Crocin facilitates osteogenesis and angiogenesis by moderating oxidative stress and ferroptosis via Nrf2/GPX4 pathway.

Bone formation is a complex multi-factor process of bone defect healing. Oxidative stress (OS) is predisposed to induce regulatory cell death (RCD), such as ferroptosis. At present, the antioxidant effects of Crocin on erastin induced oxidative damage were studied. The activity of bone marrow mesenchymal stem cells (BMSCs) and human umbilical vein endothelial cells (HUVECs) was detected by CCK-8 and EdU staining. The production of reactive oxygen species (ROS), MDA, SOD and GSH were evaluated. Western blotting assay was used to detect ferroptosis-related proteins. The osteogenic function of BMSCs was determined by alkaline phosphatase (ALP) activity, ALP staining and alizarin red S (ARS) staining. Western blotting and RT-PCR assays were used to detect the expression of osteogenic proteins and genes. Angiogenesis of HUVECs was evaluated by tube formation, RT-PCR, scratch test and Transwell assay. The results showed that Crocin can promote the osteogenic function of BMSCs and angiogenesis of HUVECs. In addition, Crocin protects cells from erastin-induced oxidative injury and inhibits ferroptosis via the Nrf2/GPX4 pathway. These findings suggest that Crocin can promote bone defect healing by regulating OS and inhibiting ferroptosis through the Nrf2/GPX4 pathway.