Seaweed-based Bio-stimulant asMultifunctional Bio-inputs: AgronomicPerformance, Bioactive Composition,and Emerging Pharmaceutical andNutraceutical Potential

Abstract

Seaweeds in recent days have been turning out to be an extremely adaptable compound in the field of sustainable agriculture, plant stress research, and even human health. They offer a direct extraction of sea macroalgae, which captures a diversity of bioactive compounds such as phytohormone-like chemicals, sulfated polysaccharides,
amino acids, antioxidants, vitamins and essential minerals into commercial preparations. Seaweed biostimulants in agricultural systems, particularly in perennial crops in adverse conditions, also assist crops to establish superior root systems, more effectively absorb nutrients, enhance photosynthesis, harmonize hormones, and overcome
abiotic and biotic stress, but not merely deposit raw nutrients. In addition to pure agriculture, experimental and pre-clinical evidence is mounting that they are also pharmaceutical-ready due to excellent antioxidant, anti-
inflammatory, antimicrobial, antiviral, immunomodulatory, metabolic-regulatory, and heart-protective properties. Fucoidan, laminarin, carrageenan, ulvan, alginates, and phlorotannins are major players in these therapeutic wins and can be included in functional foods, which depicts a good level of safety and bioavailability. This review
summarizes the existing knowledge of the sources, bioactive makeup, mechanisms, health benefits, formulations, regulation, and research gaps in the field of seaweed biostimulants, and examines the potential way they might facilitate integrated agri-nutri-pharma systems and the circular bioeconomy.