Luteolin inhibits the differentiation of RAW264.7 cells into osteoclasts through Wnt/β-catenin pathway
Objective:To explore the inhibitory effects of Luteolin on the differentiation of RAW264.7 cells into os-teoclasts through Wnt/β-catenin pathway.Methods:The effects of different concentrations of Luteolin(1,2.5,5,10 μmol/L)on the activity and osteoclast differentiation of RAW264.7 cells were detected.RAW264.7 cells were divided into Blank group,Osteoclast induction group,Luteolin group,Luteolin+siRNA NC group,Luteolin+Wnt-3a siRNA group,Luteolin+NC group and Luteolin+Wnt-3a group.Except for Blank group,cells in all other groups were induced to differentiate by osteoclas-togenesis and subsequently treated with 5 μmol/L luteolin and cell transfection.After 7 days of induction,TRAP staining and Rhodamine-phalloidin staining were used to detect the ability of RAW264.7 cells to differentiate into osteoclasts.RT-qPCR and Western blot were used to detect osteoclast differentiation markers(NFATc1,CTSK,c-Fos,MMP9,RANKL)and Wnt/β-catenin pathway(Wnt-3a,β-catenin)mRNA and protein levels.Results:Concentrations of 1,2.5,5 μmol/L Luteolin had no significant effect on the activity of RAW264.7 cells(P>0.05),but could significantly inhibit the osteogenic differentiation of RAW264.7 cells.After osteoclast induced differentiation,the number of TRAP positive multinucleated cells was increased,F-actin rings and number of cell nuclei were increased,NFATc1,CTSK,c-Fos,MMP9 and RANKL mRNA and protein levels were increased,while Wnt-3a and β-catenin mRNA and protein levels were decreased(all P<0.05).After treatment with Luteolin,the number of TRAP positive multinucleated cells was decreased,F-actin rings and number of cell nuclei were de-creased,NFATc1,CTSK,c-Fos,MMP9 and RANKL mRNA and protein levels were decreased,while Wnt-3a and β-catenin mRNA and protein levels were increased(all P<0.05).Knocking down Wnt-3a expression could weaken the effect of magno-lol on the above indicators(all P<0.05).Overexpression of Wnt-3a could enhance the effect of magnolol on the above indica-tors(all P<0.05).Conclusion:Luteolin inhibited the differentiation of RAW264.7 cells into osteoclasts through Wnt/β-catenin pathway.