In this experiment, we studied the effects of pomegranate fruit extract (PE) on the function of osteoblastic MC3T3-E1 cells and the production of local factors in osteoblasts. PE (16 approximately 250 microg/ml) significantly increased the growth of MC3T3-E1 cells (P < 0.05). Moreover, PE (50 microg/ml) caused a significant elevation of alkaline phosphatase (ALP) activity and collagen content in the cells. We then examined the effect of PE on the TNF-alpha-induced production of interleukin-6 (IL-6) and nitric oxide (NO) in osteoblasts. Treatment with PE (10 approximately 50 microg/ml) decreased the TNF-alpha (10(-10) M)-induced production of IL-6 and NO in osteoblasts.