Effects of spirulina, a blue-green alga, on bone metabolism in ovariectomized rats and hindlimb-unloaded mice

Biosci Biotechnol Biochem. 2006 Feb;70(2):363-8. doi: 10.1271/bbb.70.363.


The safety and effectiveness were examined of the spirulina alga on bone metabolism in ovariectomized estrogen-deficient rats and hindlimb-unloaded mice. The dosage range was from an amount equal to that recommended in so-called health foods for humans (0.08 g/kg BW/day) to a 100-fold higher dose. The bone mineral density (BMD) of the whole femur and tibia of ovariectomized rats in the any spirulina-treated groups was not significantly different from that of the ovariectomized group, although BMD of the distal femur and proximal tibia was significantly lower in the spirulina-treated groups than in the ovariectomized group after a 6 week-experimental period. BMD of the femur and tibia was not affected by treatment with any dose of spirulina in hindlimb-unloaded mice. These results suggest that the intake of spirulina decreased BMD in the trabecular bone of rodents under estrogen-deficient conditions.

MeSH terms

  • Aging / drug effects
  • Aging / physiology
  • Animals
  • Bacterial Proteins / pharmacology*
  • Biomarkers / blood
  • Body Weight / drug effects
  • Bone Density / physiology*
  • Bone and Bones / drug effects*
  • Bone and Bones / metabolism*
  • Cyanobacteria / metabolism*
  • Female
  • Hindlimb / drug effects*
  • Hindlimb / physiology*
  • Hindlimb Suspension*
  • Mice
  • Ovariectomy
  • Rats
  • Rats, Wistar
  • Spirulina
  • Weight-Bearing


  • Bacterial Proteins
  • Biomarkers