Compound Astragalus And Salvia Miltiorrhiza Extracts Suppress Rabbit Hypertrophic Scars

Objectives1. To investigate CASE suppress hypertrophic scars in order to further confirm its anti-scarring effects based on previous experiment which had proved that CASE can influence keloid fibroblasts by inhibiting cell multiplication, invasion and collagen synthesis;2. To explore the possible mechanisms of action of CASE, particularly its modulation of TGF-β/Smad pathway.MethodsAnimal model of hypertrophic scars, established in rabbit ears, were divided into control group, model group, low-dose group(0.94%, w/w), middle-dose group(1.88%, w/w), high-dose group(3.76%, w/w) and positive group (asiaticoside), and control group unoperated. After twenty-one day, CASE ointment (0.94%,1.88%,3.76%), ointment base or asiaticoside cream were treated to scars respectively. Hypertrophic scars were observed about growth and measured the thickness by vernier caliper. The rabbits were killed to observed histopathological detection by hematoxylin and eosin (HE) and Masson’s trichrome staining, and protein expression change of scars by Western blot and immunohistochemistry (IHC) four weeks later.Results1. Hypertrophic scars was dramatically inhibited by CASE Compared with the model group, hypertrophic scars of CASE treatment is inhibited significantly, and the longer CASE treatment, the more it inhibited.2. The content of Hyp was reduced by CASE treatment Compared with the model group, the content of Hyp was reduced by CASE treatment and had concentration-dependent feature. In addition, the Hyp of the highest dose group was closed to the normal group.3. The fibroblasts generation and collagen synthesis were decreased by CASE treatment.CASE markedly decreased fibroblasts, improved the alignment of the collagen fibers, and reduced collagen content. The effect strengthened with by concentration increasing.4. The expression of TGF-βi/Smad way was influenced by CASEThe expression of TGF-β1and Smad4protein dramatically increased in the model group, while significantly decreased in the treatment groups of CASE. Furthermore, CASE promoted evidently Smad7protein expression. It infer that CASE have anti-scarring effect by modifying TGF-β/Smad signa1pathway.Conclusions1. CASE could inhibit the proliferation and formation of hypertrophic scars, and it suggested that CASE also have anti-scarring effect in vivo.2. CASE could influence TGF-β1, Smad4and Smad7expression in hypertrophic scars, these results that might be associated with TGF-β/Smad signal pathway.