Fucoidan—a novel α-amylase inhibitor from Turbinaria ornata with relevance to NIDDM therapy

The present experiment was conducted to screen the α-amylase inhibitory activity of fucoidan extracted from Turbinaria ornata collected at the coastal area of Mandapam, Tamil Nadu, India. The sporophyll of T. ornata was used to extract fucoidan by ethanol and CaCl2 precipitation method. The average yield was 2.6% and the extracted fucoidan was found to contain 59±0.69% of fucose and 33±0.42% of sulfate. Structural elucidation (FT-IR and NMR) and in vitro α-amylase activity of purified fucoidan were performed. Fucoidan at the concentration of 31.25, 62.5 and 125 µg exhibited 49%, 78% and 86% inhibition against α-amylase respectively in a dose dependent manner and the lowest inhibition percentage (9.8%) can be seen at 15.5 µg. The IC50 value against α-amylase of fucoidan is found to be 33.6 µg which is more effective than that of acarbose (125 µg). Cytotoxic assays were performed to determine the toxicity of the fucoidan which showed no cytotoxicity effect. The diverse biological activity of fucoidan includes the anticancer, anti inflammatory and antimicrobial activity. In addition, the α-amylase inhibitory activity of native fucoidan from T. ornata for NIDDM therapy is first of its kind in the world.