Objective To explore the mechanism of Wutou Decoction (乌头汤) in treating knee osteoarthritis (KOA) by regulating Indian hedgehog factor (Ihh)-glioma associated oncogene homolog (Gli) signaling pathway. Methods Male SD rats were randomly divided into sham group, model group, celecoxib (24 mg/kg) group, Wutou Decoction low-, medium-, and high-dose (1.05, 2.10, 4.20 g/kg) groups, with 10 rats in each group. The improved anterior cruciate ligament resection technique was used to establish a KOA model, after eight weeks of drug intervention, mechanical pain threshold, thermal pain threshold and climbing ability were measured. ELISA was used to detect the levels of matrix metalloproteinase-3 (MMP-3), MMP-13 and type II collagen (Col II) in serum. The morphological changes of knee joint were observed by hematoxylin-eosin (HE) staining. Micro computed tomography (Micro-CT) technology was used to analyze the changes in bone microstructure of knee joint. Western blotting was used to detect the expressions of Ihh, patched 1 (Ptch1), Gli and MMP-13 proteins in knee joint. Results Compared with sham group, rats in model group showed defects and thinning of cartilage surface layer, decreased and disordered cell arrangement, decreased cross-sectional and coronal bone trabeculae, sparse distribution, decreased bone density, thermal pain threshold and mechanical pain threshold were significantly reduced (P < 0.001), slope angle was decreased (P < 0.001), levels of MMP-3 and MMP-13 in serum were significantly increased (P < 0.05, 0.01), Col II level was significantly decreased (P < 0.05), and expression levels of Ihh-Gli signaling pathway related proteins in knee joint were significantly increased (P < 0.001). Compared with model group, the cartilage surface of rats in Wutou Decoction group was smooth, the number of cells was increased, and the morphology was intact. The knee joint cross-section and coronal bone trabeculae were increased, and the distribution was dense. The thermal pain threshold and mechanical pain threshold were significantly increased (P < 0.05, 0.001), slope angle was increased (P < 0.01, 0.001), levels of MMP-3 and MMP-13 in serum were significantly reduced (P < 0.05), level of Col II was significantly increased (P < 0.05), and expression levels of Ihh-Gli signaling pathway related proteins in knee joint were significantly reduced (P < 0.05, 0.001). Conclusion Wutou Decoction protects articular cartilage by inhibiting excessive activation of Ihh-Gli signaling pathway, reducing abnormal proliferation and differentiation of chondrocytes.

knee osteoarthritis  /  Wutou Decoction  /  Ihh-Gli signaling pathway  /  joint cartilage  /  aconitine  /  hypaconitine  /  mesaconitine  /  paeoniflorin  /  glycyrrhizin  /  astragaloside IV