Cedrol Enhances Extracellular Matrix Production in Dermal Fibroblasts in a MAPK-Dependent Manner

Abstract

Background: The extracellular matrix (ECM) produced by dermal fibroblasts supports skin structure, and degradation and/or reduced production of ECM are the main causes of wrinkle formation.

Objective: The aim of this study was to identify the active ingredient that enhances ECM production in dermal fibroblasts.

Methods: Polarity-based fractionation was used to isolate the active ingredient from natural extracts, and the effects of cedrol (isolated from Pterocarpus indicusirginia) on ECM production in cultured human dermal fibroblasts was investigated by reverse transcription-polymerase chain reaction, enzyme linked immunosorbent assay, and Western blot analysis.

Results: Cedrol accelerated fibroblast growth in a dose-dependent manner and increased the production of type 1 collagen and elastin. Phosphorylation of p42/44 extracellular signal-regulated kinase, p38 mitogen-activated protein kinase, and Akt was markedly increased by cedrol, indicating that enhanced ECM production is linked to activation of intracellular signaling cascades.

Conclusion: These results indicate that cedrol stimulates ECM production, with possible applications to the maintenance of skin texture.

Keywords: Cedrol; Collagen; Fibroblasts.

Fig. 1

(A) Isolation of cedrol from Pterocarpus indicus. (B) Chemical structure of cedrol. Cedrol was isolated from the lignum of P. indicusirginia using bioassay-directed fractionation. After solvent fractionation, two applications of column chromatography followed by recrystallization were used to isolate the active compound. The purity of cedrol was confirmed to be ~99%, as determined by high performance liquid chromatography, nuclear magnetic resonance, and electrospray ionization mass spectrometry studies.

Fig. 2

Effect of cedrol on growth of dermal fibroblasts. Cells were treated with cedrol at the indicated concentrations for 2 d in the presence of [³H]thymidine. Radioactivity was measured using a liquid scintillation counter. Results are shown as a percentage of a control±the standard deviation (^*p<0.05 vs. control).

Fig. 3

Effect of cedrol on collagen and elastin production in dermal fibroblasts. (A) Cells were treated with cedrol at the indicated concentrations for 2 d. A conditioned medium was collected, and the amount of secreted procollagen type 1 was measured using an enzyme linked immunosorbent assay. Results are shown as a percentage of a control±the standard deviation (^*p<0.05 vs. control). (B) Cellular proteins were harvested and the protein levels of collagen type 1 α1 and elastin were verified using Western blot analysis. (C) The expression levels of the COL1A1 and COL1A2 genes were determined using reverse transcription-polymerase chain reaction. CTL: control.

Fig. 4

Effect of cedrol on intracellular signaling pathways. Cells were treated with cedrol for the indicated times. Cellular proteins were prepared and phosphorylation of ERK, p38 MAPK, Akt, and Smad 2 and 3 was determined using Western blot analysis. CTL: control, ERK: extracellular signal-regulated kinase, MAPK: mitogen-activated protein kinase.