Research Area: Cancer

Moussa, M.R., N. Fan, J. Birk, A.A. Provatas, P. Mehta, Y. Hatano, O.K. Chun, M Darooghegi Mofrad, A. Lotfi, A. Aksenov, V.N. Motta, M. Zenali, H. Vaziri, J.J. Grady, M. Nakanishi, D.W. Rosenberg, 2025. Systemic inflammation and the inflammatory context of the colonic microenvironment is improved by urolithin A. Cancer Prev Res (Phila). https://doi.org/10.1158/1940-6207.capr-24-0383

Diet affects cancer risk and plant-derived polyphenols exhibit cancer-preventive properties. Walnuts are an exceptional source of polyphenolic ellagitannins, converted into urolithins by gut microflora. This clinical study examines the impact of urolithin metabolism on inflammatory markers in blood and colon polyp tissue. We evaluate the effects of walnut consumption on urinary urolithins, serum inflammatory markers and immune cell markers in polyp tissues obtained from 39 subjects. Together with detailed food frequency data, we perform integrated computational analysis of metabolomics data combined with serum inflammatory markers and spatial imaging of polyp tissues using imaging mass cytometry. LC-MS/MS analyses of urine and fecal samples identifies a widely divergent capacity to form nine urolithin metabolites in this patient population. Subjects with higher urolithin A formation exhibit lower levels of several key serological inflammatory markers, including C-peptide, sICAM 1, sIL6R, Ghrelin, TRAIL, sVEGFR2, PDGF and MCP2, alterations that are more pronounced in obese individuals for siCAM-1, ENA-78, Leptin, GLP-1 and MIP-1D. There is a significant increase in levels of PYY associated with urolithin A formation, whereas TNF-α levels show an opposite trend, recapitulated in an in vitro system with ionomycin/PMA-stimulated PBMCs. Spatial imaging of colon polyp tissues shows altered cell cluster patterns, including a significant reduction of vimentin and CD163 expression associated with urolithin A. The ability to form urolithin A is linked to inflammation, warranting further studies to understand the role of urolithins in cancer prevention.

Fan, N., J.L. Fusco, D.W. Rosenberg, 2023. Antioxidant and anti-inflammatory properties of walnut constituents: focus on personalized cancer prevention and the microbiome. Antioxidants. 12(5): 982. https://doi.org/10.3390/antiox12050982

Walnuts have been lauded as a ‘superfood’, containing a remarkable array of natural constituents that may have additive and/or synergistic properties that contribute to reduced cancer risk. Walnuts are a rich source of polyunsaturated fatty acids (PUFAs: alpha-linolenic acid, ALA), tocopherols, antioxidant polyphenols (including ellagitannins), and prebiotics, including fiber (2 g/oz). There is a growing body of evidence that walnuts may contribute in a positive way to the gut microbiome, having a prebiotic potential that promotes the growth of beneficial bacteria. Studies supporting this microbiome-modifying potential include both preclinical cancer models as well as several promising human clinical trials. Mediated both directly and indirectly via its actions on the microbiome, many of the beneficial properties of walnuts are related to a range of anti-inflammatory properties, including powerful effects on the immune system. Among the most potent constituents of walnuts are the ellagitannins, primarily pedunculagin. After ingestion, the ellagitannins are hydrolyzed at low pH to release ellagic acid (EA), a non-flavonoid polyphenolic that is subsequently metabolized by the microbiota to the bioactive urolithins (hydroxydibenzo[b,d]pyran-6-ones). Several urolithins, including urolithin A, reportedly have potent anti-inflammatory properties. These properties of walnuts provide the rationale for including this tree nut as part of a healthy diet for reducing overall disease risk, including colorectal cancer. This review considers the latest information regarding the potential anti-cancer and antioxidant properties of walnuts and how they may be incorporated into the diet to provide additional health benefits.

Fan, N., J.L. Fusco, D.W. Rosenberg, 2023. Antioxidant and anti-inflammatory properties of walnut constituents: focus on personalized cancer prevention and the microbiome. Antioxidants. 12(5):982. https://doi.org/10.3390/antiox12050982

Walnuts have been lauded as a ‘superfood’, containing a remarkable array of natural constituents that may have additive and/or synergistic properties that contribute to reduced cancer risk. Walnuts are a rich source of polyunsaturated fatty acids (PUFAs: alpha-linolenic acid, ALA), tocopherols, antioxidant polyphenols (including ellagitannins), and prebiotics, including fiber (2 g/oz). There is a growing body of evidence that walnuts may contribute in a positive way to the gut microbiome, having a prebiotic potential that promotes the growth of beneficial bacteria. Studies supporting this microbiome-modifying potential include both preclinical cancer models as well as several promising human clinical trials. Mediated both directly and indirectly via its actions on the microbiome, many of the beneficial properties of walnuts are related to a range of anti-inflammatory properties, including powerful effects on the immune system. Among the most potent constituents of walnuts are the ellagitannins, primarily pedunculagin. After ingestion, the ellagitannins are hydrolyzed at low pH to release ellagic acid (EA), a non-flavonoid polyphenolic that is subsequently metabolized by the microbiota to the bioactive urolithins (hydroxydibenzo[b,d]pyran-6-ones). Several urolithins, including urolithin A, reportedly have potent anti-inflammatory properties. These properties of walnuts provide the rationale for including this tree nut as part of a healthy diet for reducing overall disease risk, including colorectal cancer. This review considers the latest information regarding the potential anti-cancer and antioxidant properties of walnuts and how they may be incorporated into the diet to provide additional health benefits.

Key Area: Cancer

Byerley, L. O., H.M. Chang, B. Lorenzen, J. Guidry, W.E. Hardman, 2022. Impact of dietary walnuts, a nutraceutical option, on circulating markers of metabolic dysregulation in a rodent cachectic tumor model. Biomed. Pharmacother. 155, 113728. https://doi.org/10.1016/j.biopha.2022.113728

Background: Nutraceutical foods, like walnuts which are rich in immunonutrients, can have medicinal benefits. Dietary walnuts have been shown to slow or prevent tumor growth in mice genetically programmed to grow breast or prostate tumors. This study investigated whether walnuts could exert the same preventable effect in a transplantable carcinoma rat model. Methods: Eighteen rats were randomly fed a diet containing walnuts (10% of food by weight), and 36 were fed a diet without walnuts (control) for 21 days. On day 22, 18 control diet rats were switched to the walnut diet. All other animals remained on their same diet. Within each diet group, 6 rats were implanted with the Ward colon carcinoma (TB), and 12 were sham-operated. Five days later, 6 sham-operated animals were weight-matched to a TB and then pair-fed for the remainder of the study. The remaining 6 sham-operated, or non-tumor-bearing rats, were ad-lib fed. Results: The tissue of the walnut-eating rats showed higher omega-3 fatty acid (immunonutrient) content which did not slow or prevent tumor growth or the loss of lean and fat mass typical of this TB model. In addition, blood glucose, insulin, IGF-1, and adiponectin levels were significantly lower in the TB, demonstrating metabolic dysregulation. Again, these changes were unaltered by consuming walnuts. Plasma proteomics identified six proteins elevated in the TB, but none could be connected with the observed metabolic dysregulation. Conclusion: Although walnuts’ rich immunonutrient content prevented tumor growth in genetically programmed mice models, there was no effect in this model.

Kleckner, A. S., J.E. Reschke, I.R. Kleckner, A. Magnuson, A.M. Amitrano, E. Culakova, M. Shayne, C.S. Netherby-Winslow, S. Czap, M.C. Janelsins, K.M. Mustian, L.J. Peppone, 2022. The effects of a Mediterranean diet intervention on cancer-related fatigue for patients undergoing chemotherapy: a pilot randomized controlled trial. Cancers. 14(17):4202. https://doi.org/10.3390/cancers14174202

Cancer-related fatigue is a common, burdensome symptom of cancer and a side-effect of chemotherapy. While a Mediterranean Diet (MedDiet) promotes energy metabolism and overall health, its effects on cancer-related fatigue remain unknown. In a randomized controlled trial, we evaluated a rigorous MedDiet intervention for feasibility and safety as well as preliminary effects on cancer-related fatigue and metabolism compared to usual care. Participants had stage I–III cancer and at least six weeks of chemotherapy scheduled. After baseline assessments, randomization occurred 2:1, MedDiet:usual care. Measures were collected at baseline, week 4, and week 8 including MedDiet adherence (score 0–14), dietary intake, and blood-based metabolic measures. Mitochondrial respiration from freshly isolated T cells was measured at baseline and four weeks. Participants (n = 33) were 51.0 ± 14.6 years old, 94% were female, and 91% were being treated for breast cancer. The study was feasible, with 100% completing the study and >70% increasing their MedDiet adherence at four and eight weeks compared to baseline. Overall, the MedDiet intervention vs. usual care had a small-moderate effect on change in fatigue at weeks 4 and 8 (ES = 0.31, 0.25, respectively). For those with a baseline MedDiet score <5 (n = 21), the MedDiet intervention had a moderate-large effect of 0.67 and 0.48 at weeks 4 and 8, respectively. The MedDiet did not affect blood-based lipids, though it had a beneficial effect on fructosamine (ES = −0.55). Fatigue was associated with mitochondrial dysfunction including lower basal respiration, maximal respiration, and spare capacity (p < 0.05 for FACIT-F fatigue subscale and BFI, usual fatigue). In conclusion, the MedDiet was feasible and attenuated cancer-related fatigue among patients undergoing chemotherapy, especially those with lower MedDiet scores at baseline.

Provatas, A.A., S.A. Ayers, A.A. Callas, J.W. Birk, T.A. Lacson, D.W. Rosenberg, 2021. Quantitative determination of selected urolithin metabolites in human urine by simple sample preparation and UPLC-MS/MS analysis. Curr Top Anal Chem.  Vol 13, pg 69-80.

We report a simple, reliable, and validated method for the rapid screening and quantification of nine urolithin (UL) metabolites in human urine. Ultraperformance liquid chromatograph coupled with a tandem mass spectrometer (UPLC-MS/MS) was utilized for UL analysis following a simple sample preparation. Optimization of chromatographic and mass spectrometric conditions was performed to maximize the sensitivity and selectivity of the targeted analytes. A validation of the methodology was conducted to account for matrix interferences, linearity, method detection limits (MDLs), UL chemical stability, precision and accuracy of the ULs of interest. MDLs were achieved for the selected ULs ranging from 9.2-18.2 ng·mL-1. Excellent linear coefficients of determination were obtained for the range of calibration standards of 5.0-5,000 ng·mL-1, with R2 values between 0.9991 and 0.9998. The surrogate compound, 6,7-dihydroxycoumarin, was used to monitor the extraction efficiency and chrysin as the quantitative internal standard. The recoveries of the analytes were 88-99% with surrogate recoveries greater than 82%. This analytical method was developed and validated for processing samples associated with a human study, where it is hypothesized that walnut supplementation improves colonic health and lowers colorectal cancer risk, in part through enhancing UL formation.

Park, J.M., Y.M. Han, Y.J. Park, K.B. Hahm, 2021. Dietary intake of walnut prevented Helicobacter pylori-associated gastric cancer through rejuvenation of chronic atrophic gastritis. J Clin Biochem Nutr. 68(1): 37–50.

The fact that Fat-1 transgenic mice producing n-3 polyunsaturated fatty acids via overexpressed 3-desaturase significantly mitigated Helicobacter pylori (H. pylori)-associated gastric tumorigenesis through rejuvenation of chronic atrophic gastritis (CAG) led us to study whether dietary intake of walnut plentiful of n-3 PUFAs can be nutritional intervention to prevent H. pylori-associated gastric cancer. In our model that H. pylori-initiated, high salt diet-promoted gastric carcinogenesis, pellet diet containing 100 mg/kg and 200 mg/kg walnut was administered up to 36 weeks. As results, control mice (24 weeks) developed significant chronic CAG, in which dietary walnuts significantly ameliorated chronic atrophic gastritis. Expressions of COX-2/PGE2/NF-κB/c-Jun, elevated in 24 weeks control group, were all significantly decreased with walnut (p<0.01). Tumor suppressive enzyme, 15-PGDH, was significantly preserved with walnut. Control mice (36 weeks) all developed significant tumors accompanied with severe CAG. However, significantly decreased tumorigenesis was noted in group treated with walnuts, in which expressions of COX-2/PGE2/NF-κB/IL-6/STAT3, all elevated in 36 weeks control group, were significantly decreased with walnut. Defensive proteins including HO-1, Nrf2, and SOCS-1 were significantly increased in walnut group. Proliferative index as marked with Ki-67 and PCNA was significantly regulated with walnut relevant to 15-PGDH preservation. Conclusively, walnut can be an anticipating nutritional intervention against H. pylori.