Researchers report that strawberry tree honey, a typical food in the Mediterranean region, has cancer-fighting potential in colon adenocarcinoma, the most common form of colorectal cancer.
For the study, which has now been published in the Journal of Functional Foods, the investigators researched both the phytochemical composition and the anticancer effects of honey from the strawberry tree (Arbutus unedo) on cellular proliferation, cell cycle, and apoptosis—programmed cell death—in two types of cell lines: HCT-116, derived from human colon adenocarcinoma, and LoVo cells, derived from metastatic colon adenocarcinoma.
The phytochemical analysis of the strawberry tree honey revealed that its major phenolic compounds were kaempferol and gallic acid. The honey demonstrated cytotoxic (cell-killing) effects on the cancer cell lines; effects increased with exposure time and at higher doses. The strawberry tree honey halted the cell cycle in numerous cancer cell genes. It also promoted apoptosis through its modulation of essential genes, including p53, caspase-3, and c-PARP, and various apoptotic factors. In addition, strawberry tree honey caused stress in the endoplasmic reticulum—the site where membrane and secretory proteins are synthesized and folded—through its increase in ATF-6 and XBP-1 expression, its suppression of epidermal growth factor receptor (EGFR)/human epidermal growth factor receptor 2 (HER2) and their downstream markers, and its elevation of p-p38MAPK and p-ERK1/2.
These effects did not take place when the strawberry tree honey was applied to healthy cell lines.
The study's senior author, Maurizio Battino, MD, PhD, DSc, MS, Associate Professor of Biochemistry in the Department of Clinical Sciences at the Faculty of Medicine at Marche Polytechnic University, Italy, noted that the strawberry tree honey's suppression of EGFR/HER2 and their signaling pathways "could be an attractive target in cancer therapies because of their important role in the processes of cell survival and proliferation, as well as in those of apoptosis and metastasis."
Dr. Battino emphasized the preliminary nature of the results: "With these data it is not yet possible to speak of a cure or safe prevention of colorectal cancer thanks to strawberry tree honey. This work constitutes a starting point in the effort to evaluate its possible biological and anticancer effects and indicates the main molecular mechanisms through which it exerts its effect."
He added, "It is one more piece of evidence that a healthy, balanced, and natural diet can provide bioactive compounds with possible interesting effects on the control and development of diseases as critical as this type of cancer."
For More Information
Afrina S, Giampieriba F, Cianciosi D, et al (2019). Strawberry tree honey as a new potential functional food. Part 1: strawberry tree honey reduces colon cancer cell proliferation and colony formation ability, inhibits cell cycle and promotes apoptosis by regulating EGFR and MAPKs signaling pathways. J Funct Foods, 57:439-452. DOI:10.1016/j.jff.2019.04.035
Image credit: Bernard DuPont. Licensed under CC BY-SA 2.0