Abstract

Tetramethylpyrazine (TMP) is the major bioactive constituent of Rhizoma Chuanxiong which has long been used as an important component in several Chinese medicine formulations for the clinical treatment of osteoarthritis. However, the molecular mechanism of the therapeutic effect of TMP remains unclear. In the present study, we investigated the cellular effects of TMP in cultured primary chondrocytes. Chondrocytes isolated from the knee articular cartilage of SD rats were cultured and identified using toluidine blue staining. The second generation of chondrocytes was treated with or without TMP. We found that TMP treatment could promote chondrocyte proliferation via pushing the progression of cell cycle. Furthermore, using RT-PCR and Western blotting analyses we observed that the mRNA and protein levels of Cyclin D1 and CDK4 were significantly enhanced after TMP treatment, whereas those of p21 were significantly decreased. Our study suggests that promoting the proliferation of chondrocytes is one of the mechanisms by which TMP treats osteoarthritis.

Key words: Tetramethylpyrazine, chondrocyte, osteoarthritis, cell cycle.