Suppressive effect of bacoside A on hypertrophic scar formation by downregulation of TGF-β1
Purpose: To determine the anti-scarring property of bacoside A (BA) in a rabbit model of post-burns hypertrophic scar (HS).
Methods: A total of 16 healthy male rabbits were divided into four groups (4 rabbits/group). The rabbits were subjected to full-thickness burn wound by placing a 10-mm brass rod at 90 ºC on their ears for 20s, and were untreated (HS group). The remaining rabbits also underwent HS process but were topically treated daily with 0.2, 0.4 or 0.6 % BA gel (HS + 0.2, 0.4, and 0.6 % BA groups) from day 8 to day 34.
Results: The mean values of collagen (types I & III), hydroxyproline (precursor of collagen) and hexosamine, as well as scar index significantly (p < 0.001) decreased after 28 days of topical treatment with BA. Moreover, BA application resulted in improved histological changes with proper arrangement of collagen fibers. Significant (p < 0.001) upregulation or downregulation of transforming growth factor beta-1 (TGF-β1) and matrix metalloproteinase-1 (MMP-1) were observed in the BA-treated rabbits.
Conclusion: Treatment with BA significantly lowers the scarring area of burn wounds by downregulation of TGF-β1. Thus, BA can potentially be developed into a drug for managing injury scars.
Keywords: Hypertrophic scar, Bacoside A, Scar elevation index, Transforming growth factor beta-1, Collagen