Table 2.
Clinical studies with curcumin and other natural compounds
| Disease | Dose/frequency | Patients | End point modulation | References |
|---|---|---|---|---|
| Curcumin | ||||
| Safety trials | ||||
| Phase 1 | 2,000 mg/day | 10 | Piperine enhanced bioavailability by 2,000% | Shoba et al. (1998) |
| Phase 1 | 500–12,000 mg/day × 90 days | 25 | Histologic improvement of precancerous lesions | Cheng et al. (2001) |
| Phase 1 | 500–12,000 mg/day | 24 | Safe, well-tolerated even at 12 g/day | Lao et al. (2006) |
| Efficacy trials | ||||
| Alzheimer’s disease | 1 g once daily, 4 g once daily | 36 | – | Baum et al. (2008) |
| Atherosclerosis | 10 mg; 2×/day × 28 days | 12 | Lowered LDL and ApoB, increased HDL and ApoA | Ramirez Bosca et al. (2000) |
| Cadaveric renal transplantation | 480 mg; 1–2/day × 30 days | 43 | Improved renal function, reduced neurotoxicity | Shoskes et al. (2005) |
| Cardiovascular disease | 500 mg/day × 7 days | 10 | Decreased serum lipid peroxidase (33%), increased HDL cholesterol (29%), decreased total serum cholesterol (12%) | Soni and Kuttan (1992) |
| Chronic anterior uveitis | 375 mg; 3×/day × 84 days | 32 | 86% decrease in chronic anterior uveitis | Lal et al. (1999) |
| Crohn’s disease | 360 mg; 3/day × 30 days; 4 for 60 days | 5 | Improved symptoms | Holt et al. (2005) |
| CRC | 36–180 mg/day × 120 days | 15 | Lowered GST | Sharma et al. (2001) |
| CRC | 450–3,600 mg/day × 120 days | 15 | Lowered inducible serum PGE2 levels | Sharma et al. (2004) |
| CRC | 450–3,600 mg/day × 7 days | 12 | Decreased M1G DNA adducts | Garcea et al. (2005) |
| Colon cancer | 10 g (n = 6) and 12 g (n = 6) | 12 | Pharmacokinetics | Vareed et al. (2008) |
| CRC, ACF | 2 g or 4 g/day for 30 days | 44 | A significant 40% reduction in ACF number occurred with the 4 g dose (P < 0.005), whereas ACF were not reduced in the 2 g group | Carroll et al. (2011) |
| External cancerous | 1% ointment for several months | 62 | Reduction in smell in 90% patients, reduction of itching in all cases, dry lesions in 70% patients, reduction in lesion size and pain in 10% patients | Kuttan et al. (1987) |
| FAP | 480 mg; 3/day × 180 days | 5 | Decrease in the number of polyps (60.4%), decrease in the size of polyps (50.9%) | Cruz-Correa et al. (2006) |
| H. pylori infection | 300 mg/day × 7 days | 25 | Significant improvement of dyspeptic symptoms | Di Mario et al. (2007) |
| HIV | 625 mg; 4×/day × 56 days | 40 | Well tolerated | James (1996) |
| IIOP | 375 mg; 3×/day × 180–660 days | 8 | Four patients recovered completely; one patient showed decrease in swelling, no recurrence | Lal et al. (2000) |
| Gall bladder function | 20 mg, single dose | 12 | Decreased gall bladder volume (29%) | Rasyid and Lelo (1999) |
| Gall bladder function | 20–80 mg, single dose | 12 | Decreased gall bladder volume (72%) | Rasyid et al. (2002) |
| ICF | – | 1,010 | Better MMSE score | Ng et al. (2006) |
| IBS | 72–144 mg/day × 56 days | 207 | Reduced symptoms | Bundy et al. (2004) |
| Liver metastasis | 450–3,600 mg/day × 7 day | 12 | Low bioavailability | Garcea et al. (2004) |
| Pancreatic cancer | 8 g by mouth daily every 2 months | 25 | Oral curcumin is well tolerated and, despite its limited absorption, has biological activity in some patients with pancreatic cancer | Dhillon et al. (2008) |
| Pancreatic cancer | 8 g | 21 | Safe and feasible in patients with pancreatic cancer | Kanai et al. (2010) |
| Postoperative inflammation | 400 mg; 3×/day × 5 days | 46 | Decrease in inflammation | Satoskar et al. (1986) |
| PIN | – | 24 | – | Rafailov et al. (2007) |
| Psoriasis | 1% curcumin gel | 40 | Decreased PhK2, TRR3, parakeratosis, and density of epidermal CD8+ T cells | Heng et al. (2000) |
| Psoriasis | 4.5 g/d | 18 | The response rate was low | Kurd et al. (2008) |
| Rheumatoid arthritis | 1,200 mg/day × 14 days | 18 | Improved symptoms | Deodhar et al. (1980) |
| Tropical pancreatitis | 500 mg/day × 42 days | 20 | Reduction in the erythrocyte MDA levels, increased erythrocyte GSH levels | Durgaprasad and Pai (2005) |
| Ulcerative proctitis | 550 mg; 2–3/day × 60 days | 5 | Improved symptoms | Holt et al. (2005) |
| Ulcerative colitis | 2,000 mg/day × 180 days | 89 | Low recurrence; improved symptoms | Hanai et al. (2006) |
| EGCG | ||||
| Safety trials | ||||
| Phase 1 | 200, 400, 600, and 800 mg | 20 | Systemic availability | Chow et al. (2001) |
| Efficacy trials | ||||
| OHT and OAG | 200 mg/day for 3 months | 36 | Influenced inner retinal function in eyes with early to moderately advanced glaucomatous | Falsini et al. (2009) |
| EE and fat oxidation | Catechins: 493.8–684 mg | 15 | Small acute effects on EE and fat oxidation | Gregersen et al. (2009) |
| Influenza infection | Catechins: 200 μg/mL 3/day for 3 months | 124 | Influenza infection was significantly lowered | Yamada et al. (2006) |
| Inhalation of MRSA | 3.7 mg/mL 3/day for 7 days | 72 | Reduced the MRSA count in sputum | Yamada et al. (2006) |
| Resveratrol | ||||
| Safety trial | ||||
| Pharmaco-kinetics | 0.5, 1, 2.5, or 5 g daily for 29 days | 40 | 2.5 and 5 g doses caused mild to moderate gastrointestinal symptoms | Brown et al. (2010) |
| Phase 1 | 0.5, 1, 2.5, or 5 g | 10 | High systemic levels of resveratrol conjugate metabolites | Boocock et al. (2007) |
| Efficacy trials | ||||
| Cerebral blood flow | 250 and 500 mg | 22 | Modulated cerebral blood flow variables | Kennedy et al. (2010) |
| Drug- and carcinogen-metabolizing enzymes | 1 g of resveratrol once daily for 4 weeks | 42 | Modulated enzyme systems involved in carcinogen activation and detoxification | Chow et al. (2010) |
| CRC | 8 daily doses of 0.5 or 1 g | 20 | Reduced tumor cell proliferation by 5% | Patel et al. (2010) |
| Genistein | ||||
| Safety trial | ||||
| Phase 1 | 600 mg/day for 84 days | 18 | Safe and well tolerated | Pop et al. (2008) |
| Pharmaco-kinetics | 2, 4, 8, or 16 mg/kg | 24 | Minimal clinical toxicity | Bloedon et al. (2002) |
| Efficacy trials | ||||
| Endometrial hyperplasia | 54 mg/day for 6 months | 56 | Useful for the management of endometrial hyperplasia | Bitto et al. (2010) |
| Prostate cancer | 450 mg daily for 6 months | 53 | Did not lower PSA levels | deVere White et al. (2010) |
| CV risk | 54 mg/day for 24 months | 198 | Favorable effects on both glycemic control and some cardiovascular risk markers | Atteritano et al. (2007) |
| Coronary heart disease | 71 mg | 33 | Neither harmful nor beneficial | Webb et al. (2008) |
| Bone metabolism | – | 208 | Protective against bone loss | Kritz-Silverstein and Goodman-Gruen (2002) |
| Asthma | – | 1,033 | Better lung function | Smith et al. (2004) |
ACF Aberrant crypt foci, CRC colorectal cancer, CV cardiovascular, EE energy expenditure, EGCG epigallocatechin, FAP familial adenomatous polyposis, GSH glutathione, GST glutathione S-transferase, HDL high-density lipoprotein, HIV human immunodeficiency virus, IBS irritable bowel syndrome, ICF improved cognitive function, IIOP idiopathic inflammatory orbital pseudotumors, LDL low-density lipoprotein, MDA malondialdehyde, MMSE mini-mental state examination, MRSA methicillin-resistant Staphylococcus aureus, OAG open-angle glaucoma, OHT ocular hyper-damage tension, PGE2 prostaglandin E2, PhK2 phosphorylase kinase 2, PIN prostatic intraepithelial neoplasia, PSA prostate-specific antigen, TRR3 transferrin receptor 3