Table 4.

Use of plant extracts and herbal medicine to inhibit iNOS in OA.

	Plant extract/ herbal medicine	Plant source	Outcome	Model	Reference
1	Ginkgo biloba extract (EGb)	Ginkgo biloba	EGb inhibited NO production, iNOS expression, chemokine production, and the JNK-AP1 signaling pathway.	Human OA chondrocytes	(Ho et al., 2013)
2	Cherry seed extract (SCE)	Prunus avium	Patients who were treated with SCE topically showed significant decreased inflammatory cytokines levels, decreased pain and decreased serum CRP levels.	Double-blind, placebo-controlled RCT	(Mahmoud, Al-Awadhi, & Haines, 2015)
3	Herbal-Leucine mixture (HLM)	Uncaria tomentosa, Boswellia spp., Lepidium meyenii and L-Leucine	HLM showed chondroprotective and anti-inflammatory activity in OA.	Primary OA chondrocytes or OA cartilage explants	(Akhtar, Miller, & Haqqi, 2011)
4	Ginsenoside Rb1 (G-Rb1)	Panax ginseng	G-Rb1 reduced the levels of IL-1β, TNF-α, NO, MMP-1 and MMP-13, by suppressing iNOS expression and reducing ROS production.	Rat articular chondrocytes	(S. Kim et al., 2012)
5	Duhuo Jisheng decoction (DHJSD)	Radix angelicae pubescentis and Herba taxilli	DHJSD inhibited NO-induced apoptosis in rat articular chondrocytes. DHJSD combined with Western medicine or sodium hyaluronate injection appeared to have benefits for knee OA.	Rat articular Chondrocytes, Randomized clinical trials	(Zhang et al., 2016)