Curcumin blocks Melanoma and Myeloma

Curcumin, the pungent yellow spice found in turmeric and curry powder, blocks a key biological pathway needed for development of melanoma and other cancers, M. D. Anderson researchers say.

The study, to be published in the Aug. 15 issue of the journal Cancer, and now available online, demonstrates how curcumin stops laboratory strains of melanoma from proliferating and pushes the cancer cells to commit suicide.

It does this, researchers say, by shutting down nuclear factor-kappa B (NF-kB) activation, a powerful master switch known to regulate an abnormal inflammatory response leading to a variety of disorders, including arthritis and cancer.

Results lead to studies of other cancers

Researchers treated three different melanoma strains with curcumin and assessed the activity of NF-kB. They also studied IKK, a protein kinase (enzyme/catalyst that turns other proteins on) that switches “on” NF-kB. The spice kept both proteins from being activated, so it worked to stop the growth of melanoma, and it also induced apoptosis (cell death).

“The antioxidant, anti-inflammatory and anti-carcinogenic properties of curcumin derived from turmeric are undergoing intense research here and at other places worldwide,” says one of the study’s authors, Bharat Aggarwal, Ph.D., professor of cancer medicine in the Department of Experimental Therapeutics.

At M. D. Anderson, for example, dramatic results from laboratory studies have led to two ongoing Phase I human clinical trials, testing the ability of daily capsules of curcumin to slow growth of pancreatic cancer and multiple myeloma. Given that curcumin is non-toxic, future trials are expected to begin in both animals and humans for other cancers, Aggarwal says.

Roots of spice’s healing powers run deep

Ground from the root of the Curcuma longa plant, curcumin is a member of the ginger family.

It has long been used in India and other Asian nations as a:

• Food preservative
• Coloring agent for food and textiles
• Spice (2% to 5% of turmeric is curcumin)
• Folk medicine to:
• Cleanse the body
• Heal wounds
• Prevent wrinkles
• Suppress inflammation

Knowledge of curcumin’s anti-inflammatory properties and the growing realization that cancer can result from inflammation has spurred mounting interest in the spice, Aggarwal says. Another fact that has generated further excitement: “The incidence of the top four cancers in the United States – colon, breast, prostate and lung – is as much as ten times lower in India,” he says.

Next step involves studies in animals, humans

M. D. Anderson and other institutions previously found that curcumin inhibits tumor cell proliferation and angiogenesis, the process by which new blood vessels form from existing vessels.

In the recent study, researchers found that besides inhibiting NF-kB, curcumin suppresses the STAT3 pathway that is also involved in tumor development. Both pathways play a central role in cell survival and proliferation.

An ability to suppress numerous biological routes to cancer development is important if an agent is to be effective, Aggarwal says. “Cells look at everything in a global way, and inhibiting just one pathway will not be effective.”

The study results are encouraging, Aggarwal says, yet he cautions that they are lab findings and much study needs to be done before any recommendations might be made regarding use of curcumin by the general public.