Objective The polysaccharides sulfate were extracted from three kinds of algae in-cluding porphyra tenera , Laminaria ja ponica and Sargassum fusi forme ( Harv. )Setch . in order to screen antioxidant with exploiting potential. Methods Using the assay system of DP-PH,the antioxidative activities of various extracts were studied. Results Three kinds of algae polysaccharides sulfate had different antioxidative activities. Moreover, polysaccharide extracted with different solvents had different intensities of antioxidative activity. Conclusion Polysacchride sulfate extracted with water has stronger antioxidative activity than that with others.keywolds antioxidation; porphyra tenera kjellm. ; Laminaria japonica; Sargassum fusi -forme ( Harv. )Setch.Studies on the extraction of polysaccharides sulfate from three algae and their scavenging activity on free radicalsHAN Hua,ZHOU Hai Yan,LIU Cheng-Chu,WANG Chun-bo(1.Bromatology Institute of Shanhai Aquatic University , Shanghai 200090, China; 2. Medical College , Qingdao University ,Qingdao 266021, China)Abstract:Objective The polysaccharides sulfate were extracted from three kinds of algae in-cluding porphyra tenera , Laminaria ja ponica and Sargassum fusi forme ( Harv. )Setch . in order to screen antioxidant with exploiting potential. Methods Using the assay system of DP-PH,the antioxidative activities of various extracts were studied. Results Three kinds of algae polysaccharides sulfate had different antioxidative activities. Moreover, polysaccharide extracted with different solvents had different intensities of antioxidative activity. Conclusion Polysacchride sulfate extracted with water has stronger antioxidative activity than that with others.

We studied the effect of photodynamic therapy with phycobiliproteins on human liver cancer cells in vitro. With 3-(4, 5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay (MTT assay), we used two phycobiliproteins, R-phycoerythrin (R-PE) and C-phycocyanin (C-PC) prepared from Porphyra yezoensis, to determine the killing rates and apoptosis rates of human liver cancer cells (SMMC-7721) mediated by laser. When the concentration of R-PE was 120 mg/L, the survival rate of human liver cancer cells was 27% after treated by Argon laser with 100 J/cm2 doses, while the survival rate in the control group (without adding R-PE) was 65%. When the C-PC concentration was 120 mg/L, the survival cell rate was 47% after treated by He-Ne laser with 35 J/cm2 dose, while the survival rate in the control group (without adding C-PC) was 70%. After handled only with these two kinds of phycobiliproteins for 72 h, the growth of cancer cells presented significant inhibition. The maximal inhibition rates reached up to 31% with R-PE (120 mg/L concentration) and 27% with C-PC (250 mg/L concentration) respectively. After irradiated by laser for 8 h, the maximal cell apoptosis rates were 31.54% with R-PE and 32.54% with C-PC, respectively. It indicated that R-PE and C-PC extracted from Porphyra yezoensis could develop to new photosensitizers for cancer photodynamic therapy.
Apoptosis ; drug effects ; radiation effects ; Cell Line, Tumor ; Humans ; Lasers ; Liver Neoplasms ; pathology ; Photochemical Processes ; Photochemotherapy ; methods ; Phycobiliproteins ; isolation & purification ; pharmacology ; Phycoerythrin ; isolation & purification ; pharmacology ; Porphyra ; chemistry