초록

Inhibition of osteoclast differentiation is the most important target for prevention of inflammatory bone
resorption and bone diseases. Here, we investigated the effect of spinach ethanol extract on osteoclast differentiation
in RAW264.7 cells. Spinach was extracted with ethanol at a concentration ranging from 0 to 100% (0, 25, 50, 75,
and 100% ethanol). Inhibitory effects of receptor activator of NF-κB ligan (RANKL)-induced osteoclast differentiation
were evaluated using tartrate-resistant acid phosphatase (TRAP) stain assay. The most effective eanol concentration
for osteoclast differentiation was 100%. Spinach extract (100% ethanol) suppressed RANKL-induced osteoclast differentiation and TRAP activity. Spinach extract (100% ethanol) also suppressed expression of osteoclast differentiationrelated
marker genes (NFATc1, c-FOS, cathepsin K, and TRAP) and down-regulated RANKL-induced NF-κB and
ERK phosphorylation during osteoclast differentiation. Taken together, our results suggest that spinach extract is effective
against reducing osteoclast differentiation through the NF-κB-mediated pathway.