Isolation, purification and modification of sulfated polysaccharides from spirulina platensis and its antitumor activity

ABSTRACT

The water-soluble polysaccharide obtained from a blue-green alga Spirulina platensis by boiling water extraction and ethanol precipitation [118.25g kg[-1] on dry weight basis] was fractionated by DEAE-cellulose column chromatography, and purified by Sephacry-S300 giving two active fractions termed Ca-SPIIa and Ca-SPIIb. These fractions were mainly composed of glucose, galactose, rhamnose, fructose, glucouronic acid, mannose, xylose with the molar ratio [6.5 3.3 50.0 38.5 9.6 1.5 1.0] and [7.2 3.5 55.0 40.2 8.5 2.0 1.0] and sulfate percent [2.25% and 3.47%, respectively]. Calcium ion binding with the anionic part of a molecule was replaced with various metal cation and their inhibitory effects on Ehrlich Ascites Carcinoma Cells [EACC] was determined. The Ca-SPIIb was able to kill 95% of the tumor cells when they were incubated with 200microg. While, replacement of Ca[+2] with Na[+], Ag[+], Cu[+2] and H[+] reduced the activity