Table 2.

The role of plants in OA in clinical research.

Plant Name	Plant Species/Family	Dosage	Duration	Control	Design	Placebo	Function	References
Harpagophytum procumbens	Harpagophytum procumbens (Burch.) DC. ex Meisn., Pedaliaceae R. Br.	2 × 480 × 30 mg/d, pure compound	4 weeks	Positive control	Double-blinded RCT	No	Relieve pain and improve function	[143]
Arctium lappa	Arctium lappa L., Asteraceae Bercht. and J. Presl	3 × 2 g/d, powder	6 weeks	Negative control	RCT	Yes	Alleviate the progression of OA	[147]
Psidium guajava	Psidium guajava L., Myrtaceae Juss	1 g/d, powder	12 weeks	Negative control	Double-blinded RCT	Yes	Relieve pain	[145]
Cissus quadrangularis	Cissus quadrangularis L., Vitaceae Juss	3200 mg/d, powder	8 weeks	Negative control	Double-blinded RCT	Yes	Relieve pain	[148]
Nigella sativa	Nigella sativa L., Ranunculaceae Juss	2.5 mL/8 h, extract	4 weeks	Negative control	Double-blinded RCT	Yes	Relieve pain	[144]
Vitellaria paradoxa	Vitellaria paradoxa C. F. Gaertn., Sapotaceae Juss	3 × 750 mg/d, extract	15 weeks	Negative control	Double-blinded RCT	Yes	Alleviate the progression of OA	[149]
Elaeagnus angustifolia	Elaeagnus angustifolia L., Elaeagnaceae Juss	3 × 200 mg/d, extract	4 weeks	Positive control	Double-blinded RCT	No	Relieve pain and improve function	[150]
		300 mg/d and 600 mg/d, extract	7 weeks	Positive control	Double-blinded RCT	No	Relieve pain	[151]
		15 g/d, powder	8 weeks	Negative control	Double-blinded RCT	Yes	Alleviate the progression of OA	[152]
Zingiber officinale	Zingiber officinale Roscoe., Zingiberaceae Martinov	2 × 255 mg/d, extract	6 weeks	Negative control	Double-blinded RCT	Yes	Relieve pain and improve function	[153]
		37.5 mg/d, extract	4 weeks	No	One-group, pre-test–post-test, quasi-experimental pilot study	No	Relieve pain	[154]
		25 mg/d, extract	4 weeks	No	Uncontrolled multicenter study	No	Relieve pain	[146]
		1 g/d, pure compound	11 days	Negative control	Double-blinded RCT	Yes	Relieve pain	[155]
Andrographis paniculata	Andrographis paniculata (Burm.f.) Wall. ex Nees., Acanthaceae Juss	300 mg/d and 600 mg/d, extract	12 weeks	Negative control	Double-blinded RCT	Yes	Alleviate the progression of OA	[156]
Pinus massoniana	Pinus massoniana Lamb., Pinaceae Spreng. ex F. Rudolphi	1322 mg/d, pure compound	12 weeks	Negative control	Double-blinded RCT	Yes	Alleviate the progression of OA	[157]
Curcuma longa	Curcuma longa L., Zingiberaceae Martinov	2 × 500 mg/d, extract	12 weeks	Negative control	Double-blinded RCT	Yes	Relieve pain	[158]
		2 × 46.67 mg/d and 3 × 46.67 mg/d, extract	12 weeks	Negative control	Double-blinded RCT	Yes	Relieve pain	[159]
		500 mg/d, extract	4 months	Negative control	Double-blinded RCT	Yes	Alleviate the progression of OA	[160]
		1000 mg/d, extract	4 weeks	Positive control	A clinical study	No	Relieve pain	[161]
		2 × 500 mg/d, extract	21 days, 42 days	Negative control	Single-blinded RCT	Yes	Relieve pain	[162]
Curcumin	Curcuma longa L., Zingiberaceae Martinov	3 × 500 mg/d, extract	4 weeks	Positive control	RCT	No	Relieve pain	[163]
		2 × 500 mg/d, extract	4 weeks	Negative control	RCT	Yes	Relieve pain	[164]
		1500 g/d, extract	4 weeks	Positive control	A multicenter study	No	Relieve pain and improve function	[165]
Resveratrol	Vitis vinifera L., Vitaceae Juss	500 mg/d, powder	90 days	No	A noncontrolled clinical trial	No	Relieve pain and improve function	[166]
		500 mg/d, powder	90 days	Negative control, Positive control	Double-blinded RCT	Yes	Relieve pain and inflammation	[167]
		500 mg/d, powder	90 days	Negative control, Positive control	Double-blinded RCT	Yes	Relieve pain and improve function	[168]
Artemisia annua	Artemisia annua L., Asteraceae Bercht. and J. Presl	150 mg/d and 300 mg/d, extract	12 weeks	Negative control	Double-blinded RCT	Yes	Improve the pain, stiffness, and limited function of knee joint	[169]