关键词: 骨关节炎, 脱细胞软骨细胞外基质, 氧化苦参碱, 软骨细胞, 细胞外基质

Abstract: BACKGROUND: Acellular cartilage extracellular matrix is effective in the treatment of osteoarthritis, but its efficacy is limited when applied alone. Oxymatrine alleviates interleukin-1β-induced chondrocyte apoptosis and extracellular matrix degradation.
OBJECTIVE: To observe the effect of different doses of oxymatrine combined with acellular cartilage extracellular matrix injection in knee cavity on osteoarthritis in rats.
METHODS: The femoral cartilage of SD rats was obtained. The acellular cartilage extracellular matrix was prepared by physical, chemical and enzyme methods. Fifty SD rats were selected and divided into sham operation group, osteoarthritis group, simple material group, low-dose drug group, and high-dose drug group by random number table method, with 10 rats in each group. The latter four groups were treated with modified Hulth method to establish the rat model of osteoarthritis. After successful modeling, acellular cartilage extracellular matrix homogenate was injected into the knee cavity of rats in the simple material group. Acellular cartilage extracellular matrix homogenate containing 50, 100 µg oxymatrine was injected into the knee cavity of rats in the low-dose drug group and the high-dose drug group, respectively. Samples were taken 4 weeks after injection for relevant detection.
RESULTS AND CONCLUSION: (1) Compared with the sham operation group, the concentrations of interleukin 1β, tumor necrosis factor ɑ, and malondialdehyde in the joint effusion were increased (P < 0.05), and the concentration of superoxide dismutase in the joint effusion was decreased (P < 0.05) in the osteoarthritis group. Compared with osteoarthritis group, the levels of interleukin 1β, tumor necrosis factor ɑ, and malondialdehyde in joint effusion were decreased (P < 0.05), while the level of superoxide dismutase was increased (P < 0.05) in the low-dose drug group and high-dose drug group, and the changes were more significant in high-dose drug group. (2) TUNEL staining showed that compared with sham operation group, apoptotic chondrocytes increased in osteoarthritis group. Compared with the osteoarthritis group, the apoptotic chondrocytes decreased in the simple material group, the low-dose drug group, and the high-dose drug group, and the decrease was more significant in the high-dose drug group. (3) Hematoxylin-eosin staining and immunohistochemical staining showed that the knee cartilage was seriously degraded, the expression of type II collagen was decreased (P < 0.05), and the expression of matrix metalloproteinase-9 was increased (P < 0.05) in the osteoarthritis group. Compared with the osteoarthritis group, the knee cartilage degeneration of rats in the simple material group, the low-dose drug group, and the high-dose drug group was significantly improved; the expression of type II collagen was increased (P < 0.05) and the expression of matrix metalloproteinase 9 was decreased (P < 0.05), and the improvement was most significant in the high-dose drug group. (4) Western blot assay showed that compared with sham operation group, the expression of Nrf2, HO-1, and Bcl-2 protein in cartilage tissue decreased (P < 0.05); expression levels of Cleaved-caspase-3, Cleaved-caspase-9, and Bax were increased (P < 0.05) in the osteoarthritis group. Compared with the osteoarthritis group, the protein expression levels of Nrf2, HO-1, and Bcl-2 were increased (P < 0.05), and the protein expressions of Cleaved-caspase-3, Cleaved-caspase-9, and Bax were decreased (P < 0.05) in the low-dose and high-dose drug groups. The improvement was more significant in the high-dose drug group. (5) In conclusion, intracavicular injection of acellular cartilage extracellular matrix and oxymatrine can promote the synthesis of extracellular matrix, inhibit inflammation and oxidative stress, and suppress chondrocyte apoptosis, and play a therapeutic role in osteoarthritis, which may be related to the activation of Nrf2/HO-1 pathway. 

Key words: osteoarthritis, acellular cartilage extracellular matrix, oxymatrine, chondrocyte, extracellular matrix