ACTIVITY OF COMPOUNDS ISOLATED FROM CHILEAN LICHENS AGAINST EXPERIMENTAL CUTANEOUS LEISHMANIASIS

Three secondary metabolites isolated from Chilean lichens, (+) usnic a cid, pannarine and 1'-chloropannarine, were tested against promastigot es forms of three strains of Leishmania ssp. Pannarine and 1'-chloropa nnarine exhibited in vitro activity at 50 mu g/ml and (+) usnic acid a t 25 mu g/ml. BALB/c mice infected with Leishmania amazonensis were tr eated 4 weeks post-infection with (+) usnic acid by subcutaneous or or al routes for 15 days at 25 mg/kg or by five intralesional injections at interval of 4 days at 25 mg/kg of body weight. The reference drug, N-methylglucamine antimonate (Glucantime), was administered by subcuta neous injections (regimens of 28 mg of pentavalent antimony) for 15 da ys. The subcutaneous and oral treatments with (+) usnic did not produc e any effect, but by intralesional administration we observed a signif icant effect that reduced by 43.34% the weight lesions and by 72.28% t he parasites loads in infected footpads. Copyright (C) 1997 Elsevier S cience Inc.