- The first in vitro study testing the effect of a natural mixture extract of quality elk velvet antler (QEVA) on the development of bone marrow-derived mesenchymal stem cells (MSCs) is reported. To examine cellular responses, MSCs were seeded on gold-coated glass surfaces and grown in a medium supplemented with QEVA extract or with the osteogenic agent dexamethasone (Dex), or in unsupplemented medium as control. The MSCs were analyzed by light microscopy and confocal Raman microspectroscopy at different time intervals in the culture. The microscopy revealed that the proliferation, up to day 4, of cells treated with QEVA is higher than that of cells treated with Dex or of the control group. Raman spectroscopy revealed deposition of hydroxyapatite (HA) mineral by cells exposed to QEVA and HA precursors in cells treated with Dex, but no mineralization in the control group. The extent of mineralization for MSCs treated with QEVA increased systematically with time, up to day 14. These results indicate that QEVA enhances proliferation and promotes differentiation toward osteogenic fate more effectively than Dex, suggesting that addition of QEVA to culture media might be advantageous to bone-tissue-engineering implications. Copyright © 2005 John Wiley & Sons, Ltd.