BACKGROUND: In recent years, studies have shown that excessive apoptosis of articular chondrocytes is the key factor for the start and progress of osteoarthritis. To study the progress in the use of drugs that inhibit apoptosis of chondrocytes to control osteoarthritis has become a hotspot. Clematis has obtained exact effect in the domestic clinical treatment of osteoarthritis, but the specific mechanism underlying
inhibition of chondrocytes apoptosis has not been reported.
OBJECTIVE: To observe the effect of radix clematidis extract on cell viability of the knee osteoarthritis chondrocytes.
METHODS: Joint cartilage was shredded after harvested from the patients of osteoarthritis undergoing the knee replacements, and chondrocytes were isolated and cultured by the way of enzymatic digestion. The third-passage cells in the logarithmic growth phase were cultured in vitro and randomly divided into six groups after adherence. The experimental groups were cultured in Dulbecco’s modified Eagle’s medium with 0.01, 0.05, 0.1, 0.5, and 1.0 g/L radix clematidis extract, while the control group was given normal medium alone. Live/Dead assay method was adopted to observe the effect of radix clematidis extract with different concentrations on cell viability of the knee osteoarthritis chondrocytes, and TUNEL method was used to assay apoptosis index of the knee osteoarthritis chondrocytes.
RESULTS AND CONCLUSION: 0.05 and 0.1 g/L radix clematidis extracts increased cell viability of chondrocytes, while 0.5 and 1.0 g/L radix clematidis extracts decreased the cell viability of chondrocytes. There was a significant difference in the cell viability between 0.05, 0.1, 0.5, 1.0 g/L radix clematidis extract groups and the control group (P < 0.05). 0.01, 0.05, 0.1 g/L radix clematidis extracts effectively inhibited apoptosis of chondrocytes, while 1.0 g/L radix clematidis extract promote the apoptosis of chondrocytes. There was a significant difference in the apoptotic index between 0.01, 0.05, 0.1, 1.0 g/L radix clematidis extract groups and the control group (P < 0.05). The appropriate concentration of radix clematidis extract could improve chondrocytes viability and restrain chondrocytes apoptosis, and the peak was at 0.1 g/L group. But excessive concentration of radix clematidis extract could reduce chondrocytes viability and promote chondrocytes apoptosis, representing the toxic effects on human articular chondrocytes.