Comparative study on neuroprotective activities of fucoidans from Fucus vesiculosus and Undaria pinnatifida.

This study investigated the neuroprotective activities of five different fucoidan samples with different chemical compositions prepared from Fucus vesiculosus (FE, FF, and S) and Undaria pinnatifida (UE and UF) to determine if they reduced aggregation or cytotoxicity of Aβ in neuronal PC-12 cells. Only fucoidans S, UE, and UF showed anti-aggregation effects against Aβ, as determined using Thioflavin T (ThT) fluorometric fibrillisation kinetics and transmission electron microscopy (TEM) of fibril morphology. However, all five fucoidan samples reduced the cytotoxicity of both Aβ and hydrogen peroxide in neuronal PC-12 cells and demonstrated inhibition of apoptosis induced by Aβ. Three fucoidan samples (FF, UE and UF) showed significant activity in enhancing neurite outgrowth. Fucoidan from different seaweed sources and with varying chemical compositions demonstrate a range of neuroprotective activities that may have potential to alter Aβ neurotoxicity in Alzheimer's disease.