Ameliorating effects of crude fucoidan extracts from Sargassum spp. obtained from Penghu Islands, Taiwan

The predominant species of seaweed in Taiwan's coastal waters is Sargassum species, which exhibits a broad spectrum of bioactivities. Methods: Four Sargassum species (S. crassifolium, S. siliquosum, S. hemiphyllum, and S. hemiphyllum var. chinense) were used to produce eight fucoidan extracts, namely SC, SCH, SS, SSH, SH, SHH, SHC, and SHCH. These extracts were produced with or without a compressional puffing pretreatment. The compressional-puffing process increased the extraction yield of fucoidan and decreased levels of impurities (proteins and polyphenols). Among the eight fucoidans, SS (IC50 DPPH 0.46±0.01 mg/mL; IC50 ABTS•+ 0.09±0.00 mg/mL; FRAP value 67.4±0.9 μmol/g extract, vitamin C equivalent) and SHC (IC50 DPPH 0.53±0.17 mg/mL; IC50 ABTS•+ 0.11±0.00 mg/mL; FRAP value 55.1±0.6 μmol/g extract, vitamin C equivalent) displayed the highest antioxidant activity; SS (36.4±10.1% at 5 mg/mL for alpha-amylase; 96.3±0.2% at 1 mg/mL for alpha-glucosidase) and SHC (35.0±2.2% at 5 mg/mL for alpha-amylase; 96.5±0.2% at 1 mg/mL for alpha-glucosidase) showed the strongest alpha-amylase and alpha-glucosidase inhibitory activities; SH, SHH, and SHC had the most potent anti-inflammatory activity; and SHH had a greatest protective effect against damage to pancreatic cells. Hence, SS, SH, SHH, and SHC may be effective health-promoting agents for nutraceutical products.