The antileishmanial activity of the antarctic brown alga Ascoseira mirabilis Skottsberg

Abstract

Leishmaniasis is a group of diseases that have limited and high toxic therapeutic options. Herein, we evaluated the antileishmanial potential and cytotoxicity of hexanic extract obtained from the Antarctic brown alga Ascoseira mirabilis using bioguided fractionation against Leishmania amazonensis and murine macrophages, which was fractionated by SPE, yielding seven fractions (F1-F7). The fraction F6 showed good anti-amastigote activity (IC₅₀ = 73.4 ± 0.4 μg mL⁻¹) and low cytotoxicity (CC₅₀ > 100 μg mL⁻¹). Thus, in order to identify the bioactive constituent(s) of F6, the fraction was separated in a semipreparative HPLC, yielding four fractions (F6.1-F6.4). F6.2 was the most bioactive fraction (IC₅₀ = 66.5 ± 4.5 μg mL⁻¹) and GC-MS analyses revealed that the compounds octadecane, propanoic acid, 1-monomyristin and azelaic acid correspond to 61% of its composition. These data show for the first time the antileishmanial potential of the Antarctic alga A. mirabilis.

Graphical Abstract

Keywords:

• Cutaneous leishmaniasis
• Antarctic macroalgae
• Ascoseiraceae
• Brown algae
• GC-MS
• Natural products

Acknowledgments

The authors are grateful to Professor Paul A. Michels for critically reading of this manuscript and Alessandro Desideri, Rodrigo M. Pereira, Beatriz Brunelli, Karla Peresque and Aline P. Martins, who collected the brown macroalga A. mirabilis during the OPERANTAR XXXIII in King George Island, Antarctica, in 2014.

Disclosure statement

No potential conflict of interest is reported by the authors.

Additional information

Funding

This work was financially supported by MCTI/CNPq/FNDCT - Ação Transversal Programa Antártico Brasileiro, grant number 407588/2013-2; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP), grant numbers 2017/03552-5 and 2016/06931; The scholarships for LCC, TRT, FBO were provided by Fundação Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) and to RSNT by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq).