Inhibitory Impacts of Fulvic Acid-Coated Iron Oxide Nanoparticles on the Amyloid Fibril Aggregations

Alzheimer's disease is considered as multi-factor diseases, the main hallmarks of which are extracellular amyloid-beta and intracellular tau protein aggregations, leading to neural death. With this in mind, most of the studies have been focused on eliminating these aggregations. Fulvic acid is one of the polyphenolic compounds which exhibits strong anti-inflammation and anti-amyloidogenic effects. On the other hand, iron oxide nanoparticles are able to reduce/eliminate the amyloid aggregations. Here in, the effect of fulvic acid-coated iron-oxide nanoparticles on the commonly used in-vitro model for amyloid aggregation studies, i. e., lysozyme from chicken egg white was investigated. The chicken egg white lysozyme forms the amyloid aggregation under acidic pH and high heat. The average size of nanoparticles was 10.7 +/- 2.7 nm. FESEM, XRD, and FTIR confirmed that fulvic acid was coated onto the surface of the nanoparticles. The inhibitory effects of the nanoparticles were verified by Thioflavin T assay, CD, and FESEM analysis. Furthermore, the toxicity of the nanoparticles on the neuroblastoma SH-SY5Y was assessed through MTT assay. Our results indicate that these nanoparticles efficiently inhibit amyloid aggregation formation, while exhibiting no in-vitro toxicity. This data shed light on the anti-amyloid activity of the nanodrug; paving the way for future drug development for treating Alzheimer's disease.