Table 10.
Case reports and observational studies conducted between 1971 and 2021.
| Indication | Trial Type, Size |
Results | Year | Reference |
|---|---|---|---|---|
| Chemosis | CR 1 |
Initial treatment with multiple preparations that did not lead to improvement, then with 300 mg Harpagophytum extract (not specified) 3 times daily, orally, for 6 months, leading to drastic improvement. | 1983 | Belaiche [489] |
| Familial Mediterranean fever | CR 17 |
Harpagophytum extracts characterized as aqueous (DER 1:2.4, 2.5% harpagoside)—this characterization may also apply to previous trials by Belaiche and Dahout (see above)—6–9 g single dose, duration not provided; significantly decreased recurrence in 80% of patients. | 1983 | Belaiche [490] |
| Cancer | CR 2 |
Tumor regression after taking Harpagophytum extract (500 mg daily) and/or Essiac respectively, without cytotoxic therapy. | 2009 | Wilson [491] |
| DJD | O ~120 |
Harpagophytum D4–D6, IA, and D1 orally; 1–6 months; substantial improvement of symptoms in most cases. | 1971 | Beham [492] |
| CP | O 60 |
Harpagophytum D2, IA, plus tea (2–3 tsp per 1 L water) or 3 × 2 tablets orally, duration not provided; dose-dependent response; 60% substantial improvement of symptoms, 20% improvement, 20% no change. | 1972 | Schmidt [43] |
| CP, DJD | O 146 |
Harpagophytum D2, IA, duration not provided; improvement in 134 patients. | 1972 | Zimmermann, cited in [130] |
| DJD | O 25 |
Harpagophytum D2–D3, IA, and SC, 1–2 mL, pain-free after 6 injections, or tea (1 tsp per 300 mL) daily for 3–6 weeks. | 1972 | Brantner [493] |
| DJD | O 70 |
Harpagophytum D2, IA, some + tea, some + indometacin, duration not provided; improvement in 90% of patients. | 1976 | Wilhelmer, cited in [44] |
| CP, DJD | O 21+ |
Harpagophytum D1–D3, IA, SC, and i.v., tea, orally, duration not provided; significant improvement in 30% of patients. | 1977 | Zimmermann [494] |
| DJD | O 84 |
250 or 500 mg Harpagophytum extract (not specified) 3 times daily orally for 2–6 months, improvement in 72% of patients. | 1979 | Dahout, cited in [495] |
| CP, DJD | O 600 |
Harpagosan tea (2 tea bags in 500 mL water daily) plus D2 SC for up to 6 months. Symptoms disappeared in 200 patients; 400 patients improved after having received additional conventional medication for the first 3–4 weeks. | 1983 | Warning cited in Schmidt [44] |
| Rheumatoid arthritis | O 1 |
Improvement after treatment with low-potency Harpagophytum i.v. and orally, duration not provided. | 1987 | Stübler [496,497] |
| DJD | O 553 |
Patients treated with 2–6 capsules of 400 mg Harpagophytum extract (1.5–2.5:1) for 8 to 180 days. Outcomes confirmed RCT results in terms of efficacy and safety. | 2000 | Müller et al. [498] |
| DJD | O 255 |
Post-marketing surveillance study of biopsychosocial determinants and treatment response. Patients treated with Harpagophytum extract (60 mg harpagoside/day) for 2 months. Outcome parameters were significantly worse in non-responders. | 2009 | Thanner et al. [499] |
| CP, DJD, dyspepsia, hypercholesterolemia, detoxication | O, CR 700+ |
Harpagophytum tea, up to 12 weeks, D2, SC, 20 injections, further improvement with additional D2 i.v. and tea. | 1978 | Schmidt [130] |
| Diabetes mellitus with lipometabolic disorder | OT 10 |
4 patients 3 weeks, 6 patients 4 and 3 weeks, over a total of 6 months; Harpagophytum tea, amount not specified; cholesterol, lipid, and blood sugar levels normalized. | 1974 | Hoppe [500] |
| Hypercholesterolemia and hyperuricemia | OT 100 |
Harpagophytum tea, 2 tea bags per ½ L water, 3× daily before meals 1/3 of the tea; 20–21 days; lowered cholesterol levels in 80%, normal levels in 45%, 66% improvement in hyperuricemia. | 1978 | Grünewald [405] |
| DJD | OT 13 |
Harpagophytum extract (<30 mg harpagoside/day), for 6 weeks, followed up for another six weeks; no overall statistically significant improvements in the conditions. | 1981 | Grahame and Robinson [501] |
| DJD | OT 630 |
42% to 85% of the patients (depending on grouping) showed improvements after 6 months with Harpagophytum extract (>90 mg harpagoside/day). | 1982 | Belaiche [502] |
| DJD | OT 38 |
Comparison of Formica rufa D6 with Harpagophytum D4, for 3 months; improvement in pain severity and mobility with both, Formica rufa slightly superior. | 1991 | Kröner [503] |
| Effect on eicosanoid biosynthesis | OT 34 (25/8) healthy volunteers |
Harpagophytum, 4 capsules (500 mg powder, 3% of total glucoiridoids) daily for 21 days. No effect vs. control. | 1992 | Moussard et al. [504] |
| MSD | OT 102 (51,51) |
Patients treated with Harpagophytum extract (30 mg harpagoside/day) or conventional therapy (mainly oral NSAIDs). Number of pain-free patients and changes in Arhus scores after 4 and 6 weeks of treatment was comparable between the groups. | 1997 | Chrubasik et al. [505] |
| DJD | OT 43 |
Harpagophytum powder 3 g daily for 60 days. Reduction of pain intensity in 89%, increased mobility in 83%. | 1997 | Pinget and Lecomte [506] |
| MSD | OT 2053 |
Patients treated with Harpagophytum extract (30 mg harpagoside/day) for 6 weeks. Symptoms improved over time. | 1999 | Schwarz et al. [507] |
| DJD | OT 45 |
Patients treated with Harpagophytum extract (30 mg harpagoside/day) for two weeks plus NSAID treatment, and devil’s claw alone, for four weeks. No worsening of scores was observed during treatment with devil’s claw alone. | 2000 | Szczepanski et al. [508] |
| MSD | OT 1026 |
Patients treated with Harpagophytum extract (30 mg harpagoside/day) for 6 weeks. Symptoms improved. | 2000 | Usbeck [509,510] |
| MSD | OT 130 |
Patients treated with Harpagophytum extract (~30 mg harpagoside/day) for 8 weeks. Arhus back pain index decreased significantly during treatment. Other measures also improved significantly. | 2001 | Laudahn et al. [511,512,513] |
| DJD | OT 583 |
Patients treated with Harpagophytum extract (~30 mg harpagoside/day) for 8 weeks. Symptoms improved and the dose of co-medication (NSAIDs) could be reduced. | 2001 | Schendel [514] |
| DJD | OT 675 |
Patients treated with Harpagophytum extract (~30 mg harpagoside/day) for 8 weeks. Efficacy rated good or very good in 82% of cases. The symptom scores decreased, and co-medication was successfully reduced or even discontinued. | 2001 | Ribbat and Schakau [515] |
| MSD | OT 250 |
Patients treated with Harpagophytum extract (60 mg harpagoside/day) for 8 weeks. Both generic and disease-specific outcome measures improved. | 2002 | Chrubasik et al. [516] |
| DJD | OT 614 |
Patients treated with Harpagophytum extract (480 mg twice daily) for 8 weeks. Symptoms improved in the majority of patients; treatment was well-tolerated. | 2003 | Kloker and Flammersfeld [517,518] |
| DJD | OT 75 |
Patients treated with Harpagophytum extract (50 mg harpagoside/day) for 12 weeks. WOMAC index and 10 cm VAS pain scale improved notably. | 2003 | Wegener and Lüpke [519,520] |
| MSD | OT 99 |
Patients treated with Harpagophytum extract (~30 mg harpagoside/day) for 6 weeks. Symptoms improved. | 2005 | Rütten and Kuhn [521] |
| MSD | OT 102 (29/22/51) |
Patients treated with Harpagophytum extract (~30 mg harpagoside/day) and/or conventional therapy for 6 weeks. Efficacy was found in all groups, advantages for devil’s claw were not statistically significant. | 2005 | Schmidt et al. [522,523] |
| DJD | OT 65 |
Patients treated with combination of Harpagophytum procumbens, Zingiber officinale, and Urtica sp. (ratio not disclosed) for 8 weeks. Improvements in all efficacy parameters were observed. | 2005 | Sohail et al. [524] |
| Endometriosis | OT 6, 12 |
Patients treated with Harpagophytum extract (1600 mg daily) for 12 weeks. Reduction of symptoms in 4 (6) patients after 4 weeks, in all patients after 12 weeks. | 2005, 2006 | Arndt et al. [525,526] |
| DJD | OT 259 |
Patients treated with Harpagophytum extract (1.5–3:1, 960 mg daily) and NSAIDs for 8 weeks. At the end of the treatment, 44.8% could decrease NSAID dosage. All parameters improved significantly. | 2006 | Suter et al. [527,528] |
| MSD | OT 114 |
Patients treated with Harpagophytum extract (60 mg harpagoside/day) for up to 54 weeks. Most outcome scores improved significantly over time. | 2007 | Chrubasik et al. [529] |
| DJD | OT 42 |
Patients treated with combination of Harpagophytum (1800 mg), Curcuma longa (1200 mg), and bromelain (900 mg) daily, plus conventional therapies for 2 weeks. Clinically relevant improvement of joint pain scores in all patients. | 2014 | Conrozier et al. [530] |
| DJD | OT 20 |
Patients treated with combination of 500 mg glucosamine sulfate, 400 mg chondroitin sulfate, 10 mg collagen type II, and 40 mg Harpagophytum per day for 12 months. Femoral hyaline cartilage thickness significantly improved and radiographic progression of knee osteoarthritis delayed. | 2019 | Vreju et al. [531] |
| MSD | OT 39/40/16 |
Otherwise healthy subjects with mild/moderate neck/shoulder pain related to sport; cream containing a combination of ingredients, including H. procumbens root extract + standard treatment, standard treatment, diclofenac patch + standard treatment respectively, for 2 weeks; significant improvement in pain, stiffness, mobility, and working capacity, compared to non-cream groups. | 2021 | Hu et al. [532] |
CP = chronic polyarthritis; IA = intra-articular; SC = subcutaneous; DJD = degenerative joint diseases (osteoarthritis); MSD = musculo-skeletal disorders (low back pain); OT = observational trial; O = observation; CR = case report; NSAID = non-steroidal anti-inflammatory drug; WOMAC = Western Ontario and McMaster Universities.