Study of the topical anti-inflammatory activity of Achillea ageratum on chronic and acute inflammation models

We have produced a chloroform extract from Achillea which includes stigmast erol and sitosterol. By comparing it with the pure compounds an anti-inflam matory effect (with mouse ears) is assumed. The topical anti-inflammatory effect of the chloroform extract from Achille a ageratum (Asteraceae)and of stigmasterol and beta-sitosterol, isolated of this extract has been evaluated, against to 12-0-tetradecanoylphorbol acet ate (TPA)-induced mouse ear edema, using simple (acute model) and multiple applications (chronic model) of the phlogistic agent. Myeloperoxydase activ ity also was studied in the inflamed ears. In thr acute model the extract exerted a dose-dependent effect. All the dos es assayed (1, 3 and 5 mg/ear) significantly reduced the edema (50%, 66% an d 82%, respectively). The isolated sterols stigmasterol and beta-sitosterol (with doses of 0.5 mg/ear) had similar effect as the extract with doses of 1 and 3 mg (59% and 65% respectively). In the chronic model the anti-inflammatory effect generally was a more mode rate one. nit: highest dose of the extract decreased the edema reduction to 26% with the highest dose of the extract applied. With the compounds the e ffect decreased to 36% with stigmasterol, and 40.6% with beta-sitosterol. Myeloperoxydase activity (MPO) was reduced by the extract and the compounds in the acute model, however, in the chronic edema, the enzyme inhibition w as very weak with all treatments even with the standard substance. These results indicate that the chloroform extract of Achillea ageratum and some of the its components stigmasterol and beta-sitosterol are more effec tive as topical anti-inflammatory agents in acute than in the chronic proce ss and their action is markedly influenced by the inhibition of neutrophil migration into inflamed tissue.