[Effect of Bugu Mixture on all-trans retinoic acid-induced apoptosis of bone marrow stromal cells].

OBJECTIVE We used the SD rat's bone marrow stromal cells (BMSCs) cultured in vitro to observe the effects of Bugu Mixture on the apoptosis and to explore the molecular biologic mechanism of the treatment of osteoporosis with Bugu Mixture. METHODS BMSCs were separated from the bones of the extremities of SD rats in vitro. The morphologic changes, the apoptosis cell cycles, the mitochondrion membrane potential changes, and the Bcl-2 and Bax gene expression were observed, and the effects of Bugu Mixture on the course of cell apoptosis were evaluated. RESULTS The earlier use of Bugu Mixture could decrease the cells blocked in G0/G1 phase, and promote their synthesis of DNA in S phase. The expression of Bcl-2 was higher in the Bugu Mixture group than that in the all-trans retinoic acid (ATRA) induced group, and the expression of Bax was lower in the Bugu Mixture group than that in the ATRA induced group. The mitochondrion membrane potential descended significantly in the Bugu Mixture group than that in the ATRA induced group. CONCLUSION The mechanism of the treatment of osteoporosis with Bugu Mixture is that the earlier use of Bugu Mixture can decrease the amount of apoptostic cells induced by ATRA, thus promoting the cell mitosis and restraining the apoptosis. It can also act as a protector to Bcl-2 located on the mitochondrion membrane. By preventing the transferring of the Bax protein from cell-plasma to mitochondrion membrane, it takes the advantage of Bcl-2 in forming Bcl-2/Bax homodimer so as to prevent the opening of the permeability transition pore to avoid the changing of mitochondrion membrane potential and the destruction of biosynthesis caused by the mitochondrion release of apoptosis inducing factors and to reach the objective of restraining apoptosis.