Galactofucoidans from Sargassum fusiforme and their antagonistic effects against the proliferation-inhibition of RAW264.7 macrophage induced by culture supernatants of melanoma cells

Two purified galactofucoidans, SFA1B-1 and SFA1C-2, with apparent molecular weights of 1.6 x10(5) and 8.9 x10(4), respectively, were isolated from Sargassum fusiforme via ion-exchange and gel-filtration column chromatography. SFA1B-1 and SFA1C-2 were composed of large amounts of fucose (Fuc), minor amounts of galactose (Gal), and small amounts of xylose and glucuronic acid. The backbone of these galactofucoidans consisted of alpha-(1 -> 3)-linked Fucp residues sulfated mostly at the C-2 and/or C-4 positions. The backbone was primarily branched at the C-2 and/or C-4 positions probably by side chains comprising t-Fucp residues and (1 -> 4)-Galp residues. Bioactive tests preliminarily showed that SFA1B-1 and SFA1C-2 could strongly not only antagonize against but also reverse the proliferation-inhibition of RAW264.7 cells induced by B16F10-CS. This finding suggests that SFA1B-1 and SFA1C-2 may antagonize the immunosuppressed function of macrophages. However, their possible effects on immunosuppressed peritoneal macrophages from mice or human with tumors and the underlying antagonistic mechanism warrant further investigation.

Automated summary

Two purified galactofucoidans, SFA1B-1 and SFA1C-2, isolated from Sargassum fusiforme, exhibit potential immunosuppressive antagonistic effects against macrophages, with further investigation needed on their impact on immunosuppressed peritoneal macrophages from mice or human with tumors.