ABSTRACT Leishmaniasis is a disease that affects millions of people and it is an important public health problem. The drugs currently used for the treatment of leishmaniasis present undesirable side effects and low efficacy. In this study, we evaluated the in vitro activity of Melampodium divaricatum (MD-EO) and Casearia sylvestris (CS-EO) essential oils (EO) against promastigote and amastigote forms of Leishmania amazonensis. Sesquiterpenes E-caryophyllene (56.0%), germacrene D (12.7%) and bicyclogermacrene (9.2%) were identified as the main components of MD-EO, whereas E-caryophyllene (22.2%), germacrene D (19.6%) and bicyclogermacrene (12.2%) were the main constituents of CS-EO. CS-EO and E-caryophyllene were active against promastigote forms of L. amazonensis (IC50 24.2, 29.8 and 49.9 µg/mL, respectively). However, MD-EO, CS-EO and E-caryophyllene were more active against amastigote forms, with IC50 values of 10.7, 14.0, and 10.7 µg/mL, respectively. E-caryophyllene presented lower cytotoxicity against macrophages J774-A1 (CC50 of 62.1 µg/mL) than the EO. The EOs and E-caryophyllene should be further studied for the development of new antileishmanial drugs.

Melampodium divaricatum (Rich) DC., Asteraceae é uma espécie encontrada na América Latina sendo no Brasil principalmente na região Nordeste. Popularmente vem sendo empregada como antiinflamatória e cicatrizante e dentre vários componentes químicos relatados na literatura, destaca-se a presença de óleos essenciais em suas partes aéreas. Considerando o potencial antimicrobiano in vitro e in vivo de óleos essenciais presentes em muitas plantas e do amplo potencial farmacológico destes, este trabalho teve como objetivo avaliar a atividade antibacteriana do óleo essencial obtido a partir de partes aéreas de M. divaricatum utilizando-se o método de difusão em disco frente às bactérias Staphylococcus aureus (ATCC 25923), Bacillus subtilis (ATCC 9372), Escherichia coli (ATCC 25922), Proteus mirabilis (ATCC 25933) e as cepas de campo: Pseudomonas aeruginosa, Shigella sonnei, Serratia marcescens. De acordo com os resultados obtidos no presente trabalho, apenas as espécies Gram-positivas (S. aureus e B. subtilis) mostraram se sensíveis ao óleo essencial, e as demais espécies testadas não tiveram seu crescimento inibido.

Melampodium divaricatum is a species found in Latin America and in Brazil mainly in the Northeast region. It is popularly used as anti-inflammatory and cicatrizing and among several chemical compounds it can be noteworthy the presence of essential oils in aerial parts. Considering the antimicrobial potential of essential oils in vitro and in vivo as well as its ample pharmacologic potential the objective of this work was to evaluate the antibacterial activity of the crude essential oil obtained from the aerial parts of M. divaricatum by the method of disc diffusion against Staphylococcus aureus (ATCC 25923), Bacillus subtilis (ATCC 9372), Escherichia coli (ATCC 25922), Proteus mirabilis (ATCC 25933), the clinical strains Pseudomonas aeruginosa, Shigella sonnei and Serratia marcescens. Only the gram-positive species S. aureus and B. subtilis showed sensitivity to the essential oil and the other analyzed strains did not have growth inhibited.

O efeito do óleo essencial bruto de Achillea millefolium L. (Asteraceae) foi determinado através da liberação de peróxido de hidrogênio (H2O2) e do fator de necrose tumoral-alfa (TNF-alfa) por cultura de macrófagos peritoneais de camundongos Swiss. O azuleno comercial também foi testado e comparado com o óleo essencial. Macrófagos liberam mais de cem compostos biologicamente ativos. Entre esses, citocinas e compostos intermediários do oxigênio como o TNF-alfa e o H2O2. A viabilidade dos macrófagos na presença do óleo foi analisada e as diluições de 1:100 e 1:200 do óleo essencial mostraram os melhores resultados. Pequena liberação de H2O2 e moderada produção de TNF-alfa também foram observadas. Contudo, maior liberação de H2O2 e TNF-alfa foi observada utilizando o azuleno comercial. Desse modo, observou-se que o óleo essencial de A. millefolium foi capaz de estimular os macrófagos peritoneais a produzir H2O2 e TNF-alfa sem causar superprodução desses componentes. Sugere-se que o óleo essencial pode modular a ativação de macrófagos.

Macrophages release more than one hundred compounds into the extracellular environment. Among these, there are cytokines and intermediate oxygen compounds, such as TNF-alpha and H2O2. We evaluated the effect of the crude essential oil of Achillea millefolium L. (Asteraceae) by determining hydrogen peroxide (H2O2) and tumor necrosis factor-alpha (TNF-alpha) release in cultures of peritoneal macrophages cells from Swiss mice. Commercial azulene was also tested for comparison with the essential oil. The macrophages viability in the presence of the oil was analyzed and the dilutions of 1:100 and 1:200 showed the best results. A mild production of H2O2 and a moderate liberation of TNF-alpha were observed. It was also noticed that H2O2 and TNF-alpha production using commercial azulene was higher than that produced by the oil. The essential oil of A. millefolium was able to stimulate peritoneal macrophages to produce H2O2 and TNF-alpha without causing an overproduction of these compounds. It is suggested that the essential oil can modulate macrophages activation.