RESUMEN
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...