Turmeric root is cultivated in almost all the tropical areas around the world and is well known for its use as a spice in Indian/Asian cuisines. Traditionally it has been used as antibiotic (topically or systemically), and ingested for its benefits on the digestion. The major constituent of Turmeric is Curcumin and in modern market the extract is suggested as a dietary supplement to improve memory, for arthritis, and for cancer prevention. Studies suggest that curcumin acts as a weak phytoestrogen, and exhibits neuroprotective, anti-inflammatory, immunomodulatory, anti-proliferative, and chemopreventive effects.
Turmeric and its active constituents have been investigated for their therapeutic activities in humans. Turmeric may help alleviate symptoms of irritable bowel syndrome, quiescent ulcerative colitis, arthritic pain, and cancer. In one of the studies Turmeric extract was found to be safe and equally effective as a non-steroidal anti-inflammatory drug, Ibuprofen, for the treatment of osteoarthritis of the knee. A total of 107 patients were randomized to receive 800 mg/day ibuprofen or 2g/day Curcumin extract for 6 weeks. Significant improvement in pain on level walking, pain on stairs, and functions of the knee, were observed in both groups at 0, 2, 4 and 6 weeks. The results demonstrated that Curcumin extract were equally efficacious but were safer compared with ibuprofen.
Similarly, in patients with colorectal cancer, oral curcumin (360 mg three times daily or vehicle capsule) given to patients (n=63) prior to primary surgery for a period of 10 to 30 days showed improvements in body weight gain, and the general health of patients. In a phase II trial of oral curcumin in 25 advanced-pancreatic cancer patients were given 8 g curcumin daily. Researchers observed downregulated expression of NF-kappaB, cyclooxygenase-2, and phosphorylated signal transducer and activator of transcription 3 in peripheral blood mononuclear cells from patients compared with the levels at the baseline indicating improve prognosis. Although clinically relevant biological activity was seen in only two/25 patients the results are largely encouraging because no treatment-related toxic effects were observed.
Similar results were obtained in other studies with patients with memory impairments, abnormal lipid profile, and other cancer types. Some studies have also evaluated the beneficiary effects of Curcumin as a supplement along with other chemotherapeutic drugs. Although, most of these studies are small scale the results are encouraging and thus Curcumin should be evaluated in larger, randomized trials. One of the drawbacks of native curcumin is its low solubility and thus low bioavailability. Increasing its bioavailability may render it more effective. Scientists have prepared several liposomal or nanoparticle formulations to increase the bioavailability but these formulations have not been tested for efficacy completely.
Curcumin is a powerful antioxidant and most of its activity is one way or another related to being antioxidant. Curcumin has been shown to effect several cellular pathways such as MMP-13 induction and TGF-alpha inhibition in hepatoprotection, vitamin D receptor (VDR) binding and activation in colon, anti-apoptotic/anti-necrotic mechanisms, anti-proliferative and modulatory mechanisms such as Stat3, matrix metalloproteinase, and vascular endothelial growth factor inhibition; caspase- and mitochondria-dependent apoptosis; and cyclin-dependent kinase downregulation.
Caution should be paid when using curcumin with other chemotherapeutic agents because Curcumin is known to interfere with cytochrome P450 enzymes. Curcumin may also interact with drugs that are substrates of P-glycoprotein (P-gp). Therefore, Curcumin may interact with bioavailability and thus effectiveness of chemotherapy drugs like cyclophosphamide and doxorubicin. However, in some studies, a combination of curcumin and docetaxel or gemcitabine was shown to be safe. Patients with gastrointestinal disorders or predisposed to kidney stone formation should also use this supplement with caution. Patients on blood thinner such as warfarin are also advised to use the supplement with caution. In general you should contact your healthcare provider for information before using Curcumin as a supplement.
He ZY, et al. Upregulation of p53 expression in patients with colorectal cancer by administration of curcumin. Cancer Invest. 2011 Mar;29(3):208-13.
Kuptniratsaikul V, et al. Efficacy and safety of Curcuma domestica extracts in patients with knee osteoarthritis. J Altern Complement Med. 2009 Aug;15(8):891-7.
Dhillon N, et al. Phase II trial of curcumin in patients with advanced pancreatic cancer. Clin Cancer Res. 2008 Jul 15;14(14):4491-9.