Chili peppers have an ingredient that activates a receptor on cells, which reduces the risk of colorectal tumors, a new study finds.
Researchers found that dietary capsaicin, the active ingredient in chili peppers, reduces the risk of colorectal cancer by triggering chronic activation of a receptor or ion channel called TRPV1, which is in abundance in cells lining the intestines of mice. Previous studies reveal that TRPV1, which were originally discovered as sensory neurons, guard against heat, acidity and spicy chemicals in the environment.
"These are all potentially harmful stimuli to cells," Eyal Raz, MD, professor of Medicine and senior author of the study, said in a news release. " Thus, TRPV1 was quickly described as a molecular 'pain receptor.' This can be considered to be its conventional function, which all takes place in the nervous system.
New research also reveals that TPRV1 can be found in intestinal epithelial cells. TPRV1 is activated by epidermal growth factor receptor or EGFR, an important driver of cell proliferation in the intestines and the gut.
"A basic level of EGFR activity is required to maintain the normal cell turnover in the gut," first author Petrus de Jong, MD, of the University of California, San Diego School of Medicine, said in a news release. "However, if EGFR signaling is left unrestrained, the risk of sporadic tumor development increases."
Researchers explain that the interaction between TRPV1 and EGFR lowers the risk of unwanted growth and intestinal tumor development.
The latest study revealed that mice genetically modified to be TRPV1-deficient suffered significantly higher rates of intestinal tumor growths.
"These results showed us that epithelial TRPV1 normally works as a tumor suppressor in the intestines," added de Jong.
Colorectal cancer-prone mice fed capsaicin also experienced a 30 percent longer lifespan than those not given the pepper ingredient.
"Our data suggest that individuals at high risk of developing recurrent intestinal tumors may benefit from chronic TRPV1 activation," Raz concluded. "We have provided proof-of-principle."
Colorectal cancer is a malignant tumor arising from the inner wall of the large intestine. It is the third leading cause of cancer in males and fourth in females in the U.S. Risk factors for this disease include heredity, colon polyps, and long-standing ulcerative colitis.
Most colorectal cancers develop from polyps. Removal of colon polyps can prevent colorectal cancer. Colon polyps and early cancer can have no symptoms. Therefore, regular screening is important.
Diagnosis of this illness can be made by barium enema or by colonoscopy with biopsy confirmation of cancer tissue. It depends on the location, size, and extent of cancer spread, as well as the health of the patient. Surgery is the most common treatment for colorectal cancer though chemotherapy can extend life and improve quality of life for those living with this illness.
The findings are published in The Journal of Clinical Investigation.