Effects of ginsenoside Rb1 on hypertrophic scar remodeling in rabbit model

Ginsenoside, one of the active compounds in Panax ginseng, inhibits tumor growth factor-beta 1 (TGF-β1) and reduces the level of collagen type 1. Ginsenoside Rb1 promotes burn wound healing. Our study evaluated the effects of ginsenoside Rb1 on hypertrophic scar remodeling. A total of 72 hypertrophic scars were generated on the ears of six New Zealand white rabbits. Treatment groups were administered with intradermal injections of ginsenoside Rb1 at various amounts (0.07mg, 0.28mg and 0.56mg), and evaluated on postoperative Day 35. Scar elevation index was used as a quantitative measure, and picrosirius staining of histological sections was used to assess collagen arrangement. We determined relative mRNA expression of collagen type 1 as well as scar related factors; matrix metalloproteinase 2 (MMP2), tissue-inhibitor of metalloproteinase 1 (TIMP1), alpha-smooth muscle actin (α-SMA), and TGF-β1. Immunohistochemistry assays were performed additionally. Application of 0.56mg of ginsenoside Rb1 resulted in significant decrement of scar elevation index, in comparison with control and lower dosage groups, furthermore achieved broader and randomly arranged collagen fibers resembling findings in normal dermis. Ginsenoside Rb1 concentration inversely correlated with the mRNA expression and immunohistochemical reactivity of scar related factors; MMP2, TIMP1, α-SMA, and TGF-β1. In addition, ginsenoside Rb1 suppressed collagen type 1 expression. Ginsenoside Rb1 is therapeutic in hypertrophic scar remodeling with the highest efficacy at 0.56mg of dosage. Ginsenoside Rb1 demonstrated inhibitory effects on hypertrophic scar in quantitative and histologic analysis. Further research is needed to determine optimal ginsenoside Rb1 application and exposure conditions.