sugerindo que a DEN influencia na função hepática. Entretanto, não houve diferença significativa entre o grupo DEN e o tratado com epigalocatequina. A lactato desidrogenase (LDH) éconsiderada um marcador bioquímico comum para avaliação da progressão tumoral, e em relação ao LDH, as amostras não apresentaram diferenças significativas entre o grupo DEN (1385,5±43,13) e DEN + EGCG 150mg ou DEN + EGCG 200mg 1537,5±1010,45). Neste trabalho foi demonstrado que a epigalocatequina nas concentrações de 150 e 200 mg/Kg não induziram alterações hepáticas e também não foi possível verificar nenhuma quimioproteção pela EGCG em animais inicialmente tratados comDEN durante 24 horas. Sendo assim, novos experimentos com diferentes concentrações de EGCG sãonecessários para comprovar seu possível efeito quimioprotetor.
Diethylnitrosamine (DEN), a known hepatotoxic and carcinogenic substance, was used in the induction of centrilobular hepatic necrosis in isogenic Lewis rats divided into 5 groups with 5 animals. The aim of this study was to evaluate the chemopreventive effect of epigallocatechin-3-gallate (EGCG)from Camellia sinensis (green tea) in the treatment of cellular hepatotoxicity induced by DEN. It was measured the serum concentration of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) of the different experimental groups. In the biochemistry assay for AST and ALT, there was significant difference between median values of control group (163±70.32) compared to DEN group(1631±1039.44), suggesting that DEN influences on hepatic function. However, there was no significant difference between DEN group to that treated with epigallocatechin. Lactate dehydrogenase (LDH) is considered a common biochemical marker for evaluation of tumor progression, and regarding LDH,the samples presented no significant differences between the DEN group (1385.5±43.13) and DEN + EGCG 150mg or DEN + EGCG 200mg (1537.5± 1010.45). In this work it was demonstrated that epigallocatechin concentrations of 150 and 200 mg/kg did not induce liver alterations and though was not verified any chemoprotective effect by EGCG in animals initially treated with DEN for 24 hours. Moreover, new experiments with different concentrations of EGCG are needed to verify its possiblechemoprotector effect.