Alpha-glucosidase inhibitory activity of some brown seaweeds collected in Nha Trang bay, Khanh Hoa province

Abstract

Diabetes has become a global problem in recent years. Inhibition of α-glucosidase is one of the effective approaches to control the postprandial blood glucose and thereby managing diabetes. This study evaluated inhibitory activity of seven brown seaweed extracts (Colpomenia sinuosa, Padina australis, Sargassum aquifolium, Sargassum mcclurei, Sargassum duplicatum, Sargassum polycystum and Sargassum swartzi) against α-glucosidase. The results indicated that all seaweed extracts inhibited enzyme activity with the IC50 values ranging from 154.27 to 426.27 μg/mL. The seaweed Sargassum mcclurei showed the highest α-glucosidase inhibitory activity. The effects of extraction conditions and extraction solvent fractions on α-glucosidase inhibitory activity of Sargassum mcclurei were investigated. The suitable extraction conditions were found to be the solid to liquid ratio (g/mL) of 1/40, the extraction time of 60 min and the extraction temperature of 60oC. The ethyl acetate extracted fraction showed the highest α-glucosidase inhibitory activity compared with other fractions.