Table 1.

Mechanisms of action of algal bioactive compounds in bone treatment

Bioactive compound	Algae	Mechanisms of action	Effects on bone health
Fucoidan	Brown algae (Fucus, Laminaria)	Stimulates osteoblast differentiation Inhibits osteoclast activity Enhances mineralization	Promotes bone formation Reduces bone resorption.[17]
Omega-3 fatty acids	Microalgae (Spirulina, Chlorella)	Modulates inflammatory and cytokines Enhances calcium absorption  Supports osteoblast function	Improves bone density Reduces inflammation-related bone loss.[18]
Calcium	Various algae (macro and micro)	Provides essential mineral for bone formation Enhances osteoblast activity	Essential for maintaining bone density and strength[19]
Carrageenan	Red algae (Porphyra, Gracilaria)	Supports cell signaling pathways Promotes osteogenic differentiation	Aids in bone healing and regeneration[20]
Phycocyanin	Blue–green algae (Aphanizomenon)	Antioxidant properties Modulates osteogenic genes	Protects bone cells from oxidative stress Promotes bone regeneration[21]
Alginates	Brown algae (Laminaria, Fucus)	Binds to minerals and increases their bioavailability, anti-inflammatory effects	Enhances calcium absorption Reduces inflammation-induced bone loss[22]