Cancer researchers are looking into a possible new tool in the fight against colon cancer: cinnamon.
Research conducted at the University of Arizona Cancer Center and UA College of Pharmacy indicates that a compound derived from cinnamon is a potent inhibitor of colorectal cancer.
Georg Wondrak, PhD, and Donna Zhang, PhD, recently completed a study in which they proved that adding cinnamaldehyde, the compound that gives cinnamon its distinctive flavor and smell, to the diet of mice protected the mice against colorectal cancer. In response to cinnamaldehyde, the animals’ cells had acquired the ability to protect themselves against exposure to a carcinogen through detoxification and repair.
• READ MORE: COP researchers discover component of cinnamon prevents colorectal cancer in mice (UA College of Pharmacy)
“This is a significant finding,” says Zhang. “Because colorectal cancer is aggressive and associated with poor prognoses, there is an urgent need to develop more effective strategies against this disease.”
According to the American Cancer Society, there will be more than 132,000 new cases of colo-rectal cancer in 2015, with more than 2,400 occurring in Arizona. It is the third-leading cause of cancer-related deaths in the United States, with nearly 50,000 deaths per year. Can something as simple as cinnamon can provide some protection against this deadly disease?
Dr. Wondrak is a member of the UACC’s Therapeutic Development Program and Dr. Zhang is a member of the Cancer Prevention and Control Program. Both also belong to the College of Pharmacy’s Department of Pharmacology and Toxicology.
Wondrak and Zhang’s study, “Nrf2-Dependent Suppression of Azoxymethane/Dextrane Sulfate Sodium-Induced Colon Carcinogenesis by the Cinnamon-Derived Dietary Factor Cinnamaldehyd,” has been published online and will appear in a print issue of Cancer Prevention Research later this spring.
Wondrak notes that cinnamon is the third most consumed spice in the world. Other compounds found in food have been extensively researched for their cancer-preventive properties, but relatively little research has been done on cinnamon and its constituent compounds.
“Given cinnamon’s important status as one of the major spices in the world,” he says, “there’s relatively little research on its potential health benefits. If we can ascertain the positive effects of cinnamon, we would like to leverage this opportunity to potentially improve the health of people around the globe.”
The two major types of cinnamon in the world are known as cassia cinnamon and true (or “Ceylon”) cinnamon. The compound cinnamaldehyde used in Wondrak and Zhang’s work can be derived from both types.
The two researchers’ discovery came about in part because their specialties complement one another. Wondrak researches molecular interventions targeting skin and other epithelial cancers, and Zhang is a worldwide expert on the Nrf2 (link is external) molecular pathway, which is involved in strengthening cells against stressors such as carcinogen exposure. The common denominator between their labs is the identification of molecules that might protect cells from environmental damage and cancer.
“We look for compounds that can activate the Nrf2 pathway,“ Wondrak says, “– synthetic ones, or preferably things we already eat, because we know they are not toxic. I’m the person who brings in the molecules, the molecular agents that might modulate this pathway.”
Zhang laughs, “He has sharp eyes – he always predicts, ‘Donna, this may be an Nrf2 inducer!’”
The two scientists have been working together since 2006. They started off doing structure-activity relationship studies to find molecular dietary factors that induce the Nrf2 pathway. Their investigation led to the identification of cinnamaldehyde as an Nrf2 inducer.
After that discovery, the duo began studying the effects of cinnamaldehyde on the Nrf2 pathway and on cancer outcomes. Their first joint publication came out in 2008.
Because the Nrf2 pathway is so important in cellular protection, their most recent study suggests that cinnamaldehyde may also protect cells from other kinds of chemical carcinogens, UV-induced cancers and more.
“We are not preaching at this point, ‘You have to eat a lot of cinnamon,’” says Wondrak. “We are just saying that cinnamaldehyde has interesting properties that are consistent with protecting cells through activation of the Nrf2 pathway.”
The next step is to test whether cinnamon, as opposed to cinnamaldehyde, prevents cancer using this same cancer model. Because cinnamon is a common food additive already considered safe – it’s not a synthetic, novel drug – a study in humans may not be too far off.
Wondrak outlines questions to investigate going forward: “Can cinnamon do it, now that we know pure cinnamaldehyde can? And can we use cinnamaldehyde or cinnamon as a weapon to go after other major diseases, such as inflammatory dysregulation and diabetes? These are big questions to which we might be able to provide encouraging answers using a very common spice.”
This research has been funded by the NIH as follows: main funding: 5R21CA166926-02 (G.T.W.; D.D.Z.); additional funding: 2R01 ES015010, R01 CA154377 (D.D.Z.); ES007091, ES06694, Arizona Cancer Center Support Grant CA023074.
-Elizabeth Harris, communications assistant, College of Pharmacy, April 27, 2015