Curcumin may suppress tumor proliferation

Houston - Diferuloylmethane or curcumin, an ingredient in common turmeric or curry powder spice, may lead to a cure for melanoma, as well as many other cancers without toxic side effects, says Bharat Aggarwal, Ph.D., professor of cancer medicine and chief, Cytokine Research Laboratory, M.D. Anderson Cancer Center, here.

Recently published findings by Dr. Aggarwal and colleagues show positive results in vitro against melanoma, while clinical trials testing its effects on colon cancer, pancreatic cancer, multiple myeloma and breast cancer are under way.

"Curcumin should work for several cancers and we are going through a list of cancers showing that it does work," Dr. Aggarwal says. "Curcumin has been shown to suppress nuclear factor-kappaB (NF-kB), the master switch that controls inflammation, which is considered a mediator of tumor angiogenesis. The master switch also controls tumor proliferation and metastases."

Dr. Aggarwal and fellow researchers at the University of Texas M.D. Anderson Cancer Center studied three melanoma cell lines with B-raf mutations that were treated with curcumin. NF-kB binding activity and upstream regulator IkappaBalpha kinase (IKK) were down regulated by curcumin, which also induced apoptosis. The researchers also found that curcumin appeared to influence an interleukin-6 to allow for Akt phosphorylation instead of suppressing it.

Efforts are under way to begin animal studies and eventually clinical trials to show the safety and efficacy of curcumin on melanoma.

Earlier research shows similar results for all cell lines in head and neck squamous cell carcinomas by curcumin, again suppressing IKK-mediated NF-kappaB activation and regulated gene expression.

Other inflammatory disease

Numerous studies have also been published showing the anti-inflammatory effects of curcumin and other spices at the cellular level.

Dr. Aggarwal was involved in a recent study showing the association of NF-kappaB with other inflammatory diseases, including cancer, diabetes, arthritis, psoriasis and multiple sclerosis. In addition to curcumin, red pepper (capsaicin), cloves, ginger, basil, rosemary, garlic and others also appear to block NF-kappaB.

"This is the reasoning for seasoning," write the investigators.

"Nutritional epidemiologists are also pointing a finger at curcumin, which is traditionally used in India quite extensively," Dr. Aggarwal says. "The incidence of some cancers is very, very low over there."

The top four cancers in the United States, including colon, lung, prostate and breast cancer, is 10 times lower in India.

Psoriasis

More data from the University of California, Los Angeles (Sepulveda) supports the use of curcumin to treat psoriasis by altering phosporylase kinase (PhK) activity.

The clinical trial involving 40 patients showed the most phosporylase kinase activity among patients with active untreated psoriasis followed by those treated with calcipotriol. The PhK activity was only lowest among patients with normal skin followed by those treated with curcumin.

Safety

Dr. Aggarwal says many drug treatments for cancers often fail because patients cannot tolerate them.

"More than 50 percent of drugs fail because of the toxicity and here is something (curcumin) where there is no known toxicity," he tells Dermatology Times. "There have been studies using up to 12 g/day for three months and there is no toxicity.

"Clinical trials are the only way to get unequivocal answers, but the major limitation is money. Major pharmaceutical companies cannot get a patent on curcumin. Physicians are ready to do the trials, but until they get funding, they are on hold."

Dr. Aggarwal's most recent research was funded by the National Cancer Institute and the Department of Defense.

Dosing

Curcumin has been manufactured in a variety of vehicles, including oral capsules, topicals, as well as intravenous and subcutaneous injections.

However, systematical human trials are still needed to determine dosing, treatment and whether there is a need for maintenance therapy.