Table 1.

Characteristics of included studies

Author, year, location	Included Analysis	N Patients	Age (yr)	% Female	Intervention	Bioavailability Information, Curcumin	Comparator	Rescue Analgesia	Baseline Radiographic Status	Treatment duration (wk)	Industry Sponsored?
*Boswellia vs. Placebo*
Kimmatkar, et al., 2003⁴¹ India	Yes	30	59.0	60.0	Boswellia serrata extract, 333 mg capsule TID	NA	Placebo capsule TID	Current use of NSAIDs and physiotherapy were inclusion criteria	“clinico-radiological osteoarthritis”	8	Yes
Sengupta, et al., 2008⁴² India	Yes	70	52.7	71.0	Boswellia serrata extract (5-Loxin), 50 mg capsule BID Boswellia serrata extract (5-Loxin), 125 mg capsule BID	NA	Placebo capsule BID	Eligibility required patients to meet specific flare criteria upon medication washout. Ibuprofen rescue medication (maximum 1,200 mg/day) was allowed ≥ 3 days prior to examination.	ND	12	Yes
Sengupta, et al., 2010⁴³ India	Yes	57	52.4	66.7	Boswellia serrata extract (5-Loxin), 50 mg capsule BID Boswellia serrata extract (Aflapin), 50 mg capsule BID	NA	Placebo capsule BID	Eligibility required patients to meet specific flare criteria upon medication washout. Ibuprofen rescue medication (maximum 1,200 mg/day) was allowed ≥ 3 days prior to examination.	ND	12	Yes
Vishal, et al., 2011⁴⁴ India	Yes	59	54.2	62.7	Boswellia serrata extract (Aflapin), 50 mg capsule BID	NA	Placebo capsule BID	Ibuprofen rescue medication (maximum 1,200 mg/day) was allowed ≥ 3 days prior to examination.	ND	4	Yes
*Curcumin vs. Placebo*
Haroyan, et al., 2018⁴⁰ (Arm 1 and Placebo) Armenia	Yes	134	55.4	93.3	CuraMed capsule (contains 552–578 mg of BCM-95 as a dry extract, corresponding to 500 mg curcuminoids, and 49–52 mg volatile oil from Curcuma longa L. rhizome, 22–23.4 mg aromatic turmerone) TID	“… studies… have indicated that the relative bioavailability of curcumin from BCM-95 complex is approximately 6.93-fold greater than that of normal curcumin…”	Placebo capsule TID	Washout of NSAIDs and/or turmeric required 1 week prior to randomization Rescue medication use not described/indicated	Participants with “degenerative hypertrophic knee OA”… Kellgren - Lawrence grades I–III	12	Yes
Madhu, et al., 2013³⁶ India	Yes	60	56.7	56.7	Curcuma longa extract (NR-INF-02), 500 mg capsule BID	Capsules contained 12.6 % w/w polysaccharides “These polysaccharides have been demonstrated to have good bioavailability after oral administration”	Placebo capsule BID	Acetaminophen rescue medication (2,000–4,000 mg/day) was allowed ≥24 hours before clinical exam	“…tibiofemoral osteophytes of at least 1 mm and Kellgren and Lawrence grade 2 or 3.”	6	Not reported
Moharam zad, et al., 2011³⁹ Iran	Yes	67	ND	ND	Curcumin capsule, 600 mg/day	Not reported	Placebo capsule	ND	“…documented knee osteoarthritis (using knee x-ray).”	10	Not reported
Nakagawa, et al., 2014³⁸ Japan	Yes	41	68.6	78.9	Highly-bioavailble curcumin (Theracurmin), 180 mg capsule six times/day	Surface-controlled water-dispersible curcumin (Theracurmin)	Placebo capsule six times/day	Oral Celecoxib rescue medication (maximum 200 mg/day) or pain relief patches were permitted	Kellgren Lawrence grade II (80.5%) or III (19.5%)	8	Yes
Panahi, et al., 2014³⁷ Iran	Yes	53	57.4	77.0	C3 curcuminoid complex, 500 mg capsule TID	Each curcuminoid capsule contained 5 mg Bioperine to enhance oral bioavailability	Placebo capsule TID	Naproxen rescue medication was permitted	“…radio logical criteria defined by the American College of Rheumatology.	6	No
*Curcumin+Boswellia vs. Placebo*
Badria, et al., 2013⁴⁸ Egypt	No	45	ND	ND	Turmeric+Boswellia carteri extract, 500 mg capsule TID	Turmeric powder; no additional processing	Placebo capsule TID	ND	ND	12	Not reported
Haroyan, et al., 2018⁴⁰ (Arm 2 and Placebo) Armenia	Yes	135	57.0	94.1	Curamin capsule (350 mg BCM-95 and 150 mg Boswellia serrata gum resin extract consisting of 75% boswellic acids and 10% 3-O-AKBA) TID	“…studies…have indicated that the relative bioavailability of curcumin from BCM-95 complex is approximately 6.93-fold greater than that of normal curcumin…”	Placebo capsule TID	Washout of NSAIDs and/or turmeric required 1 week prior to randomization Rescue medication use not described/indicated	Participants with “degene rative hypertrophic knee OA”…Kellgren Lawrence grades I-III	12	Yes
*Boswellia vs. NSAID*
Sontakke, et al., 2007⁴⁷ India	No	66	ND	ND	Boswellia serrata extract, 333 mg capsule TID	NA	Valdecoxib, 10 mg capsule QD	Ibuprofen 400 mg TID was provided as rescue medication and given until symptomatic improvement	“…diag nosis was based on clinical presentation and X-ray findings and confirmed by the orthopedician.”	24	Not reported
*Curcumin vs. NSAID*
Kuptniratsaikul, et al., 2009⁴⁵ Thailand	Yes	107	60.7	80.4	Curcuma domestica extract, 500 mg capsule QID	Not reported	Ibuprofen, 400 mg capsule BID	1 week washout of NSAIDs and other OA medication Use of rescue medication was not permitted.	Evidence of radiographic osteophytes at baseline required	6	No
Kuptniratsaikul, et al., 2014⁴⁶ Thailand	Yes	331	60.6	89.4	Curcuma domestica extract, 250 mg capsule six times/day	Not reported	Ibuprofen, 200 mg capsule six times/day	Tramadol rescue medication was allowed, but other medications were not permitted	Kellgren Lawrence grade I (13%), II (40%), III (31%), IV (16%)	4	No
Kizhakkedath, 2013⁴⁹ India	No	28	48.5	57.0	Curcuma longa extract + Boswellia serrata extract, 500 mg capsule BID	Curcumin formulation is described as having “enhanced bioavailability.”	Celecoxib, 100 mg capsule BID	ND	“…moderate form of OA, evidenced by the narrowing of the medial joint space.	12	No

N= “number of…”; yr= years; wk= weeks; ND= “No data”; NA= “Not applicable”; TID= three times per day; NSAID= non-steroidal anti-inflammatory drug; BID= twice per day; AKBA= acetyl-11-keto-boswellic acid; QID= four times per day