In vitro activity of Erythrophleum ivorense extract against the promastigote stage of cutaneous Leishmania parasite, a member of Leishmania (Mundinia) enriettii complex isolates from Ghana

Background: Cutaneous leishmaniasis causes physical disfigurement and impairment on affected individuals, however, little attention has been paid to it eradication. The situation of this neglected disease is complicated with the expansion of the non-human pathogenic Leishmania enriettii complex causing infection in humans. We have previously shown that the extract from Erythrophleum ivorense has leishmanicidal activity against promastigote stages of the L. enriettii complex isolate from Ghana and L eishmania donovani. The extract of E. ivorense has shown to have anti-inflammatory, wound-healing ability, antiallergic, antimalarial and antischistosomal activity. However, the concentration threshold of E. ivorense extract required for leishmanicidal activity against the emerging human pathogenic L. enriettii complex isolates is not clear.

Aim: To test for the concentration threshold of E. ivorense extract required to obtain ideal leishmanicidal activity against the promastigote stage of human pathogenic L. enriettii complex isolates from Ghana.

Method: The ethanolic leaf extract of E. ivorense was serially diluted and tested against the promastigote stage of the L. enriettii complex. Parasite inhibition was measured at 590 nm using a spectrophotometer after staining parasites with trypan blue. To select the threshold concentration for maximum inhibition of the promastigote stage of the L. enriettii complex, the concentration cut-off statistic was used.

Results: The MIC of E. ivorense extract for L. enriettii promastigote inhibition was 62.3 μg ml^-1. The highest promastigote inhibition was observed at 72 h.

Conclusion: We show that a MIC of 62.3 μg ml^-1 of E. ivorense leaf extract exhibits an ideal leishmanicidal activity against the promastigote stage of L. enriettii complex isolates.

Keywords: Cutaneous leishmaniasis; Erythrophleum ivorense; Ghana; Leishmania enriettii complex; leishmanicidal; promastigotes stage.