Effect of Sulfation Modification on Antioxidation and Antitumor Activity of Intracellular Polysaccharide from Chlorella vulgaris

In order to explore the effect of Chlorella polysaccharide sulfation modification on biological activity, Chlorella sp.22 was used as experimental material in this study. The purified polysaccharide HDB-1 was obtained by extracting intracellular polysaccharides and separated and purified by DEAE-52 cellulose anion exchange column. The purified polysaccharide HDB-1 was sulfated to obtain SHDB-1. The antioxidant activity and antitumor activity of polysaccharides before and after sulfation modification were studied. The results showed that the purified component HDB-1 was mainly α-furanose. SHDB-1 was obtained by sulfation modification of HDB-1 by sulfur trioxide-pyridine method. Its degree of substitution was 1.046. The antioxidant activity results showed that the IC₅₀ (semi-inhibitory concentration) values of HDB-1 and SHDB-1 DPPH radical clearance were 29.28 mg/mL and 14.49 mg/mL, respectively. The IC₅₀ values of hydroxyl radical scavenging were 36.75 mg/mL and 28.59 mg/mL, respectively, indicating that the antioxidant effect of SHDB-1 was better than that of HDB-1. The antitumor results showed that HDB-1 and SHDB-1 were not toxic to cells at 1 mg/mL concentrations. The IC₅₀ values of HDB-1 and SHDB-1 were 960.16 μg/mL and 658.19 μg/mL, respectively, indicating that SHDB-1 inhibited the proliferation of Hela in cervical cancer cells better than HDB-1. The above results show that compared with HDB-1, the antioxidant activity and in vitro inhibition of cancer cell proliferation of the sulfation-modified Chlorella intracellular polysaccharides SHDB-1 are significantly improved.