Résumé
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 mug/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 mumols) (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 mug/ml. This plant may have therapeutic potential in the immunological and microbiological control of TB.
Sujets)
Animaux , Souris , Antibiotiques antituberculeux/pharmacologie , Dilleniaceae/composition chimique , Macrophages/microbiologie , Mycobacterium tuberculosis/effets des médicaments et des substances chimiques , Antibiotiques antituberculeux/isolement et purification , Peroxyde d'hydrogène/métabolisme , Tests de sensibilité microbienne , Macrophages/métabolisme , Monoxyde d'azote/biosynthèse , Extraits de plantes/pharmacologie , Facteur de nécrose tumorale alpha/biosynthèseRésumé
Macrophages release more than one hundred compounds into the extracellular environment. Among these, there are cytokines and intermediate oxigen compounds, such as TNF-"ALPHA" and 'H POT. 2''O POT. 2'. We evaluated the effect of the crude essential oil of Achillea millefolium L. (Asteraceae) by determining hydrogen peroxide ('H POT. 2''O POT. 2') and tumor necrosis factor-a (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 dilutions of 1:100 and 1:200 showed the best results. A mild production of 'H POT. 2''O POT. 2' and a moderate liberation of TNF-"ALPHA" were observed...