Table 4.

Effects and mechanisms of terpenoids on bone destruction in rheumatoid arthritis (RA).

Bioactivecompounds	Source	Chemical structure	Targets	Functions	References
Triptolide	Tripterygium wilfordii Hook.f.		Down-regulated: IL-1α, IL-1β, TNF-α, cIAP2, RANKL Up-regulated: IL-10, TGF-β1, OPG	promote the apoptosis of osteoclast and inhibit osteoclast differentiation	(Wang et al., 2018) (Wang S. et al., 2019) (Liu et al., 2013) (Xu et al., 2016)
Celastrol	Tripterygium wilfordii Hook.f.		Down-regulated: IL-6, IL-1β, NF-κB, 90β protein, c-Fos, c-Jun, NFATc1, TRAP, CTSK, CTR, MMP-9, RANKL, GM-CSF, M-CSF, OPN, IGF-1, MMP-9	inhibit osteoclast differentiation and function	(Astry et al., 2015) (Cascao et al., 2017) (Gan et al., 2015) (Nanjundaiah et al., 2012)
Artesunate	Artemisia annua L.		Down-regulated: MMP-9, TNF-α, IL-1β, IL-17, ERK, JNK, TRAP, CTSK, c-Fos, NFATc1	inhibit osteoclast differentiation	(Li Y. et al., 2013) (Wei et al., 2018)