FoxO1 as the critical target of puerarin to inhibit osteoclastogenesis and bone resorption.

Background: Elevated reactive oxygen species levels promote excessive osteoclastogenesis and bone resorption. Puerarin, a natural antioxidant, can prevent bone loss through its antioxidant effects; however, the underlying molecular mechanism remains unclear. This study aimed to explore the effects of puerarin on osteoclast differentiation and bone resorption by regulating the PI3K/AKT/FoxO1 signaling pathway.

Materials and methods: An ovariectomized (OVX) rat model of osteoporosis and H2O2-induced oxidative cell model of RAW 264.7 cells were established. The following indices were measured including bone μ-CT scanning and the protein expression levels of FoxO1, p-FoxO1, and catalase were detected using western blotting.

Results: Puerarin strongly alleviated oxidative stress-induced bone loss in OVX rats in vivo owing to its antioxidant effects. Puerarin improved the oxidative stress status of cells and inhibited osteoclast formation in vitro. Moreover, the protein expression of FoxO1 and its downstream target, catalase, was upregulated by puerarin.

Conclusions: Puerarin improved the OPG/RANKL ratio, upregulated the protein expression and transcriptional activity of FoxO1, and suppressed the differentiation of RAW264.7 cells into osteoclasts. FoxO1 is a pivotal target of puerarin to confer anti-osteoporosis effects.