Effectiveness of red alga Asparagopsis taxiformis extracts against Leishmania infantum

Leishmaniasis is a disease with a worldwide distribution affecting both humans and animals. There is a need to identify and develop new drugs for the treatment of leishmaniasis. This study showed that crude ethanolic extracts of the red alga Asparagopsis taxiformis have a powerful effect against L. infantum, the prevalent species of the genus Leishmania in the Mediterranean basin. L. infantum demonstrated decreased vitality with increasing concentration of the algal extracts. At a concentration of 40 μg/mL, the extracts achieved 100% mortality of the parasite and the LD50 value was 25 μg/mL for promastigotes and 9 μg/mL for amastigotes. Algal extracts caused morphological alterations and apoptosis in Leishmania cells. The potential cytotoxic action of crude extracts was investigated by a MTT viability assay on DH82 and Vero cell lines but there was no cytotoxic effect. The potential of red alga A. taxiformis metabolites as anti-leishmanial agents merits further pharmacological investigation.