Fig. 1.

Inhibition of IL-1β-induced expression of COX-2 (A) and PGE₂ levels (B) by delphinidin.

Serum-starved primary human chondrocytes were pre-treated with delphinidin (10 µg/ml) and BAY 11-7082 (2.5 µM) for 2 h and then treated with IL-1β for 24 h. Total RNA was isolated and real-time analysis was performed using TaqMan assay for COX-2. β-actin was used as endogenous control. Protein expression was investigated by immunoblotting using antibodies against COX-2 (Cell Signaling Technologies). β-actin was used as a control for equal loading. PGE₂ levels in the culture supernatant were measured using the PGE₂ EIA kit (Oxford Biomedical Research). Data were plotted using Origin 8.1 software. Results of real-time PCR and PGE₂ EIA were averaged from three separate experiments (n = 3) each performed in duplicate and are presented as relative gene expression ±s.d. within parentheses (real-time) and percentage of untreated control with s.d. within parentheses (PGE₂ EIA) (*P < 0.05, **P < 0.01). Protein expression data are presented as representative of three blots.