Acer truncatum leaves extract modulates gut microbiota, improves antioxidant capacity, and alleviates lipopolysaccharide-induced inflammation in broilers.

This study investigated the appropriate way of dietary Acer truncatum leaves (ATL) addition, the effect of disease prevention and its mechanism of action. In experiment 1, 192 Arbor Acres broilers were assigned to 4 treatment groups, fed with basal diets containing 2% bran, replacing it with primary and fermented ATL, and additional 0.3% ATL extract to the basal diet for 42 d, respectively. In experiment 2, 144 broilers were assigned to 3 treatment groups for 21-d trial: (1) C-N group, basal diets, and injected with 0.9% (w/v) sterile saline; (2) C-L group, basal diets, and injected with lipopolysaccharide (LPS); (3) T-L group, ATL diets and injected with LPS. In experiment 1, ATL significantly decreased the index of abdominal fat at 42 d (P < 0.05). ATL extract had a better ability to improve antioxidant capacity and reduce inflammatory levels among all treatment groups, which significantly decreased the content of MDA in the liver and ileum mucosa at 21 d, and increased the expression of IL-10 and Occludin in jejunal mucosa at 42 d (P < 0.05). In experiment 2, ATL significantly increased the level of T-AOC in the liver, decreased the expression of NF-κB in the jejunal mucosa and ileum mucosa (P < 0.05), and restored LPS-induced the changed level of CAT in jejunal mucosa, the expression of IL-6, Claudin-1, and ZO-1 in jejunal mucosa and IL-1ß in ileum mucosa (P < 0.05). Analysis of gut microbiota indicated that ATL enhanced the abundances of Bacteroidota and reduced the proportion of Firmicutes (P < 0.05), and the changed levels of T-AOC in body, IL-1ß, IL-6, IL-10, and NF-κB in jejunum mucosa and propionic acid in cecal were associated with gut microbiota. Collectively, our data showed that the extract of ATL had a better antioxidant and anti-inflammatory effects than primality and fermented. Extraction of ATL modulated intestinal microbiota, and had a protective effect on oxidative stress, inflammation, and intestinal barrier function in broilers challenged with LPS.

The relevance of urolithins-based metabotyping for assessing the effects of a polyphenol-rich dietary intervention on intestinal permeability: A post-hoc analysis of the MaPLE trial.

A polyphenol-rich diet reduced intestinal permeability (IP) in older adults. Our aim was to evaluate if participants categorized according to urolithin metabotypes (UMs) exhibited different responses in the MaPLE trial. Fifty-one older adults (mean age: 78 years) completed an 8-week randomized-controlled-crossover trial comparing the effects of a polyphenol-rich vs. a control diet on IP, assessed through zonulin levels. Plasma and urinary metabolomics were evaluated with a semi-targeted UHPLC-MS/MS method. Gut microbiota was characterized by 16S rRNA gene profiling. UMs were determined according to urolithin excretion in 24 h urine samples. Multivariate statistics were used to characterize the differences in metabolomic and metataxonomic responses across UMs. Thirty-three participants were classified as urolithin metabotype A (UMA), 13 as urolithin metabotype B (UMB), and 5 as urolithin metabotype 0 (UM0) according to their urinary excretion of urolithins. Clinical, dietary, and biochemical characteristics at baseline were similar between UMs (all p > 0.05). After the polyphenol-rich diet, UMB vs. UMA participants showed a 2-fold higher improvement of zonulin levels (p for interaction = 0.033). Moreover, UMB vs. UMA participants were characterized for alterations in fatty acid metabolism, kynurenine pathway of tryptophan catabolism, and microbial metabolization of phenolic acids. These changes were correlated with the reduction of zonulin levels and modifications of gut microbes (increased Clostridiales, including, R. lactaris, and G. formicilis). In conclusion, urolithin-based metabotyping identified older adults with a higher improvement of IP after a polyphenol-rich diet. Our results reinforce the concept that UMs may contribute to tailor personalized nutrition interventions.

Assembly and comparative analysis of the first complete mitochondrial genome of Acer truncatum Bunge: a woody oil-tree species producing nervonic acid.

BACKGROUND: Acer truncatum (purpleblow maple) is a woody tree species that produces seeds with high levels of valuable fatty acids (especially nervonic acid). The species is admired as a landscape plant with high developmental prospects and scientific research value. The A. truncatum chloroplast genome has recently been reported; however, the mitochondrial genome (mitogenome) is still unexplored. RESULTS: We characterized the A. truncatum mitogenome, which was assembled using reads from PacBio and Illumina sequencing platforms, performed a comparative analysis against different species of Acer. The circular mitogenome of A. truncatum has a length of 791,052 bp, with a base composition of 27.11% A, 27.21% T, 22.79% G, and 22.89% C. The A. truncatum mitogenome contains 62 genes, including 35 protein-coding genes, 23 tRNA genes and 4 rRNA genes. We also examined codon usage, sequence repeats, RNA editing and selective pressure in the A. truncatum mitogenome. To determine the evolutionary and taxonomic status of A. truncatum, we conducted a phylogenetic analysis based on the mitogenomes of A. truncatum and 25 other taxa. In addition, the gene migration from chloroplast and nuclear genomes to the mitogenome were analyzed. Finally, we developed a novel NAD1 intron indel marker for distinguishing several Acer species. CONCLUSIONS: In this study, we assembled and annotated the mitogenome of A. truncatum, a woody oil-tree species producing nervonic acid. The results of our analyses provide comprehensive information on the A. truncatum mitogenome, which would facilitate evolutionary research and molecular barcoding in Acer.

Neuroprotective effects of Acer palmatum thumb. leaf extract (KIOM-2015E) against ischemia/reperfusion-induced injury in the rat retina.

Purpose: The present study aimed to determine whether the administration of Acer palmatum thumb. leaf extract (KIOM-2015E) protects against the degeneration of rat retinal ganglion cells after ischemia/reperfusion (I/R) induced by midbrain cerebral artery occlusion (MCAO). Methods: Sprague-Dawley rats were subjected to 90 min of MCAO, which produces transient ischemia in both the retina and brain due to the use of an intraluminal filament that blocks the ophthalmic and middle cerebral arteries. This was followed by reperfusion under anesthesia with isoflurane. The day after surgery, the eyes were treated three times (eye drop) or one time (oral administration) daily with KIOM-2015E for five days. Retinal histology was assessed in flat mounts and vertical sections to determine the effect of KIOM-2015E on I/R injury. Results: A significant loss of brain-specific homeobox/POU domain protein 3A (Brn3a) and neuron-specific class III beta-tubulin (Tuj-1) fluorescence and a marked increase in glial fibrillary acidic protein (GFAP) and glutamine synthetase (GS) expression were observed after five days in the PBS-treated MCAO group compared to the sham-operated control group. However, KIOM-2015E treatment reduced (1) MCAO-induced upregulation of GFAP and GS, (2) retinal ganglion cell loss, (3) nerve fiber degeneration, and (4) the number of TUNEL-positive cells. KIOM-2015E application also increased staining for parvalbumin (a marker of horizontal cell associated calcium-binding protein and amacrine cells) and recoverin (a marker of photoreceptor expression) in rats subjected to MCAO-induced retinal damage. Conclusions: Our findings indicated that KIOM-2015E treatment exerted protective effects against retinal damage following MCAO injury and that this extract may aid in the development of novel therapeutic strategies for retinal diseases, such as glaucoma and age-related macular disease.

Nitrate transformation and immobilization in particulate organic matter incubations: Influence of redox, iron and (a)biotic conditions.

Nitrate can be reduced to other N inorganic species via denitrification and incorporated into organic matter by immobilization; however, the effect of biotic/abiotic and redox condition on immobilization and denitrification processes from a single system are not well documented. We hypothesize nitrate (NO3-) transformation pathways leading to the formation of dissolved- and solid-phase organic N are predominantly controlled by abiotic reactions, but the formation of soluble inorganic N species is controlled by redox condition. In this study, organic matter in the form of leaf compost (LC) was spiked with 15NO3- and incubated under oxic/anoxic and biotic/abiotic conditions at pH 6.5. We seek to understand how variations in environmental conditions impact NO3- transformation pathways through laboratory incubations. We find production of NH4+ is predominantly controlled by redox whereas NO3- conversion to dissolved organic nitrogen (DON) and immobilization in solid-phase N are predominantly controlled by abiotic processes. Twenty % of added 15N-NO3- was incorporated into DON under oxic conditions, with abiotic processes accounting for 85% of the overall incorporation. Nitrogen immobilization processes resulted in N concentrations of 4.1-6.6 µg N (g leaf compost)-1, with abiotic processes accounting for 100% and 66% of the overall (biotic+abiotic) N immobilization under anoxic and oxic conditions, respectively. 15N-NMR spectroscopy suggests 15NO3- was immobilized into amide/aminoquinones and nitro/oxime under anoxic conditions. A fraction of the NH4+ was produced abiotically under anoxic conditions (~10% of the total NH4+ production) although biotic organic N mineralization contributed to most of NH4+ production. Our results also indicate Fe(II) did not act as an electron source in biotic-oxic incubations; however, Fe(II) provided electrons for NO3- reduction in biotic-anoxic incubations although it was not the sole electron source. It is clear that, under the experimental conditions of this investigation, abiotic and redox processes play important roles in NO3- transformations. As climatic conditions change (e.g., frequency/intensity of rainfall), abiotic reactions that shift transformation pathways and N species concentrations from those controlled by biota might become more prevalent.

Metabolic Profiling of Different Parts of Acer truncatum from the Mongolian Plateau Using UPLC-QTOF-MS with Comparative Bioactivity Assays.

Acer truncatum is an important ornamental, edible, and medicinal plant resource in China. Previous phytochemical research has focused on the leaf (AL) due to its long history as a tea for health. Other parts such as the branch (ABr), bark (ABa), fruit (AF), and root (AR) have drawn little attention regarding their metabolites and bioactivities. The strategy of an in-house chemical library combined with Progenesis QI informatics platform was applied to characterize the metabolites. A total of 98 compounds were characterized or tentatively identified, including 63 compounds reported from this species for the first time. Principal component analysis showed the close clustering of ABr, ABa, and AR, indicating that they share similar chemical components, while AL and AF clustered more distantly. By multiple orthogonal partial least-squares discriminant analyses (OPLS-DA), 52 compounds were identified as potential marker compounds differentiating these different plant parts. The variable influence on projection score from OPLS-DA revealed that catechin, procyanidins B2 or B3, and procyanidins C1 or C2 are the significant metabolites in ABa extracts, which likely contribute to its antioxidant and cytotoxic activities.

The effect of a doubled glutathione level on parameters affecting the germinability of recalcitrant Acer saccharinum seeds during drying.

Approximately 20% of plant species, including silver maple (Acer saccharinum L.), produce seeds that are sensitive to desiccation, which is reflected in their poor storage potential and viability. In the search for a compound that can improve seed recalcitrance, freshly harvested seeds were soaked in either 2.5 mM reduced glutathione (GSH) or water and desiccated to comparable water levels of 55-20%. We examined the impact of a doubled endogenous level of glutathione on the seed germination capacity, the activity of enzymes involved in glutathione metabolism, the cell membrane components and integrity, reactive oxygen species, and ascorbate levels. GSH treatment resulted in slower dehydration and a higher germination capacity. The increased glutathione was mainly consumed by glutathione S-transferase, leading to more efficient detoxification, and by dehydroascorbate reductase (DHAR), accelerating the ascorbate regeneration. As a result, the cellular environment became more reduced, and protection of the membrane structures was enhanced. The ameliorated membrane integrity was manifested via a lower electrolyte leakage and a lower lipid peroxide level despite the higher level of hydrogen peroxide (H2O2) detected in the GSH-treated seeds. The degradation of phospholipids (PLs) was less intense and related to the phosphatidylinositol (PI) level, which is the precursor of the phospholipase D cofactor, whereas in water-soaked seeds, PL degradation was promoted by H2O2. The germination capacity of the dehydrated seeds depended primarily on the level of H2O2, lipid hydroxyperoxides, electrolyte leakage, GSH, the half-cell reduction potential of glutathione, PI, and the activity of DHAR and γ-glutamylcysteine synthetase. Interestingly, H2O2 affected all of the parameters. The germination of GSH-boosted seeds was strongly impacted by the pool of ascorbate, the half-cell reduction potential of ascorbate, and the glutathione peroxidase activity. In general, germination was DHAR activity-dependent. A strong negative correlation was detected in the water-soaked seeds, whereas a strong positive correlation was detected in the GSH-treated seeds. The enhanced level of glutathione likely improved the efficiency of the ascorbate-glutathione cycle, confirming its effect on seed germinability after dehydration.

Antiangiogenic Activity of Acer tegmentosum Maxim Water Extract in Vitro and in Vivo.

Angiogenesis, the formation of new blood vessels, is critical for tumor growth and metastasis. Notably, tumors themselves can lead to angiogenesis by inducing vascular endothelial growth factor (VEGF), which is one of the most potent angiogenic factors. Inhibition of angiogenesis is currently perceived as one of the most promising strategies for the blockage of tumor growth. In this study, we investigated the effects of Acer tegmentosum maxim water extract (ATME) on angiogenesis and its underlying signal mechanism. We studied the antiangiogenic activity of ATME by using human umbilical vein endothelial cells (HUVECs). ATME strongly inhibited VEGF-induced endothelial cell proliferation, migration, invasion, and tube formation, as well as vessel sprouting in a rat aortic ring sprouting assay. Moreover, we found that the p44/42 mitogen activated protein (MAP) kinase signaling pathway is involved in the inhibition of angiogenesis by ATME. Moreover, when we performed the in vivo matrigel plug assay, VEGF-induced angiogenesis was potently reduced when compared to that for the control group. Taken together, these results suggest that ATME exhibits potent antiangiogenic activity in vivo and in vitro and that these effects are regulated by the extracellular regulated kinase (ERK) pathway.

Effects of Acer okamotoanum sap on the function of polymorphonuclear neutrophilic leukocytes in vitro and in vivo.

Sap is a plant fluid that primarily consists of water and small amounts of mineral elements, sugars, hormones and other nutrients. Acer mono (A. mono) is an endemic Korean mono maple which was recently suggested to have health benefits due to its abundant calcium and magnesium ion content. In the present study, we examined the effects of sap from Acer okamotoanum (A. okamotoanum) on the phagocytic response of mouse neutrophils in vivo and rat and canine neutrophils in vitro. We tested the regulation of phagocytic activity, oxidative burst activity (OBA) and the levels of filamentous polymeric actin (F-actin) in the absence and presence of dexamethasone (DEX) in vitro and in vivo. Our results showed that DEX primarily reduced OBA in the mouse neutrophils, and that this was reversed in the presence of the sap. By contrast, the phagocytic activity of the mouse cells was not regulated by either DEX or the sap. Rat and canine polymorphonuclear neutrophilic leukocytes (PMNs) responded in vitro to the sap in a similar manner by increasing OBA. However, regulation of phagocytic activity by the sap was different between the species. In canine PMNs, phagocytic activity was enhanced by the sap at a high dose, while it did not significantly modulate this activity in rat PMNs. These findings suggest that the sap of A. okamotoanum stimulates neutrophil activity in the mouse, rat and canine by increasing OBA in vivo and in vitro, and thus may have a potential antimicrobial effect in the PMNs of patients with infections.

Ethylene is involved in stress responses induced by fusicoccin in sycamore cultured cells.

The phytohormone ethylene is involved in many physiological and developmental processes of plants, as well as in stress responses and in the development of disease resistance. Fusicoccin (FC) is a well-known phytotoxin, that in sycamore (Acer pseudoplatanus L.) cultured cells, induces a set of stress responses, including synthesis of ethylene. In this study, we investigated the possible involvement of ethylene in the FC-induced stress responses of sycamore cells by means of Co(2+), a well-known specific inhibitor of ethylene biosynthesis. Co(2+) inhibited the accumulation of dead cells in the culture, the production of nitric oxide (NO) and of the molecular chaperone Binding Protein (BiP) in the endoplasmic reticulum induced by FC. By contrast, Co(2+) was ineffective on the FC-induced accumulation of cells with fragmented DNA, production of H(2)O(2) and release of cytochrome c from the mitochondrion, and only partially reduced the accumulation of regulative 14-3-3 proteins in the cytosol. In addition, we compared the effect of FC on the above parameters with that of the ethylene-releasing compound ethephon (2-chloroethane phosphonic acid). The results suggest that ethylene is involved in several stress responses induced by FC in sycamore cells, including a form of cell death that does not show apoptotic features and possibly involves NO as a signaling molecule.

Proteome analysis of Norway maple (Acer platanoides L.) seeds dormancy breaking and germination: influence of abscisic and gibberellic acids.

BACKGROUND: Seed dormancy is controlled by the physiological or structural properties of a seed and the external conditions. It is induced as part of the genetic program of seed development and maturation. Seeds with deep physiological embryo dormancy can be stimulated to germinate by a variety of treatments including cold stratification. Hormonal imbalance between germination inhibitors (e.g. abscisic acid) and growth promoters (e.g. gibberellins) is the main cause of seed dormancy breaking. Differences in the status of hormones would affect expression of genes required for germination. Proteomics offers the opportunity to examine simultaneous changes and to classify temporal patterns of protein accumulation occurring during seed dormancy breaking and germination. Analysis of the functions of the identified proteins and the related metabolic pathways, in conjunction with the plant hormones implicated in seed dormancy breaking, would expand our knowledge about this process. RESULTS: A proteomic approach was used to analyse the mechanism of dormancy breaking in Norway maple seeds caused by cold stratification, and the participation of the abscisic (ABA) and gibberellic (GA) acids. Forty-four proteins showing significant changes were identified by mass spectrometry. Of these, eight spots were identified as water-responsive, 18 spots were ABA- and nine GA-responsive and nine spots were regulated by both hormones. The classification of proteins showed that most of the proteins associated with dormancy breaking in water were involved in protein destination. Most of the ABA- and GA-responsive proteins were involved in protein destination and energy metabolism. CONCLUSION: In this study, ABA was found to mostly down-regulate proteins whereas GA up-regulated proteins abundance. Most of the changes were observed at the end of stratification in the germinated seeds. This is the most active period of dormancy breaking when seeds pass from the quiescent state to germination. Seed dormancy breaking involves proteins of various processes but the proteasome proteins, S-adenosylmethionine synthetase, glycine-rich RNA binding protein, ABI3-interacting protein 1, EF-2 and adenosylhomocysteinase are of particular importance. The effect of exogenously applied hormones was not a determining factor for total inhibition (ABA) or stimulation (GA) of Norway maple seed dormancy breaking and germination but proteomic data has proven these hormones play a role.

Linking phenolic oxidation in the midgut lumen with oxidative stress in the midgut tissues of a tree-feeding caterpillar Malacosoma disstria (Lepidoptera: Lasiocampidae).

Tannins are believed to function as plant defenses against caterpillars, in part, as a result of their oxidation in the midgut lumen. One putative mode of action that has not been examined in leaf-feeding larvae is oxidative stress in midgut tissues that results from tannin oxidation in the midgut lumen. The test species used in this study, Malacosoma disstria Hübner (Lasiocampidae), is known to have higher levels of phenolic oxidation in its midgut contents when it consumes the oxidatively active leaves of sugar maple (Acer saccharum Marshall) than when it consumes the leaves of red oak (Quercus rubra L.). This study tested the hypothesis that increased phenolic oxidation in the midgut lumen of M. disstria is associated with increased oxidative stress in its midgut tissues. Three markers (oxidized ascorbate:total ascorbate, oxidized glutathione:total glutathione, and oxidized proteins) were measured in larvae fed either sugar maple or red oak leaves. In addition, we examined whether superoxide dismutase (SOD) activity might be a useful inducible marker of oxidative stress in M. disstria midgut tissues. Three of the markers indicated that significantly higher levels of oxidative stress were produced in the midgut tissues of M. disstria that fed on sugar maple than on red oak. However, SOD activity did not differ between sugar maple- and red oak-feeding larvae. This study is the first to show a link between phenolic oxidation in the midgut contents of caterpillars and oxidative stress in their midgut tissues.

Seasonal patterns of cytokinins and microclimate and the mediation of gas exchange among canopy layers of mature Acer saccharum trees.

Seasonal patterns of cytokinins (CKs) and microclimate were examined in the upper, middle and lower canopy layers of mature Acer saccharum Marsh. (sugar maple) trees to elucidate the potential role of CKs in the mediation of gas exchange. The upper canopy showed a distinctly dissimilar microclimate from the middle and lower canopy layers with higher photosynthetically active radiation and wind speed, but showed no corresponding differences in transpiration (E) or stomatal conductance (g(s)). Although E and g(s) tended to be higher in the upper canopy than in the middle and lower canopies, the differences were not significant, indicating regulation beyond the passive response to changes in microclimate. The upper canopy accumulated significantly higher concentrations of CKs, predominantly as ribosides, and all canopy layers showed distinct seasonal patterns in CK profiles. Multiple regression models showed significant relationships between both g(s) and E and foliar CK concentration, although these relationships varied among canopy layers. The relationships were strongest in the middle and lower canopy layers where there was less fluctuation in leaf water status and less variability in abiotic variables. The relationships between gas exchange parameters and leaf CK concentration began to decouple near the end of the growing season as foliar phytohormone concentrations changed with the approach of dormancy.

An important pool of sucrose linked to starch biosynthesis is taken up by endocytosis in heterotrophic cells.

We have recently shown the occurrence of endocytic sucrose uptake in heterotrophic cells. Whether this mechanism is involved in the sucrose-starch conversion process was investigated by comparing the rates of starch accumulation in sycamore cells cultured in the presence or absence of the endocytic inhibitors wortmannin and 2-(4-morpholynyl-)-8-phenyl-4H-1 benzopyran-4-1 (LY294002). These analyses revealed a two-phase process involving an initial 120 min wortmannin- and LY294002-insensitive starch accumulation period, followed by a prolonged phase that was arrested by the endocytic inhibitors. Both wortmannin and LY294002 led to a strong reduction of the intracellular levels of both sucrose and the starch precursor molecule, ADPglucose. No changes in maximum catalytic activities of enzymes closely linked to starch and sucrose metabolism occurred in cells cultured with endocytic inhibitors. In addition, starch accumulation was unaffected by endocytic inhibitors when cells were cultured with glucose. These results provide a first indication that an important pool of sucrose incorporated into the cell is taken up by endocytosis prior to its subsequent conversion into starch in heterotrophic cells. This conclusion was substantiated further by experiments showing that sucrose-starch conversion was strongly prevented by both wortmannin and LY294002 in both potato tuber discs and developing barley endosperms.