Table 3.

Bioactive compounds found in Chlorella sp. and Spirulina (Arthrospira) sp. that are most relevant for cosmetic applications, and their corresponding activities [57,58].

Bioactive Compound	Biological Activity
Carotenoids	Scavenges free radicals, fights wrinkles, delays aging, soothes eye skin. Antioxidant, anti-inflammatory. Provides blue light and UV protection. β-Carotene serves as a natural colorant in cosmetics. Lutein promotes regeneration of normal retinal blood vessels.
Vitamin C	Prevents melanin deposits, whitens the skin. Repairs the skin barrier, capillaries, and photo-aging skin, reduces erythema and telangiectasia, and lightens skin wrinkles. Stimulates collagen synthesis in the skin.
Vitamin E	Antioxidant. Repairs the skin barrier, treats some skin diseases.
Polysaccharides	Antioxidant, antibacterial. Good film-forming properties, reduces water evaporation on the skin surface and provides a moisturizing effect.
Peptides	Anti-inflammatory. Protects skin , reduces UVB and UVC-effects.
Flavonoids Phenols	Antioxidant activity. Stimulates collagen synthesis in the skin, reduces wrinkle formation.