Antioxidants from Edible Seaweeds

There is a long history of seaweed consumption including Phaeophyceae, Chlorophyceae and Rhodophyceae taxonomies in Asia and the Pacifics, versus low to zero intakes in Europe and the Americas. This dietary difference between populations coincides with dramatic differences in diet-related chronic disease risks such as breast cancer in these groups. Animal model evidence points to a role for edible algae in antioxidant-mediated effects in vivo. As intertidal organisms, seaweeds require an endogenous antioxidant capacity to protect against oxidative stress from UV light and dessication during tidal fluctuations. The antioxidant capacity of algae include L-ascorbic acid, glutathione, carotenoids, tocopherols, chlorophyll derivatives, polyphenols such as the phlorotannins in brown kelp and mycosporine-like amino acids in red algae. This chapter reviews the evidence underlying the antioxidant mechanisms of these algal constituents and discusses various issues for their analysis.