Introduction:
The aim of the present study is to investigate the effects of pregabalin (PGB) on chondrocyte proliferation and collagen type II (COL2A1), hypoxia-inducible factor 1- (HIF-1), and chondroadherin (CHAD) gene expression in osteoarthritic chondrocytes.

Material and methods:
Standard primary chondrocyte cultures were prepared using osteochondral tissues that were surgically obtained from 6 patients with gonarthrosis. Cell morphology was evaluated using an inverted microscope, and cell death and proliferation were determined through MTT analysis, which was confirmed by AO/PI staining and statistically evaluated. The expression levels of CHAD, COL2A1, and HIF-1 genes were assessed using gene-specific TaqMan Gene Expression Assays.

Results:
MTT analyses showed that PGB administration did not have a negative or toxic effect on cell viability and proliferation in cultured chondrocytes (p < 0.001), but in our morphological evaluation extracellular matrix development was observed to be weaker in cultures treated with PGB. After 24 h of treatment, COL2A1, HIF-1, and CHAD gene expression decreased in the groups to which PGB was applied compared to gene expression before the experiment (at 0 h); at 48 h, CHAD and HIF-1 expression increased to the same level as the control group, but the expression of COL2A1 continued to decrease.

Conclusions:
Further studies need to be conducted with more participants to prove that there is a negative correlation between extracellular matrix formation and PGB administration. Our preliminary data show that even at low doses and over short-term administration, PGB may affect chondrocyte cells at the gene-expression level.