Effect of Pinus massoniana bark extract on IFN-gamma-induced ICAM-1 expression in HaCaT human keratinocytes.

Aims Of The Study: Pinus massoniana bark extract (PMBE) with known anti-oxidant activity is comprised of various flavonoids including several bioactive compounds. We found that PMBE contains 1.27% taxifolin, a well-studied compound with known anti-inflammatory activity. Therefore, in the present study, we evaluated the effects of PMBE and taxifolin on intercellular adhesion molecule-1 (ICAM-1) expression.

Materials And Methods: PMBE and taxifolin were prepared. After HaCaT cells were pre-treatmented with PMBE and taxifolin, HaCaT cells were treatmented with 1000 U/ml IFN-gamma for 24 h.

Results: Treatment of HaCaT cells with 1000 U/ml IFN-gamma for 24 h markedly increased ICAM-1 expression. However, PMBE pre-treatment (40 microg/ml for 24 h) significantly inhibited IFN-gamma-induced ICAM-1 expression. In equal concentrations of taxifolin, PMBE-mediated inhibition of ICAM-1 mRNA and protein expression was greater than taxifolin mediated-inhibition, and the front on inhibition of ICAM-1 protein expression was 2.24-2.30-fold of the latter. When cells were treated with both compounds at a concentration of 40 microg/ml, PMBE-mediated inhibition of ICAM-1 mRNA was also greater than taxifolin-mediated inhibition and PMBE on inhibition of ICAM-1 protein expression was 2.60-3.00-fold the inhibition mediated by taxifolin.

Conclusions: PMBE including additional bioactive compounds may possibly synergize to inhibit transcription and translation of inducible ICAM-1expression and PMBE was greater than monomeric flavonoid taxifolin. These results indicate that PMBE exhibits great potential as a therapeutic treatment for inflammatory skin diseases.