BCL2 and osteoporosis: The results suggest that the mechanism of action of morroniside and loganin on osteoporosis was as follows (Figure 4): on the one hand, both of them could not only promote differentiation of osteoblasts by increasing secretion of alkaline phosphatase, osteocalcin and collagen type I, but also could inhibit apoptosis of osteoblasts by down-regulating the expressions of caspase-3 and caspase-9, up-regulating the expressions of bcl-2 to raise survival rate of osteoblasts.