Biological activity of the essential oils from Cinnamodendron dinisii and Siparuna guianensis

This study had analyzed the antibacterial, antifungal and trypanocidal activity of the essential oils from Cinnamodendron dinisii Schwacke (Canellaceae) and Siparuna guianensis Aublet (Siparunaceae). The essential oils were obtained from fresh leaves by hydrodistillation, using a modified Clevenger apparatus. Chemical analysis by gas-liquid chromatography coupled to mass spectrometry (GC-MS) showed that these essential oils are rich in monoterpene and sesquiterpene hydrocarbons. Activity against the pathogenic bacteria Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella choleraesuis and Staphylococcus aureus was evaluated with the agar cavity diffusion method, while activity on the filamentous fungi Aspergillus flavus, Aspergillus niger, Aspergillus carbonarius and Penicillium commune was evaluated by the disk diffusion technique. Trypanocidal activity was tested against Trypanosoma cruzi epimastigotes, using the Tetrazolium salt (MTT) colorimetric assay. Both essential oils exhibited low inhibitory effect towards bacteria, showing high MIC values (125–500 μg mL−1), with Gram positive bacteria being more susceptible. Better inhibitory effect was obtained for the evaluated fungi, with lower MIC values (7.81–250 μg mL−1), being A. flavus the most susceptible species. Both essential oils presented low trypanocidal activity, with IC50/24 h values of 209.30 μg mL−1 for S. guianensis and 282.93 μg mL−1 for C. dinisii. Thus, the high values observed for the MIC of evaluated bacteria and for IC50/24 h of T. cruzi, suggest that the essential oils have a low inhibitory activity against these microorganisms. In addition, the low MIC values observed for the tested fungi species indicate good inhibitory activity on these microorganismss growth.(AU)

Atividade alelopática de óleos essenciais de plantas medicinais na germinação e vigor de aquênios de alface / Allelopathic activity of medicinal plant essential oils on seed germination and vigor of lettuce achenes

Os óleos essenciais vêm despertando interesse comercial na área agrícola, principalmente por suas propriedades alelopáticas, inseticidas, antifúngicas, antimicrobianas e antioxidantes, e, por serem compostos naturais, geralmente, de reduzida toxicidade, custo relativamente baixo e que se degradam rapidamente no ambiente. As plantas medicinais se destacam como potenciais fornecedores de óleos essenciais por sua utilização etnofarmacológica já explorada. O objetivo desta pesquisa foi avaliar o potencial alelopático dos óleos essenciais extraídos de folhas frescas de capim-limão (Cymbopogon citratus), alfavaca (Ocimum gratissimum L.) e manjericão (Ocimum basilicum L.), comparando-os com seus constituintes majoritários (citral, eugenol e cineol, respectivamente), em diferentes formas de aplicação (contato direto e efeito volátil), sobre a germinação e o vigor de aquênios de alface (cultivar Regina SF 3500). Os efeitos dos óleos e seus componentes majoritários foram avaliados pelas variáveis: primeira contagem de germinação, germinação , IVG (índice de velocidade de germinação), massa seca de plântulas e comprimentos médios de parte aérea e radicular de plântulas. Os óleos essenciais de capim-limão e alfavaca apresentaram potenciais alelopáticos sobre a germinação e o vigor de aquênios de alface que podem ser atribuídos aos conteúdos dos respectivos constituintes majoritários, citral e oeugenol, enquanto que o efeito alelopático do óleo essencial de manjericão é consequência do efeitoconjunto de todos os componentes do mesmo, independente da metodologia de aplicação.(AU)

In recent years, essential oils have gained commercial interest in the agricultural area, mainly for their allelopathic, insecticidal, antifungal, antimicrobial and antioxidant properties, and, also for their natural compounds, which have generally displayed low toxicity, relatively low cost and rapid degradation in the environment. Medicinal plants have emerged as potential suppliers of essential oils because of their ethnopharmacological utility. The aim of this study was to evaluate the allelopathic potential of essential oils extracted from fresh leaves of lemon grass (Cymbopogon citratus), wild basil (Ocimum gratissimum L.) and sweet basil (Ocimum basilicum L.) with regard to their major constituents (citral, eugenol and cineol, respectively) in different application forms (direct contact and the effect of volatile constituents) on the germination and vigor of lettuce seeds (cultivar Regina SF 3500). The effects of the oils and their major components were evaluated with regard to the variables: first germination count, total germination, GVI (germination velocity index), seedling dry weight and average lengths of shoots and lettuce roots. The essential oils from lemon grass and basil displayed allelopathic potentials on seed germination and vigor of lettuce achenes that can be assigned to their respective major constituents citral and eugenol. On the other hand, allelopathic effect of the essential oil from basil was a consequence of the combined effect of all the components, regardless the application method.(AU)

Atividade alelopática de óleos essenciais de plantas medicinais na germinação e vigor de aquênios de alface / Allelopathic activity of medicinal plant essential oils on seed germination and vigor of lettuce achenes

Os óleos essenciais vêm despertando interesse comercial na área agrícola, principalmente por suas propriedades alelopáticas, inseticidas, antifúngicas, antimicrobianas e antioxidantes, e, por serem compostos naturais, geralmente, de reduzida toxicidade, custo relativamente baixo e que se degradam rapidamente no ambiente. As plantas medicinais se destacam como potenciais fornecedores de óleos essenciais por sua utilização etnofarmacológica já explorada. O objetivo desta pesquisa foi avaliar o potencial alelopático dos óleos essenciais extraídos de folhas frescas de capim-limão (Cymbopogon citratus), alfavaca (Ocimum gratissimum L.) e manjericão (Ocimum basilicum L.), comparando-os com seus constituintes majoritários (citral, eugenol e cineol, respectivamente), em diferentes formas de aplicação (contato direto e efeito volátil), sobre a germinação e o vigor de aquênios de alface (cultivar Regina SF 3500). Os efeitos dos óleos e seus componentes majoritários foram avaliados pelas variáveis: primeira contagem de germinação, germinação , IVG (índice de velocidade de germinação), massa seca de plântulas e comprimentos médios de parte aérea e radicular de plântulas. Os óleos essenciais de capim-limão e alfavaca apresentaram potenciais alelopáticos sobre a germinação e o vigor de aquênios de alface que podem ser atribuídos aos conteúdos dos respectivos constituintes majoritários, citral e oeugenol, enquanto que o efeito alelopático do óleo essencial de manjericão é consequência do efeitoconjunto de todos os componentes do mesmo, independente da metodologia de aplicação.

In recent years, essential oils have gained commercial interest in the agricultural area, mainly for their allelopathic, insecticidal, antifungal, antimicrobial and antioxidant properties, and, also for their natural compounds, which have generally displayed low toxicity, relatively low cost and rapid degradation in the environment. Medicinal plants have emerged as potential suppliers of essential oils because of their ethnopharmacological utility. The aim of this study was to evaluate the allelopathic potential of essential oils extracted from fresh leaves of lemon grass (Cymbopogon citratus), wild basil (Ocimum gratissimum L.) and sweet basil (Ocimum basilicum L.) with regard to their major constituents (citral, eugenol and cineol, respectively) in different application forms (direct contact and the effect of volatile constituents) on the germination and vigor of lettuce seeds (cultivar Regina SF 3500). The effects of the oils and their major components were evaluated with regard to the variables: first germination count, total germination, GVI (germination velocity index), seedling dry weight and average lengths of shoots and lettuce roots. The essential oils from lemon grass and basil displayed allelopathic potentials on seed germination and vigor of lettuce achenes that can be assigned to their respective major constituents citral and eugenol. On the other hand, allelopathic effect of the essential oil from basil was a consequence of the combined effect of all the components, regardless the application method.

Preliminary assessment of Hedychium coronarium essential oil on fibrinogenolytic and coagulant activity induced by Bothrops and Lachesis snake venoms

Background The search for new inhibitors of snake venom toxins is essential to complement or even replace traditional antivenom therapy, especially in relation to compounds that neutralize the local effects of envenomations. Besides their possible use as alternative to traditional antivenom therapy, some plant species possess bioactive secondary metabolites including essential oils, which can be extracted from weeds that are considered substantial problems for agriculture, such as Hedychium coronarium.Methods The essential oils of leaves and rhizomes from H. coronarium were extracted by hydrodistillation, and their potential inhibitory effects on the coagulant and fibrinogenolytic activities induced by the venoms of Lachesis muta,Bothrops atrox and Bothrops moojeniwere analyzed. Citrated human plasma was used to evaluate the clotting time whereas changes in fibrinogen molecules were visualized by electrophoresis in polyacrylamide gel. The experimental design used for testing coagulation inhibition was randomized in a 3 × 2 factorial arrangement (concentration × essential oils), with three replications. The essential oils were compared since they were extracted from different organs of the same botanical species, H. coronarium.Results The results suggest that the oils interact with venom proteases and plasma constituents, since all oils evaluated, when previously incubated with venoms, were able to inhibit the clotting effect, with less inhibition when oils and plasma were preincubated prior to the addition of venoms.Conclusions Thus, after extensive characterization of their pharmacological and toxicological effects, the essential oils can be used as an alternative to complement serum therapy, especially considering that these plant metabolites generally do not require specific formulations and may be used topically immediately after extraction.(AU)

Preliminary assessment of Hedychium coronarium essential oil on fibrinogenolytic and coagulant activity induced by Bothrops and Lachesis snake venoms

The search for new inhibitors of snake venom toxins is essential to complement or even replace traditional antivenom therapy, especially in relation to compounds that neutralize the local effects of envenomations. Besides their possible use as alternative to traditional antivenom therapy, some plant species possess bioactive secondary metabolites including essential oils, which can be extracted from weeds that are considered substantial problems for agriculture, such as Hedychium coronarium. The essential oils of leaves and rhizomes from H. coronarium were extracted by hydrodistillation, and their potential inhibitory effects on the coagulant and fibrinogenolytic activities induced by the venoms of Lachesis muta, Bothrops atrox and Bothrops moojeni were analyzed. Citrated human plasma was used to evaluate the clotting time whereas changes in fibrinogen molecules were visualized by electrophoresis in polyacrylamide gel. The experimental design used for testing coagulation inhibition was randomized in a 3 × 2 factorial arrangement (concentration × essential oils), with three replications. The essential oils were compared since they were extracted from different organs of the same botanical species, H. coronarium. The results suggest that the oils interact with venom proteases and plasma constituents, since all oils evaluated, when previously incubated with venoms, were able to inhibit the clotting effect, with less inhibition when oils and plasma were preincubated prior to the addition of venoms. Thus, after extensive characterization of their pharmacological and toxicological effects, the essential oils can be used as an alternative to complement serum therapy, especially considering that these plant metabolites generally do not require specific formulations and may be used topically immediately after extraction.(AU)

Preliminary assessment of Hedychium coronarium essential oil on fibrinogenolytic and coagulant activity induced by Bothrops and Lachesis snake venoms

The search for new inhibitors of snake venom toxins is essential to complement or even replace traditional antivenom therapy, especially in relation to compounds that neutralize the local effects of envenomations. Besides their possible use as alternative to traditional antivenom therapy, some plant species possess bioactive secondary metabolites including essential oils, which can be extracted from weeds that are considered substantial problems for agriculture, such as Hedychium coronarium. The essential oils of leaves and rhizomes from H. coronarium were extracted by hydrodistillation, and their potential inhibitory effects on the coagulant and fibrinogenolytic activities induced by the venoms of Lachesis muta, Bothrops atrox and Bothrops moojeni were analyzed. Citrated human plasma was used to evaluate the clotting time whereas changes in fibrinogen molecules were visualized by electrophoresis in polyacrylamide gel. The experimental design used for testing coagulation inhibition was randomized in a 3 × 2 factorial arrangement (concentration × essential oils), with three replications. The essential oils were compared since they were extracted from different organs of the same botanical species, H. coronarium. The results suggest that the oils interact with venom proteases and plasma constituents, since all oils evaluated, when previously incubated with venoms, were able to inhibit the clotting effect, with less inhibition when oils and plasma were preincubated prior to the addition of venoms. Thus, after extensive characterization of their pharmacological and toxicological effects, the essential oils can be used as an alternative to complement serum therapy, especially considering that these plant metabolites generally do not require specific formulations and may be used topically immediately after extraction.

Essential oil of Rosmarinus officinalis L. as natural sanitizer for controlling the sessile bacteria and as antimicrobial on the food-cutting surfaces / Óleo essencial de Rosmarinus officinalis L. como sanitizante natural para controle de bactérias sésseis em superfície utilizada para corte de alimentos

The objective of this study was to determine the minimum inhibitory concentrations (MIC) and the minimum bactericidal concentrations (MBC) by using broth macro-dilution method in essential oil (EO) of Rosmarinus officinalis L. on the standard strains of Staphylococcus aureus, Escherichia coli, Salmonella Choleraesuis and Pseudomonas aeruginosa. The antibacterial activity of EO solutions on these bacteria adhered to the polypropylene surface used for cutting food was also evaluated, after 12 h at 37º C under shaking on. The sanitizers EO solutions were formulated based on MBC findings, separately for each bacterial strain. The sanitizing action of the solutions on the bacterial cells-adhered surface was evaluated after being contacted for 20 and 40 min. For E. coli, S. Choleraesuis and P. aeruginosa, the contact for 20 min was sufficient for inducing complete elimination of adhered cells, and S. aureus populations were significantly reduced at both evaluated periods of time. The EO of R. officinalis may represent as natural alternative form to carry out the pathogenic and contaminants bacteria control in food industry.(AU)

Objetivou-se neste estudo determinar as concentrações mínimas inibitórias (CMI) e as concentrações bactericidas mínimas (CBM) pela técnica de macrodiluição em caldo do óleo essencial (OE) de Rosmarinus officinalis L. sobre as cepas padrões de Staphylococcus aureus, Escherichia coli, Salmonella Choleraesuis e Pseudomonas aeruginosa. Avaliou-se também a ação antibacteriana de soluções do OE sobre estes micro-organismos aderidos, por 12 h a 37º C sob agitação, em superfície de polipropileno utilizada para corte de alimentos. As soluções sanitizantes de OE foram formuladas com base nos valores encontrados nas CBM, para cada estirpe bacteriana separadamente. A ação sanitizante da solução contra as células aderidas à superfície foi avaliada após 20 e 40 minutos de contato. Para E. coli, S. Choleraesuis e P. aeruginosa, o tempo de 20 minutos de contato foi suficiente para a remoção total das células aderidas, e para S. aureus houve redução significativa para ambos os períodos avaliados. O OE de alecrim pode ser considerado como alternativa natural para realizar o controle de bactérias patogênicas e contaminantes na indústria de alimentos.(AU)

Composição química e atividade antibacteriana dos óleos essenciais de Cymbopogon winterianus (citronela), Eucalyptus paniculata (eucalipto) e Lavandula angustifolia (lavanda) / Chemical composition and antibacterial activity of essential oils from Cymbopogon winterianus (citronella), Eucalyptus paniculata (eucalyptus) and Lavandula angustifolia (lavender)

Neste estudo, foi determinada a composição química de óleos essenciais obtidos de três espécies de plantas medicinais cultivadas na região Sul do Brasil: Cymbopogon winterianus (citronela), Eucalyptus paniculata (eucalipto) e Lavandula angustifolia (lavanda), e as atividades antimicrobianas foram avaliadas frente a 11 espécies de bactérias, incluindo-se espécies de importância em alimentos e em saúde pública. A composição dos óleos essenciais, obtidos por destilação a vapor, foi determinada por CG/DIC e CG/ EM; a atividade antimicrobiana foi detectada pela técnica de difusão em disco; a CMI e a CMB foram determinadas pela metodologia de microdiluição. Os óleos essenciais de lavanda e citronela apresentaram monoterpenos oxigenados como componentes majoritários e, no óleo essencial de eucalipto, os monoterpenos hidrocarbonados foram os principais constituintes. O óleo essencial de citronela foi o mais ativo contra a maioria das bactérias testadas, com valores de CMI e CMB, respectivamente, de 0,075 e 0,31 mg/mL para Yersinia enterocolitica . O óleo essencial de lavanda destacou-se pela atividade inibitória contra Escherichia coli e Salmonella Typhimurium, e o óleo de eucalipto foi ativo contra Pseudomonas aeruginosa . Este estudo demonstra que os óleos essenciais avaliados apresentam potencial para aplicação como agentes antimicrobianos naturais.(AU)

The chemical composition of essential oils derived from three medicinal plant species growing in the South of Brazil: Cymbopogon winterianus (citronella), Eucalyptus paniculata (eucalyptus) , and Lavandula angustifolia (lavender) was determined, and their antimicrobial activities were evaluated against 11 bacterial species, including those related to foodborne and human pathogens. The essential oils were obtained by steam distillation, and its chemical composition was analyzed by GC and GC/MS. Antimicrobial activity was screened by disc-diffusion assay. MIC and MBC of the sensitive strains were determined by microdilution methodology. The main components of lavender and citronella essential oils were the oxygenated monoterpenes, and the monoterpene hydrocarbons in eucalyptus oil. Citronella oil showed the lowest MIC and MBC values on the majority of the tested bacteria, and the MIC and MBC values against Yersinia enterocolitica were of 0.075 and 0.31 mg/mL, respectively. The lavender oil was active against Escherichia coli and Salmonella Typhimurium, and the eucalyptus inhibited the growth of Pseudomonas aeruginosa . This study showed that the evaluated essential oils might be potentially used as natural antimicrobial agents.(AU)

Atividade antifúngica de óleo essencial de limão (Citrus aurantifolia) frente a fungos filamentosos isolados de pães

Os óleos essenciais (OE) constituem os elementos voláteis contidos em muitos órgãos vegetais, e estão relacionados com diversas funções necessárias à sobrevivência vegetal, exercendo papel fundamental na defesa contra micro-organismos. O objetivo do presente trabalho foi isolar e identificar fungos presentes em pães de forma, assim como, avaliar in vitro a atividade antifúngica de óleo essencial de limão frente a estes fungos. O isolamento e a identificação dos fungos foram realizados pelas técnicas de esgotamento por estriamento e pela técnica de microcultivo, respectivamente. A atividade antifúngica do OE de limão (Citrus aurantifolia) nas concentrações de 0; 100; 200; 400; 600; 800; 1200 µg/mL, do meio, foram testadas sobre A. niger, A. flavus, Rhizopus sp. e Penicillium sp. pelo método de diluição em ágar, acrescido do OE, onde fez-se um orifício de 5mm e adicionou-se 1mL do inoculo dos fungos incubando a 30º/72h. Após o período de incubação, para as espécies de A. niger e A. flavus, com o OE analisado nas concentrações a partir de 800µ/mL, e para Penicillium sp. e Rhizopus sp. com a concentração de 1200 µg/mL., os resultados mostraram um efeito superior ao da amostra controle em 80% do diâmetro do halo de crescimento. Pode-se concluir que a maior incidência de fungos nos pães avaliados foi de A. flavus, A. niger, Rhizopus sp. e Penicillium sp. sendo o A. flavus e A. niger mais sensíveis ao uso de OE de Citrus aurantifolia. No entanto, a concentração de 1200 µg/ml. de OE mostrou um efeito expressivo sobre todos os fungos avaliados.(AU)

Essential oils (EO) are volatile elements contained in many plant organs, and are related to various functions necessary for plant survival, playing a key role in the defense against microorganisms. The goal of this study was to isolate and identify fungi present in pan breads, as well as to evaluate "in vitro'' antifungal activity of lemon essential oil against these fungi. The isolation and identification of the fungi were performed by depletion induced by stretching as well as by microcultive technique, respectively. The antifungal activity of the lemon essential oil (Citrus aurantifolia), at concentrations of 0; 100; 200; 400; 600; 800; 1200 mcg/ml of the medium, were tested on A. niger, A. flavus, Rhiropus sp. and Penicillium sp. by the agar dilution method plus the lemon essential oil, where it was made a hole of 5 mm, in which was added 1 mL of the inoculum of the fungi incubating at 30º/72h. Afier the incubation period, for the species A. flavus and A. niger, with the EO examined at concentrations of 800 mcg/ml, andfor Penicillium sp. and Rhizopus sp., with the OE at the concentration of 1200 g/ml, the results showed a superior effect to the control sample by 80% of the diameter of the halo of growth. It is possible to conclude that the higher incidence of fungi in the evaluated bread were of the species A. flavus, A. niger, Rhizopussp. and Penicillium sp., being A. flavus and A. niger more sensitive to the use of the EO of Citrus aurantifolia. However, the concentration of 1200 mcg/ml of EO showed a substantial effect on all fungi analyzed.(AU)