Flaxseed Lignan Alleviates the Paracetamol-Induced Hepatotoxicity Associated with Regulation of Gut Microbiota and Serum Metabolome

This study examined the protective effect of flaxseed lignans on liver damage caused by an overdose of paracetamol (PAM). The findings demonstrated that administering 800 mg/kg/d flaxseed lignan prior to PAM significantly decreased the serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and total bilirubin (TBi) levels, while it increased liver superoxide dismutase (SOD) and glutathione (GSH) levels in mice. Flaxseed lignan renovated the gut microbiota dysbiosis induced by PAM by promoting the proliferation of sulfonolipid (SL) producing bacteria such as Alistipes and lignan-deglycosolating bacteria such as Ruminococcus while inhibiting the growth of opportunistic pathogen bacteria such as Acinetobacter and Clostridium. Furthermore, flaxseed lignan modulated the serum metabolomic profile after PAM administration, specifically in the taurine and hypotaurine metabolism, phenylalanine metabolism, and pyrimidine metabolism. The study identified eight potential biomarkers, including enterolactone, cervonyl carnitine, acutilobin, and PC (20:3(5Z, 8Z, 11Z)/20:0). Overall, the results suggest that flaxseed lignan can alleviate PAM-induced hepatotoxicity and may be beneficial in preventing drug-induced microbiome and metabolomic disorders.

Combined Omics Approaches Reveal Distinct Mechanisms of Resistance and/or Susceptibility in Sugar Beet Double Haploid Genotypes at Early Stages of Beet Curly Top Virus Infection

Sugar beet is susceptible to Beet curly top virus (BCTV), which significantly reduces yield and sugar production in the semi-arid growing regions worldwide. Sources of genetic resistance to BCTV is limited and control depends upon insecticide seed treatments with neonicotinoids. Through double haploid production and genetic selection, BCTV resistant breeding lines have been developed. Using BCTV resistant (R) [KDH13; Line 13 and KDH4-9; Line 4] and susceptible (S) [KDH19-17; Line 19] lines, beet leafhopper mediated natural infection, mRNA/sRNA sequencing, and metabolite analyses, potential mechanisms of resistance against the virus and vector were identified. At early infection stages (2- and 6-days post inoculation), examples of differentially expressed genes highly up-regulated in the 'R' lines (vs. 'S') included EL10Ac5g10437 (inhibitor of trypsin and hageman factor), EL10Ac6g14635 (jasmonate-induced protein), EL10Ac3g06016 (ribosome related), EL10Ac2g02812 (probable prolyl 4-hydroxylase 10), etc. Pathway enrichment analysis showed differentially expressed genes were predominantly involved with peroxisome, amino acids metabolism, fatty acid degradation, amino/nucleotide sugar metabolism, etc. Metabolite analysis revealed significantly higher amounts of specific isoflavonoid O-glycosides, flavonoid 8-C glycosides, triterpenoid, and iridoid-O-glycosides in the leaves of the 'R' lines (vs. 'S'). These data suggest that a combination of transcriptional regulation and production of putative antiviral metabolites might contribute to BCTV resistance. In addition, genome divergence among BCTV strains differentially affects the production of small non-coding RNAs (sncRNAs) and small peptides which may potentially affect pathogenicity and disease symptom development.

Activities and metabolomics of Cordyceps gunnii under different culture conditions

Many active metabolites have been identified from various species of the fungal genus Cordyceps. A predominant species of this genus is Cordyceps gunnii, but there are limited reports on the active ingredients from this species. This study aimed to conduct activity assays and metabolome analysis on extracts of C. gunnii obtained under different culture conditions. Five different solid media were selected to culture the mycelium of C. gunnii and the metabolites were extracted with organic solvents; concurrently, the wild stroma and host complexes of C. gunnii were extracted by ethyl acetate. Extracts were subsequently assayed for various biological activities and were analyzed by untargeted metabolomics. There were significant differences in the activities and metabolites of C. gunnii extracts from different culture conditions and from wild stroma and host complexes. The extracts of stroma and host complexes and mycelia cultured on WGA medium for 21 days exhibited similar effective inhibitory activity against five cell lines. A total of 51 metabolites were annotated and included various structural types. The literatures indicate that most of the identified compounds have a variety of different biological activities. These findings provide the basis for further systematic excavation of C. gunnii and improved utilization of this fungal species.

Combined Metabolomic and Transcriptomic Analysis Reveals Allantoin Enhances Drought Tolerance in Rice

Drought is a misfortune for agriculture and human beings. The annual crop yield reduction caused by drought exceeds the sum of all pathogens. As one of the gatekeepers of China's "granary", rice is the most important to reveal the key drought tolerance factors in rice. Rice seedlings of Nipponbare (Oryza sativa L. ssp. Japonica) were subjected to simulated drought stress, and their root systems were analyzed for the non-targeted metabolome and strand-specific transcriptome. We found that both DEGs and metabolites were enriched in purine metabolism, and allantoin accumulated significantly in roots under drought stress. However, few studies on drought tolerance of exogenous allantoin in rice have been reported. We aimed to further determine whether allantoin can improve the drought tolerance of rice. Under the treatment of exogenous allantoin at different concentrations, the drought resistant metabolites of plants accumulated significantly, including proline and soluble sugar, and reactive oxygen species (ROS) decreased and reached a significant level in 100 μmol L^-1. To this end, a follow-up study was identified in 100 μmol L^-1 exogenous allantoin and found that exogenous allantoin improved the drought resistance of rice. At the gene level, under allantoin drought treatment, we found that genes of scavenge reactive oxygen species were significantly expressed, including peroxidase (POD), catalase (CATA), ascorbate peroxidase 8 (APX8) and respiratory burst oxidase homolog protein F (RbohF). This indicates that plants treated by allantoin have better ability to scavenge reactive oxygen species to resist drought. Alternative splicing analysis revealed a total of 427 differentially expressed alternative splicing events across 320 genes. The analysis of splicing factors showed that gene alternative splicing could be divided into many different subgroups and play a regulatory role in many aspects. Through further analysis, we restated the key genes and enzymes in the allantoin synthesis and catabolism pathway, and found that the expression of synthetase and hydrolase showed a downward trend. The pathway of uric acid to allantoin is completed by uric acid oxidase (UOX). To find out the key transcription factors that regulate the expression of this gene, we identified two highly related transcription factors OsERF059 and ONAC007 through correlation analysis. They may be the key for allantoin to enhance the drought resistance of rice.

Heterologous Expression of SiFBP, a Folate-Binding Protein from Foxtail Millet, Confers Increased Folate Content and Altered Amino Acid Profiles with Nutritional Potential to Arabidopsis

The mechanism underlying folate degradation in foxtail millet grains remains unclear. Here, we identified SiFBP (Setaria italica folate-binding protein) from foxtail millet. A phylogenetic tree revealed that FBPs have close genetic relationships among cereal crop species. Docking analysis and heterologous expression of SiFBP in yeast showed that it could bind folic acid (FA). The SiFBP localized to the plasma membrane in tobacco mesophyll cells by transient expression. In Arabidopsis, it was expressed specifically in the roots and germinating seeds. Overexpressing SiFBP in yeast and Arabidopsis significantly increased folate contents. Untargeted metabolome analysis revealed differentially accumulated metabolites between the transgenic lines (TLs) and wild type (WT); these metabolites were mainly enriched in the amino acid metabolism pathway. The relative contents of lysine and leucine, threonine, and l-methionine were significantly higher in the TLs than in WT. Genes related to the folate and lysine synthesis pathways were upregulated in the TLs. Thus, SiFBP can be used for biofortification of folate and important amino acids in crops via genetic engineering.

Untargeted Metabolomics Analysis Revealed the Major Metabolites in the Seeds of four Polygonatum Species

Most Polygonatum species are widely used in China as a source of medicine and food. In this study, a UPLC-QTOF-MS/MS system was used to conduct an untargeted metabolomics analysis and compare the classes and relative contents of metabolites in the seeds of four Polygonatum species: P. sibiricum (Ps), P. cyrtonema (Pc), P. kingianum (Pk), and P. macropodium (Pm). The objectives of this study were to clarify the metabolic profiles of these seeds and to verify their medicinal and nutritional value via comparative analyses. A total of 873 metabolites were identified, including 185 flavonoids, 127 lipids, 105 phenolic acids, and 36 steroids. The comparative analysis of metabolites among Polygonatum seed samples indicated that flavonoids, steroids, and terpenoids were the main differentially abundant compounds. The results of principal component analysis and hierarchical clustering were consistent indicating that the metabolites in Ps and Pm are similar, but differ greatly from Pc and Pk. The data generated in this study provide additional evidence of the utility of Polygonatum seeds for producing food and medicine.

Algal Oil Rich in Docosahexaenoic Acid Alleviates Intestinal Inflammation Induced by Antibiotics Associated with the Modulation of the Gut Microbiome and Metabolome

In this study, the effect of algal oil rich in docosahexaenoic acid on the mucosal injury with gut microbiota disorders caused by ceftriaxone sodium (CS) was evaluated. The results showed that algal oil treatment (500 mg kg^-1 day^-1) significantly reduced the levels of pro-inflammatory cytokines, including interleukin 6 , interleukin 1β, and tumor necrosis factor α, in the colon. Algal oil restored the CS-induced gut microbiota dysbiosis by elevating some short-chain-fatty-acid-producing bacteria, e.g., Ruminococcus and Blautia. The CS-induced metabolic disorder was also regulated by algal oil, which was characterized by the modulations of tryptophan metabolism, phospholipid metabolism, and bile acid metabolism. Our results suggested that supplementation of algal oil could alleviate inflammation and promote mucosal healing, which could be a functional food ingredient to protect aganist antibiotic-induced alteration of gut microbiota and metabolic dysbiosis.

Untargeted Global Metabolomic Analysis Reveals the Mechanism of Tripropylamine-Enhanced Lycopene Accumulation in Blakeslea trispora

We previously determined that the cyclase inhibitor tripropylamine (TPA) significantly enhances lycopene accumulation in Blakeslea trispora. To elucidate the mechanism of TPA-enhanced lycopene accumulation, the untargeted metabolome of B. trispora treated with TPA was analyzed by UHPLC-Q-TOF/MS. Forty-two differential metabolites were identified, of which 15 significantly differential metabolites meeting the following parameters were screened: variable importance for the projection > 1, P < 0.05, and fold change > 1.5. The down-regulated metabolites were mainly cyclic dipeptides, bacteriostatic compounds, and lipids, while the up-regulated metabolites were mainly unsaturated fatty acid. Furthermore, the bacteriostatic ability was poor, the extracellular and intracellular pH levels were high, and hyphae with vesicles were swollen locally in B. trispora after treatment with TPA. Our data suggest that the TPA enhances lycopene accumulation not only by inhibiting the cyclization of β-carotene but also by down-regulating cyclic dipeptides for quorum sensing; up-regulating unsaturated fatty acids, 1-palmitoyl-2-hydroxy-sn-glycero-3-phosphoethanolamine, and 4-hydroxybenzoate and down-regulating choline, resulting in locally swelling mycelium with vacuoles; and down-regulating bacteriostatic metabolites for metabolic flux redistribution.