Turmeric and cancer - Worth considering

source: http://www.mskcc.org/

Turmeric is a plant that is native to South Asia but is cultivated in tropical areas around the world. The rhizome is used as a spice in regional cuisines, and as coloring agent in food and cosmetics for its yellow-orange color. 

It is also used in traditional medicine for circulation and digestion. The extract is marketed as a dietary supplement to improve memory, for arthritis, and for cancer prevention. 

The active constituents are turmerone oil and water-soluble curcuminoids, mainly curcumin which is the focus of most research. In vitro studies suggest that curcumin, the principal bioactive ingredient of turmeric, acts as a weak phytoestrogen, and exhibits neuroprotective, choleretic, anti-inflammatory, immunomodulatory, anti-proliferative, and chemopreventive effects. Curcumin, its analogs, and liposomal formulations have also produced chemosensitizing and radiosensitizing effects 

Mechanism of action

Curcumin’s hepatoprotective effects may occur via MMP-13 induction and TGF-alpha inhibition, as well as anti-apoptotic/anti-necrotic mechanisms. However, it has also been shown to inhibit cell-cycle progression during normal liver regeneration. In vitro and animal lung models point to 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 . Curcumin appears to synergize with isoflavones, suppressing PSA production in prostate cells through anti-androgen effects . Curcumin induced apoptosis via AKT-mTOR inhibition in uterine leiomyosarcoma cells . In pancreatic cancer patients, downregulation of NF-kappa B and cyclooxygenase-2 were observed. Another possible chemopreventive mechanism of curcumin may be via vitamin D receptor (VDR) binding and activation, thereby protecting tissues of the small intestine and colon where VDRs are expressed and vitamin D is known to serve anticancer functions . Curcumin-induced apoptosis may be p21-dependent in colon cancer . Upregulation of p53 modulation of Bax and Bcl- 2 was also observed in colorectal cancer patient tissues. Curcumin may inhibit chemotherapy-induced apoptosis via JNK pathway inhibition and reactive oxygen species generation.