口腔粘膜下纤维化（OSF）是一种慢性、隐匿性、具有癌变倾向的的口腔粘膜疾病。流行病学调查表明OSF发病与咀嚼槟榔有关，迄今OSF发病机理仍不甚明了，治疗效果仍不理想。前期的研究发现，中药复方制剂-丹玄口康具有良好的治疗OSF的作用，丹玄口康能拮抗TGFβ1的分泌，抑制成纤维细胞的增殖和胶原合成，推测其机制与TGFβ1/Smads信号转导通路的调控有关。本项目拟采用免疫组化、分子生物学等方法研究丹玄口康对槟榔提取物诱导的OSF模型大鼠TGFβ1、TβR 、Smads分子表达的影响；采用细胞培养、药物血清、原位杂交、基因干扰等技术方法研究丹玄口康对转染Smad7-siRNA的成纤维细胞TGFβ1/Smad信号转导通路的影响。本项目首次从TGFβ1/Smads信号转导通路的角度研究中医药治疗OSF的疗效机制，将为OSF的临床治疗提供新的实验依据。

Oral submucous fibrosis (OSF) is a chronic, insidious oral mucosal disease with potential canceration tendency. Epidemiology showed that the main aetiological factor causing OSF may be related to chewing of areca nut, but the pathogenesis leading to OSF is still unclear, and treatment of it has not been satisfactory. Earlier research found that treatment with the traditional Chinese medicine compound recipe Dan Xuan Kou Kang is an effective approach for patients with OSF, application of Dan Xuan Kou Kang lead to antagonize the secretion of TGFβ1 and inhibit the proliferation and collagen synthesis of the fibroblasts, and it is assumed that the functioning of the mechanism was related to regulation of TGFβ1/Smads signaling pathway. This study intends to apply methods of immunohistochemistry staining, molecular biology to explore the effect of Dan Xuan Kou Kang on expression of TGFβ1、TβR 、Smads in OSF model rats induced by Areca Nut Extract; The study will adopt methods of cell culture, drug serum, in situ hybridization and RNA interference to investigate the effect of Dan Xuan Kou Kang on TGFβ1/Smads signaling pathway of fibroblasts transfected with Smad7-siRNA. As a pioneering study, for the first time, this project chooses the TGFβ1/Smads signaling pathway to explore the therapeutic mechanism of traditional Chinese medicine on repairing of OSF, The findings of this study will provide newly experimental foundation for clinical therapy.