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Evidence-Based Complementary and Alternative Medicine
Volume 2012 (2012), Article ID 837581, 10 pages
Research Article

Curative Effects of Oleanolic Acid on Formed Hypertrophic Scars in the Rabbit Ear Model

1Department of Pharmacognosy, School of Pharmacy, Second Military Medical University, Shanghai 200433, China
2Key Laboratory of Standardization of Chinese Herbal Medicines of Ministry of Education, Pharmacy College, Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China
3Department of Pharmacology, School of Pharmacy, Ningxia Medical University, Yinchuan 750004, China
4Shanghai Anshan Experimental Middle School, Shanghai 200433, China
5The School of Pharmacy & Biomolecular Sciences, Faculty of Science, Liverpool John Moores University, Liverpool L3 3AF, UK

Received 9 November 2012; Revised 11 December 2012; Accepted 11 December 2012

Academic Editor: Ke Liu

Copyright © 2012 Hong Zhang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Hypertrophic scarring is a common proliferative disorder of dermal fibroblasts characterized by collagen overproduction and excessive deposition of extracellular matrix (ECM). There is no consensus about the best therapeutics to produce complete and permanent improvement of scars with few side effects. To investigate the therapeutic effects of oleanolic acid (OA) on hypertrophic scars and explore the possible mechanism of action involved, a rabbit ear model with hypertrophic scars was established. OA (2.5%, 5%, and 10%) was given once daily to the scars for 28 consecutive days. As a result, OA significantly alleviated formed hypertrophic scars on rabbit ears. The levels of TGF- , MMP-1, TIMP-1, and collagens I and III were notably decreased, and the number of apoptosis cells and mRNA expression of MMP-2, caspase-3, and caspase-9 were markedly increased in the scar tissue. The scar elevation index (SEI) was also evidently reduced. Histological findings exhibited significant amelioration of the collagen tissue. These results suggest that OA has the favorable curative effects on formed hypertrophic scars in the rabbit ear model, and the possible mechanism of action is that OA decreases HSFs proliferation and increases HSFs apoptosis by reduction of P311 gene expression and TGF- production, inhibition of TIMP-1 secretion, enhancement of MMP-2 activity, and subsequently facilitation of degradation of collagen types I and III.