Structural characterization and antioxidant activities of polysaccharides extracted from Epimedium acuminatum.

The polysaccharides were extracted from Epimedium acuminatum by hot water extraction, ultrasonic-assisted extraction, enzyme extraction, and microwave-assisted extraction. The physicochemical properties of Epimedium polysaccharides were then determined by chemical composition analysis, Fourier transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM) analysis. Further, the antioxidant activities were studied via different methods, including DPPH assay, ABTS assay, FRAP assay and AAPH-induced erythrocyte hemolysis assay. Results showed that the physicochemical properties of different polysaccharides were similar. Antioxidant assay indicated that four polysaccharides exhibited significant antioxidant activities in a dose-dependent manner. The antioxidant activities of the polysaccharides which obtained by hot water extraction were higher than those of other polysaccharides. Overall, E. acuminatum polysaccharides might be used as potential natural antioxidant.