Leishmaniasis, malaria, and neosporosis are parasitic diseases that affect humans
and animals, causing public health problems and billions in economic losses.
Despite the advances in the development of new drugs, the severe side effects of
available leishmaniasis treatments, the Plasmodium spp. resistance to
antimalarial drugs, and the lack of a specific treatment against neosporosis
lead us to the search for new anti-protozoan molecules from underexplored
sources such as the Antarctic marine environment. Herein, we describe for the
first time the chemical profile of Desmarestia antarctica crude extract
and fractions using GC-MS and LC-MS/MS (molecular networking)
approaches, and evaluate their antiparasitic activity against Leishmania
amazonensis, Neospora caninum, and multi-drug-resistant
Plasmodium falciparum. Furthermore, the cytotoxicity in 3T3
BALB/c fibroblasts and Vero cells was evaluated. D. antarctica
fraction E ( IC50 of 53.8±4.4 μg
mL− 1 and selectivity index of 3.3) exhibited
anti-promastigote activity and was fourfold more selective to L.
amazonensis rather than to the host cells. D. antarctica fraction
D (IC50 of 1.6±1.3 μg
mL− 1 and selectivity index of 27.8), D.
antarctica fraction F (IC50 of
3.1±2.1 μg mL− 1 and
selectivity index of 23.1), and D. antarctica fraction H (IC50
of 3.1±2.0 μg mL− 1 and
selectivity index of 12.9) presented the highest antiparasitic effects against
N. caninum with no cytotoxic effects. Also, D. antarctica
fraction D presented a significant antiplasmodial inhibitory effect
(IC50 of 19.1±3.9 μg
mL− 1 and selectivity index of 6.0). GC-MS
analysis indicated palmitic acid, myristic acid, fucosterol, phthalic acid,
di(2-methylbutyl) ester, loliolide, and neophytadiene as the main components in
the active fractions. In addition, this is the first report of a biological
screening of macroalgae secondary metabolites against N. caninum
parasites.