We studied the role of intracellular signaling molecules PI3K, МАРK ERK1/2, and р38 in stimulation of realization of the growth potential of mesenchymal progenitor cells by alkaloid songorine in vitro. Inhibitors of PI3K, ERK1/2 and р38 canceled the increase in proliferative activity of progenitor cells, the blockers of ERK1/2 and р38 reduced the intensity of progenitor cell differentiation.