Effect of asiaticoside on hypertrophic scar in the rabbit ear model.
BACKGROUND
Previous observations suggested that asiaticoside had a possible antiscaring effect. However, the precise pathological mechanism still remain unknown. We questioned whether asiaticoside might alleviate the formation of hypertrophic scar by affecting the expression of Transform growth factor beta (TGF-beta)/Smad signaling.


OBJECTIVE
To investigate the effect of asiaticoside on the expression of TGF-beta/Smad signaling in the rabbit ear model of hypertrophic scar and to clarify the mechanism of asiaticoside on the scar treatment.


METHODS
The rabbit model with hypertrophic scar was created and applied topically with a low-dose (0.5%) or high-dose (1%) asiaticoside three times daily for 1, 2 or 3 months and then we examined the changes of macroscopic and histopathologic characteristics of scars, and the expression of TGF-beta(1) and Smad protein was studied by applying reverse transcription-polymerase chain reaction and western blotting.


RESULTS
Asiaticoside could remarkably alleviate the scar in the rabbit ear model. Western blotting showed that the asiaticoside could decrease TGF-beta(1) expression, and further study revealed that asiaticoside could remarkably enhance the expression of inhibitory Smad7, but it had no effect on the expression of Smad2.


CONCLUSIONS
Asiaticoside suggested a possible antiscaring effect probably by enhancing the expression of inhibitive Smad7.
Ju-Lin
Xie
X
Department of Burns, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China. xiejl90@sina.com
Shao-Hai
Qi
Q
Tian-Zeng
Li
L
Bin
Huang
H
Jing-Ming
Tang
T
Ying-Bin
Xu
X
Xu-Sheng
Liu
L
Bin
Shu
S
Hui-Zhen
Liang
L
Yong
Huang
H
D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology*; D017439:Cicatrix, Hypertrophic / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D004195:Disease Models, Animal; D004423:Ear / Q000473:pathology; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects*; D011817:Rabbits; D015398:Signal Transduction / Q000187:drug effects; D051899:Smad2 Protein / Q000096:biosynthesis*; D051906:Smad7 Protein / Q000096:biosynthesis*; D053773:Transforming Growth Factor beta1 / Q000378:metabolism*; D014315:Triterpenes / Q000494:pharmacology*
D000890:Anti-Infective Agents; D051899:Smad2 Protein; D051906:Smad7 Protein; D053773:Transforming Growth Factor beta1; D014315:Triterpenes; C004446:asiaticoside