Este estudo foi conduzido com a proposta de avaliar a efetividade de eugenol, beta-pineno e alfa-pineno em inibir o crescimento de cepas de bactérias Gram-positivas potencialmente causadoras de endocardite infecciosa. A Concentração Inibitória Mínima-CIM dos fitoconstituintes foi determinada através do método de difusão em meio sólido, enquanto a interferência da CIM sobre a viabilidade celular bacteriana foi avaliada através da contagem de células viáveis. Cepas de Staphylococcus aureus, S. epidermidis, Streptococcus pneumoniae e S. pyogenes foram utilizadas como microrganismos teste nos ensaios antimicrobianos. Os fitoconstituintes ensaiados mostraram efetividade em inibir todas as cepas bacterianas utilizadas como microrganismos testes apresentando valores de CIM entre 2.5 e 40 µL/mL. Eugenol apresentou os menores valores de CIM, os quais estiveram entre 2,5 e 5 µL/mL para a maioria das cepas bacterianas. Os valores de CIM encontrados para os fitoconstituintes foram capazes de inibir a viabilidade celular de S. aureus causando uma total eliminação do inóculo bacteriano em um tempo máximo de 24 horas de exposição. Estes dados mostram o intenso potencial antibacteriano dos fitoconstituintes ensaiados e suportam sua possível e racional aplicação na terapia antimicrobiana.

This study was led with the purpose of evaluating the effectiveness of eugenol, beta-pinene and alpha-pinene in inhibiting the growth of potential infectious endocarditis causing gram-positive bacteria. The phytochemicals Minimum Inhibitory Concentration-MIC was determined by solid medium diffusion procedure, while the interference of the MIC values on the bacterial cell viability was performed by viable cells count. Staphylococcus aureus, S. epidermidis, Streptococcus pneumoniae and S. pyogenes strains were used as test microorganisms. The assayed phytochemicals showed effectiveness in inhibiting all assayed bacteria strains presenting MIC values between 2.5 and 40 µL/mL. Eugenol showed the lowest MIC values which were between 2.5 and 5 µL/mL for the most bacteria strains. MIC values found to the phytochemicals were able to inhibit the cell viability of S. aureus providing a total elimination of the bacteria inoculum in a maximum time of 24 hours of exposure. These data showed the interesting antibacterial property of the assayed phytochemicals and support their possible and rational use in the antimicrobial therapy.

Cissampelos sympodialis Eichl. (Menispermaceae) has been investigated about its botanical, chemical, pharmacological and toxicological aspects in our laboratory. Previous acute toxicology studies demonstrated that in dogs as well as in Wistar rats, 5 g/kg, p.o., and 2 g/kg, i.p. of the aqueous fraction of the ethanol extract of the leaves of Cissampelos sympodialis (AFL), induced a significant increase in the phosphatase alkaline and gama glutamil tranferase (GGT) levels, that were completely reversed in 15 days after interruption of AFL treatment. The aim of the present work was to investigate the subacute toxicology effects induced by AFL in dogs. We used the methods proposed by Portaria 116/96 of the Secretaria Nacional de Vigilância Sanitária, which regulates studies of toxicity for phytomedicines in Brazil. Daily administration (p.o.) of AFL, 45 mg/kg/day (5 times the dose used by human beings), during 4 weeks, was devoid of any effect on haematological (haemogram and platelets) and on blood biochemical parametes. In conclusion, the present study, using dogs, demonstrated that AFL, in a popularly used dose, by human beings, was devoid of any toxicological effect.