Polyamine Content Research Articles

Unprecedented reactivity of polyamines with aldehydic DNA modifications: structural determinants of reactivity, characterization and enzymatic stability of adducts.

Apurinic/apyrimidinic (AP) sites, 5-formyluracil (fU) and 5-formylcytosine (fC) are abundant DNA modifications that share aldehyde-type reactivity. Here, we demonstrate that polyamines featuring at least one secondary 1,2-diamine fragment in combination with aromatic units form covalent DNA adducts upon reaction with AP sites (with concomitant cleavage of the AP strand), fU and, to a lesser extent, fC residues. Using small-molecule mimics of AP site and fU, we show that reaction of secondary 1,2-diamines with AP sites leads to the formation of unprecedented 3'-tetrahydrofuro[2,3,4-ef]-1,4-diazepane ('ribodiazepane') scaffold, whereas the reaction with fU produces cationic 2,3-dihydro-1,4-diazepinium adducts via uracil ring opening. The reactivity of polyamines towards AP sites versus fU and fC can be tuned by modulating their chemical structure and pH of the reaction medium, enabling up to 20-fold chemoselectivity for AP sites with respect to fU and fC. This reaction is efficient in near-physiological conditions at low-micromolar concentration of polyamines and tolerant to the presence of a large excess of unmodified DNA. Remarkably, 3'-ribodiazepane adducts are chemically stable and resistant to the action of apurinic/apyrimidinic endonuclease 1 (APE1) and tyrosyl-DNA phosphoesterase 1 (TDP1), two DNA repair enzymes known to cleanse a variety of 3' end-blocking DNA lesions.

Physiological and Biochemical Parameters of Field Bean (Vicia faba var. minor) Seeds Stored for 33 Years

Changes occurring in seeds of two field bean cultivars during long-term storage at −14 °C, +4 °C and +20 °C were examined. It was found that after 33 years of storage at low temperatures, the seeds showed a significant decline in biological quality, and the seeds stored at +20 °C completely lost their germination capacity. As the seeds aged, changes in their phenolic composition, concentrations of polyamines and activity of enzymes associated with redox homeostasis and phenolic metabolism could be easily observed. The activity of ascorbate peroxidase and phenylalanine ammonia-lyase in deteriorated seeds was higher than in high-quality seeds. The activity of guaiacol peroxidase, catalase and glutathione reductase in low-quality seeds was decreased. With superoxide dismutase, the pattern was less clear-cut and depended on both seed biological quality and cultivar. Whole seed levels of spermine and spermidine decreased in ageing seeds and were lowest in non-germinating seeds. However, the opposite pattern was observed regarding spermine and spermidine, as well as putrescine, in seed coats. The obtained results indicate that changes in the activity of redox and protective systems in seeds have a clear relationship with the seed biological quality and can be detected even at a moderate level of seed deterioration. The analyses of such changes can significantly facilitate the assessment of seed quality and can therefore be of interest for seed companies and seed banks.

Regulation of cold resistance by the polyamine biosynthetic gene SlSPDS2 via modulating the antioxidant enzyme system and osmotic regulatory substances in Solanum lycopersicum

The essential role of polyamine in cold stress resistance in tomato has been widely studied. However, the involvement of Spermidine synthase (SPDS) in the regulation of cold stress and their relationship with the antioxidant enzyme system and osmotic regulatory substances in tomato are not well characterized. In the current study, we found that cold stress induced the expression of polyamine biosynthetic genes and the accumulation of polyamine. The overexpression of SlSPDS2 (SlSPDS2-OE), a key Spermidine biosynthetic gene, significantly improved seedlings growth and increased seedlings index as well as alleviated the cold stress injury with decreased O2∙−, H2O2 and malondialdehyde contents. In SlSPDS2 overexpression lines, the contents of free polyamine, free salicylic acid, chlorophyll, proline and soluble sugar were increased compared with wild type (WT) under cold stress. The antioxidant enzyme activities and their coding genes expression were increased compared with WT under cold stress. SlSPDS2 silencing seedlings with weakened cold resistance showed oxidative damage and inhibition of growth. These results indicated that SlSPDS2 plays a positive role in tomato cold tolerance by regulating polyamine metabolism, antioxidants, and osmolytes.

Exogenous spermidine enhanced the water deficit tolerance of Anoectochilus roxburghii by modulating plant antioxidant enzymes and polyamine metabolism

Water stress is an important factor affecting herb quality and yield and exogenous spermidine (Spd) addition can enhance dehydration tolerance of plants. Anoectochilus roxburghii (Wall.) Lindl is a perennial herb widely used in medicine, health care, and beauty industry, yet, its dehydration resistance remains largely unknown. In this view, the current research aimed at elucidating the drought resistance mechanism of A. roxburghii under PEG-induced water stress at different levels (10%, 20%, and 30% PEG6000). In particular, the morphological, physiological, and biochemical changes occurring in leaves treated with (0.5 mM, 5 mM) or without Spd were discussed under moderate water stress (20% PEG6000). Results showed that water stress significantly inhibited the growth of A. roxburghii by decreasing the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), arginine decarboxylase (ADC), S-adenosylmethionine decarboxylase (SAMDC), and polyamine oxidase (PAO). The contents of soluble protein, soluble proline, hydrogen peroxide (H2O2), malondialdehyde (MDA), and the relative conductivity (REC) of leaves increased by 27.32%, 31.37%, 68.84%, 103.61%, and 63.64%, respectively. Under dehydration condition, foliar spraying Spd effectively improved plant growth with the contents of soluble protein and soluble proline increased, while the H2O2, REC, and MDA contents decreased. The SOD activity of 0.5 mM and 5 mM treatments were 1.13 and 1.01 times higher than only 20% PEG treatment, respectively. Similarly, the POD activity of 0.5 mM and 5 mM treatments increased by 52.82% and 34.11%, while the CAT activity of 0.5 mM and 5 mM treatments increased by 34.39 and 33.15 U/mgprot, respectively. In addition, exogenous Spd application significantly increased the key enzyme activities of polyamine metabolism (ADC, SAMDC, and PAO) under moderate water stress. In conclusion, exogenous Spd addition with low concentration (0.5 mM) improved the resistance of A. roxburghii against water stress by increasing the antioxidant enzymes activities and endogenous polyamines contents. This study helps to the understanding of dehydration resistance of A. roxburghii and provide guidelines for its cultivation under water deficit condition.

Arbuscular mycorrhizal fungi as an effective approach to enhance the growth and metabolism of soybean plants under thallium (TI) toxicity

Thallium (TI) is a toxic metal that can trigger harmful impacts on growth and metabolism of plants. Utilizing arbuscular mycorrhizal fungi (AMF) proves to be an effective strategy for alleviating heavy metal toxicity in plants. To this end, AMF were applied to mitigate TI toxic effects on the growth, primary and secondary metabolism of soybean plants. Here, TI stress inhibited the growth and photosynthetic parameters of soybean plants. It also increased the oxidative damage as demonstrated by increased levels of oxidative markers, (MDA and lipoxygenase (LOX) activity). However, AMF could mitigate the reduction in growth and photosynthesis induced by TI, as well as the induction of oxidative damage. To overcome TI toxicity, AMF increased the levels and metabolism of osmolytes such as proline in soybean plants. This was in line with the increased activities of key enzymes that involved in proline biosynthesis (e.g., P5CS (pyrroline-5-carboxylate synthetase), P5CR (pyrroline-5-carboxylate reductase) and OAT (ornithine aminotransferase) under the AMF and/or TI treatments. Furthermore, soybean plants could benefit from the synergism between AMF and TI to enhance the contents of individual (e.g., spermine and spermidine) and total polyamines as well as their metabolic enzymes (e.g., arginine decarboxylase and ornithine decarboxylase). Overall, the combined application of AMF emerges as a viable approach for alleviating TI toxicity in soybean plants.

Exogenous Putrescine Modulates Nitrate Reductase-Dependent NO Production in Cucumber Seedlings Subjected to Salt Stress.

Polyamines (PAs) are small aliphatic compounds that participate in the plant response to abiotic stresses. They also participate in nitric oxide (NO) production in plants; however, their role in this process remains unknown. Therefore, the study aimed to investigate the role of putrescine (Put) in NO production in the roots of cucumber seedlings subjected to salt stress (120 mM NaCl) for 1 and 24 h. In salinity, exogenous Put can regulate NO levels by managing NO biosynthesis pathways in a time-dependent manner. In cucumber roots exposed to 1 h of salinity, exogenous Put reduced NO level by decreasing nitrate reductase (NR)-dependent NO production and reduced nitric oxide synthase-like (NOS-like) activity. In contrast, during a 24 h salinity exposure, Put treatment boosted NO levels, counteracting the inhibitory effect of salinity on the NR and plasma membrane nitrate reductase (PM-NR) activity in cucumber roots. The role of endogenous Put in salt-induced NO generation was confirmed using Put biosynthesis inhibitors. Furthermore, the application of Put can modulate the NR activity at the genetic and post-translational levels. After 1 h of salt stress, exogenous Put upregulated CsNR1 and CsNR2 expression and downregulated CsNR3 expression. Put also decreased the NR activation state, indicating a reduction in the level of active dephosphorylated NR (dpNR) in the total enzyme pool. Conversely, in the roots of plants subjected to 24 h of salinity, exogenous Put enhanced the NR activation state, indicating an enhancement of the dpNR form in the total NR pool. These changes were accompanied by a modification of endogenous PA content. Application of exogenous Put led to an increase in the amount of Put in the roots and reduced endogenous spermine (Spm) content in cucumber roots under 24 h salinity. The regulatory role of exogenous Put on NO biosynthesis pathways may link with plant mechanisms of response to salt stress.

Polyamines in Canadian barley grains: Determination of their content and relationship with protein level

Barley is one of the important crops with diverse end-use purposes. In every use of barley grains, the protein fraction plays an important function impacting the quality of final products. Polyamines, having multiple nitrogen atoms in their chemical structure (e.g., putrescine, spermidine, and spermine), may be linked to the levels of protein and nitrogen reserves. In this study, thirteen Canadian barley varieties were characterized for their total polyamines and protein content. The effects of extractants on the extractability of polyamines were considered, and HCl (1 M) was found to be more effective than trichloroacetic acid (5% w/v) in extracting free polyamines from whole barley flour. The total polyamines content of barley grains varied from 6.46 to 11.47 mg/100 g dry basis and spermidine was the most abundant. Polyamine represented 0.045–0.071% w/w grain protein. Significant and positive correlations were found between protein content and levels of total polyamines (r = 0.798), putrescine (r = 0.771), and spermine (r = 0.668). Principal Component Analysis and K-Means Cluster Analysis divided the barley samples into one cluster (hulless barley for food) differentiated from the other (hulled barley for malting and feed) by their superiority in polyamine and protein content.

Investigation of the Influence of Polyamines on Mature Embryo Culture and DNA Methylation of Wheat (Triticum aestivum L.) Using the Machine Learning Algorithm Method.

Numerous factors can impact the efficiency of callus formation and in vitro regeneration in wheat cultures through the introduction of exogenous polyamines (PAs). The present study aimed to investigate in vitro plant regeneration and DNA methylation patterns utilizing the inter-primer binding site (iPBS) retrotransposon and coupled restriction enzyme digestion-iPBS (CRED-iPBS) methods in wheat. This investigation involved the application of distinct types of PAs (Put: putrescine, Spd: spermidine, and Spm: spermine) at varying concentrations (0, 0.5, 1, and 1.5 mM). The subsequent outcomes were subjected to predictive modeling using diverse machine learning (ML) algorithms. Based on the specific polyamine type and concentration utilized, the results indicated that 1 mM Put and Spd were the most favorable PAs for supporting endosperm-associated mature embryos. Employing an epigenetic approach, Put at concentrations of 0.5 and 1.5 mM exhibited the highest levels of genomic template stability (GTS) (73.9%). Elevated Spd levels correlated with DNA hypermethylation while reduced Spm levels were linked to DNA hypomethylation. The in vitro and epigenetic characteristics were predicted using ML techniques such as the support vector machine (SVM), extreme gradient boosting (XGBoost), and random forest (RF) models. These models were employed to establish relationships between input variables (PAs, concentration, GTS rates, Msp I polymorphism, and Hpa II polymorphism) and output parameters (in vitro measurements). This comparative analysis aimed to evaluate the performance of the models and interpret the generated data. The outcomes demonstrated that the XGBoost method exhibited the highest performance scores for callus induction (CI%), regeneration efficiency (RE), and the number of plantlets (NP), with R2 scores explaining 38.3%, 73.8%, and 85.3% of the variances, respectively. Additionally, the RF algorithm explained 41.5% of the total variance and showcased superior efficacy in terms of embryogenic callus induction (ECI%). Furthermore, the SVM model, which provided the most robust statistics for responding embryogenic calluses (RECs%), yielded an R2 value of 84.1%, signifying its ability to account for a substantial portion of the total variance present in the data. In summary, this study exemplifies the application of diverse ML models to the cultivation of mature wheat embryos in the presence of various exogenous PAs and concentrations. Additionally, it explores the impact of polymorphic variations in the CRED-iPBS profile and DNA methylation on epigenetic changes, thereby contributing to a comprehensive understanding of these regulatory mechanisms.

Wheat germ, a byproduct of the wheat milling industry, as a beneficial source of anti-aging polyamines: A quantitative comparison of various forms.

Polyamines have received a lot of attention since the 1990s because of their anti-aging, anti-chronic disease, and proliferative effects. Wheat germ was reported as one of the natural sources of high polyamine, especially spermidine. The current study used three types of wheat germ: group A was industrially separated germ from whole grain, group B was the commercially available germinated wheat germ, and group C was manually separated wheat germ from germinated grain. The polyamine content of putrescine, spermidine, and spermine has been determined using a simplified isocratic LC-MS/MS method. An optimized extraction procedure was performed on all seven samples for obtaining a polyamine-enriched extract. The three dominant carbomylated polyamines were identified by analyzing the extracted samples in order to determine their relative abundance. Wheat germ powders contain the highest amount of polyamines (220-337 μg/g) of which spermidine is one of the most important. Germinated wheat grains, on the other hand, contain the least amount of this polyamine. The commercially available separated wheat germs are suggested as a good nutrition source of these polyamines.

Polyamine-producing bacteria inhibit the absorption of Cd by spinach and alter the bacterial community composition of rhizosphere soil

Polyamines (PAs) are small aliphatic nitrogenous bases with strong biological activity that participate in plant stress response signaling and the alleviation of damage from stress. Herein, the effects of the PA-producing bacterium Bacillus megaterium N3 and PAs on the immobilization of Cd and inhibition of Cd absorption by spinach and the underlying mechanisms were studied. A solution test showed that strain N3 secreted spermine and spermidine in the presence of Cd. Both strain N3 and the PAs (spermine+spermidine) immobilized Cd and increased the pH of the solution. Untargeted metabolomics results showed that strain N3 secreted PAs, N1-acetylspermidine, 3-indolepropionic acid, indole-3-acetaldehyde, cysteinyl-gamma-glutamate, and choline, which correlated with plant growth promotion and Cd immobilization. A pot experiment showed that rhizosphere soil inoculation with strain N3 and PAs improved spinach dry weight and reduced spinach Cd absorption compared with the control. These positive effects were likely due to the increase in rhizosphere soil pH and NH4+-N and PA contents, which can be attributed primarily to Cd immobilization. Moreover, inoculation with strain N3 more effectively inhibited the absorption of Cd by spinach than spraying PAs, mainly because strain N3 enabled a better relative abundance of bacteria (Microvirga, Pedobacter, Bacillus, Brevundimonas, Pseudomonas, Serratia, Devosid, and Aminobacter), that have been reported to have the ability to resist heavy metals and produce PAs. Strain N3 regulated the structure of rhizosphere functional bacterial communities and inhibited Cd uptake by spinach. These results provide a theoretical basis for the prevention of heavy metal absorption by vegetables using PA-producing bacteria.

In vivo polyamine applications to globe artichoke: Effects on plant growth-development and some bioactive components

The globe artichoke, Cynara cardunculus var. scolymus (L.), is an important member of the Asteraceae family, being used as a food and due to it has certain health-improving qualities in the treatment of various disorders since ancient times. Low molecular weight organic compounds with a role in several crucial cellular and physiological processes of plants are known as polyamines. They participate in processes such as cell division, differentiation, and growth, the sprouting of seeds, root formation, and flower and fruit development. They have been identified as particularly efficient against biotic and abiotic stress factors. The present research aimed that the evaluation of effects of various polyamine (PA) types and concentrations on three different artichoke cultivars by biometric measurements and biochemical analyses. For this purpose, seedlings of three artichoke cultivars (‘Sakız OP’, ‘Bayrampaşa OP’, and ‘Olympus F1’) were sprayed with various concentrations (0, 50, 100 and 250 mg L-1) of three distinct types of significant polyamines, including putrescine, spermidine, and spermine. Several growth parameters were examined in the current research. The effects on the total phenol and antioxidant capacities, as well as changes in the amounts of cynarin and 1,5-O-dicafeoylquinic acid, were also evaluated. The results revealed that there were statistically differences based on cultivars and treatment concentrations. Among the three forms of PA spermine was potent at increasing total phenolic content, while putrescine was effective at increasing total antioxidant content. On the other hand, putrescine, spermine and, spermidine had no positive effects on cynarin and 1,5-O-dicaffeoyquinic acid levels. Results clearly revealed that each biometric data and biochemical content could not be determined by a single polyamine type and concentration. It can be concluded that to improve the biometric values and biochemical content are depending on cultivar and dosage of various PAs.

Supramolecular Modulation of Tumor Microenvironment through Pillar[5]arene-Based Host-Guest Recognition to Synergize Cancer Immunotherapy.

Despite the tremendous breakthrough of immunotherapy, the low response rate and resistance of immune checkpoint inhibitors (ICIs) toward solid tumors occur frequently. A highly hypoxic tumor microenvironment (TME) provides tumor cells with high concentrations of HIF-1α and polyamines to evade immune cell destruction. Reprogramming of an immunogenic TME has exhibited a brilliant future to boost immunotherapeutic performances. Herein, a supramolecular nanomedicine (TAPP) is developed on the basis of host-guest molecular recognition and metal coordination, showing the capability to remodel the immunosuppressive TME. Tamoxifen (Tmx) and Fe3+ are encapsulated into TAPP to achieve the combination of chemotherapy and chemodynamic therapy (CDT). Tmx directly downregulates HIF-1α, and a pillar[5]arene-based macrocyclic host successfully eliminates polyamines in tumors. Enhanced immunogenic cell death is achieved by Tmx and Fe3+, and the therapeutic efficacy is further synergized by immune checkpoint blockade (ICB) therapy. This supramolecular reprogramming modality encourages cytotoxic T lymphocyte infiltration, achieving pre-eminent immune response and long-term tumor suppression.

Correlation analysis of polyamine metabolism and reproductive hormone levels in goose ovarian follicles

To investigate the relationship between polyamine metabolism and reproductive hormones in ovarian follicles of Sichuan white geese, follicle polyamine content and reproductive hormone levels and gene expressions related to polyamine metabolism, steroidogenesis and steroid hormone receptors were detected by HPLC, ELISA and RT-qPCR. The results showed that the overall trend of spermidine and spermine levels increased first and then decreased as increasing follicle size, with the highest level in F3 and F5 follicles (P < 0.05). Putrescine and 17β-estradiol (E2) levels in hierarchical follicles were significantly lower than those in prehierarchical follicles (P < 0.05). Progesterone (P4) first increased and then decreased, with the highest level in the F5 follicle (P < 0.05). The expression levels of estrogen receptor 1 (ER1) showed an overall increase as increasing follicle size (except in F3 follicles), while estrogen receptor 2 (ER2) in hierarchical follicles was significantly lower than that in the prehierarchical follicles (P < 0.05). In addition, the overall expression level of progesterone receptor (PR) decreased, with no significant differences among F1, F2 and F3 follicles (P > 0.05). Yolk putrescine contents were positively correlated with yolk E2 concentrations and PR expression levels (P < 0.05), A significant positive correlation of spermidine levels with yolk P4 concentrations and PR expressions was also observed, as well as the spermine levels with yolk P4 concentrations (P < 0.05). In summary, polyamines were involved in the regulation of follicular development in geese, and this regulation played a role in affecting steroidogenesis and the expression of genes related to hormone receptors.

Structural and Kinetic Characterization of the SpeG Spermidine/Spermine N-acetyltransferase from Methicillin-Resistant Staphylococcus aureus USA300.

Polyamines are simple yet critical molecules with diverse roles in numerous pathogenic and non-pathogenic organisms. Regulating polyamine concentrations affects the transcription and translation of genes and proteins important for cell growth, stress, and toxicity. One way polyamine concentrations are maintained within the cell is via spermidine/spermine N-acetyltransferases (SSATs) that acetylate intracellular polyamines so they can be exported. The bacterial SpeG enzyme is an SSAT that exhibits a unique dodecameric structure and allosteric site compared to other SSATs that have been previously characterized. While its overall 3D structure is conserved, its presence and role in different bacterial pathogens are inconsistent. For example, not all bacteria have speG encoded in their genomes; in some bacteria, the speG gene is present but has become silenced, and in other bacteria, it has been acquired on mobile genetic elements. The latter is the case for methicillin-resistant Staphylococcus aureus (MRSA) USA300, where it appears to aid pathogenesis. To gain a greater understanding of the structure/function relationship of SpeG from the MRSA USA300 strain (SaSpeG), we determined its X-ray crystal structure in the presence and absence of spermine. Additionally, we showed the oligomeric state of SaSpeG is dynamic, and its homogeneity is affected by polyamines and AcCoA. Enzyme kinetic assays showed that pre-incubation with polyamines significantly affected the positive cooperativity toward spermine and spermidine and the catalytic efficiency of the enzyme. Furthermore, we showed bacterial SpeG enzymes do not have equivalent capabilities to acetylate aminopropyl versus aminbutyl ends of spermidine. Overall, this study provides new insight that will assist in understanding the SpeG enzyme and its role in pathogenic and non-pathogenic bacteria at a molecular level.

Effect of Phosphorus and Polyamine Fertilizers on Kufi Apple Transplants Growth

This experiment was conducted in the Lath-house/Department of Horticulture and Landscape Design/College of Agriculture and Forestry/University of Mosul on Kufi apple transplants (Malus domestica L.) at one year old, planted on plastic containers containing 9 kg of soil, by using the a Randomized Complete Block Design (RCBD) for each experimental unit, with two factors, three replications, and four transplants, the first factor was three levels of phosphorus (0,100 and 200 mg P kg−1 soil), second factor was three levels of organic polyamine fertilizer (0,1.5 and 3 gm l−1). The transplants were fertilized with phosphorus once during the season on 26/4/2021,while Polyamine fertilizer was applied five times during the season, 20 days between them, first application was done in 26/4/2021. The results obtained showed that the application of phosphorus at a concentration of 200 mg P kg−1 soil significantly increased transplant leaves area and section length only as compared with control and 100 mg P kg−1soil treatments, while polyamine fertilizer at a concentration of 3 gm−1 significantly increased dry weight of vegetative growth and roots dry weight as compared with control and 1.5 gm−1 treatments and transplant leaves area and section diameter parameters as compared with control treatment only. The interaction between the concentrations of phosphorus and polyamine reveals that there was a significant effect on all studied parameters, the treatment of 200gm P kg−1 soil + 3 gm polyamine l−1 gave the highest means of leaves number, leaf area, transplant leaves area and ratio of roots dry weight /dry weight of vegetative growth, meanwhile 100gm P kg−1 soil + 3 gm polyamine l−1 treatment gave the highest means of section length, section diameter, dry weight of vegetative growth and roots dry weight.

Evaluation of the effect of urea foliar application on polyamine content, grain protein content, and the agronomic traits of bread wheat cultivars under dryland and supplemental irrigation conditions

The purpose of the experiment was to investigate the relationship between the accumulation of polyamines during the filling period of wheat grain with yield and grain protein under dryland and supplemental irrigation (SI) conditions and also the effect of foliar spraying of urea on the amount of polyamines in grain a factorial experiment was conducted based on randomized complete block design with three replications during two cropping seasons. The examined treatments included water availability (dryland and SI), wheat cultivars (Homa, Sardari, Rijaw, Ouhadi, and Azar2), and foliar application of urea (control and 4% urea foliar application). The results demonstrated that SI (10%) reduced and urea foliar (12%) application increased the percent of grain protein. SI reduced the contents of three PAs by 24%: spermine, spermidine, and putrescine. But urea foliar application increased the three PAs in the first and second years by 31% and 27% in dryland conditions and 12% and 4% in SI conditions, respectively. These results indicated that there is less need for PAs in SI conditions, and they thus exhibit poorer accumulation in the grain; in dryland conditions, however, their content increases with greater access to foliar nitrogen. Older cultivars Sardari and Azar 2 had more polyamines. According to the observed positive correlation between 1000-grain weight and the three PAs under stress conditions, PAs are probably involved in the improvement of grain filling, and urea foliar application can affect drought tolerance by increasing PA accumulation. Moreover, cadaverine exhibited a different function from the other PAs.

Microflora, Contents of Polyamines, Biogenic Amines, and TVB-N in Bovine Offal and Game Meat for the Raw-Feeding of Adult Dogs.

Microflora and contents of biogenic amines/polyamines and total volatile basic nitrogen (TVB-N) in 99 samples of bovine offal (red offal, n = 41 and other offal and mixes, n = 45) and wild game meat (n = 13) for raw meat-based diets (RMBD) for dogs were analyzed. Samples were bought in 11 local pet food shops and in one game-handling establishment in Austria (Lower Austria, Styria, and Vienna) in September and October 2022. Median contents (first and third quartiles in brackets) of cadaverine, histamine, tyramine, spermidine, and spermine were 20.7 [16.7; 28.6]; 25.4 [17.1; 47.2]; 18.9 [13.6; 38.9]; 15.2 [11.2; 21.2]; and 41.9 [<limit of detection; 64.5] mg/kg wet weight, respectively. The sum of putrescine + cadaverine + histamine + tyramine was >50 mg/kg in 85.9% of samples, indicating the use of low-quality ingredients or inappropriate storage conditions. However, only 10.1% of samples were determined to be not compliant with a maximum amine content proposed for pet food. Median contents of the total aerobic bacteria counts (TACs), Pseudomonas, and Enterobacteriaceae were 7.4 [6.4; 8.0]; 6.5 [5.5; 7.7]; and 4.8 [3.9; 5.6] log CFU/g, respectively, with significantly lower counts in red offal RMBD (p < 0.05). TVB-N exceeded 150 mg/kg in 87.9% of samples. The TACs and Enterobacteriaceae numbers in red offal RMBD were comparable to those in food-grade red offal after 6 days of aerobic storage at 7 °C, i.e., temperatures higher than required for food-grade offal, but acceptable for animal by-products intended for RMBD production. In 80.8% of samples, numbers of Enterobacteriaceae exceeded the EU legal limit. From 12 of these samples, Salmonellae was able to be isolated, with counts from 0.03 MPN/g to 110 MPN/g. Salmonella enterica ser. Montevideo (n = 3), and S. enterica ser. Give and S. enterica ssp. Diarizonae (n = 2 each) were the most frequently isolated, while Listeria monocytogenes was rarely recovered (2%). Whilst exposure of humans handling such pet food can be reduced by hygiene precautions, the risk remains that dogs can acquire a feed-borne salmonellosis and shed the pathogen.

Levilactobacillus brevis with High Production of Putrescine Isolated from Blue Cheese and Its Application.

Polyamine intake has been reported to help extend the lifespan of animals. Fermented foods contain high concentrations of polyamines, produced by fermenting bacteria. Therefore, the bacteria, isolated from fermented foods that produce large amounts of polyamines, are potentially used as a source of polyamines for humans. In this study, the strain Levilactobacillus brevis FB215, which has the ability to accumulate approximately 200 µM of putrescine in the culture supernatant, was isolated from fermented foods, specifically the Blue Stilton cheese. Furthermore, L. brevis FB215 synthesized putrescine from agmatine and ornithine, which are known polyamine precursors. When cultured in the extract of Sakekasu, a byproduct obtained during the brewing of Japanese rice wine containing high levels of both agmatine and ornithine, L. brevis FB215 grew to OD600 = 1.7 after 83 h of cultivation and accumulated high concentrations (~1 mM) of putrescine in the culture supernatant. The fermentation product also did not contain histamine or tyramine. The Sakekasu-derived ingredient fermented by the food-derived lactic acid bacteria developed in this study could contribute to increasing polyamine intake in humans.

Age-associated polyamines in peripheral blood cells and plasma in 20 to 70 years of age subjects

Dietary polyamines have been associated with slowing ageing processes and various pathologies, raising the importance of establishing reference values at different ages throughout life. This study aimed to analyse age-dependent variations in polyamine content using peripheral blood cells and plasma in a healthy and homogeneous population. Peripheral blood of 193 volunteers of both sexes (20–70 years), selected by convenience, was processed to separate cells and plasma. A pre-column derivatization method was used to determine the amines by HPLC (nmol or pmol/mg protein or nmol/ml) to analyse their association with the age (continuous or ordinal in decades) of the subjects. Putrescine and spermine weakly declined significantly in mononuclear cells with age. In erythrocytes and plasma, putrescine showed an evident decrease in the 60–70-year-old group compared to the rest. The ratios between polyamines, mainly in erythrocytes, decreased in the 60–70 years age group and increased the ratio of putrescine in mononuclear cells/erythrocytes. The ratio of putrescine in mononuclear cells/erythrocytes was higher in the 60–70-year-old age group than in the rest. In a sample of subjects (20–29 vs. 60–70 years), whole blood polyamines were not significantly different when differences existed in erythrocytes. Polyamine homeostasis in blood cells and plasma changed with age. Putrescine declined in mononuclear cells and decreased in erythrocytes and plasma in the decade of the 60 s. Further studies should establish an age-dependent phenotype and whether polyamines’ supplementation could restore the decreased values and be associated with long-term overall biological benefits.

Influence of microbial polyamines on the IL-10 production by peripheral blood leukocytes of healthy donors

As is known, bacterial polyamines, which include cadaverine and putrescine, are capable of influencing the activity of immunocompetent cells in many ways. In particular, this situation is observed in long-term inflammatory diseases, especially with intensive reproduction of microorganisms capable of producing polyamines. It is of interest to study the production of one of the main anti-inflammatory cytokines, IL-10, under the influence of bacterial polyamines. For research, a population of mononuclear leukocytes was isolated from the peripheral blood of healthy donors by gradient centrifugation. The cell suspension was placed in a round-bottomed plates with preliminarily added polyamines at concentrations of 5, 25, 50, 75, and 100 mmol/L. Wells not containing polyamines were used as a control. After incubation for 72 h at 37 °C and 5% CO2, the supernatants were harvested and used to determine the concentration of IL-10. We used a kit for determining the concentration of IL-10 using the enzyme immunoassay method (Russia). Statistical analysis was performed using the Statistica 6.0 software package. In the case of a distribution close to normal, Student’s t-test was used; in the rest, the Mann–Whitney test was used to assess the significance of differences. Studies have shown that leukocytes in the presence of concanavalin A produce IL-10 at a concentration of 17.13±6.08 pg/mL. It has been established that under the influence of polyamines of bacterial origin, the production of IL-10 is enhanced only if putrescine and cadaverine are at concentrations of 50 mmol/L and higher. At low concentrations of polyamines, no significant increase in IL-10 production was detected. Since IL-10 is an anti- inflammatory cytokine, for which the analgesic effect is also known, it should be expected that with an increase in its concentration in the focus of invasion of opportunistic bacteria, the inflammatory process will develop latently, when the symptoms are mild. In general, it can be expected that polyamine-producing bacteria will contribute to the maintenance of few symptomatic inflammation.