Experimental treatment of cutaneous leishmaniasis with argentilactone isolated from Annona haematantha.

From the hexanic extract of roots of Annona haematantha an alpha,beta-unsaturated delta-lactone was isolated and identified as argentilactone. This compound exhibited in vitro activity against various strains of Leishmania ssp. at 10 micrograms/ml. BALB/c mice infected with Leishmania amazonensis were treated four weeks after infection with argentilactone by oral or subcutaneous routes for 14 days at 25 mg/kg daily. The reference drug, N-methylglucamine antimonate, was administered by subcutaneous injections at 100 mg/kg for 14 days. In these conditions, argentilactone showed the same efficacy as the reference drug, reducing by 96% the parasite loads in the lesion and by 50% the parasite burden in spleen.