Mycobacterium tuberculosis is responsible for over 8 million cases of tuberculosis (TB) annually. Natural products may play important roles in the chemotherapy of TB. The immunological activity of Davilla elliptica chloroform extract (DECE) was evaluated in vitro by the determination of hydrogen peroxide (H2O2), nitric oxide (NO), and tumor necrosis factor-alpha (TNF-alpha) release in peritoneal macrophages cultures. DECE was also tested for its antimycobacterial activity against M. tuberculosis using the microplate alamar blue assay. DECE (50, 150, 250 µg/ml) stimulated the production of H2O2 (from 1,79 ± 0,23 to 7,27 ± 2,54; 15,02 ± 2,86; 20,5 ± 2,1 nmols) (means ± SD), NO (from 2,64 ± 1,02 to 25,59 ± 2,29; 26,68 ± 2,41; 29,45 ± 5,87 µmols) (means ± SD) and TNF-alpha (from 2,44 ± 1,46 to 30,37 ± 8,13; 38,68 ± 1,59; 41,6 ± 0,90 units/ml) (means ± SD) in a dose-dependent manner and also showed a promising antimycobacterial activity with a minimum inhibitory concentration of 62,5 µg/ml. This plant may have therapeutic potential in the immunological and microbiological control of TB.

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.