Effect of essential oil from Ageratum fastigiatum on beta-integrin (CD18) expression on human lymphocytes stimulated with phorbol myristate acetate in vitro.

Agareratum fastigiatum is a Brazilian medicinal plant used as anti-inflammaroty and for wound healing by the folk medicine. In vitro and in vivo studies involving A. fastigiatum essential oil (EOAF) showed indications of anti-inflammatory activity, however, its effect on membrane integrins involved on cell migration is still unclear. Hence, it was evaluated in the present study the effect of EOAF on CD18 frequency on human lymphocytes. By using gas chromatography/mass spectrometry it was identified 9 compounds on EOAF: α-pinene; β-pinene; β-myrcene; d-limonene; β-ocimene; sesquiterpenes; α-copaene; 4,8-β-epóxi-caryophyllene; germacrene and bicyclogermacrene. On in vitro tests, 6.25 × 10^-3 and 12.5 × 10^-3 µL/mL EOAF reduced CD18 frequency on phorbol-12-myristate-13-acetate (PMA)-stimulated lymphocytes. Such cells were obtained from peripheral blood of healthy volunteers, and were treated or not with EOAF. They were stained with fluorescent anti-CD18 monoclonal antibodies, after 24 hours incubation. Our data corroborates previous findings, indicating a possible anti-inflammatory activity of EOAF.