Free fatty acids, cell viability and caspase activation in human articular chondrocytes. (A) Cell viability in normal human articular chondrocytes treated with different concentrations of palmitate or oleate alone or with IL-1β (1 ng/ml) for 72 hours. (B) Caspase 3/7 activation in normal human articular chondrocytes treated with palmitate (0.5 mM), oleate (0.5 mM), or IL-1β (1 ng/ml) as indicated for 72 hours. (C) Cell viability in normal human articular chondrocytes treated with palmitate (0.5 mM), IL-1β (1 ng/ml) or Z-VAD-FMK (100 μM) for 72 hours. Values are expressed as mean ± SEM. *, p<0.05.