Introduction: Seaweeds are the reservoir of bioactive constituents such as proteins, polysaccharides, alkaloids, steroids and terpenoids that possess antioxidant, antiinflammatory and anti-cancerous properties. Dictyota bartayresiana is a brown seaweed with high antioxidant activity, making this species very valuable for human health. Fucoidan is the sulphated polysaccharide obtained from brown algae. Objectives: The study aimed to extract, purify and characterize fucoidan from Dictyota bartayresiana and investigate its antioxidant and anti-cancer properties. Materials and Methods: Fucoidan was isolated from Dictyota bartayresiana and was investigated for its antioxidant property by DPPH and ABTS assays, whereas cytotoxicity in SK-Hep-1 cells was checked using MTT assay. The apoptosis assay was achieved via the Annexin-V-Apoptosis detection kit, and images were obtained. To detect autophagy, western blotting was performed for protein Atg5. Results: Fucoidan revealed positive radical scavenging actions even at minor concentrations. The results acquired from the MTT assay revealed that cell death initiated at minor concentrations of 0.781μg/ml and was in a dose-dependent mode. The IC50 value obtained was 30.96 (μg/ml). In our study, SK-Hep-1 cells revealed that the intensities of the emission bands altered in response to apoptosis. It was observed that after 24 hr of fucoidan treatment, the level of Atg5 increased with an increase in fucoidan concentration and the band size observed for Atg5 was 55kDa. Conclusion: Fucoidan possessed antioxidant and cytotoxic properties and was found helpful in managing hepatocellular carcinoma.
Keywords: Dictyota bartayresiana, Radical scavenging, Polysaccharide, Antioxidant potential, Apoptosis.