Bioactivities of sulfated polysaccharides extracted by enzyme, ultrasound and enzyme-ultrasound methods.

Sulfated polysaccharide (fucoidan) was isolated from by enzyme (alcalase), ultrasonic and enzyme-ultrasonic methods. The extracted fucoidans were assessed for their chemical compositions, molecular characteristics, anticancer and immunomodulatory activities. Enzyme-ultrasonic isolated fucoidan showed the maximum extraction yield (7.87%) while that obtained by ultrasonic had the minimum value (3.6%). fucoidans were composed of different levels of carbohydrates (52.78-58.65%), proteins (6.98-8.91%), sulfates (21.78-29.6%) and uronic acids (0.42-1.08%). The weight mean average molecular weight of fucoidans varied between 443.7 and 1020.85 kDa. The polysaccharide chains were consisted of fucose, galactose, glucose, mannose and xylose. All the recovered fucoidans showed strong growth inhibition against HeLa and Hep-G cancer cells. The isolated fucoidans were non-toxic and considerably stimulated the macrophage cells to release nitric oxide. Enzyme extraction produced fucoidan with the most macrophage stimulation capacity (> 42 µmol). These results suggested that enzyme treatment preserved more sulfate groups in fucoidan structure influencing its anticancer and immunostimulatory activities.