Table 3.

iNOS inhibition by plant-derived molecules in chondrocytes and animal OA models.

	Molecule	Source	Outcome	Model	Reference
1	EGCG	Green tea	EGCG inhibited the IL-1 beta-induced activity and expression of iNOS via blocking the NF-κB pathway activation	Human chondrocytes	(Ahmed et al., 2002; Singh, Ahmed, Islam, Goldberg, & Haqqi, 2002)
2	Wogonin	Scutellaria baicalensis	Wogonin suppressed the IL1-β- induced NO production and iNOS expression via activation of the ROS/ERK/Nrf2 signaling pathway	Human chondrocytes	(Khan et al., 2017)
3	Gallic acid (GA)	Gallnuts	GA suppressed the AGE-induced expression of iNOS in articular chondrocytes, playing a chondroprotective role against OA progression	Rabbit model of knee OA	(Wen et al., 2015)
4	Silibinin	Siltbum Marianum	Silibinin inhibited the IL1-β-induced NO production and iNOS expression via inhibiting the NF-κB pathway	Human chondrocytes	(Zheng et al., 2017)
5	Carvacrol	Oregano and thyme	Carvacrol inhibited the IL1-β-induced NO production and iNOS expression via inhibiting the NF-κB pathway	Human chondrocytes	(Xiao et al., 2018)
6	Sinapic acid	Vinegar and wine	Sinapic acid inhibited the IL1-β-induced NO production and iNOS expression via inhibiting the MAPK pathway	Rat chondrocytes	(Huang et al., 2018)
7	Sulforaphane	Broccoli, cabbage	Sulforaphane treatment inhibited NO synthesis and cartilage matrix degradation	Human chondrocytes and DMM model of osteoarthritis in mouse	(Davidson et al., 2013)