The present invention discloses oxygenic oxygenic oxysterols. Also disclosed, agents and methods for protecting, blocking or rescuing marrow stromal cells from the inhibitory effects of oxidative stress on their osteoblastic cellular differentiation. Exemplary agents include oxysterols, rhBMP2, alone or in combination which are demonstrated to specifically combat oxidative stress caused by inflammatory oxidized lipids, such as xanthine/xanthine oxidase and minimally oxidized LDL. The synergistic effects of oxysterols and bone morphogenic proteins are disclosed.