Inhibitory effect of genistein on osteoclast-like cell formation in mouse marrow cultures

Abstract

The effect of genistein on osteoclast-like cell formation in mouse marrow culture in vitro was investigated. The bone marrow cells were cultured for 7 days in α-minimal essential medium containing a well-known bone resorbing agent [parathyroid hormone (1–34) (PTH), prostaglandin E 2 (PGE 2), 1,25-dihydroxyvitamin D 3 (VD 3), or lipopolysaccharide (LPS)] with an effective concentration. Osteoclast-like cell formation was estimated by staining for tartrate-resistant acid phosphatase (TRACP), a marker enzyme of osteoclasts. The presence of PTH (10 −8 M), PGE 2 (10 −6 M), VD 3 (10 −8 M), or LPS (1 μg/mL) induced a remarkable increase in osteoclast-like multinucleated cells. These increases were inhibited significantly in the presence of genistein (10 −7 to 10 −5 M). The inhibitory effect of genistein (10 −5 M) was equal to that of 17 β-estradiol (10 −8 M), calcitonin (10 −9 M), or zinc sulfate (10 −5 M). Genistein (10 −5 M) significantly inhibited dibutyryl cyclic adenosine monophosphate (10 −5 M)-induced osteoclast-like cell formation. However, genistein (10 −5 M) did not inhibit phorbol 12-myristate 13-acetate-induced osteoclast-like cell formation. The present study demonstrated that genistein has a potent inhibitory effect on osteoclast-like cell formation in mouse marrow culture. The inhibitory action of genistein may involve in cyclic AMP signaling.