Red clover extracts stimulate differentiation of human osteoblastic osteosarcoma HOS58 cells.

Different extracts from red clover (Trifolium pratense L.) were tested for their ability to stimulate the activity of osteoblastic osteosarcoma cells (HOS58). As a key marker of osteoblasticity we chose the activity of alkaline phosphatase (ALP). Whereas butanol and methanol extracts had no influence on either ALP or cellular protein production, enzyme activity was increased significantly on incubation with chloroform extracts. All extracts were analysed for isoflavone content. The data clearly suggest a role for red clover isoflavonoids in the stimulation of osteoblastic cell activity.