A glucan isolated from flowers of Lonicera japonica Thunb. inhibits aggregation and neurotoxicity of Aβ42

Inhibition of A beta aggregation and attenuation of its cytotoxicity are considered to valuable therapeutics for Alzheimer's disease (AD). Here, a glucan named as LJW0F2 was purified from flowers of Lonicera japonica Thunb. Using monosaccharides composition analysis, methylation analysis, IR and NMR spectroscopy, this polysaccharide was elucidated to be an alpha-D-(1 -> 4)-glucan with an alpha-(1 -> 4) linked branch attached to the C-6 position. Its inhibitory effect on A beta(42) aggregation was measured by fluorescence spectroscopic analysis with thioflavine T (ThT) and atomic force microscopy (AFM). We showed that polysaccharide LJW0F2 could inhibit A beta(42) aggregation in a dose-dependent-manner. Besides, LJW0F2 could attenuate the cytotoxicity induced by A beta(42) aggregation in SH-SY5Y neuroblastoma cells. To the best of our knowledge, this was the first report that the exogenous plant-derived polysaccharide might block A beta(42) aggregation directly and reduce its toxicity in SH-SY5Y cells. (C) 2014 Elsevier Ltd. All rights reserved.