Evaluation of Antimicrobial and Cytotoxic Activities of Plant Extracts From Southern Minas Gerais Cerrado

Abstract

The antimicrobial activity of plant hidroethanolic extracts on bacteria Gram positive, Gram negative, yeasts, Mycobacterium tuberculosis H37 and Mycobacterium bovis was evaluated by using the technique of Agar diffusion and microdilution in broth. Among the extracts evaluated by Agar diffusion, the extract of Bidens pilosa leaf presented the most expressive average of haloes of growth inhibition to the microorganisms, followed by the extract of B. pilosa flower, of Eugenia pyriformis' leaf and seed, of Plinia cauliflora leaf which statistically presented the same average of haloes inhibitory formation on bacteria Gram positive, Gram negative and yeasts. The extracts of Heliconia rostrata did not present activity. Mycobacterium tuberculosis H37 and Mycobacterium bovis (BCG) appeared resistant to all the extracts. The susceptibility profile of Candida albicans and Saccharomyces cerevisiae fungi were compared to one another and to the Gram positive Bacillus subtilis, Enterococcus faecalis and the Gram negative Salmonella typhimurium bacteria (p > 0.05). The evaluation of cytotoxicity was carried out on C6-36 larvae cells of the Aedes albopictus mosquito. The extracts of stem and flower of Heliconia rostrata, leaf and stem of Plinia cauliflora, seed of Anonna crassiflora and stem, flower and root of B. pilosa did not present toxicity in the analyzed concentrations. The highest rates of selectivity appeared in the extracts of stem of A. crassiflora and flower of B. pilosa to Staphylococcus aureus, presenting potential for future studies about a new drug development.

Quantitative Phytochemical Estimation and Evaluation of Antioxidant and Antibacterial Activity of Methanol and Ethanol Extracts of Heliconia rostrata

“…The 70% ethanol extract of rhizomes of H. rostrata collected from Areado city, Brazil, displayed the presence of flavonoids and absence of alkaloids, tannin and saponin [30] . Meanwhile, rhizomes of H. rostrata collected from Columbia showed the presence of terpenoids, proteins, phenolic compounds and carbohydrates [3,31] , when percolated with ethanol without defatting.…”

“…The present study is helpful in finding the extract which showed better antibacterial activity. Literature survey revealed the fact that H. rostrata when extracted with 70% w/v ethanol showed no antibacterial activity at a concentration of 10 mg/ml [30] . Chavasco et al reasoned that this could be due to the solvent chosen for extraction such as 70% w/v ethanol, which failed to extract the active constituents responsible for antibacterial activity.…”

Avaliação da atividade antimicrobiana de extratos de Eugenia anomala e Psidium salutare (Myrtaceae) frente à Escherichia coli e Listeria monocytogenes

“…Obtidos os valores de CIM e CBM, os extratos vegetais de E. anomala e P. salutare foram avaliados quanto a sua ação antimicrobiana de acordo com os valores de CIM contra os patógenos estudados onde extratos que apresentam CIM<100 µg/mL têm potencial antimicrobiano promissor (bom), CIM entre 100 -500 µg/mL possui atividade inibitória moderada, CIM entre 500 -1.000 µg/mL apresenta atividade inibitória fraca e extratos que apresentaram CIM superior a 1.000 µg/mL são inativos frente aos patógenos (Fabry et al, 1998;Holetz et al, 2002;Dall'Agnol et al, 2003;Tanaka et al, 2005;Chavasco et al, 2014).…”

In Vitro Anti-infective and Antioxidant Activity of Plumbago zeylanica Linn.

“…2). Chavasco et al (2014), isolated compounds from plant extracts rich in alkaloids have demonstrated antimicrobial activity in several studies (Osborn, 2003). The antimicrobial activity of flavonoids is also established due to their ability to complex with extracellular and soluble proteins and also with the bacterial cell wall.…”