Ellagic Acid Curbs Pancreatic Cancer Development in Hamsters by Targeting IL-6/STAT3 Signaling

Pancreatic ductal adenocarcinoma remains one of the deadliest human cancers, with a five-year survival rate of roughly 13 percent between 2014 and 2020, and about 10 percent cited in the new study’s abstract despite recent therapeutic advances. Its aggressive biology, late diagnosis and limited treatment options have long pushed researchers to look beyond therapy toward prevention. Now, an open-access study published on 2 March 2026 in the journal Genes and Environment reports that ellagic acid, a naturally occurring polyphenol found in pomegranates, berries, grapes and walnuts, was associated with significantly reduced pancreatic carcinogenesis in an animal model, and points to the IL-6/STAT3 signaling pathway as a principal molecular target of the compound under the experimental conditions tested.

The research, led by Hiroyuki Kato, Aya Naiki-Ito and Satoru Takahashi at Nagoya City University School of Medical Sciences in Japan, used a well-established hamster model of pancreatic cancer. Six-week-old female Syrian golden hamsters received subcutaneous injections of N-nitrosobis(2-oxopropyl)amine, a carcinogen abbreviated BOP, at 10 milligrams per kilogram on four alternate days. One week after the final injection, the animals were placed on a high-fat diet for fifteen weeks and then divided into three groups: a control group of seventeen animals fed the high-fat diet alone, and two groups of fifteen animals each fed the high-fat diet supplemented with ellagic acid at 0.01 percent or 0.1 percent by weight. The higher concentration corresponds to an approximate dose of 50 milligrams per kilogram per day, which the authors note has shown antitumor effects in preclinical studies of prostate, colorectal and lung cancers, and would extrapolate to roughly 3 grams per day in humans based on body weight.

Over the experimental period, all hamsters remained healthy with no mortality, and there were no significant differences in body weight, food intake, or final liver and kidney weights among the groups. The striking differences emerged in the pancreas. The incidence and multiplicity of pancreatic ductal adenocarcinomas were significantly reduced in the 0.1 percent ellagic acid group compared with controls, in a dose-dependent manner. The tumors that did develop resembled human pancreatic cancer histologically, forming gland-like structures on a fibrotic background, which strengthens the model’s relevance. When the researchers classified all pancreatic ducts larger than 200 micrometers in the duodenal lobe as normal, PanIN1, PanIN2, PanIN3 or invasive cancer, the proportion of histologically normal ducts rose significantly in the high-dose group while the proportion of cancers fell, and a weighted progression score across these lesion stages was also significantly reduced.

Cellular analysis pointed to a mechanism centered on proliferation rather than cell death. The Ki-67 labeling index, a standard measure of cell division calculated from an average of nearly 3,000 cells in low-grade pancreatic intraepithelial neoplasia lesions, was significantly suppressed in the 0.1 percent ellagic acid group. By contrast, TUNEL staining for apoptotic cells revealed that cell death was rare in both precancerous lesions and tumors, and quantitative analysis showed no statistically significant differences among the groups. The authors caution that TUNEL-positive cells were so infrequent that the assay’s limited sensitivity may have obscured any real apoptotic effect, but the overall picture is that ellagic acid appears to slow pancreatic carcinogenesis chiefly by restraining tumor cell proliferation. Incidental lesions in the liver, gallbladder, lungs and kidneys showed no significant differences among the groups, suggesting the compound’s effects were concentrated in the pancreas.

To probe the direct effects on cancer cells, the team turned to laboratory experiments using two human pancreatic cancer cell lines, MIAPaCa2 and PANC1, and a hamster pancreatic cancer line called HPD1NR. Exposure to ellagic acid at concentrations up to 80 micromolar reduced cell growth in a dose-dependent manner in all three lines. Cell cycle analysis of the human lines showed a decrease in the G2/M population and an increase in the G0/G1 population, indicating G1 cell cycle arrest, a halt that prevents cells from proceeding to DNA replication. Wound-healing assays demonstrated reduced migration, and Matrigel invasion assays showed that the invasive capacity of all three cell lines was diminished after treatment. Together, these in vitro findings mirror the antiproliferative pattern observed in the living animals.

The molecular explanation emerged from an unusually broad screen. Using multiplex Western blotting, the researchers examined the phosphorylation status of eighteen proteins associated with cell proliferation in the two human cell lines. Six phosphorylated proteins were consistently decreased by ellagic acid at all tested concentrations: pMEK, pERK, p-p38 MAPK, pSAPK, pPDK and, most strikingly, pSTAT3 at tyrosine 705, which showed the most pronounced and concentration-dependent suppression. Follow-up immunoblots revealed that IL-6 expression itself declined in a dose-dependent manner in both cell lines, as did two downstream effectors of STAT3 signaling: SNAIL, which is linked to invasion, and Cyclin D1, which drives proliferation. Notably, total NF-κB protein fell only in MIAPaCa2 cells, and its phosphorylation at serine 536 was essentially unchanged, suggesting that the NF-κB axis, implicated in earlier ellagic acid studies, was minimally altered here. The IL-6/STAT3 pathway, by contrast, was consistently suppressed across both cell lines.

The team then confirmed that the pathway change seen in cultured cells also occurred in the animals. Immunohistochemical staining for phosphorylated STAT3 in pancreatic tissue showed that the pStat3 labeling index was significantly lower in the ellagic acid groups than in controls, both in low-grade PanIN lesions and in established cancers. Because STAT3 signaling is known to be particularly important at early stages of pancreatic cancer, contributing to tumor cell proliferation, resistance to apoptosis and invasiveness, this reduction across premalignant and malignant tissue supports the idea that the pathway is a genuine in vivo target of the compound rather than an artifact of cell culture. The authors note that pJAK2, the kinase classically upstream of STAT3, was not detectable by Western blotting even after prolonged exposure, possibly reflecting the transient nature of JAK2 phosphorylation or antibody limitations, although total JAK2 protein was reduced, hinting that ellagic acid may decrease JAK2 abundance itself.

The study also tested, and largely ruled out, an alternative hypothesis. Because high-fat diets elevate adipocytokines, and prior work had linked the hormone resistin to STAT3 regulation through its receptor CAP1, the researchers examined whether ellagic acid might work by lowering resistin. In vitro, recombinant resistin did not affect proliferation of MIAPaCa2 or PANC1 cells, and pSTAT3 and CAP1 expression were unchanged after resistin exposure, although the hormone did significantly promote migration and invasion in both cell lines. In the hamsters, serum resistin levels measured by ELISA showed no significant change after ellagic acid intake, and resistin concentrations in adipose tissue, pancreas and tumor tissue were likewise not significantly reduced. The authors conclude that while resistin may play a role in promoting the migratory and invasive properties of pancreatic cancer cells, its contribution to the inhibitory effects of ellagic acid in this model appears minimal.

The authors describe their report as the first to demonstrate chemopreventive potential of ellagic acid against pancreatic carcinogenesis in an in vivo model, extending earlier findings that had mainly evaluated the compound in vitro or in xenografts of human pancreatic cancer cells, where it suppressed tumor growth partly by reducing COX-2 and NF-κB expression. Ellagic acid has an established safety profile, and oral dosing has been investigated clinically in nonalcoholic fatty liver disease, type 2 diabetes and prostate disorders; in an eight-week double-blind trial in type 2 diabetes patients, improvements in insulin resistance and oxidative stress and reductions in inflammatory cytokines including IL-6 were reported. Because diabetes is a recognized risk factor for pancreatic cancer, the authors suggest such high-risk populations may be suitable candidates for future studies of ellagic acid as a preventive agent.

Important limitations temper the enthusiasm. The findings come from a carcinogen-induced hamster model combined with a high-fat diet, and the effective animal dose would translate to roughly 3 grams per day in humans, a level approached only in small clinical studies. In the one clinical trial of ellagic acid in hormone-refractory prostate cancer cited by the authors, the compound did not significantly improve overall survival, though it was associated with reduced serum prostate-specific antigen levels and decreased chemotherapy-related myelotoxicity. The precise upstream mechanism connecting ellagic acid to IL-6 suppression, and the possible involvement of kinases other than JAK2, remain unresolved. What the study does establish, under controlled experimental conditions, is a consistent association between dietary ellagic acid, reduced pancreatic lesion burden, restrained tumor cell proliferation and dampened IL-6/STAT3 signaling, a combination that the authors argue justifies further investigation of this common dietary polyphenol as a candidate for pancreatic cancer prevention.

Subject of Research: Chemopreventive effects of the dietary polyphenol ellagic acid on pancreatic carcinogenesis and IL-6/STAT3 signaling in a hamster model

Article Title: Ellagic acid is associated with reduced pancreatic carcinogenesis and modulation of the IL-6/STAT3 pathway

Article References: Kato, H., Naiki-Ito, A., Komura, M., Nagayasu, Y., Sato, M., Kuang, X., Nagano, A., & Takahashi, S. (2026). Ellagic acid is associated with reduced pancreatic carcinogenesis and modulation of the IL-6/STAT3 pathway. Genes and Environment, 48(1), Article 7. https://doi.org/10.1186/s41021-026-00353-3

Image Credits: AI Generated

DOI: 10.1186/s41021-026-00353-3

Keywords: ellagic acid, pancreatic cancer, IL-6/STAT3 pathway, chemoprevention, hamster model, STAT3 phosphorylation, pancreatic intraepithelial neoplasia, cell proliferation, resistin, polyphenols, Ki-67, BOP carcinogen