Abstract:

Antioxidant, antitumor polysaccharides were prepared from Mytilus coruscus muscle by hot water extraction
alone or followed by sequential hydrolysis with papain and trypsin, and analyzed for physiochemical properties. After
chromatographic purification on a DEAE-Cellulose 52 column, the antioxidant and antitumor activities in vitro were
investigated. Combined enzymatic hydrolysis, giving rise to a yield of crude polysaccharides of 23.69%, was advantageous
over single enzymatic hydrolysis and hot water extraction as far as the yield, purity and bioactivity of crude polysaccharides
were concerned. The in vitro antioxidant activity of crude polysaccharides obtained from combined enzymatic hydrolysis
showed a concentration for 50% of maximal effect (EC50) of 3.75, 5.01 and 2.41 mg/mL in scavenging DPPH, superoxide
anion and lipid peroxide radicals, respectively, and an IC50 of 2.93 mg/mL against the growth of prostate cancer cells DU-
145 cultured for 48 h. Analysis of the yield and chemical composition of purified polysaccharide fractions indicated that
higher contents of glycosaminoglycan-like polysaccharide (MT3) with a molecular weight of roughly 18 kD in crude
polysaccharides were obtained by combined enzymatic hydrolysis and the monosaccharide composition consisted of Man,
GlcN, GlcUA, Gal and Fuc. Meanwhile, MT3 was more effective against tumor cells DU-145 in vitro with an IC50 of
2.71 mg/mL after 48 h of culture in its presence. The results of activity-guided separation demonstrated that combined
enzymatic hydrolysis after hot water extraction could not only increase the purity of polysaccharides through protein
degradation, but could significantly enhance the content of glycosaminoglycans as well, and glycosaminoglycans were the
main active polysaccharides in Mytilus coruscus muscle that possessed good antitumor activity.

Key words: Mytilus coruscus, polysaccharide, extraction process, antioxidant, antitumor