Modulation of the Anti-cancer Activity of Sulfated Polysaccharides, Synthesized in Spirulina platensis, Due to Varying Degree of Sulfation Induced by Nutrient and Physical Stress

Abstract

Marine algae like Spirulina platensis are the subject of interest as prospective source organisms of bioactive metabolites like sulfated polysaccharides with applications in therapeutic and cosmetic industries. The biological activity of these polymers is influenced by the presence of specific chemical groups. In the present study, stress (nutrient and physical) induced chemical modification of sulfated polysaccharides was performed which led to varying degrees of sulfation of the polymer. It was further correlated with the anti-cancer activity of the modified sulfated polysaccharides. Our observations showed that cells subjected to ultra-violet radiation treatment yielded polysaccharides with the highest degree of sulfation (14.63 %) and also demonstrated maximum anti-cancer activity against MCF7 breast cancer cell line (IC50 = 62 µg/ml). The lowest degree of sulfation of sulfated polysaccharides was observed in cells subjected to nitrogen stress and it also had the least anti-cancer activity. Our findings showed a positive correlation between the degree of sulfation and the biological activity of sulfated polysaccharides. It also indicated that radiation treatment of algal cells yielded sulfated polysaccharides with enhanced anti-cancer activity. The present study provides researchers and industry experts insights for the development of improved anti-cancer medications and accentuates the commercial potential of cyanobacteria like Spirulina for biomaterial synthesis with therapeutic properties.