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 _1–42 in neuronal PC-12 cells. Only fucoidans S, UE, and UF showed anti-aggregation effects against Aβ _1–42 , 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 _1–42 and hydrogen peroxide in neuronal PC-12 cells and demonstrated inhibition of apoptosis induced by Aβ _1–42 . 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 _1–42 neurotoxicity in Alzheimer's disease.