Reconstructing hepatic metabolic profile and glutathione-mediated metabolic fate of acrylamide.

The toxicity of acrylamide (AA) has continuously attracted wide concerns as its extensive presence from both environmental and dietary sources. However, its hepatic metabolic transformation and metabolic fate still remain unclear. This study aims to unravel the metabolic profile and glutathione (GSH) mediated metabolic fate of AA in liver of rats under the dose-dependent exposure. We found that exposure to AA dose-dependently alters the binding of AA and GSH and the generation of mercapturic acid adducts, while liver as a target tissue bears the metabolic transformation of AA via regulating GSH synthesis and consumption pathways, in which glutamine synthase (GSS), cytochrome P450 2E1 (CYP2E1), and glutathione S-transferase P1 (GSTP1) play a key role. In response to high- and low-dose exposures to AA, there were significant differences in liver of rats, including the changes in GSH and cysteine (CYS) activities and the conversion ratio of AA to glycidamide (GA), and liver can affect the transformation of AA by regulating the GSH-mediated metabolic pathway. Low-dose exposure to AA activates GSH synthesis pathway in liver and upregulates GSS activity and CYS content with no change in γ-glutamyl transpeptidase 1 (GGT1) activity. High-dose exposure to AA activates the detoxification pathway of GSH and increases GSH consumption by upregulating GSTP1 activity. In addition, molecular docking results showed that most of the metabolic molecules transformed by AA and GA other than themselves can closely bind to GSTP1, GSS, GGT1, N-acetyltransferase 8, and dimethyl sulfide dehydrogenase 1. The binding of AA-GSH and GA-GSH to GSTP1 and CYP2E1 enzymes determine the tendentiousness between toxicity and detoxification of AA, which exerts a prospective avenue for targeting protective role of hepatic enzymes against in vivo toxicity of AA.

Circulating fatty acids, genetic risk, and incident coronary artery disease: A prospective, longitudinal cohort study.

The role of fatty acids (FAs) in primary prevention of coronary artery disease (CAD) is highly debated, and the modification effect by genetic risk profiles remains unclear. Here, we report the prospective associations of circulating FAs and genetic predisposition with CAD development in 101,367 U.K. Biobank participants. A total of 3719 CAD cases occurred during a mean follow-up of 11.5 years. Plasma monounsaturated FAs (MUFAs) were positively associated with risk of CAD, whereas the risk was significantly lower with higher n-3 polyunsaturated FAs (PUFAs) and more reductions in risk were detected among TT carriers of rs174547. Furthermore, increased plasma saturated FAs (SFAs) and linoleic acid were related to a significant increase in CAD risk among participants with high genetic risk (genetic risk score > 90%). These findings suggest that individuals with high genetic risk need to reduce plasma SFAs levels for CAD prevention. Supplementation of n-3 PUFAs for CAD prevention may consider individuals' genetic makeup.

Association of Fish Oil Supplementation with Risk of Coronary Heart Disease in Individuals with Diabetes and Prediabetes: A Prospective Study in the UK Biobank.

This study aimed to explore the association between habitual intake of fish oil supplementation and the risk of developing CHD in patients with prediabetes and diabetes. Habitual use of fish oil was assessed by repeated questionnaires. Cox proportional hazard models were applied to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). Over a median follow-up of 11.6 years, 4304 and 3294 CHD cases were documented among 47,663 individuals with prediabetes and 22,146 patients with diabetes in the UK Biobank, respectively. After multivariable adjustment, the HRs (95% CI) of CHD were 0.91 (0.85-0.98) and 0.87 (0.80-0.95) for individuals utilizing fish oil supplementation compared with non-users among the participants with prediabetes and diabetes, respectively. Furthermore, we identified an inverse relationship between fish oil use and CHD incidence, which was significantly mediated by serum C-reactive protein (CRP) levels in individuals with prediabetes and by very-low-density lipoprotein cholesterol (VLDL-C) in patients with diabetes at baseline. The inverse associations were consistent in the analyses stratified by potential confounders. In conclusion, the consumption of fish oil supplements was linked to decreased serum CRP and VLDL-C levels and subsequent CHD risk among adults with prediabetes and diabetes. Our findings highlight the important role of the habitual intake of fish oil supplements in preventing CHD in individuals with impaired glucose metabolism.

Potato consumption, polygenic scores, and incident type 2 diabetes: An observational study.

Whether the consumption of different processed potatoes is detrimental to type 2 diabetes (T2D) is highly debated. This study aimed to assess the relations between potato consumption and the risk of T2D and whether the relationship was modified by the genetic predisposition to T2D. We included 174,665 participants from the UK Biobank at baseline. Potato consumption was evaluated using the 24-hour dietary questionnaire. The genetic risk score (GRS) was calculated based on 424 variants associated with T2D. After adjustment for demographic, lifestyle, and dietary factors, the consumption of total potatoes was significantly and positively associated with T2D risk [hazard ratio (HR) comparing two or more servings/day with non-consumers was 1.28 (95% CI: 1.13-1.45)]. HRs (95% CIs) of T2D for each 1-SD increment in boiled/baked potatoes, mashed potatoes, and fried potatoes were 1.02 (0.99-1.05), 1.05 (1.02-1.08), and 1.05 (1.02-1.09), respectively. There were no significant interactions between the consumption of total or different processed potatoes and overall GRS on T2D risk. Theoretically, replacing one serving/day of total potatoes with the same amount of non-starchy vegetables was related to a 12% (95% CI: 0.84-0.91) lower T2D risk. These results showed the positive associations of the consumption of total potatoes, mashed potatoes or fried potatoes and genetic risk with higher incident T2D. An unhealthy potato-based diet is associated with higher diabetes risk regardless of genetic risk.

Metabolomics strategy comprehensively unveils the effect of catechins intervention on the biomarkers of exposure to acrylamide and biomarkers of cardiometabolic risk.

Polyphenolic antioxidants have been suggested to control the generation of acrylamide during thermal reactions. However, their role in protecting against the toxicity of acrylamide and the mechanism of action regarding profile alteration of biomarkers and metabolome remains unclear. A total of 65 adults were randomized into tea polyphenols (TP) and control groups and served with potato chips, which corresponded to an intake level of 12.6 µg/kg·bw of acrylamide, followed by capsules containing 200 mg, 100 mg or 50 mg TP, or equivalent placebo. Moreover, nontargeted urinary metabolomics analysis in acrylamide exposed rats was conducted using ultra-high performance liquid chromatography linked with a quadrupole-orbitrap high-resolution mass spectrometry. Our results showed that supplementation with catechins promoted the excretion of N-acetyl-S-(2-carbamoyl-2-hydroxyethyl)-l-cysteine in both humans and rats. We also found that epigallocatechin gallate (EGCG) or epicatechin (EC) intervention attenuated the ratio of hemoglobin adduct of glycidamide to hemoglobin adduct of acrylamide in rat blood. Metabolomics analysis revealed that EGCG/EC intervention regulated the differential expressed metabolites, including l-glutamic acid, 2-oxoglutarate, citric acid, and cysteinylglycine. Kyoto Encyclopedia of Genes and Genomes pathway analysis further showed acrylamide-induced metabolic disorders were improved after EGCG/EC supplementation by glycolipid metabolism (alanine, aspartate and glutamate metabolism, and d-Glutamine and d-glutamate metabolism) and energy metabolism (tricarboxylic acid cycle). Notably, the supplement use of EGCG prevented the cardiometabolic risk after exposure to acrylamide by mediating the phenylalanine and hippuric acid in phenylalanine metabolism. Here we showed the beneficial effect of catechins as major polyphenolic antioxidant ingredients on the toxicity of acrylamide by the changes in biomarkers from metabolic profile analysis based on human and animal studies. These findings shed light into the catechins as natural polyphenolic antioxidants that could be a therapeutic ingredient for preventing acrylamide-induced cardiometabolic toxicity.

Association of fish oil supplementation with risk of incident dementia: A prospective study of 215,083 older adults.

BACKGROUND & AIMS: Evidence linking the use of omega-3 PUFA supplements with incident dementia is scarce. We aim to assess the relationship between fish oil supplementation and incident dementia risk among older adults with different apolipoprotein E (APOE) genotypes in a large population-based cohort. METHODS: We included 215,083 participants (average age: 64.1 ± 2.9 y) without dementia at baseline from UK Biobank study. Fish oil use was assessed by a touch screen questionnaire at baseline. Dietary intake was assessed by a food frequency questionnaire. The APOE genotypes were determined by allele variations on rs429358 and rs7412 from genome-wide genotyping of blood samples. Dementia was diagnosed using the International Classification of Diseases (ICD-9 and ICD-10). Cox proportional hazards regression models were used to calculate the associations of fish oil supplement use with dementia risk. RESULTS: During an average 7.92 years of follow-up, 2054 participants were diagnosed with dementia. After multivariable adjustment for major risk factors, the use of fish oil supplements was significantly associated with a lower risk of all-cause dementia (p for trend = 0.004). Compared with non-users, the multivariable-adjusted hazard ratio (95% confidence interval) of dementia was 0.87 (0.79-0.96) for fish oil users. A marginal interaction was found between fish oil supplementation and APOE gene variants on the risk of dementia (p for interaction = 0.057). However, fish oil supplementation was not associated with the risk of any subtype of dementia, including Alzheimer's disease (AD), vascular dementia (VD), and frontotemporal dementia (FTD). CONCLUSIONS: Intake of fish oil supplements was associated with lower risk of all-cause dementia among 60-73 y elders. Our findings provide new population-based evidence for linking fish oil supplement use with dementia prevention.

Urinary non-targeted toxicokinetics and metabolic fingerprinting of exposure to 3-monochloropropane-1,2-diol and glycidol from refined edible oils.

The widespread presence of 3-monochloropropane-1,2-diol (3-MCPD) and glycidol in refined edible oils have raised food industrial and public health concerns, but their specific biomarkers of exposure and urinary metabolic pathways indicating nephrotoxicity remain largely unknown. Here, we unraveled the in vivo biotransformation of these two contaminants and revealed how they affect metabolic pathways in rats. Urine metabolomes in rats administered with glycidol or 3-MCPD were investigated using ultra-high performance liquid chromatography combined with a quadrupole-orbitrap high-resolution mass spectrometry. Compared to the currently acknowledged metabolite which is only 2,3-dihydroxypropyl mercapturic acid, we identified 8 and 4 new specific exposure biomarkers of glycidol and 3-MCPD, respectively, via mapping the glyceryl polymerization and glutathione and sulfur conjugation. The changes of metabolites in the surrounding metabolic network were investigated to further gain insight into their metabolic fates. Exposure to glycidol up-regulated citrate, isocitrate, ketoglutarate, malate, and pyruvate in the tricarboxylic acid cycle and glycolysis pathways, while 3-MCPD intake down-regulated these signal molecules in both pathways. Nonetheless, L-cysteine, proline, and arginine were significantly decreased by the effect of either glycidol or 3-MCPD. Our findings first map the urinary metabolomics of both contaminants from edible oils and advance the omics-level recognition for their observational health hazards.

Eicosapentaenoic and docosahexaenoic acids attenuate hyperglycemia through the microbiome-gut-organs axis in db/db mice.

BACKGROUND: Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been suggested to prevent the development of metabolic disorders. However, their individual role in treating hyperglycemia and the mechanism of action regarding gut microbiome and metabolome in the context of diabetes remain unclear. RESULTS: Supplementation of DHA and EPA attenuated hyperglycemia and insulin resistance without changing body weight in db/db mice while the ameliorative effect appeared to be more pronounced for EPA. DHA/EPA supplementation reduced the abundance of the lipopolysaccharide-containing Enterobacteriaceae whereas elevated the family Coriobacteriaceae negatively correlated with glutamate level, genera Barnesiella and Clostridium XlVa associated with bile acids production, beneficial Bifidobacterium and Lactobacillus, and SCFA-producing species. The gut microbiome alterations co-occurred with the shifts in the metabolome, including glutamate, bile acids, propionic/butyric acid, and lipopolysaccharide, which subsequently relieved ß cell apoptosis, suppressed hepatic gluconeogenesis, and promoted GLP-1 secretion, white adipose beiging, and insulin signaling. All these changes appeared to be more evident for EPA. Furthermore, transplantation with DHA/EPA-mediated gut microbiota mimicked the ameliorative effect of DHA/EPA on glucose homeostasis in db/db mice, together with similar changes in gut metabolites. In vitro, DHA/EPA treatment directly inhibited the growth of Escherichia coli (Family Enterobacteriaceae) while promoted Coriobacterium glomerans (Family Coriobacteriaceae), demonstrating a causal effect of DHA/EPA on featured gut microbiota. CONCLUSIONS: DHA and EPA dramatically attenuated hyperglycemia and insulin resistance in db/db mice, which was mediated by alterations in gut microbiome and metabolites linking gut to adipose, liver and pancreas. These findings shed light into the gut-organs axis as a promising target for restoring glucose homeostasis and also suggest a better therapeutic effect of EPA for treating diabetes. Video abstract.

Physicochemical characterization and antioxidant effects of green microalga Chlorella pyrenoidosa polysaccharide by regulation of microRNAs and gut microbiota in Caenorhabditis elegans.

A novel polysaccharide from Chlorella pyrenoidosa (CPP) was separated and purified with the average molecular weight 15.8 kDa. It was composed of seven monosaccharides including mannose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, and arabinose. FT-IR and NMR spectra analysis further revealed that CPP was an acidic polysaccharide consisting of ß-L-Arap-(1→, →2)-α-L-Rhap-(1→, ß-D-GlcpA-(1→, →4)-α-D-GalpA-(1→, →6)-ß-D-Glcp-(1→, →3)-ß-D-Manp-(1→, and →3, 6)-ß-D-Galp-(1→. The CPP treatment could effectively prolong lifespan of Caenorhabditis elegans under the oxidative stress conditions and inhibit the accumulation of reactive oxygen species (ROS) and malondialdehyde (MDA) as well as enhancing the level of superoxide dismutase (SOD). It could up-regulate the expressions of Daf-16 and Skn-1 genes via declining miR-48-3p, miR-48-5p, and miR-51-5p translocation. Moreover, 16S rRNA sequencing revealed that the CPP-enriched Faecalibacterium, Haemophilus, Vibrio, and Shewanella were strongly correlated with SOD, MDA, apoptosis, and ROS. These results indicated that CPP may be considered as a desired ingredient on regulating the aging and oxidative diseases.

Physicochemical Characterization of a Polysaccharide from Green Microalga Chlorella pyrenoidosa and Its Hypolipidemic Activity via Gut Microbiota Regulation in Rats.

A bioactive polysaccharide from microalga Chlorella pyrenoidosa (CPP) was successively prepared via DEAE-52 and G-100 columns. Nuclear magnetic resonance analysis showed that the main glycosidic bonds were composed of 1,2-linked-α-l-Fucp, 1,4-linked-α-l-Rhap, 1,4-linked-ß-l-Araf, 1-linked-α-d-Glcp, 1,3-linked-ß-d-GlcpA, 1,4-linked-ß-d-Xylp, and 1,3,6-linked-ß-d-Manp. Its molecular weight was 5.63 × 106 Da. The hypolipidemic effect and intestinal flora regulation of CPP on diet-induced rats were evaluated through histopathology and biochemistry analyses. CPP could improve plasma and liver lipid metabolism and accelerate the metabolism of the cecal total bile acids and short-chain fatty acids. CPP has also upregulated the adenosine-monophosphate-activated protein kinase α and downregulated the acetyl-CoA carboxylase, sterol regulatory element-binding protein 1c, and ß-hydroxy ß-methylglutaryl-CoA expressions. Moreover, with the 16S rRNA gene sequencing, it was revealed that the composition of intestinal flora changed drastically after treatment, such as the bloom of Coprococcus_1, Lactobacillus, and Turicibacter, whereas there was a strong reduction of the [Ruminococcus]_gauvreauii_group. The above results illustrated that CPP might be served as an effective ingredient to ameliorate lipid metabolism disorders and intestinal flora in hyperlipidemia rats.

Anti-diabetic effect of oligosaccharides from seaweed Sargassum confusum via JNK-IRS1/PI3K signalling pathways and regulation of gut microbiota.

Brown seaweed Sargassum confusum (C. Agardh) has been used in traditional Chinese medicine to treat a variety of diseases. The aim of the present study was to evaluate the anti-diabetic effect of oligosaccharides from brown seaweed S. confusum (SCO). The anti-diabetic effect of SCO was evaluated in vivo using high-fat/high-sucrose fed hamsters. Molecular mechanisms of modulating gene expression of specific members of insulin signaling pathways were determined. The components of the intestinal microflora in diabetic animals were also analyzed by high-throughput 16S rRNA gene sequencing. And it was found that SCO had a sequence of sulfated anhydrogalactose and methyl sulfated galactoside units. Fasting blood glucose levels were significantly decreased after SCO administration. Histology showed that SCO could protect the cellular architecture of the liver. SCO could also significantly increase the relative abundance of Lactobacillus and Clostridium XIVa and decrease that of Allobaculum, Bacteroides and Clostridium IV. The active role of SCO in anti-diabetic effect was revealed by its regulation of insulin receptor substrate 1/phosphatidylinositol 3-kinase and c-Jun N-terminal kinase pathways. These results suggested that SCO might be used as a functional material to regulate gut microbiota in obese and diabetic individuals.

Effect of Marine Microalga Chlorella pyrenoidosa Ethanol Extract on Lipid Metabolism and Gut Microbiota Composition in High-Fat Diet-Fed Rats.

Effects of marine microalga Chlorella pyrenoidosa 55% ethanol extract (CPE55) on lipid metabolism, gut microbiota and regulation mechanism in high fat diet-fed induced hyperlipidaemia rats were investigated. Structure characterizations of major compounds in CPE55 were determined by ultra-performance liquid chromatography-quadrupole/time of flight mass spectrometry (UPLC-Q-TOF-MS/MS). The compositions of gut microbiota in rats were analyzed by high-throughput next-generation 16S rRNA gene sequencing. Oral administration with CPE55 markedly alleviated dyslipidemia through improving adverse blood lipid profile and inhibiting hepatic lipid accumulation and steatosis. CPE55 has downregulated the gene expression levels of acetyl CoA carboxylase, sterol regulatory element-binding transcription factor-1c, and 3-hydroxy-3-methyl glutaryl coenzyme A reductase and upregulated adenosine 5'-monophosphate-activated protein kinase-α. It has also improved the abundance of bacteria Alistipes, Prevotella, Alloprevotella, and Ruminococcus1 and decreased the abundances of Turicibacter and Lachnospira. Turicibacter and Lachnospira were both positive correlations of metabolic phenotypes. The findings above illustrated that CPE55 might be developed as food ingredients to ameliorate lipid metabolic disorders and hyperlipidaemia.

Regulatory Efficacy of the Polyunsaturated Fatty Acids from Microalgae Spirulina platensis on Lipid Metabolism and Gut Microbiota in High-Fat Diet Rats.

Ultra-high performance liquid chromatography coupled with photo-diode array detector and electrospray ionization-mass spectrometry was employed to analyze the major fatty acids in Spirulina platensis 95% ethanol extract (SPL95). The effects of SPL95 on hepatoprotection were evaluated, including liver tissue histopathology, liver, and serum biochemical analysis. The active principle of SPL95 revealed a hypolipidemic effect, as indicated by down-regulating the mRNA and protein levels of sterol regulatory element-binding transcription factor-1c, 3-hydroxy-3-methyl glutaryl coenzyme A reductase, acetyl CoA carboxylase pathway, and upregulating adenosine 5'-monophosphate-activated protein kinase-α in liver. SPL95 enriched the beneficial bacteria, including Prevotella, Alloprevotella, Porphyromonadaceae, Barnesiella, and Paraprevotella. Treatment with SPL95 led to a decrease in microbes, such as Turicibacter, Romboutsia, Phascolarctobacterium, Olsenella, and Clostridium XVIII, which were positively correlated with serum triglyceride, total cholesterol, and low-density-lipoprotein cholesterol levels, but negatively correlated with the serum high-density-lipoprotein cholesterol levels. These results provide evidence that the fatty acid from SPL95 may be used as a novel adjuvant therapy and functional food to regulate gut microbiota in obese and diabetic individuals.