Researchers from the Hormel Institute at the University of Minnesota have reported that capsaicin formulated in pain relief creams may promote skin cancer. The study, published in Cancer Research, found the raw material induce to inflammation, which may affect cancer development.
Capsaicin, a component of chili peppers, is found in food and topical creams for pain relief but researchers were concerned over the material's topical use. To assess its effects, researchers applied capsaicin topically to the dorsal skin of wildtype or TRPV1 knockout mice and found the material induced tumors. The effect appears to be mediated through the epidermal growth factor receptor (EGFR) rather than the transient receptor potential vanilloid subfamily member 1 (TRPV1). The researchers also found an elevated level of the inflammatory enzyme cyclooxygenase-2 (COX-2) following treatment with capsaicin.
Ann Bode, professor of the institute's cellular and molecular biology research section, along with Mun Kyung Hwang, Zigang Dong, Sanguine Byun, Nu Ry Song, Hyong Joo Lee and Ki Won Lee, note that the molecular mechanisms of the cancer-promoting effects of capsaicin are still unknown and remain controversial.