Tatarinan T, an α‐asarone‐derived lignin, attenuates osteoclastogenesis induced by RANKL via the inhibition of NFATc1/c‐Fos expression

Abstract We have previously reported that the lignin‐like compounds,Tatarinan O(TO) andTatarinan N(TN), extracted from the roots ofAcorus tatarinowii Schott, inhibit receptor activator of nuclear factor‐κB ligand (RANKL)‐induced osteoclastogenesis. In the present study, the potential function of the α‐asarone‐derived lignins,Tatarinan T(TT) andTatarinan A(TA), to regulate RANKL‐induced osteoclastogenesis was investigated, and it was found that only early treatment with TT may inhibit RANKL‐triggered formation of osteoclasts and resorption. The results revealed repressed expression levels of several osteoclast marker genes, including ATPase H+‐transporting V0 subunit d2 (Atp6v0d2),αvβ3integrin, and osteoclast‐associated receptor (OSCAR), following TT treatment during osteoclastogenesis. Moreover, TT reduced the expression levels of the core transcription elements, nuclear factor of activated T‐cells cytoplasmic 1 (NFATc1) andc‐Fos. However, western blotting analysis showed that TT treatment did not alter nuclear factor‐κΒ (NF‐κB) activation or mitogen‐activated protein kinase (MAPK) or Syk/Btk/phospholipase Cγ2 (PLCγ2) phosphorylation. Taken together, these results suggest the potential of TT in the treatment of diseases of increased bone resorption.