Fuscoside Attenuates Bone Loss in Bone Defects by Regulating The Rankl/Nlrp3/Opg Pathway in Rats

Objective: This study evaluated the beneficial effect of fuscoside in the repair of bone defects (BDs) and the possible molecular mechanism thereof.

Materials and methods: In this experimental study, a BD was induced by drilling the rat tibia. The rats were then administered oral fuscoside, at 200 or 300 mg/kg, for 2 weeks. The effect of treatment was assessed based on the bone formation score and on the levels of cytokines and biochemical markers in serum. Tibial expression of the proteins involved in the RANKL/Nlrp3/Opg pathway was determined by quantitative reverse-transcription polymerase chain reaction and western blot assay, and histopathological changes by haematoxylin and eosin and TRAP staining.

Results: In the fuscoside-treated BD rats, the bone formation score improved and inflammatory cytokine levels were reduced. The levels of biochemical markers improved as well, as did the expression of Apoptosis proteins. Fuscoside also attenuated the expression of RANKL, Opg, Nlrp3, Runx2, Osterix, and Osteocalcin (Oc) proteins in the tibial tissue of the BD rats and reversed the abnormal histopathological changes.

Conclusion: These results suggest that fuscoside improves BD repair by reducing the differentiation of osteoclasts and by regulating the RANKL/Nlrp3/Opg pathway.