Inhibition of hypertrophic scar formation with oral asiaticoside treatment in a rabbit ear scar model.

Hypertrophic scar (HS) is a fibrotic skin disease characterised by over-productive collagen and excessive inflammatory reaction, which can be functionally and cosmetically problematic. A scar-prone constitute will accelerate HS formation and functional disorder, which deserves systemic therapy with oral medicine. To examine the oral therapeutic effectiveness on HS with convincing evidence of gross view and histological improvement, a rabbit ear HS model was employed with oral administration of asiaticoside (AS) at the doses of 12 and 24 mg kg-1  d-1 daily for 60 consecutive days. Gross observation and histological findings showed that oral AS treatment could significantly inhibit HS formation in a dose dependent manner. Semi-quantification of scar elevation index at days 7, 15, 30, and 60, and quantitative polymerase chain reaction at days 30 and 60 also provided the evidences of reduced scar thickness and inhibited fibrotic gene expressions of collagens I, III, TGF-β1, interleukins 1β, 6 and 8, and enhanced gene expression of SMAD 7 and PPAR-γ with a dose-dependent manner. These results indicated that AS is likely to serve as a systemic therapeutic agent of HS treatment for those who may have scar-prone constitute via anti-inflammation, inhibiting fibrotic process, and enhancing matrix degradation.