Fucogalactan from the giant mushroom Macrocybe titans inhibits melanoma cells migration

An aqueous extract containing polysaccharides was obtained from the giant mushroom Macrocybe titans, and it was purified by amylase treatment, freeze-thawing process and dialysis. The purified fraction (ESP) was analyzed by HPSEC and GC-MS which showed a homogenous polysaccharide with Mw 14.2 × 103 g/mol composed by galactose and fucose. NMR and methylation analysis of ESP confirmed the presence of a fucogalactan with a (1 → 6)-linked α-d-Galp main chain partially substituted at O-2 by non reducing end units of α-l-Fucp residues in the side chain. Its biological activity was evaluated against murine melanoma cells B16-F10. The fucogalactan did not alter the viability, proliferative capacity and morphology of cells. However, this polysaccharide was able to reduce the cell migration in vitro at 40% (100 μg/mL) and 33% (250 μg/mL). The results obtained showed that Macrocybe titans fucogalactan is a promising agent capable of altering melanoma cell migration without decrease the cell viability.