Anti-cancer Effects of Polysaccharide and Phycocyanin from Porphyra Yezoensis

In this paper, phycocyanin and one component (PY-D2) in polysaccharide were obtained from Porphyra yezoensis to study for their potential anti-tumor effects. MTT proliferation assays showed that, at concentration of 500 mg/L for 72 h, PY-D2 treatment significantly inhibited the growth of four tumor cell lines, HO-8910, MCF-7, K562 and SMMC-7721, with the respective inhibition rates of 21.2%, 23.6%, 19.8%, and 21%. Flow cytometry analysis indicated that the anti-tumor effect of PY-D2 was associated with the cell cycle arrest at G0/G1 or G2/M check-points. Two cancer cell lines, Hep-2 and A375 were treated by different concentrations of phycocyanin, followed by radiation with He-Ne laser at the density of 20 J/cm and the wavelength of 632 nm. MTT assays displayed the minimal survival rate of 29.8% (Hep-2) and 16.2% (A375) at 100 μg/ml and 165 μg/ml respectively. These results suggest that both polysaccharide and phycocyanin from Porphyra yezoensis might be useful in the treatment of human cancers. These results suggest that phycocyanin and one component (PY-D2) in polysaccharide which had been obtained both from Porphyra yezoensis were potential medicaments in the treatment of some kinds of human cancers.