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The occurrence of damage on bacterial DNA (mediated by antibiotics, for example) is intimately associated with the activation of the SOS system. This pathway is related to the development of mutations that might result in the acquisition and spread of resistance and virulence factors. The inhibition of the SOS response has been highlighted as an emerging resource, in order to reduce the emergence of drug resistance and tolerance. Herein, we evaluated the ability of betulinic acid (BA), a plant-derived triterpenoid, to reduce the activation of the SOS response and its associated phenotypic alterations, induced by ciprofloxacin in Staphylococcus aureus. BA did not show antimicrobial activity against S. aureus (MIC &gt, 5000 &micro, g/mL), however, it (at 100 and 200 &micro, g/mL) was able to reduce the expression of recA induced by ciprofloxacin. This effect was accompanied by an enhancement of the ciprofloxacin antimicrobial action and reduction of S. aureus cell volume (as seen by flow cytometry and fluorescence microscopy). BA could also increase the hyperpolarization of the S. aureus membrane, related to the ciprofloxacin action. Furthermore, BA inhibited the progress of tolerance and the mutagenesis induced by this drug. Taken together, these findings indicate that the betulinic acid is a promising lead molecule in the development helper drugs. These compounds may be able to reduce the S. aureus mutagenicity associated with antibiotic therapies.

Introducao: Cinamaldeido (CND) e o principal componente ativo do oleo essencial da canela ( Cinnamomum sp) e tem sido amplamente utilizado em atividades biologicas e farmacologicas, tendo sido relatado atividade antimicrobiana, antioxidante, antidiabetica, dentre outras. Objetivo: Devido os diversos relatos das propriedades farmacologicas do composto, esse foi escolhido para revisao de literatura. A selecao da bibliografia foi obtida a partir de bases de dados (google scholar, NCBI - National Center for Biotechnology Information , PubMed e Scielo - Scientific Electronic Library Online ). Discussao: A composicao quimica do CND tem compostos terpenoides que tem poderosa atividade antimicrobiana contra fungos, bacterias Gram-positivas e Gram-negativas tais como Aeromonas hydrophila , Enterococcus faecalis , Clostridium botulinum , Staphylococcus aureus , Escherichia coli O157: H7 e Salmonella enterica serovar Typhimurium . A atividade anti-inflamatoria induz a apoptose e inibi a proliferacao celular, nas respostas imunes mediadas por monocitos/macrofagos, alem de diminuir a producao de oxido nitrico induzido por lipopolissacaridos de um modo dependente da dose. CND ao ser administrado por via oral em ratos diabeticos demonstrou melhora no conteudo de glicogenio muscular e hepatico aumentando a liberacao de insulina. Alem disso CND estimulou a angiogenese in vivo e in vitro , regulando positivamente o fator de crescimento endotelial vascular. Conclusao: A partir do que foi relatado constatou-se que o CND possui muitas atividades com potencial farmacologico, mas percebe-se que se faz necessario estudos sobre o(s) mecanismos(s) de acao dessas atividades a fim de se proporcionar o uso seguro e eficaz do cinamaldeido.