Abstract: Objective: To evaluate the in vitro hypolipidemic activity of three sulfated polysaccharide fractions purified from the edible red alga Bangia fusco-purpurea for the purpose of providing a scientific basis for deep processing and high-valued utilization of Bangia fusco-purpurea. Methods: The crude polysaccharide was prepared by hot water extraction followed by 75% ethanol precipitation, deproteinized with the Savage method, purified by Sephadex G75 column chromatography, and fractionated by DEAE-cellulose 52 column chromatography into three fractions (F1, F2 and F3). The inhibitory effects of the polysaccharides on pancreatic lipase were analyzed, and the effect on the viability of Caco-2 and HepG2 cells was measured by the MTT assay. The in vitro hypolipidemic potentials were evaluated using HepG2 cell model and Caco-2 cell model. Results: F3 significantly inhibited pancreatic lipase activity in a competitive and reversible manner. All three fractions showed no significant cytotoxicity at tested concentrations (0–500 mg/mL). Interestingly, F1 significantly inhibited the absorption of free fatty acids by Caco-2 cells, whereas F3 exhibited potent inhibitory effects on triglyceride synthesis in the hyperlipidemic HepG2 cell model and lipid synthesis in the high cholesterol HepG2 cell model. Conclusion: The polysaccharides from B. fusco-purpurea can effectively inhibit pancreatic lipase activity, and obviously suppress the absorption of free fatty acids by cells and the synthesis of cholesterol and triglycerides in cells, thereby exhibiting hypolipidemic potentials.

Key words: Bangia fusco-purpurea polysaccharide; pancreatic lipase; inhibitory effect; hypolipidemic activity