Fucosterol from marine algae: a multifunctional marine phytosterol with health benefits-from dietary component to functional ingredient.

Fucosterol is the predominant sterol in brown algae, exhibits multiple bioactivities relevant to human health, including regulation of lipid metabolism, improvement of insulin resistance, as well as anti-inflammatory, antioxidant, neuroprotective, and antitumor effects. These effects are primarily mediated through the modulation of key metabolic and inflammatory signaling pathways, including LXR, PPARγ, and NF-κB. However, its high hydrophobicity (LogP≈7.9), poor aqueous solubility, and low oral bioavailability (<10%), together with its susceptibility to oxidative degradation during processing and storage, significantly limit its application in functional food systems. This review systematically summarizes the distribution, content variability, and structural characteristics of fucosterol in edible seaweeds, as well as its diet-related health benefits and underlying molecular mechanisms. Furthermore, recent advances in food-grade delivery and encapsulation strategies for improving the stability and bioavailability of lipophilic sterols are discussed, with emphasis on systems such as liposomes, nanoemulsions, and biopolymer-based carriers. A comparative evaluation of the advantages and limitations of these delivery systems is also provided in the context of functional food development. Future research directions are proposed to support the development of fucosterol as a marine-derived functional food ingredient.