Physicochemical, radical–scavenging, and anti-proliferative analyses of enzyme-assisted extracted polysaccharides unravel the potential of tropical green seaweeds

This study focused on enzyme-assisted extraction of polysaccharides from four selected tropical green seaweeds (Caulerpa scalpelliformis, Ulva fasciata, Ulva lactuca, and Acrosiphonia orientalis). The polysaccharides were physicochemically characterized by using advanced analytical tools and also evaluated for their scavenging and anti-proliferative activities. Enzyme-assisted extraction yielded a higher polysaccharide content compared with traditional techniques. The extracted crude and purified polysaccharides were rich in sugars, including galactose and mannose. Functional group analysis based on Fourier-transform infrared spectroscopy confirmed the presence of characteristic polysaccharide groups, such as hydroxyl, carboxyl, and sulfate. The extracted polysaccharides were amorphous in nature with a fibrous and porous morphology, showing uneven aggregates. Different biological tests, including the ferric reducing antioxidant power and phosphomolybdate assays, revealed significant antioxidant activity. Furthermore, the anti-proliferative studies performed on two cancer cell lines (Huh-7 and HeLa) showed different degrees of inhibition, with certain purified fractions showing higher efficacy. Overall, the results indicate that these extracted polysaccharides have potential applications in nutraceutical, pharmaceutical, and therapeutic products, particularly as antioxidants and anti-cancer agents.