Antileishmanial activity of furoquinolines and coumarins from Helietta apiculata

The bark infusion of H. apiculata are used to treat wound healing related to cutaneous leishmaniasis and as anti-inflammatory. To isolate, purify active constituents of H. apiculata stem bark, and evaluate their in vitro and in vivo antileishmanial activities. Isolation by chromatographic methods and chemical identification of furoquinoline alkaloids and coumarins, then evaluation of the in vitro leishmanicidal activity of these compounds against three strains of Leishmania sp. promastigotes and in vivo against Leishmania amazonensis in Balb/c mice. Furoquinoline alkaloids and coumarins presented a moderate in vitro activity against promastigote forms of Leishmania sp. with IC 50 values in the range between 17 and >50 μg/ml. Balb/c mice infected with Leishmania amazonensis were treated with γ-fagarine by oral route, or with 3-(1’-dimethylallyl)-decursinol or (-)-heliettin by subscutaneous route for 14 days at 10 mg/kg daily. In these conditions, γ-fagarine, 3-(1’-dimethylallyl)-decursinol and (-)-heliettin showed the same efficacy as the reference drug reducing by 97.4, 95.6 and 98.6% the parasite loads in the lesion, respectively. These compounds showed significant efficacy in L. amazonensis infected mice, providing important knowledge to improve its potential role for a future use in the treatment of cutaneous leishmaniasis.