ABSTRACT
The evaluation of the activity of the aqueous and ethyl acetate extracts of the leaves of Piper regnellii was tested against gram-positive and gram-negative bacteria. The aqueous extractdisplayed a weak activity against Staphylococcus aureus and Bacillus subtilis with minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of 1000 æg/ml. The ethyl acetate extract presented a good activity against S. aureus and B. subtilis with MIC and MBC at 15.62 æg/ml. In contrast to the relative low MICs for gram-positive bacteria, gram-negative bacteria were not inhibited by the extracts at concentrations < 1000 mg/ml. The ethyl acetate extract was fractionated on silica gel into nine fractions. The hexane and chloroform fractions were active against S. aureus (MIC at 3.9 æg/ml) and B. subtilis (MIC at 3.9 and 7.8 æg/ml, respectively). Using bioactivity-directed fractionation, the hexane fraction was rechromatographed to yield the antimicrobial compounds 1, 2, 5, and 6identified as eupomatenoid-6, eupomatenoid-5, eupomatenoid-3, and conocarpan, respectively. The pure compounds 1 and 2 showed a good activity against S. aureus with MIC of 1.56 æg/ml and 3.12 æg/ml, respectively. Both compounds presented MIC of 3.12 æg/ml against B. subtilis. The pure compound 6 named as conocarpan was quite active against S. aureus and B. subtilis with MIC of 6.25 æg/ml. The antibacterial properties of P. regnellii justify its use in traditional medicine for the treatment of wounds, contaminated through bacteria infections.
Subject(s)
Anti-Bacterial Agents/pharmacology , Gram-Negative Bacteria , Gram-Positive Bacteria , Herbal Medicine , Lignans , Anti-Bacterial Agents/chemistry , Lignans , Magnetic Resonance Spectroscopy , Microbial Sensitivity Tests , Plant ExtractsABSTRACT
Extracts of 13 Brazilian medicinal plants were screened for their antimicrobial activity against bacteria and yeasts. Of these, 10 plant extracts showed varied levels of antibacterial activity. Piper regnellii presented a good activity against Staphylococus aureus and Bacillus subtilis, a moderate activity on Pseudomonas aeruginosa, and a weak activity against Escherichia coli. Punica granatum showed good activity on S. aureus and was inactive against the other standard strains. Eugenia uniflora presented moderate activity on both S. aureus and E. coli. Psidium guajava,Tanacetum vulgare, Arctium lappa, Mikania glomerata, Sambucus canadensis, Plantago major and Erythrina speciosa presented some degree of antibacterial activity. Spilanthes acmella, Lippia alba, and Achillea millefolium were considered inactive. Five of the plant extracts presented compounds with Rf values similar to the antibacterial compounds visible on bioautogram. Of these, three plants belong to the Asteraceae family. This may mean that the same compounds are responsible for the antibacterial activity in these plants. Anticandidal activity was detected in nine plant extracts (P. guajava, E. uniflora, P. granatum, A. lappa, T. vulgare, M. glomerata, L. alba, P. regnellii, and P. major). The results might explain the ethnobotanical use of the studied species for the treatment of various infectious diseases
Subject(s)
Humans , Anti-Infective Agents , Candida , Gram-Negative Bacteria , Gram-Positive Bacteria , Medicine, Traditional , Plant Extracts , Plants, Medicinal , Antifungal Agents , Brazil , Microbial Sensitivity TestsABSTRACT
No presente trabalho foram investigados os efeitos antibacteriano e antidiabético da planta Cissus sicyoides (CS) coletada no Brasil. Ratos diabéticos receberam água (grupo A) ou extratos da parte aérea da planta (grupo CS) durante 4 semanas. Após este período, os níveis séricos de glicose, colesterol e triglicerídeos dos ratos foram determinados. A glicemia näo foi afetada pelo tratamento com CS. Entretanto, houve aumento nos níveis de colesterol e triglicerídeos nos ratos do grupo CS. Em adiçäo, fracionamento biomonitorado foi realizado para o isolamento de compostos com atividade antibacteriana. á-sITOSTEROL E SITOSTEROL á-D-glucopiranosídeo isolados mostram atividade antibacteriana contra Bacillus subtilis com concentrações mínimas inibitórias MICs de 50 ug/ml e 100 ug/ml, respectivamente. Apesar da crença popular, CS näo mostrou atividade antidiabética. Entretanto, dois compostos isolados da parte aérea da planta (á-sitosterol e sitosterol á-D-flucopiranosídeo) apresentaram fraca atividade antibacteriana