Inhibitory effect of some phytochemicals in the growth of yeasts potentially causing opportunistic infections

Opportunistic infections caused by yeasts have been characterized as emerging diseases all over the world and this has caused the search for new products capable of inhibiting the survival of their etiological agents. In this study the sensitivity of some yeast potentially causing infections to alpha-pinene, beta-pinene, citral and eugenol was evaluated. All phytochemicals showed inhibitory action on the assayed yeast strains: Candida. albicans, C. tropicalis, C. guilliermondii, C. stellatoidea, C. krusei, C. parapsilosis and Cryptococcus neoformans, presenting their MIC values in the range of 1 and 4%. The phytochemicals presented effectiveness to provide high fungicide effect in a short time. These data support the possible use of some phytochemicals as useful tools to control the occurrence of opportunistic infections caused by yeasts.Infecções oportunistas causadas por leveduras têm sido caracterizadas como doenças emergentes em todo o mundo e este fenômeno tem levado ao desenvolvimento de novos produtos capazes de inibir a sobrevivência de seus agentes etiológicos. Este estudo avaliou o perfil de sensibilidade de leveduras potencialmente causadoras de infecções oportunistas frente aos fitoconstituintes alfa-pineno, beta-pineno, citral e eugenol. Todos os fitoconstituintes mostraram ação inibitória sobre as leveduras ensaiadas, as quais foram Candida albicans, C. tropicalis, C. guilliermondii, C. stellatoidea, C. krusei, C. parapsilosis e Cryptococcus neoformans, tendo valores de CIM oscilando entre 1 e 4%. Os fitoconstituintes mostraram eficácia para provocar um alto efeito fungicida em curto tempo de ação. Estes dados subsidiam o possível uso de alguns fitoconstituintes como ferramentas úteis para controlar a ocorrência de infecções oportunistas causadas por leveduras

Evaluation of antitumour and antiinflammatory effects and acute toxicity of extracts obtained from Streptomyces spp. isolated from m Soils of Paraiba (Brazil)

Bioactive metabolites produced by Streptomyces spp. commonly exhibit a variety of pharmacological properties such as antibiotic, antitumor, enzymatic and anti-helminthic. The study evaluated the possible antitumor and anti-inflammatory effects and the degree of toxicity of extracts isolated from Streptomyces in experimental models with animals. The extracts Sp-1 and Sp-3 did not have anti-inflammatory effect. In the Sarcoma 180 model the effects of Sp-1 and Sp-3 were significant with decreased average weights of tumors at 10 mg/kg, and reduction of up to 73 % of initial weight of the implanted tumor. For tumors of Ehrlich Carcinoma, the doses showed no significant effect on the average weight of tumors. Stimulant effects, such as exophthalmia, agitation, escape reaction, irritability, tremors and dermatitis were observed after 1 h of administration, depressive reactions were also observed, such as prostration and decreased respiratory rate, and no deaths were highlighted.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Seasonal variation and antimicrobial activity of Myrcia myrtifolia essential oils

This work reports the seasonal variation of the composition of leaf volatile oils and the composition of volatile oils from flowers and fruits of Myrcia myrtifolia DC harvested in the sand dunes of Salvador, Bahia, northeastern region of Brazil between 2002 and 2003. The oils were analyzed by GC-FID and GC-MS so that 28 components were identified. alpha-Pinene was predominant in a range from 61.5 to 90.9% in all samples analyzed. The leaf oil collected in October 2002 had their antimicrobial properties tested against six bacteria, two yeasts and five filamentous fungi being active against Staphylococcus aureus, methicilin-resistant Staphylococcus aureus, Candida albicans, Cryptococcus neoformans and Aspergillus fumigatus, and showed strongest activity against Microsporum canis and Trichophyton rubrum. The oil displayed moderate toxicity against Artemia salina showing a LC50 of 479.16 µg mL-1

Herbal therapy associated with antibiotic therapy: potentiation of the antibiotic activity against methicillin – resistant Staphylococcus aureus by Turnera ulmifolia L

<p>Abstract</p> <p>Background</p> <p><it>Staphylococcus </it>genus is widely spread in nature being part of the indigenous microbiota of skin and mucosa of animal and birds. Some <it>Staphylococcus </it>species are frequently recognized as etiological agents of many animal and human opportunistic infections This is the first report testing the antibiotic resistance-modifying activity of <it>Turnera ulmifolia </it>against methicillin-resistant <it>Staphylococcus aureus </it>– MRSA strain.</p> <p>Methods</p> <p>In this study an ethanol extract of <it>Turnera ulmifolia </it>L. and chlorpromazine were tested for their antimicrobial activity alone or in combination with aminoglycosides against an MRSA strain.</p> <p>Results</p> <p>The synergism of the ethanol extract and aminoglycosides were verified using microdillution method. A synergistic effect of this extract on gentamicin and kanamycin was demonstrated. Similarly, a potentiating effect of chlorpromazine on kanamycin, gentamicin and neomycin, indicating the involvement of an efflux system in the resistance to these aminoglycosides.</p> <p>Conclusion</p> <p>It is therefore suggested that extracts from <it>Turnera ulmifolia </it>could be used as a source of plant-derived natural products with resistance-modifying activity, constituting a new weapon against the problem of bacterial resistance to antibiotics demonstrated in MRSA strains.</p

In vitro anti-staphylococcal activity of Hyptis martiusii Benth against methicillin-resistant Staphylococcus aureus: MRSA strains

This is the first report about the antibacterial activity of Hyptis martiusii Benth. In this study the ethanol extract of H. martiusii was tested for its antimicrobial activity against strains of Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. The growth of all bacterial strains tested was inhibited by the extract. The diameter of inhibition zones varied from 13 to 20 mm for the extract. The MIC and MBC values ranged from 128 to > 1024mg/mL and 256 to > 1024 mg/mL, respectively. It is therefore suggested that extracts from H. martiusii could be used as an anti-Staphylococcus agent. Compared with methicillin and gentamicin, the extract was more effective, being a promising antibacterial agent