In-vitro inhibitory impacts of fulvic acid-coated iron oxide nanoparticles on the amyloid fibril aggregations

Abstract

Alzheimer’s Disease is a multi-factor malady, the main hallmarks of which are, extracellular amyloid-beta and intracellular tau protein aggregations, leading to a pathological cascade of events and ultimately neural death. With this in mind, most of the studies have been concentrated on eliminating the amyloid and tau aggregations. Fulvic acid is one of the polyphenolic compounds which exhibits strong anti-inflammation and anti-amyloidogenic activity. On the other hand, iron oxide nanoparticles exhibit anti-amyloid activity on their own, therefore, this study investigates the interactions between fulvic acid-coated iron oxide nanoparticles and the commonly used in-vitro model, lysozyme from chicken egg white, that forms the amyloid aggregation under acidic pH and appropriate heat. The average size of nanoparticles was 10.7±2.7nm. FESEM, XRD, and FTIR characterization confirmed that fulvic acid was coated onto the surface of the nanoparticles. The inhibitory effects of the fulvic acid coated iron oxide nanoparticles were verified by Thioflavin T assay, circular dichroism (CD), and FESEM analysis. Furthermore, the toxicity of the nanoparticles on the neuroblastoma SH-SY5Y human cell line was assessed through MTT assay. Our results indicate that fulvic acid-coated iron oxide nanoparticles can efficiently inhibit formation of amyloid aggregations while exhibiting no in-vitro toxicity. This data shed light on the anti-amyloid activity of combination of fulvic acid and iron oxide nanoparticles; paving the way for future drug development for treating Alzheimer’s Disease.