Objective: We aimed to explore the mechanism of Pizhan Powder in regulating the Wnt4/β-catenin signaling pathway to promote wound healing in mice with chronic skin ulcer. Methods: Male BALB/c mice were divided into blank, model, Pizhan Powder, Pizhan powder removed bark medications, bark medications, inhibitor, and Pizhan Powder + inhibitor groups using the random number table method, with six mice per group. Except for the blank group, chronic skin ulcer wound models were prepared in the other groups by implanting foreign bodies. The blank control group received no treatment, whereas the wounds of the model group were cleaned with furacilin solution. The Pizhan Powder, Pizhan Powder removed bark medications, and bark medications groups were each administered 0.1 g of the corresponding medication on the skin wounds. The inhibitor group received an intraperitoneal injection of 3-(4-methylphenylsulfonamido) benzoic acid methyl ester (MSAB) at a dosage of 10 mg/kg. The Pizhan Powder + inhibitor group was administered 0.1 g of Pizhan Powder on the skin wound, and an intraperitoneal injection of MSAB was also administered (10 mg/kg). These treatments were administered once a day for 14 consecutive days. Wound healing was observed on the first, third, seventh, and 14th day of treatment; hematoxylin and eosin staining was used to observe the pathological changes of ulcerated skin; keratin 10 (CK10), keratin 14 (CK14), cell proliferation nuclear antigen (Ki-67), α-smooth muscle actin (α-SMA), and β-catenin expression in wounds was observed through immunofluorescence; Western blotting was used to detect the expression of signaling pathway-related proteins (Wnt4 and β-catenin). Results: Compared to the model group, the Pizhan Powder group showed a reduced wound area and an increased wound healing rate (P<0.05) and elevated CK10, CK14, Ki-67, α-SMA, β-catenin, and Wnt4 protein expressions (P<0.05). Compared to the Pizhan Powder group, the wound healing rate of the bark medications and Pizhan Powder removed bark medications groups was reduced (P<0.05). The wound healing rate and the fluorescence expression of CK10, CK14, Ki-67, and α-SMA in the Pizhan Powder removed bark medications group were lower than that in the bark medications group (P<0.05). Compared to the Pizhan Powder group, the wound healing rate of the Pizhan Powder + inhibitor group was reduced, and CK10, CK14, Ki-67, α-SMA, β-catenin and Wnt4 protein expression were lower (P<0.05). Conclusion Pizhan Powder promotes wound healing in chronic skin ulcers of mice by regulating the Wnt4/β-catenin signaling pathway. The bark medications (buffalo hide, white mulberry root-bark, and Chinese wolfberry root-bark) play a crucial role, representing a concrete application of the traditional Chinese medicine theory of " treating skin with skin.

As a chronic progressive lung disease with poor prognosis,the pathogenesis of idiopathic pulmonary fibrosis(IPF)has not yet been clarified,and its treatment is still being explored.Animal models are important tools for studying the pathogenesis and therapeutic effects of diseases.Based on the similarity between animal models and human of IPF in terms of disease phenotype,this paper will review the research progress of IPF animal models in terms of the fibrosis mechanism induced by drugs and environmental factors,histopathological alterations,fibrosis stage,modelling time,etc.,and describe the advantages and disadvantages of different animal models,their characteristics and application profiles.

As a chronic progressive lung disease with poor prognosis,the pathogenesis of idiopathic pulmonary fibrosis(IPF)has not yet been clarified,and its treatment is still being explored.Animal models are important tools for studying the pathogenesis and therapeutic effects of diseases.Based on the similarity between animal models and human of IPF in terms of disease phenotype,this paper will review the research progress of IPF animal models in terms of the fibrosis mechanism induced by drugs and environmental factors,histopathological alterations,fibrosis stage,modelling time,etc.,and describe the advantages and disadvantages of different animal models,their characteristics and application profiles.