Effect of interleukin-1beta on transforming growth factor-beta and bone morphogenetic protein-2 expression in human periodontal ligament and alveolar bone cells in culture: modulation by avocado and soybean unsaponifiables

J Periodontol. 2006 Jul;77(7):1156-66. doi: 10.1902/jop.2006.050356.


Background: In periodontal disease, interleukin-1beta (IL-1beta) is responsible for the matrix breakdown through excessive production of degrading enzymes by periodontal ligament fibroblasts and osteoblasts. Transforming growth factor-beta (TGF-beta) plays an important role in tissue regeneration as one of the factors capable of counteracting IL-1beta effects. In this study, we investigated the in vitro effect of avocado and soya unsaponifiables (ASU) on the expression of TGF-beta1, TGF-beta2, and bone morphogenetic protein-2 (BMP-2) by human periodontal ligament (HPL) and human alveolar bone (HAB) cells in the presence of IL-1beta.

Methods: HPL and HAB cells were incubated for 48 hours with ASU (10 microg/ml) in the presence or absence of IL-1beta (10 ng/ml). The steady-state levels of TGF-beta1, TGF-beta2, and BMP-2 mRNAs were determined by Northern blot or reverse transcription-polymerase chain reaction (RT-PCR). The amounts of TGF-beta1 and TGF-beta2 proteins were measured by enzyme-linked immunosorbent assay (ELISA).

Results: The data indicated that IL-1beta strongly decreases the expression of TGF-beta1 and TGF-beta2 by HPL cells. ASU were capable of opposing the cytokine effect. In HAB cells, TGF-beta1 and BMP-2 mRNA levels were downregulated by the cytokine. ASU were found to reverse the IL-1beta-inhibiting effect. In contrast, the cytokine stimulated the production of TGF-beta2 in alveolar bone cells, with no significant effect of ASU.

Conclusions: The results indicate that the IL-1beta-driven erosive effect in periodontitis could be enhanced by a decreased expression of members of the TGF-beta family. The ASU stimulation of TGF-beta1, TGF-beta2, and BMP-2 expression may explain their promoting effects in the treatment of periodontal disorders, at least partly. These findings support the hypothesis that ASU could exert a preventive action on the deleterious effects exerted by IL-1beta in periodontal diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Alveolar Process / cytology
  • Alveolar Process / drug effects*
  • Alveolar Process / metabolism
  • Bone Morphogenetic Protein 2
  • Bone Morphogenetic Proteins / biosynthesis*
  • Cells, Cultured
  • Female
  • Fibroblasts / drug effects
  • Fibroblasts / metabolism
  • Hemolysis
  • Humans
  • Inflammation Mediators / antagonists & inhibitors*
  • Interleukin-1 / antagonists & inhibitors*
  • Male
  • Periodontal Ligament / cytology
  • Periodontal Ligament / drug effects*
  • Periodontal Ligament / metabolism
  • Persea / chemistry
  • Plant Oils / chemistry
  • Plant Oils / pharmacology*
  • Soybean Oil / chemistry
  • Soybean Oil / pharmacology
  • Sterols / pharmacology
  • Transforming Growth Factor beta / biosynthesis*
  • Up-Regulation


  • BMP2 protein, human
  • Bone Morphogenetic Protein 2
  • Bone Morphogenetic Proteins
  • Inflammation Mediators
  • Interleukin-1
  • Plant Oils
  • Sterols
  • Transforming Growth Factor beta
  • Soybean Oil