Repair Effects of Xiaoyusan New Formula on Cartilage Injury and MMP-13 Expression in Knee Osteoarthritis Model Rabbits

Abstract

ObjectiveTo study the effect of Xiaoyusan new formula on the articular cartilage of knee osteoarthritis (KOA) rabbits and its mechanism.MethodsA total of 42 New Zealand white rabbits aged 6 months were randomly divided into normal group, model group, ointment of Xiaoyusan group, and ointment of Xiaoyusan new formula group, with 10 rabbits in each group (the other 2 rabbits were used for model validation). Except for the normal group, the right knee joints of all rabbits in the other groups were prepared as KOA models according to the modified Hulth method. After 5 weeks of molding, the rabbits in ointment of Xiaoyusan group, ointment of Xiaoyusan New Formula group were given corresponding ointments for knee arthritis treatment, once a day, each time for 10 hours. After 2-week continuous administration and treatment, the knee joint cartilage of the four groups of rabbits was taken and the cartilage damage of each group was evaluated by Outerbridge grading method. The pathological changes of the cartilage, calcified layer and subchondral bone of the knee joint of rabbits in each group were observed by HE staining method under the light microscope, and the degree of cartilage degeneration was evaluated by Mankin's method. The expression of matrix metalloproteinase-13 (MMP-13) in the cartilage of rabbit knee joint in each group was deteced by immunohistochemistry. Results After the general observation of articular cartilage, the Outerbridge grading showed that the number of high-grade animals in ointment of Xiaoyusan group was reduced compared with the model group (P<0.05), and the number of high-grade animals in ointment of Xiaoyusan new formula group was also reduced (P<0.05) compared with ointment of Xiaoyusan group. HE staining showed that Mankin's scores of articular cartilage in the four groups ranked from high to low: model group (10.82±1.76), ointment of Xiaoyusan group (6.19±1.23), ointment of Xiaoyusan new formula group (2.64±1.18) and normal group (0.28±0.17). The difference among four groups was statistically significant (P<0.05). Immunohistochemical detection showed that the positive rates of MMP-13 expression in rabbit articular cartilage tissues in each group were (67.90±13.94)% of model group, (37.10±19.16)% of ointment of Xiaoyusan group, (13.60±3.10)% of ointment of Xiaoyusan new formula group and (3.20±2.39) % of normal group, ranking from high to low, and the difference among four groups was statistically significant (P<0.05).ConclusionXiaoyusan new formula can repair articular cartilage degeneration in KOA rabbits and decrease the expression of MMP-13 in cartilage, which may be one of the mechanisms of the treatment.

Keywords

• xiaoyusan new formula
• knee osteoarthritis
• articular cartilage
• matrix metalloproteinase-13