Algal bioactive compounds: A review on their characteristics and medicinal properties

Bioactive compounds derived from marine algae drawn increasing interest in pharmaceuticals, nutraceuticals, and cosmetics due to their wide range of therapeutic properties. These natural molecules, which include polysaccharides, polyphenols, phlorotannins, carotenoids, and pigments, exhibit potent antioxidant, antimicrobial, anti-inflammatory, antiviral, and antitumor activities. Algal bioactives are safer and more sustainable options for drug discovery since they often have less negative effects than synthesized compounds. This review highlights the structural diversity of algal biomolecules and their mechanisms of action, with emphasis on validated bioactivities supported by recent studies. It also critically examines challenges such as the low bioavailability of high-molecular-weight compounds like fucoidans, variability in metabolite production linked to environmental factors, and limitations in scalable extraction processes. Recent advances in nano-encapsulation, metabolic engineering, and eco-friendly extraction methods are explored as promising strategies to enhance bioavailability and industrial applicability. By integrating traditional knowledge with biotechnological innovations, this review underscores the underexploited potential of macroalgae in addressing chronic diseases and the urgent need for standardized protocols to facilitate the clinical translation of algal-derived bioactives.