To investigate the effect of Guling Cream（骨灵膏）on bone regeneration and chondrocyte apoptosis in rabbit knee cartilage defect model.

Thirty male rabbits（New Zealand）were randomly divided into model group，blank control group and Guling Cream low，medium and high dose groups，with 6 rabbits in each group. The model of knee cartilage defect was established by modified joint scoring method. The blank control group did not drill，and the Guling Cream low，medium and high dose groups were given Guling Cream with dose of 1.16 mL/kg（3.70 g/kg），3.47 mL/kg（11.10 g/kg），10.41 mL/kg（33.31 g/kg）by gavage，respectively. The the model group blank and control group were given 3.47 mL/kg normal saline，once every 3 days for 12 weeks. The Wakitani score was used for histological score. Masson staining was used for pathological evaluation，and terminal transferase-mediated dUTP nick end labeling（TUNEL）method was used to detect synovial and chondrocyte apoptosis. The levels of superoxide dismutase（SOD），nitric oxide（NO），lipid peroxide（LPO）in synovial fluid and pyridine phenol（PYD）in urine were detected by enzyme-linked immunosorbent assay.

At the 12th week after administration，the wound area in the model group was uneven，and the cartilage defect area in each dose group was filled in. The surface of the low dose group was rough，while the medium dose group showed less smoothness. The surface of the high dose group was relatively smooth，and the joint cartilage structure was good. Compared with those in the model group，the arrangement of chondrocytes in each dose group was more regular，and chondrocytes secreted more collagen fibers. The histological scores and apoptosis rates of synovial and chondrocytes in the low，medium and high dose groups of were higher than those in the control group and lower than those in the model group. As the dose increased，the histological scores and apoptosis rates of synovial and chondrocytes showed a decreasing trend（P<0.05）. The levels of joint fluid NO and LPO and urine PYD in the low，medium and high dose groups were higher than those in the control group，but lower than those in the model group. As the dose increased，the expression levels showed a descending trend，and the difference was statistically obvious（P<0.05）. The SOD levels in the joint fluid of the low，medium and high dose groups were lower than those of the control group and higher than those of the model group. As the dose increased，the expression level showed an growing trend，and the difference was statistically obvious（P<0.05）.

Guling Cream can improve the cartilage injury and accelerate the repair of cartilage tissue in rabbits with knee cartilage defect possibly by regulating the expressions of oxidative stress factors to inhibit chondrocyte apoptosis and promote cartilage tissue regeneration.