Molecular Mechanisms of Edible Macro- and Microalgae as Functional Foods or Sources of Nutraceuticals

Consumption of macro- and microalgae from the Ochrophyta, Chlorophyceae, and Rhodophyceae Divisions as well as Dinoflagellata, Cryptophyta, Raphidophyta, and Cyanophyta Divisions for the former and latter taxonomies by ancient cultures throughout Asia and the Pacific and more recently in Western cultures is based not only on nutritional benefits but also on chronic disease risk reduction, trade, sustainable coastal harvests, and retention of local cultural practices. These varied dietary patterns parallel differences in human diet-related chronic disease risks and burden of disease, including cardiovascular diseases, and breast and colorectal cancers. in vitro, animal model as well as clinical studies suggest bioactive roles for edible macro- and microalgal constituents including macro- and micronutrients and secondary metabolites as functional foods and nutraceuticals. For example, as photosynthetic organisms subject to oxidative stress including desiccation and UV irradiation, macro- and microalgae require extensive endogenous antioxidant capacity. Biological activities ascribed to macro- and microalgae and their constituents include cardioprotective, anticarcinogenic (e.g. breast, colorectal, liver), antidiabetic, modulation of blood glucose, lipoprotein profiles, antioxidant capacities, and antiviral activities. This chapter reviews the evidence underlying the biological and molecular mechanisms of action of selected macro- and microalgae and their constituents as functional foods and nutraceuticals in reducing chronic disease risk factors.