Abstract

Sinomenine (SN) is an alkaloid extracted from the medicinal plant, Sinomenium acutum which has been utilized to treat rheumatoid arthritis (RA) in China for centuries. Previous studies showed that SN had anti-inflammatory and anti-rheumatic effects. The aim of the present study was to investigate the effect of SN on interleukin-1beta (IL-1beta)-induced expression of major cartilage damaging proteases in human osteoarthritic chondrocytes. Human osteoarthritic chondrocytes were obtained from the knee of patients undergoing total knee arthroplasty surgery due to OA. Human osteoarthritic chondrocytes and SW1353 cells were plated in monolayer culture. Cell viability was evaluated using MTT assay. SN was added before stimulation with 10 ng/mL human recombinant IL-1beta. mRNA expression of MMPs was measured by RT-PCR. Protein expression was detected by Western blotting. SN suppressed IL-1beta-induced MMP-1, MMP-3, MMP-9, and MMP-13 mRNA and protein expression in SW1353 cells and human osteoarthritic chondrocytes. SN inhibited the catabolic effect of IL-1beta by interception of proteolytic enzymes expression. The cartilage catabolic proteases inhibitory ability and the well-known anti-inflammatory activity make SN a potentially novel therapeutic agent for OA.

Key words: Sinomenine, interleukin-1, osteoarthritis, chondrocytes, matrix metalloproteinases.