A SULFATED POLYSACCHARIDE FROM RED SEAWEED GRACILARIA CAUDATA EXHIBITS ANTIOXIDANT AND ANTI-ADIPOGENIC ACTIVITIES IN VITRO
Sulfated polysaccharide; oxidative stress; 3T3-L1 cells; anti-obesity; sulfated galactan
This study investigated the antioxidant and anti-adipogenic activities of sulfated polysaccharide from the red seaweed Gracilaria caudata. Initially, sulfated polysaccha-ride-rich extracts (SPREs) from fifteen tropical seaweeds were screened for chemical composition and antioxidant potential. Among them, G. caudata exhibited the highest total antioxidant capacity, guiding its selection for detailed characterization. Sequential acetone precipitation yielded three SPs (F1.5, F2.0, and F3.0), which differed in sulfate content, monosaccharide composition, and molecular weight. In vitro assays revealed that F1.5 displayed the highest total antioxidant capacity and strong iron-chelating activity, while F2.0 was the most effective hydroxyl radical scavenger. Importantly, only F1.5 was non-cytotoxic to non-tumor cell lines. In 3T3-L1 preadipocytes, F1.5 attenuated H₂O₂-induced oxidative stress by reducing ROS and MDA levels and restoring GSH and SOD activity, achieving effects comparable to quercetin. Moreover, F1.5 inhibited adipogenic differentiation in a dose-dependent manner, as evidenced by decreased Oil Red O staining and reduced glycerol release. Overall, F1.5 demonstrates dual antioxidant and anti-adipogenic properties, highlighting G. caudata as a promising natural source of bioactive polysaccharides for potential nutraceutical applications. However, further studies are needed to elucidate the molecular mecha-nisms underlying these effects, confirm efficacy in vivo, and assess bioavailability and safety profiles before considering clinical translation.