The effect of kampo formulae on bone resorption in vitro and in vivo. II. Detailed study of berberine

We previously isolated berberine from aqueous extracts of tsu-kan-gan, a Ka mpo formula used for the treatment of osteoporosis. Berberine caused an inh ibitory effect on parathyroid hormone (PTH)-stimulated bone resorption in n eonatal mouse bone. In this report we describe the inhibitory effect of ber berine on the formation of osteoclast-like multinucleated cells (OCLs) in t he co-culture of mouse osteoblastic cells and bone marrow cells in the pres ence of 1 alpha,25-dihydrosvitamin D-3 [1 alpha,25(OH)(2)D-3], PTH and inte rleukin-1 alpha (IL-1 alpha). Berberine dose-dependently inhibited the form ation of tartrate-resistant acid phosphatase (TRAP)-positive OCLs induced b y 1 alpha,25(OH)(2)D-3, PTH and IL-1 alpha. We prepared OCLs in the co-cult ure of osteoblastic cells and bone marrow cells. The effect of berberine on pit formation by OCLs was examined using dentin slices. As OCLs are termin ally differentiated multinucleated cells, the survival of OCLs affects the bone-resorbing activity of OCLs. This prompted us to count the number of TR AP-positive OCLs on the slices. Berberine dose-dependently inhibited pit fo rmation and caused a decrease in the number of TRAP-positive OCLs, Calciton in (CT) inhibited pit formation without affecting the number of OCLs. Berbe rine accelerated the cell death in OCLs cultivated on a culture plate, but CT did not affect the cell death of OCLs. This suggests that the decrease i n the number of OCLs on dentin slices may be due to apoptotic cell death in OCLs. In fact, Hoechst 33258 staining revealed that the treatment of OCLs with berberine resulted in condensed nuclei and a decrease in cell size. Or al administration of the berberine (30 and 50 mg/kg/d) to ovariectomized ra ts prevented a decrease in bone mineral density (BMD) of the lumbar vertebr a without affecting the weight of the uterus and plasma concentration of es tradiol. These results suggested that berberine prevented a decrease in BMD in vivo by inhibiting osteoclastic bone resorption.