In vitro antioxidant and antitumor activities of different sulfated polysaccharides isolated from three algae

•Ultrasonic extraction coupled with radial flow chromatography to separate sulfated polysaccharides from three algae.•Antioxidant and antitumor activities in vitro were studied and compared.•UFP with lower sulfate content exhibited excellent antioxidant activities but showed the least inhibitory effects for cancer cells.•The relationships between properties and bioactivities are preliminarily revealed.

Three sulfated polysaccharides(Ulva fasciata (UFP), Gloiopeltis furcata (GFP), Sargassum henslouianum (SHP))were isolated from three algae including green alga Ulva fasciata, red alga Gloiopeltis furcata and brown alga Sargassum henslouianum by ultrasonic extraction and radial flow chromatography. Their in vitro antioxidant and antitumor activities were investigated and compared. Among these three polysaccharides, UFP, with relatively lower sulfate content, exhibited excellent antioxidant activities in superoxide radical assay, ABTS assay and DPPH assay; however, it demonstrated the minimal inhibitory effects on growth of MKN45 gastric cancer cells and DLD intestinal cancer cells. SHP with the lowest sulfate content gained relatively lower radical scavenging rates but showed significantly higher antitumor activities. These results indicated that the in vitro antitumor and antioxidant activities of the three polysaccharides may be related to combined effects of sulfate content and uronic acid content.