| Background:Traditional Chinese medicine has a long history and unique therapeutic effect on wound healing.Although the development of modern medical technology,the traditional Chinese medicine in the treatment of wound healing is still widely used,and with the development of cytology and molecular biology,experimental research on Chinese medicine treatment mechanism has gradually increased,and has achieved considerable results,making more accurate and reasonable application of traditional Chinese medicine.According to the infection treatment principle summed by the ancient physicians of"Activating blood circulation to dissipate blood stasis,removing slough and promoting growth of tissue regeneration",we made compound catechu gel with extractions of six herbs including Catechu,Astragali,Dragon ’s Blood,Phellodendron,Frankincernse and Myrrh after science develops out formula and rigorous screening.This study assesses the treatment effect of our gel in treating infectious wound,and explores its mechanism,in order to providing a better theoretical basis for the clinical research and development of new Chinese medicine for promoting wound healing.Objective:This study explored the mechanism of the compound catechu gel on infectious wound healing through observing the therapeutic effect of the gel on canine infection wound and the regulation of inflammatory cells,wound repair cells,fibroblast growth factor-2(fibroblast growth factor-2,FGF-2),vascular endothelial growth factor-A(vascular endothelial growth factor-A,VEGF-A)and transforming growth factor-beta 1(transforming growth factor-beta 1,TGF-β1).Methods:(1)Preparation of the drugs:The orthogonal test was used to select the prescription,and the compound catechu gel was prepared according to the test indexes and sensory indexes.(2)The establishment of animal model:Full-thickness skin defect were infected with Staphylococcus aureus and Pseudomonas aeruginosa on the back of the dogs.(3)Twelve dogs were divided into four groups randomly:The negative control group,the positive control group(treated with sulfadiazine zinc),the high-dose and low-dose groups(treated with compound catechual gel),3 dogs in each group with 8 wounds on each dog.After the infectious wounds were made successfully,these drugs were separately used in each group once a day for fourteen days consecutively.The biopsies on the 3rd,7th and 14th day were histologically assessed.(4)Study on the mechanism:The treatment group and sampling were the same with clinical trial.The level of FGF-2(mRNA),VEGF-A(mRNA)and TGF-β1(mRNA)were detected by real time qPCR,the expressions of FGF-2,VEGF-A and TGF-β1 protein were compared by immunohistochemical staining(IHC).Results:The compound catechu gel has good adhesion,easy absorption,convenient to use and to clean.A successful infection model was established by infecting the full-thickness defect on the back of the dogs with Staphylococcus aurees and Pseudomonas aeruginosa.The clinical observation showed that the high-dose group and the positive control group had higher wound contraction percentage and took shorter time for healing in comparison to the negative control group(P<0.01).In the early period of the treatment,the high-dose group and the positive control group recruited more macrophages and then emerged more neovascularization,myofibroblast and granulation compared to the negative control group according to the histological assessment.There was nostatistically significant difference between the high-dose group and the positive control group.As the real time qPCR and IHC showed,the expression of FGF-2,VEGF-A and TGF-β1 mRNA and protein of high dose group and chemical drug group increased rapidly and maintained at a high level at pretreatment,and then decreased in the late healing,while the expressions of low dose group and blank control group rise slowly consistently and keeping lower than the former two groups.Conclusion:The findings indicated that high-dose compound catechual gel can significantly promote wound healing by anti-infection and accelerate re-epithelialization,neovascularization,myofibroblast proliferationand collagen discoloration.High dose compound catechu gel can raise and maintaine the expressions of FGF-2,VEGF-A,TGF-β1 mRNA and protein,which can stimulate the proliferation and migration of inflammatory cells and repair cells,thereby speeding up the process of granulation and epithelization,stimulating collagen deposition which is the main component of extracellular matrix which provides stability of the wound tissue structure.In the late of healing,the decrease of growth factor levels inhibits inflammation which prevents excessive matrix deposition and scar hyperplasia. |
