Acidic Oligosaccharide Sugar Chain, a Marine-Derived Acidic Oligosaccharide, Inhibits the Cytotoxicity and Aggregation of Amyloid Beta Protein

In this paper, we investigated interactions of the acidic oligosaccharide sugar chain (AOSC), derived from brown algae Echlonia kurome OKAM, with amyloid beta protein (Aβ). We observed that AOSC inhibited the toxicity induced by Aβ in both primarily cortical cells and the SH-SY5Y cell line. We also observed that AOSC inhibited the apoptosis induced by Aβ in SH-SY5Y by reducing the elevated level of intracellular calcium concentration ([Ca2+]i) and suppressing the generation of reactive oxygen species. Surface plasmon resonance analysis demonstrated that AOSC had affinity for both freshly-dissolved Aβ and 48-h incubated Aβ. Furthermore, AOSC blocked the fibril formation of Aβ, which may be responsible for its anti-cytotoxic effects. Thus, our results indicate that AOSC might be a potentially therapeutic compound for Alzheimer’s disease.