Consumption of Grapes Modulates Gene Expression, Reduces Non-Alcoholic Fatty Liver Disease, and Extends Longevity in Female C57BL/6J Mice Provided with a High-Fat Western-Pattern Diet

Abstract

A key objective of this study was to explore the potential of dietary grape consumption to modulate adverse effects caused by a high-fat (western-pattern) diet. Female C57BL/6J mice were purchased at six-weeks-of-age and placed on a standard (semi-synthetic) diet (STD). At 11 weeks-of-age, the mice were continued on the STD or placed on the STD supplemented with 5% standardized grape powder (STD5GP), a high-fat diet (HFD), or an HFD supplemented with 5% standardized grape powder (HFD5GP). After being provided with the respective diets for 13 additional weeks, the mice were euthanized, and liver was collected for biomarker analysis, determination of genetic expression (RNA-Seq), and histopathological examination. All four dietary groups demonstrated unique genetic expression patterns. Using pathway analysis tools (GO, KEGG and Reactome), relative to the STD group, differentially expressed genes of the STD5GP group were significantly enriched in RNA, mitochondria, and protein translation related pathways, as well as drug metabolism, glutathione, detoxification, and oxidative stress associated pathways. The expression of Gstp1 was confirmed to be upregulated by about five-fold (RT-qPCR), and, based on RNA-Seq data, the expression of additional genes associated with the reduction of oxidative stress and detoxification (Gpx4 and 8, Gss, Gpx7, Sod1) were enhanced by dietary grape supplementation. Cluster analysis of genetic expression patterns revealed the greatest divergence between the HFD5GP and HFD groups. In the HFD5GP group, relative to the HFD group, 14 genes responsible for the metabolism, transportation, hydrolysis, and sequestration of fatty acids were upregulated. Conversely, genes responsible for lipid content and cholesterol synthesis (Plin4, Acaa1b, Slc27a1) were downregulated. The two top classifications emerging as enriched in the HFD5GP group vs. the HFD group (KEGG pathway analysis) were Alzheimer’s disease and nonalcoholic fatty liver disease (NAFLD), both of which have been reported in the literature to bear a causal relationship. In the current study, nonalcoholic steatohepatitis was indicated by histological observations that revealed archetype markers of fatty liver induced by the HFD. The adverse response was diminished by grape intervention. In addition to these studies, life-long survival was assessed with C57BL/6J mice. C57BL/6J mice were received at four-weeks-of-age and placed on the STD. At 14-weeks-of-age, the mice were divided into two groups (100 per group) and provided with the HFD or the HFD5GP. Relative to the HFD group, the survival time of the HFD5GP group was enhanced (log-rank test, p = 0.036). The respective hazard ratios were 0.715 (HFD5GP) and 1.397 (HFD). Greater body weight positively correlated with longevity; the highest body weight of the HFD5GP group was attained later in life than the HFD group (p = 0.141). These results suggest the potential of dietary grapes to modulate hepatic gene expression, prevent oxidative damage, induce fatty acid metabolism, ameliorate NAFLD, and increase longevity when co-administered with a high-fat diet.

Influence of grape consumption on the human microbiome

“…It is also possible that this process represents naturally occurring DNA depurination whose repair is enhanced by one or more grape constituents. Furthermore, in two previously reported investigations of grape administration to mice, we also observed elevations of 2′-deoxyribonic acid that were associated with administration of a grape diet 6 , 12 , and inter-individual variation was observed in human intervention studies 49 .…”

“…Consistent with this suggestion, we have reported the addition grapes to both a standard diet and a high-fat diet in mice is associated with an up-regulation of the malate-aspartate shuttle and therefore the efficiency of glucose utilization by the liver 12 . Moreover, 2-hydroxybutanoic acid is primarily produced in the liver during glutathione synthesis, which we have also reported to be elevated in relation to a grape diet in mice 6 .…”

“…Recently, employing mouse models provided with dietary grapes, we have shown remarkable effects on gene expression, prevention or delay of fatty liver, and enhancement of lifespan 6 , as well as effects on cognition and gene expression in the brain 7 . Although a prominent chemical constituent of the grape is resveratrol, the biologic potential of which has been extensively investigated 8 , only small quantities of this substance are provided through a normal human diet.…”

A critical review exploring science communication of nutrition and dietetic research: a case‐based approach exploring methodologies

“…25 This work was also promoted by the university's own press release which was slightly more muted, headlined 'Study finds astounding effects of grapes and the potential for health benefits', which at least referred in its first paragraph to it being an animal study. 26 The notable point about the press release from the declared funder, who was not involved in the study or the two study publications, 27,28 was that the detail that the research was undertaken in mice was a footnote and only mentioned again in the link to the research paper. This is important, as when this press release was syndicated to sites such as Medical Xpress, this footnote was lost.…”

Multi-Organ Nutrigenomic Effects of Dietary Grapes in a Mouse Model

“…In our work with female C57BL6/J mice, as expected, the provision of a high-fat western-pattern diet led to significant increases in body weight and reduced lifespan. However, the addition of grapes to an isocaloric high-fat diet enhanced longevity and reduced fatty liver [11]. Simultaneously, significant alteration of hepatic gene expression was observed.…”