ABSTRACT
RESUMO Estudo experimental in vitro que objetivou investigar o potencial antimicrobiano e citotóxico de quatro frações e um extrato etanólico da espécie Pouteria venosa usada como planta medicinal. A atividade antimicrobiana foi determinada pelos testes de sensibilidade microbiana, como o método de difusão em disco e o método da microdiluição em caldo, para a determinação da Concentração Inibitória Mínima (CIM). Obteve-se a avaliação da citotoxicidade por meio do método colorimétrico do Metiltetrazolium. No estudo da atividade antimicrobiana, os principais resultados foram obtidos contra Staphylococus aureus para a fração AcOEt das cascas do caule, CIM de 125 µg/mL; Streptococcus pneumoniae e Proteus mirabilis para a fração AcOEt das cascas do caule, CIMde250 µg/mL; Staphylococus epidermidis, Pseudomonas aeruginosa para a fração AcOEt das folhas e cascas do caule, CIM de 250 µg/mL. Todas as amostras foram inativas para os fungos testados. A fração AcOEt das cascas do caule foi considerada atóxica, podendo ser utilizada em testes pré-clínicos in vivo
ABSTRACT Study of antimicrobial and cytotoxic potential of Pouteria venosa species (Sapotaceae). This experimental in vitro study aimed to investigate the antimicrobial and cytotoxic potential of four fractions and one ethanolic extract of the specie Pouteria venosa used as a medicinal plant. The antimicrobial activity was determined by microbial sensitivity tests, as the method of disk diffusion and the broth microdilution method for determination of Minimum Inhibitory Concentration (MIC). The evaluation of the cytotoxicity was obtained by the Metiltetrazolium colorimetric method. In the antimicrobial activity research, the main results were obtained against the Staphylococcus aureus for the AcOEt fraction of the stem bark MIC 125 µg/mL, Streptococcus pneumoniae and Proteus mirabilis for the AcOEt fraction from the stem bark, CIM 250 µg/mL, Staphylococcus epidermidis, Pseudomonas aeruginosa to the AcOEt fraction of the leaves and stem bark, MIC 250 µg/mL. All samples did not react for the fungi tested. The AcOEt fraction of the stem bark was considered non-toxic and can be used at in vivo pre-clinical testing
Subject(s)
Microbial Sensitivity Tests/methods , Cytotoxins/analysis , Pouteria/metabolism , Anti-Infective Agents/analysis , Plants, Medicinal/classification , Cell Survival/physiologyABSTRACT
Endophytic microorganisms represent promising alternatives for obtaining new drugs of biotechnological importance. In this study, the endophytic species Acremonium cavaraeanum (A1a) isolated from Cocos nucifera was cultivated for the production of secondary metabolites, and its extracts and fractions were evaluated by the dilution method (MIC). The EtOAc extracts and MeOH fractions were tested against Gram-positive and -negative bacteria, and had an MIC of 125 µg/mL when evaluated in the EtOAc extract (EBI). The EtOAc extract (EBII) had an MIC of 62.25 µg/mL for Staphylococcus aureus and an MIC between 125 and 250 µg/mL for Gram-negative bacteria. The methanolic fractions showed activity with MIC between 125 and 250 µg/mL for all bacteria tested. The IGS region of the rDNA repeat unit of genomic DNA was analyzed by PCR/RFLPs, including endonucleases PstI, BamHII, HinfI, and EcoRI. The physical maps showed different restriction sites for the 6 Acremonium sp isolates, and revealed 5 RFLP patterns. The results showed that isolates of the same Acremonium species exhibited variation in this specific region. The sequences of ITS1-5.8S-ITS2 regions were aligned by Clustal W using the neighbor joining method, which grouped the isolates into 5 distinct clusters. This study aimed to evaluate the genetic diversity of A. cavaraeanum crops exhibiting antibacterial activity. The results of this study indicate that different fungal genetic isolates have biotechnological potential for the production of active bio-compounds against several human pathogens.
