Acid heteropolysaccharides with potent antileishmanial effects

The present study investigated in vitro the effects of sulphated heterorhamnan (Go3), iota-/nu-carrageenans (G3d and EHW-I) and arabinogalactan (ARAGAL) polysaccharides on macrophage activation and inhibition of intracellular amastigotes of Leishmania (L.) amazonensis. All the sulphated polysaccharides (Go3, G3d and EHW-I) promoted increased nitric oxide production varying from 71 to 110%. The leishmanicidal activity of all compounds was compared to the inhibition effect of Meglumine Antimoniate at 300 μg/mL (∼79%), used as positive control. Inhibition of Leishmania (L.) amazonensis growth was 55% with 5 μg/mL of Go3, 50% and 98% to G3d and EHW-I, respectively at 10 μg/mL, and 88% with 10 μg/mL of ARAGAL. The superoxide anion scavenging activity for the sulphated polysaccharides varied from approximately 30-55% at 10 μg/mL. In conclusion, the results of the present study indicate the promising potential of these polysaccharides for the development of new alternative therapeutic agents against leishmaniasis.