Periodate oxidation of polysaccharides from Agaricus blazei edible mushroom and their toxicity in adult zebrafish (Denio rerio)

Abstract

This study characterizes periodate-oxidized polysaccharides through FTIR, NMR, and thermogravimetric analysis, confirming successful oxidation with degrees ranging from 5.4 % to 36.3 % (theoretical degrees: 10 to 50 %). The materials exhibited reduced molecular weights (2.74 × 10⁶ to 5.78 × 10⁵ Da), negative zeta potentials (most pronounced in P50), decreased particle sizes, and pseudoplastic behavior. Zebrafish toxicity assessments revealed low acute toxicity (no significant mortality at 96 h, preventing IC₅₀ determination), though adverse effects including pigmentation changes, photophobia, and hyperactivity were observed. Open-field tests demonstrated CNS activity, with P0/P10 groups showing anxiolytic effects and P30/P50 exhibiting sedation. While the results confirm the materials' biocompatibility, the observed neurological effects warrant further investigation into their CNS interactions. The combination of low toxicity, and tunable rheological behavior suggests promising applications in food technology (particularly as safer alternatives to conventional crosslinkers) and biomaterial development. Future studies should focus on: elucidating structure-activity relationships governing CNS effects, optimizing oxidation protocols for specific applications, and evaluating performance in functional food and biomedical formulations. This work establishes oxidized polysaccharides as versatile biomaterials with dual potential as emulsifiers and bioactive carriers, while highlighting the need for targeted neuroactivity studies.