Metabonomics Approaches and the Potential Application in Foodsafety Evaluation

Protective effects of oyster polypeptide on cyclophosphamide-induced immunosuppressed rats

BACKGROUND

Oyster polypeptide (OP) is a mixture of oligopeptides extracted from oysters through enzyme lysis, separation, and purification. It is associated with immunomodulatory effects, but the underlying mechanisms are not known. This study therefore combined proton nuclear magnetic resonance (1H-NMR) urinary metabolomics and 16S rRNA gene sequencing of the gut microbiome to determine the immunoprotective mechanisms of OP in rats subjected to cyclophosphamide-induced immunosuppression.

RESULTS

Oyster polypeptide restored the body weight and the structure of spleen and thymus in rats with cyclophosphamide-induced immunosuppression. It upregulated the levels of white blood cells (WBCs), hemoglobin (HGB), platelets (PLT), red blood cells (RBCs), immunoglobulin G (IgG), immunoglobulin M (IgM), cytokines such as interleukin‑6 (IL-6) and tumor necrosis factor-α (TNF-α), and increased the numbers of CD3+ and CD4+ T cells in the immunosuppressed rats. The 1H-NMR metabolomics results showed that OP significantly reversed the levels of ten metabolites in urine, including 2-oxoglutarate, citrate, dimethylamine, taurine, N-phenylacetylglycine, alanine, betaine, creatinine, uracil, and benzoate. The 16S rRNA gene sequencing results showed that OP restored the gut microbiome homeostasis by increasing the abundance of beneficial bacteria and reducing the abundance of pathogenic bacteria. Finally, a combination of metabolomics and microbiomics found that the metabolism of taurine and hypotaurine, and the metabolism of alanine, aspartate, and glutamate were disturbed, but these metabolic pathways were restored by OP.

CONCLUSION

This study demonstrated that OP had immunoprotective effects in rats with cyclophosphamide-induced immunosuppression by restoring key metabolic pathways and the gut microbiome homeostasis. Our findings provide a framework for further research into the immunoregulatory mechanisms of OP and its potential use in drugs and nutritional supplements. © 2024 Society of Chemical Industry.

Rewiring cis-2-butene-1,4-dial mediated urinary metabolomics fingerprints of short-term exposure to furan

Furan represents one of the dietary-sourced persistent organic pollutants and thermal processing contaminants. Given its widespread occurrence in food and various toxicological effects, accurately assessing furan exposure is essential for informing public health risks. Furan is metabolized to a reactive primary product, cis-2-butene-1,4-dial (BDA) upon absorption. Some of the resulting BDA-derived metabolites have been proposed as potential exposure biomarkers of furan. However, the lack of quantification for recognized and feasible furan biomarkers has hampered the development of internal exposure risk assessment of furan. In this study, we employed reliable non-targeted metabolomics techniques to uncover urinary furan metabolites and elucidate their chemical structures. We characterized 8 reported and 11 new furan metabolites derived from the binding of BDA with glutathione (GSH), biogenic amines, and/or amino acids in the urine of male rats subjected to varying doses of furan. Notably, a mono-GSH-BDA adduct named cyclic GSH-BDA emerged as a highly prospective specific biomarker of furan exposure, as determined by an ultrahigh-performance liquid chromatography-tandem mass spectrometry method. Cyclic GSH-BDA demonstrated a robust mass spectrometry ion response intensity and exhibited evident time- and dose response. Additionally, we conducted a comprehensive profiling of the kinetics of potential furan biomarkers over time to capture the metabolic dynamics of furan in vivo. Most urinary furan metabolites reached peak concentrations at either the first (3 h) or second (6 h) sampling time point and were largely eliminated within 36 h following furan treatment. The present study provides novel insights into furan metabolism and sheds light on the biomonitoring of furan exposure.

Unveiling the distribution of chemical constituents at different body parts and maturity stages of Ganoderma lingzhi by combining metabolomics with desorption electrospray ionization mass spectrometry imaging (DESI)

Ganoderma lingzhi is an important medicinal fungus, which is widely used as dietary supplement and for pharmaceutical industries. However, the spatial distribution and dynamic accumulation pattern of active components such as ganoderic acids (GAs) among different parts of G. lingzhi fruiting body are still unclear. In this study, desorption electrospray ionization mass spectrometry imaging (DESI-MSI) with untargeted metabolomics analysis was applied to investigate the metabolites distribution within G. lingzhi fruiting body at four different maturity stages (squaring, opening, maturation and harvesting stage). A total of 132 metabolites were characterized from G. lingzhi, including 115 triterpenoids, 11 fatty acids and other component. Most of the GAs content in the cap was significantly higher than that in the stipe, with six components such as ganoderic acid B being extremely significant. GAs in the cap was mainly present in the bottom edge of the mediostratum layer, such as ganoderic A-I and ganoderic GS-1, while in the stipe, they were mainly distributed in the shell layer and the context layer, such as ganoderic A-F. Most ganoderic acids content in both the stipe and the cap of G. lingzhi was gradually decreased with the development of G. lingzhi. The GAs in the stipe was gradually transferred from the shell layer to the content layer, while the distribution of GAs among different tissues of the cap was not significantly changed. In addition, linoleic acid, 9-HODE, 9-KODE and other fatty acids were mainly accumulated in the opening and maturing stage of the caps. This study further clarifies the spatial dynamic distribution of GAs in G. lingzhi fruiting body at four different maturity stages (squaring, opening, maturation and harvesting stage), which provides a basis for the rational utilization of the medicinal parts of G. lingzhi. Furthermore, mass spectrometry imaging combined with non-target metabolome analysis provides a powerful tool for the spatial distribution of active substances in the different regions of the medicinal edible fungi.

Metabolomic analysis of the effects of cadmium and copper treatment in Oryza sativa L. using untargeted liquid chromatography coupled to high resolution mass spectrometry and all-ion fragmentation

While the knowledge of plant metabolomes has increased in the last few years, their response to the presence of toxicants is still poorly understood. Here, we analyse the metabolomic changes in Japanese rice (Oryza sativa var. Japonica) upon exposure to heavy metals (Cd(ii) and Cu(ii)) in concentrations from 10 to 1000 μM. After harvesting, rice metabolites were extracted from aerial parts of the plants and analysed by HPLC (HILIC TSK gel amide-80 column) coupled to a mass spectrometer quadrupole-Orbitrap (Q-Exactive). Full scan and all ion fragmentation (AIF) mass spectrometry modes were used during the analysis. The proposed untargeted metabolomics data analysis strategy is based on the application of the multivariate curve resolution alternating least squares (MCR-ALS) method for feature detection, allowing the simultaneous resolution of pure chromatographic profiles and mass spectra of all metabolites present in the analysed rice extracts. All-ion fragmentation data were used to confirm the identification of MCR-ALS resolved metabolites. A total of 112 metabolites were detected, and 97 of them were subsequently identified and confirmed. Pathway analysis of the observed metabolic changes suggested an underlying similarity of the responses of the plant to Cd(ii) and Cu(ii), although the former treatment appeared to be the more severe of the two. In both cases, secondary metabolism and amino acid-, purine-, carbon- and glycerolipid-metabolism pathways were affected, in a pattern consistent with reduction in plant growth and/or photosynthetic capacity and with induction of defence mechanisms to reduce cell damage.

Metabonomics analysis of quercetin against the nephrotoxicity of acrylamide in rats

This research aimed at studying the effect of quercetin against the nephrotoxicity of acrylamide by metabonomics analysis of kidney tissue.

The Use of "Omics" in Lactation Research in Dairy Cows

“Omics” is the application of genomics, transcriptomics, proteomics, and metabolomics in biological research. Over the years, tremendous amounts of biological information has been gathered regarding the changes in gene, mRNA and protein expressions as well as metabolites in different physiological conditions and regulations, which has greatly advanced our understanding of the regulation of many physiological and pathophysiological processes. The aim of this review is to comprehensively describe the advances in our knowledge regarding lactation mainly in dairy cows that were obtained from the “omics” studies. The “omics” technologies have continuously been preferred as the technical tools in lactation research aiming to develop new nutritional, genetic, and management strategies to improve milk production and milk quality in dairy cows.