Spirulina contains an abundance of bioactive compounds, including pigments, polyphenols, peptides, fatty acids, complex carbohydrates, vitamins, and minerals, which makes its mechanism of action fairly complicated and still incompletely understood. Phycocyanin, a blue-colored pigment that is structurally similar to bilirubin, is the most abundant protein in spirulina and is suggested to be the major active compound.[1]
The antioxidant and anti-inflammatory properties of spirulina are the most thoroughly studied and likely arise from a variety of compounds including phycocyanin, carotenoids, chlorophyll, and vitamin E. Spirulina may increase the activity of antioxidant enzymes (e.g., superoxide dismutase), prevent lipid peroxidation, reduce NF-κB activity, and inhibit enzymes involved in the generation of reactive oxygen species and inflammatory compounds — nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and cyclooxygenase-2 (COX-2), respectively.[1][2][3]
Spirulina may enhance cardiometabolic health through various mechanisms. It could potentially lower blood pressure by increasing nitric oxide production, thereby inhibiting angiotensin I converting enzyme, and/or simply due to its high potassium content (~18 mg per gram).[4][5] Moreover, spirulina may influence lipid metabolism, reduce the digestion and absorption of dietary fats and carbohydrates, promote cholesterol excretion, increase satiety, and stimulate insulin secretion.[6][7][8][9]