The objective of this study was to examine the effect of (-)-epigallocatechin-3-gallate (EGCG) on cyclooxygenase 2 (COX-2) and matrix metalloproteinase (MMP) 3, 9, and 13 expressions induced by IL-1b in rat meniscal fibrochondrocytes. Rat normal meniscal fibrochondrocytes were enzymatically isolated from meniscal tissue from the hind leg knee joint. Cells were pretreated with EGCG at a concentration of 50 mM to examine its effect in the presence of IL-1b insult. Reverse transcriptase-polymerase chain reaction (RT-PCR) and real-time PCR were used to assess the COX-2 and MMP3, 9, and 13 gene expressions, respectively.
COX-2 gene upregulation induced by IL-1b in primary cultures of rat meniscal fibrochondrocytes was significantly suppressed by EGCG (p < 0.05). MMP 3, 9, and 13 gene expressions were also significantly induced by IL-1b stimulation and significantly inhibited by EGCG treatment (p < 0.05). These results indicated that EGCG may be of value in the treatment of meniscal inflammation associated with IL-1b secretion.