Planta Med 2006; 72(4): 324-328
DOI: 10.1055/s-2005-916227
Original Paper
Biochemistry and Molecular Biology
© Georg Thieme Verlag KG Stuttgart · New York

Asiaticoside Induces Human Collagen I Synthesis through TGFβ Receptor I Kinase (TβRI Kinase)-Independent Smad Signaling

Jongsung Lee1 , 2 , Eunsun Jung1 , Youngji Kim1 , Junho Park1 , Jinil Park1 , Sungtaek Hong1 , Jieun Kim1 , Changgu Hyun1 , Yeong Shik Kim2 , Deokhoon Park1
  • 1Biospectrum Life Science Institute, Gunpo City, Gyunggi Do, Korea
  • 2Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul, Korea
Further Information

Publication History

Received: June 15, 2005

Accepted: September 6, 2005

Publication Date:
30 January 2006 (online)

Abstract

Skin aging appears to be principally related to a decrease in the levels of type I collagen, the primary component of the skin dermis. Asiaticoside, a saponin component isolated from Centella asiatica, has been shown to induce type I collagen synthesis in human dermal fibroblast cells. However, the mechanism underlying asiaticoside-induced type I collagen synthesis, especially at a molecular level, remains only partially understood. In this study, we have attempted to characterize the action mechanism of asiaticoside in type I collagen synthesis. Asiaticoside was determined to induce the phosphorylation of both Smad 2 and Smad 3. In addition, we detected the asiaticoside-induced binding of Smad 3 and Smad 4. In a consistent result, the nuclear translocation of the Smad 3 and Smad 4 complex was induced via treatment with asiaticoside, pointing to the involvement of asiaticoside in Smad signaling. In addition, SB431542, an inhibitor of the TGFβ receptor I (TβRI) kinase, which is known to be an activator of the Smad pathway, was not found to inhibit both Smad 2 phosphorylation and Type 1 collagen synthesis induced by asiaticoside. Therefore, our results show that asiaticoside can induce type I collagen synthesis via the activation of the TβRI kinase-independent Smad pathway.

Abbreviations

TGF:transforming growth factor

Smad:sma- and Mad-related protein

TβRI kinase:TGFβ receptor I kinase

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Prof. Yeong Shik Kim

Natural Products Research Institute

College of Pharmacy

Seoul National University

28 Yeonkun Dong

Jongro Gu

Seoul 110-460

Korea

Phone: +82-2-740-8929

Fax: +82-2-4563979

Email: kims@plaza.snu.ac.kr

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