Effects of equol on apoptosis and proliferation of osteoblast through PI3K/AKT pathway in high glucose and high fat environment

Abstract

Objective To explore the effect and mechanism of equol(Eq) on the proliferation and apoptosis of osteoblasts in high-glucose and high-fat environment. Methods High-glucose and high-fat model of ROS17/2.8 osteoblasts was established, and cells were divided into the control group (C group) and the model group (M group), the Eq-7 group (1×10-7mol/L Eq), the Eq-6 group(1×10-6mol/L Eq) and the Eq-5 group(10-5mol/L Eq). CCK-8 assay and HE staining was used to detect the viability and morphology of osteoblasts; Flow cytometry was used to test the apoptosis and cell cycle; Western blotting was used to detect the phosphorylation of PI3K/AKT signaling pathway and expression of associated proteins of osteoblasts. PI3K inhibitor was added to confirm the role of PI3K/AKT signaling pathway in the osteoprotective effect of Eq. Results Compared with the C group, the cell structure of the M group was significantly damaged, the cell survival rate, proportion of S phase of cell cycle, the degree of phosphorylation of PI3K/AKT pathway, the expression of Cyclin D1 and Bcl-2 in the M group decreased, while cell inhibition rate, cell apoptosis, proportion of G1 phase of cell cycle, the expression of Bax and cleaved caspase-3 of the M group increased (P < 0.05); Compared with the M group, the Eq groups had increased cell survival rate, decreased cell inhibition rate, enhanced fraction of osteoblast in the S phase and decreased osteoblast apoptosis rate(P < 0.05). Eq treatment enhanced the phosphorylation of PI3K/AKT pathway of osteoblasts and increased expression level of Cyclin D1 and Bcl-2 protein and decreased expression of Bax and cleaved caspase-3 (P < 0.05). The intervention effect of Eq enhanced with the increase of concentration of Eq. However, this regulatory effect of Eq almost disappeared after co-administration of PI3K inhibitor. Conclusion Eq can reduce the apoptosis and promote the proliferation of osteoblasts in the high-glucose and high-fat environment by activating the PI3K/AKT pathway.

Keywords

• equol
• high-glucose and high-fat
• osteoblasts
• apoptosis
• proliferation