Recommended Dose for Spirulina/ Phycocyanobilin

Estimated Doses of Phycocyanobilin for Humans

In an extensive series of investigations, Romay and coworkers have reported that phycocyanin administered orally to mice and rats exerts a number of dose-dependent anti-inflammatory effects in a dose range of 50–300 mg/kg/day. Since phycocyanobilin (PCB) constitutes about 4.7% of the mass of holo-phycocyanin, this amounts to a PCB intake of 2.35–14.1 mg/kg. If extrapolated on a mg/kg basis, this corresponds to a daily intake of 165–990 mg in a 70 kg human. Extrapolation by the 3/4 power standard (roughly equivalent to the ratio of metabolic rates – Kleiber’s law, commonly used for interspecies dosage extrapolations) gives human daily intakes of 21.2–127 mg (using mice) and 37.6–226 mg (using rats).

Studies in which whole Spirulina has been administered orally to rodents have also shown anti-inflammatory effects, in doses ranging from 150 to 1,000 mg/kg/day. Assuming spirulina with a 14% content of phycocyanin by dry weight, this amounts to intakes of 1–6.6 mg/kg/day PCB. Extrapolating on the basis of relative weight, this corresponds to an intake of 70–462 mg PCB in a 70 kg human. Extrapolating on the basis of the 3/4 power standard, it corresponds to an intake of 9–59 mg (mouse studies) or 16–106 mg (rat studies).

A heaping tablespoon of Spirulina (about 15 g) containing 14% phycocyanin by dry weight provides approximately 100 mg of PCB. Thus, a regimen of 1-2 heaping tablespoons per day would provide about 100-200 mg of PCB. This intake is within—and in some instances a bit beyond— the extrapolated dose ranges noted above. It should follow that—assuming that humans digest and metabolize Spirulina-bound PCB much like rodents do—a daily intake of 1-2 heaping tablespoons of Spirulina daily should have clinically useful antioxidant activity in humans. Thus, it would be reasonable to test such a regimen in the prevention or treatment of the wide range of clinical disorders in which overactivity of NADPH oxidase plays a pathogenic role.