The DPPH assay was used to test the ability of the antioxidative
compounds functioning as proton radical scavengers
or hydrogen donors [47]. Many species of seaweed possess
scavenging ability for hydrogen peroxide [48-49]. It can
cross membranes and may slowly oxidize a number of compounds.
Hydrogen peroxide itself is not very reactive, but
sometimes it can be toxic to cells because of the rise in the
hydroxyl radicals in the cells [50].