| Osteoporosis (OP) is a chronic disease that seriously threatens bone health, increases the risk of fractures, and significantly impacts quality of life. Macrophages, as important members of the immune system, polarize into pro-inflammatory M1 macrophages and anti-inflammatory and pro-repair M2 macrophages under specific stimuli. Imbalance in the M1/M2 ratio lead to pathological changes in osteoporosis, including increased bone resorption, decreased bone mineral density, and increased risk of fractures. This article provides an overview of macrophage polarization and the mechanisms of different macrophage subtypes in osteoporosis. M1 macrophages secrete inflammatory factors such as TNF-α, IL-23, and IL-1, trigger the RANKL/OPG system, promote osteoclast differentiation, and inhibit osteoblasts, thereby exacerbating the development of osteoporosis. On the other hand, M2 macrophages secrete inflammatory factors such as BMP2, TGF-β, and IL-4, stimulate signaling pathways like NF-κB, inhibit osteoclast activation, and promote osteoblast activity, relieving the condition of osteoporosis. Additionally, this article discusses the communication between macrophages and other cells and its impact on bone formation. Regarding macrophage polarization, this article introduces the latest strategies in the fields of chemical drugs, bioactive molecules, and traditional Chinese medicine for the treatment and prevention of osteoporosis by regulating the M1/M2 ratio of macrophages. It aims to provide new perspectives and directions for the treatment of osteoporosis. |