Protective effect of Pycnogenol® on ovariectomy-induced bone loss in rats

Phytother Res. 2012 Jan;26(1):153-5. doi: 10.1002/ptr.3541. Epub 2011 Jun 28.


Pycnogenol® (PYC) is a natural plant extract from the bark of Pinus pinaster and has potent antioxidant activities. The protective effect of PYC on bone loss was studied in multiparous ovariectomized (OVX) female rats. Pycnogenol® (30 or 15 mg/kg body weight/day) was administered orally to 8-month-old OVX rats for 3 months. At the end of the experiment, bone strength was measured by a three-point bending test and bone mineral density was estimated by peripheral quantitative computed tomography. Ovariectomy significantly decreased femur bone strength and bone density. Supplementation with PYC suppressed the bone loss induced by OVX. The OVX treatment significantly increased serum osteocalcin (OC) and C-terminal telopeptide of type I collagen (CTx). Supplementation with PYC reduced the serum OC and CTx in OVX rats to a level similar to that of the sham-operated group. The results indicated that orally administered PYC can decrease the bone turnover rate in OVX rats, resulting in positive effects on the biomechanical strength of bone and bone mineral density.

MeSH terms

  • Animals
  • Antioxidants / pharmacology
  • Antioxidants / therapeutic use*
  • Bone Density / drug effects*
  • Bone Density Conservation Agents / pharmacology
  • Bone Density Conservation Agents / therapeutic use
  • Bone Resorption / blood
  • Bone Resorption / etiology
  • Bone Resorption / prevention & control*
  • Bone and Bones / drug effects
  • Collagen Type I / blood
  • Dietary Supplements
  • Female
  • Femur / drug effects
  • Flavonoids / pharmacology
  • Flavonoids / therapeutic use*
  • Osteocalcin / blood
  • Osteoporosis / blood
  • Osteoporosis / etiology
  • Osteoporosis / prevention & control*
  • Ovariectomy
  • Peptides / blood
  • Phytotherapy*
  • Pinus / chemistry*
  • Plant Bark
  • Plant Extracts / pharmacology
  • Plant Extracts / therapeutic use
  • Rats
  • Rats, Inbred Strains


  • Antioxidants
  • Bone Density Conservation Agents
  • Collagen Type I
  • Flavonoids
  • Peptides
  • Plant Extracts
  • collagen type I trimeric cross-linked peptide
  • Osteocalcin
  • pycnogenols