Purification, characterization and antioxidant activities in vitro of polysaccharides from L.

BACKGROUND

L. is an annual, erect or less commonly ascending herb that is a member of the family. Polysaccharides extracted from traditional Chinese medicines may be effective substances with antioxidant activity.

METHODS

In this study, we isolated crude polysaccharides from (AHP-M) using microwave-assisted extraction. Then, the AHP-M was purified by chromatography with DEAE-32 cellulose, and two fractions, AHP-M-1 and AHP-M-2, were obtained. The structural characteristics of AHP-M-1 and AHP-M-2 were investigated, and their antioxidant activities were analyzed in vitro.

RESULTS

We found that the monosaccharide composition of AHP-M-1 was different from that of AHP-M-2. The molecular weights of AHP-M-1 and AHP-M-2 were 77.625 kDa and 93.325 kDa, respectively. The results showed that the antioxidant activity of AHP-M-2 was better than that of AHP-M-1. For AHP-M-2, the DPPH radical scavenging rate at a concentration of 2 mg/mL was 78.87%, the hydroxyl radical scavenging rate was 39.34%, the superoxide anion radical scavenging rate was 80.2%, and the reduction ability of Fe was approximately 0.90. The total antioxidant capacity per milligram of AHP-M-2 was 6.42, which was higher than that of Vitamin C (Vc).

CONCLUSION

The in vitro test indicated that AHP-M-1 and AHP-M-2 have good antioxidant activity, demonstrating that L. polysaccharide has immense potential as a natural antioxidants.