['The aim of this study was to investigate the effects of PRP on SAOS-2 cells in terms of cytokine expression, cell activity and oxidative stress.', 'Cell line SAOS-2 (1×10(5)cells/mL) were grown in culture medium α-MEM with 10% FBS for 24h and stimulated (or not) with PRP at concentrations of 3, 10 and 20%, LPS (E. coli, 10g/mL) and IL-1β (1mg/mL) for 24h. The supernatant was collected and analyzed for the expression of cytokines in a panel array, ALP using a commercial kit and NO(2)(-) with Griess reaction method. Also, the cells were analyzed using Western blot for RANKL and slot blotting for nitrotyrosine expression.', 'There were no significant differences amongst the groups in terms of NO(2)(-), protein nitrotyrosine content and RANKL expression. However, all stimuli increased ALP activity and in case of PRP, it was in a dose-dependent manner (p<0.001). Also, all stimuli induced an increase in cytokines and chemokines expression, but only PRP promoted an increase of component C5, sICAM-1 and RANTES expression. Whilst IL-1 receptor antagonist (IL-1ra) expression was down-regulated by PRP, both LPS and IL-1β caused up-regulation of this cytokine.'] Does platelet-rich plasma stimulate cytokine expression and alkaline phosphatase activity in osteoblast-derived osteosarcoma cells?