The Research On Bama Minipig Skin Scar Under The Affection Of A&M Compound Anti-Scar Cream

Purpose:To establish skin scar model on the back of Bama minipig pigs and then study the effect of compound artesunate anti-scar ointment and examine the expression of collagen type Ⅰ and Ⅲ in porcine dorsal scar tissue after the compound artesunate anti-scar ointment was used on scar of the porcine skin, and to provide the evidence of treating skin scar by the compound artesunate anti-scar ointment.Method:Anti-scarring agents prepared containing artesunate and pearls hydrolyzate of the compound named Green Pearl anti-scar ointment.6 female 4 months old Bama miniature pigs were selected to build porcine back model of hyperplastic scar. Prepared pig burn wound on the back. The wounds were exposed after self-made heat burn instrument scald (temperature 100℃,20s). Bama minipigs were fed separately after the operation. These pigs were randomly divided into six groups:untreated group, matrix control group, pearl hydrolyzate group, artesunate group, compound artesunate anti-scar ointment group, and silicone condensate gel group.Medications started on the 28th day postoperatively (2 times per day).These miniature pigs were sacrificed on the 56th day postoperatively and the rate of wound healing was calculated by Nageschmidt method. Their scars were incised for specimen collection. Scar stratum corneum, acanthosis and basal cells and fibrous changes of each group were observed by HE staining. Masson trichrome collagen stain and light microscopy were used to observe the arrangement of collagen fiber bundles. Immunohistochemistry was used to detect the expression of collagen type I and collagen type Ⅲ in porcine dorsal scar tissue. The expression level of mRNA of collagen type Ⅰ and collagen type Ⅲ in porcine dorsal scar tissue was detected by fluorescence quantitative RT-PCR method. SPSS 17.0 statistical software was used to manipulate and analyze the experimental results. The experimental results were expressed as mean±standard deviation and the significance level a=0.05. Differences were considered significant when P values below 0.05 were obtained.Results:1. Scars collected from untreated group and paste matrix control group were deep red, hard and significantly higher than porcine dorsal skin after continuous medication for 28 days (56 days after modeling). The pearl hydrolyzate group’s scar was red, soft touch of medium quality and slightly higher than the pig back surface of the skin. The artesunate, compound artesunate anti-scar ointment groups’scars were flat and soft with color close to the normal color of pig back. Silicone condensate gel group was flattened, soft and smooth, and the color was closer to normal skin color.2. HE staining showed that the number of fibroblasts was reduced and collagen fibers appeared to be regulated and sparse in medication groups, among which, the effect was clearest in compound artesunate anti-scar ointment group. The matrix layers of the stratum corneum of the untreated group and the control group were disarranged and obviously increased in thickness, which contained a lot of disorganized collagen fibers vortex-like arranged. Masson trichrome staining showed that the density of collagen fibers in scars decreased after treatment, no significant collagen whirlpool and nodules were observed.3. Immunohistochemistry was used to detect the expression of collagen type Ⅰ,Ⅲ in porcine dorsal scar tissues. Compared with untreated group, the expression of collagen type Ⅰ of compound artesunate anti-scar ointment, artesunate, pearl hydrolyzate and silicone gel groups were reduced, the difference was statistically significant (P<0.01), and the difference between matrix group and untreated group was not statistically significant (P> 0.05). Compared with untreated group, the expression of collagen type Ⅲ of compound artesunate anti-scar ointment, artesunate, pearl hydrolyzate and silicone gel groups were increased, the difference was statistically significant (P<0.01), and the difference between matrix group and untreated group was not statistically significant (P> 0.05).4. Fluorescence quantitative RT-PCR showed thatthe mRNA expression of collagen type Ⅰ of compound artesunate anti-scar ointment, artesunate, pearl hydrolyzate and silicone gel groups were significantly reduced compared with untreated group, the difference was statistically significant (P<0.01), and the difference between matrix group and untreated group was not statistically significant (P> 0.05). Compared with untreated group, the mRNA expression of collagen type Ⅲ of compound artesunate anti-scar ointment, artesunate, pearl hydrolyzate and silicone gel groups appeared varying degree rise, the difference was statistically significant (P<0.01), and the difference between matrix group and untreated group showed no statistical significance (P> 0.05). Conclusion:1. The application of pearl hydrolyzate, artesunate and compound artesunate anti-scar ointment can suppress the scar hyperplasia, among which the compound artesunate anti-scar ointment has the best healing effect.2. Compound artesunate anti-scar ointment significantly inhibited the deposition of collagen Ⅰ of porcine dorsal scar tissue and promoted the secretion of collagen Ⅲ to a certain extent, which makes the content ratio of collagen I and collagen Ⅲ closer to normal skin. This may be one of the mechanisms that compound artesunate anti-scar cream inhibits the scar on pig back.