In vivo macrophage activation and physicochemical property of the different polysaccharide fractions purified from Angelica sinensis

The water-soluble crude polysaccharide (CAP) was extracted from Angelica sinensis and was further fractionated by Sephacryl S-400 column chromatography, giving three polysaccharide fractions termed APF1, APF2 and APF3. The obtained results showed that the uronic acid linkages in the polysaccharides were more stable and resistant to thermal hydrolysis than neutral sugar linkages. APF2 exhibited higher thermal stability, followed by APF1, APF3 and CAP in decreasing order. APF1 contained the highest carbohydrate content (80.5%) and the lowest uronic acid content (28.4%) in comparison with APF2 (77.7% and 39.2%) and APF3 (70.1% and 34.6%). Further bioactive investigation showed that intraperitoneal administration of the polysaccharide fractions significantly induced peritoneal macrophage to release nitric oxide (NO), reactive oxygen species (ROS) and enhanced cellular lysosomal enzyme activity (p < .05) and the highest activity was achieved by APF2. Taken together, APF2 had the high thermal stability and immunostimulatory activity and so should be explored as a novel potential immunostimulants.