Production and characterization of exopolysaccharides from Chlorella zofingiensis and Chlorella vulgaris with anti-colorectal cancer activity

The production, physicochemical characteristics, antioxidant and antitumor activities of partial purified exopolysaccharides from Chlorella zofingiensis, Chlorella vulgaris were investigated. The final exopolysaccharides productions were 208.4, 364.3 mg/L and the average molecular weights were 2.66×104, 1.88×104 Da, respectively. Monosaccharide analysis indicating that these exopolysaccharides consisted of 10 or 11 different kinds of sugars and derivatives, respectively. Additionally, they exhibited obvious radical scavenging activities on DPPH and hydroxyl radicals, which reached to 59.6-71.5% and 44.5-70.4%, respectively. Moreover, the antitumor effects were studied using human colon cancer cell lines HCT8. The results showed that they had significant antitumor effects considering the inhibitory effects on cell viabilities (28.3-18.0% on HCT8, respectively). Thus, these exopolysaccharides from microalgae species are worth further investigating as alternative potential antitumor agents.