Fucoidan - An α-amylase inhibitor from Sargassum wightii with relevance to NIDDM

The present experiment was conducted to screen the alpha-amylase inhibitory activity of fucoidan extracted from Sargassum wightii collected at the coastal area of Mandapam, Tamil Nadu, India. Fucoidan was extracted from the sporophyll of S. Wightii by ethanol and CaCl2 precipitation method. The average yield was 1.8 +/- 0.16% and the extracted fucoidan was found to contain 53 +/- 0.52% of fucose and 36 +/- 0.60% of sulphate. Structural elucidation (FT-IR and NMR) and in vitro alpha-amylase activity of purified fucoidon were performed. Fucoidan at the concentration of 62.5, 125 and 250 mu g exhibited 24.81, 62.50 and 99.24% inhibition against alpha-amylase, respectively, in a dose dependent manner. Fucoidan from S. wightii also inhibits alpha-glucosidase which clearly indicates dual inhibitory activity of the compound. The IC50 value against alpha-amylase of fucoidan is found to be 103.83 mu g which is more effective than that of acarbose (16 mg). (C) 2015 Elsevier B.V. All rights reserved.