Albiflorin improves osteoporotic bone regeneration by promoting osteogenesis-angiogenesis coupling of bone marrow mesenchymal stem cells.

Albiflorin (ALB) has been shown to promote osteogenesis, however, its effect on angiogenesis still remains unclear. This research aimed to explore the effect of ALB on angiogenesis and bone regeneration under osteoporotic conditions. The pro-osteogenesis capacity of ALB was assessed by osteogenic differentiation assays. Subsequent research examined the effect of ALB on angiogenesis. After revealing the pro-angiogenesis capacity of ALB, we explored the relationship between the pro-osteogenesis capacity and the pro-angiogenesis capacity of ALB by angiogenesis-related assays. Whereafter, the osteoporotic bone defect rat model was constructed to explore the effect of ALB on osteoporotic bone regeneration. Our research found that ALB promoted osteogenesis of bone marrow mesenchymal stem cells (BMSCs) and enhanced the expression of angiogenesis-specific markers, but it couldn't promote angiogenesis of human umbilical vein endothelial cells (HUVECs) directly. Further research revealed that ALB enhanced HUVECs migration and tube formation when the cells cultured in BMSCs-conditioned medium. Subsequently, it is observed that ALB facilitated bone regeneration under osteoporotic conditions by promoting osteogenesis and the formation of CD31EMCN type H-positive vessels. To sum up, this research indicated that ALB could improve osteoporotic bone regeneration by promoting osteogenesis-angiogenesis coupling of BMSCs, which provided a novel perspective for improving osteoporotic bone regeneration.