Curcumin, an ingredient of the Indian spice Turmeric, has been shown to stop the formation of metastases in prostate cancer patients, researchers from Ludwig-Maximilians-Universität (LMU) in Munich, Germany, reported in the journal Carcinogenesis today.

Tumeric, in powdered form, has been used for hundreds of years for the treatment of various illnesses, such as osteoarthritis. Curcumin, its active ingredient, stops inflammatory reactions, the scientists explained.

Several studies over the last few years have discovered a wide range of potential medicinal uses for curcumin. In March 2012 researchers from Michigan State University found that curcumin may be beneficial for people with Parkinson's disease.

Prostate cancer is one of the most common malignancies in Western societies. Unfortunately, it is often diagnosed too late, when tumors have metastasized - spread to other parts of the body. When a cancer metastasizes, the chances of dying from the disease increase dramatically.

PD Dr. Beatrice Bachmeier and team have been carrying out research on how a natural product that inhibits the formation of metastases behaves. Curcumin, as mentioned above, is found in turmeric, a plant that has had medicinal properties and has been widely used for thousands of years; it is also a major ingredient of curry. Curcumin is the polyphenol that gives curry its characteristic color.

As curcumin is well tolerated, it can be used both as preventive therapy (prophylactic) as well as treating prostate cancer patients whose tumors have already metastasized (secondary prevention).

Bachmeier and team had already shown that curcumin undermines the formation of metastatic tumors in the lungs in animal models with advanced breast cancer.

Curcumin may have medicinal uses for several types of cancer

Mitigating metastasis

In this new study, Bachmeier and colleagues set out to determine how effective curcumin might be in preventing metastases in patients with prostate cancer. They also wanted to find out what the agent's mechanism of action is.

They first looked at the molecular processes that are abnormally regulated in the cells of prostate carcinomas. Prostate and breast cancer have a lot in common. They are often linked to latent or chronic inflammatory reactions. Tumor cells in both types of cancers were found to produce the cytokines CXCL1 und CXCL2, both of them are pro-inflammatory immunomodulators.

In a mouse model, they discovered and then demonstrated that curcumin reduces the expression of CXCL1 und CXCL2, which resulted in fewer cases of metastases.

Bachmeier said:

"Due to the action of curcumin, the tumor cells synthesize smaller amounts of cytokines that promote metastasis. As a consequence, the frequency of metastasis formation in the lungs is significantly reduced, in animals with breast cancer, as we showed previously, or carcinoma of the prostate, as demonstrated in our new study."

Curcumin and chemoprevention

The authors believe that curcumin may have useful properties for the prevention of cancers associated with inflammation, such as prostate and breast cancers, as well as inhibiting metastases.

The authors wrote:

"This does not mean that the compound should be seen as a replacement for conventional therapies. However, it could play a positive role in primary prevention - before a full-blown tumor arises - or help to avert formation of metastases. In this context the fact that the substance is well tolerated is very important, because one can safely recommend it to individuals who have an increased tumor risk."

Bachmeier said that humans can consume up to 8gm of curcumin safely. Its anti-inflammatory properties have been used in traditional Chinese and Indian medicine for hundreds of years.

An example of prophylaxis might be for patients with BHP (benign hyperplasia of the prostate), or females with a family history of breast cancer.

The researchers believe that curcumin might also have beneficial qualities as a supplement for other cancers. A study carried out at the University of Michigan Comprehensive Cancer Center showed that curcumin was beneficial for patients with head and neck cancers.

Further studies are required to confirm these findings, preferably controlled clinical tests, they added. The team is currently planning to carry out a controlled clinical trial on patients with therapy-resistant prostate cancer.

Written by Christian Nordqvist