Polyamines in Food

Dietary intake of polyamines in a Spanish adult population: Age-dependent correlation with Healthy Eating Index and Dietary Inflammatory Index scores

OBJECTIVES

A healthy and balanced diet is crucial to maintaining optimal health. Understanding the benefits of different food components is essential. The polyamine spermidine is linked to age-related disease protection, but daily intakes and whether these vary with age are unknown. This study aimed to determine polyamine intake in a Mediterranean diet population and its association with participants' age and Healthy Eating Index (HEI) and Dietary Inflammatory Index (DII) scores.

METHODS

A database was created with references concerning polyamine content in foods to determine the daily intake of foods frequently consumed by 203 participants (84 males and 119 females), ages 18 to 90 y, using a nutritional survey (VioScreen) that includes HEI and DII scores.

RESULTS

The participants' characteristics were as reported in the corresponding 2020 Spanish nutritional survey. Two-thirds demonstrated moderate to high adherence to the Mediterranean diet. The mean HEI score was 74.45 (out of 100), and the mean DII was -1.94 (anti-inflammatory). The median intake of polyamines was 45.59 mg/d/person (mean, 46.89 mg/d/person, 410.57 µmol/d/person), without sex differences. After normalizing the intake per kilocalorie, the Kruskal-Wallis test showed significant differences among age groups for total polyamines ingested, putrescine, and spermidine. The intake of putrescine and spermidine was significantly higher in the 60 to 69 age group compared with the 24 to 59 and 18 to 23 age groups, respectively. HEI scores were positively correlated with polyamine intake, whereas DII scores were negatively correlated.

CONCLUSIONS

Polyamine intake was higher than reported in other populations, did not decrease based on age, and was associated with healthy eating and anti-inflammatory foods.

Impact of gut microbiota on cardiac aging

Recent research has suggested imbalances in gut microbiota composition as contributors to cardiac aging. An individual's physical condition, along with lifestyle-associated factors, including diet and medication, are significant determinants of gut microbiota composition. This review discusses evidence of bidirectional associations between aging and gut microbiota, identifying gut microbiota-derived metabolites as potential regulators of cardiac aging. It summarizes the effects of gut microbiota on cardiac aging diseases, including cardiac hypertrophy and fibrosis, heart failure, and atrial fibrillation. Furthermore, this review discusses the potential anti-aging effects of modifying gut microbiota composition through dietary and pharmacological interventions. Lastly, it underscores critical knowledge gaps and outlines future research directions. Given the current limited understanding of the direct relationship between gut microbiota and cardiac aging, there is an urgent need for preclinical and clinical investigations into the mechanistic interactions between gut microbiota and cardiac aging. Such endeavors hold promise for shedding light on the pathophysiology of cardiac aging and uncovering new therapeutic targets for cardiac aging diseases.

Dietary selective effects manifest in the human gut microbiota from species composition to strain genetic makeup

Diet significantly influences the human gut microbiota, a key player in health. We analyzed shotgun metagenomic sequencing data from healthy individuals with long-term dietary patterns-vegan, flexitarian, or omnivore-and included detailed dietary surveys and blood biomarkers. Dietary patterns notably affected the bacterial community composition by altering the relative abundances of certain species but had a minimal impact on microbial functional repertoires. However, diet influenced microbial functionality at the strain level, with diet type linked to strain genetic variations. We also found molecular signatures of selective pressure in species enriched by specific diets. Notably, species enriched in omnivores exhibited stronger positive selection, such as multiple iron-regulating genes in the meat-favoring bacterium Odoribacter splanchnicus, an effect that was also validated in independent cohorts. Our findings offer insights into how diet shapes species and genetic diversity in the human gut microbiota.

Supplementation of spermidine at 40 mg/day has minimal effects on circulating polyamines: An exploratory double-blind randomized controlled trial in older men

This study represents the first investigation into the safety of a novel, high-purity spermidine trihydrochloride supplement (hpSPD) in humans. Spermidine, a natural compound found in various foods, has demonstrated potential health benefits in animal and epidemiological studies. However, evidence from clinical trials and safety evaluations of spermidine supplements is limited because pure spermidine for human administration has not been available. In this randomized, double-blind, within-subject and placebo-controlled trial, 37 healthy men (age 50-70 years; body mass index, 18.5-28 kg/m2) were administered either hpSPD or a placebo. We hypothesized that 7-day and 28-day dosing of 40 mg/day of hpSPD would have minimal effects on safety, although metabolic and polyamine homeostasis has not previously been examined at this dosage level. Consistent with our hypothesis, 40 mg/day hpSPD did not result in any significant changes in clinical, lipids, chemistry, or hematological parameters compared to placebo. Compliance was high, and no study product-related adverse events were reported. Substantial changes in serum and urine polyamine concentrations were not observed following hpSPD supplementation, suggesting effective homeostatic control of full-dose highly purified spermidine supplements with no evidence of adaptation of spermidine metabolism at 40 mg/day. These findings suggest that hpSPD at 40 mg/day for up to 28 days is safe and well-tolerated in healthy older men. The study is consistent with preclinical results and provides important evidence supporting the safety of high-purity spermidine supplementation, enabling further research with single-molecule spermidine to investigate its potential biology for improving human health. This trial was registered at clinicaltrials.gov (NCT05459961).

Absorption, anti-inflammatory, antioxidant, and cardioprotective impacts of a novel fasting mimetic containing spermidine, nicotinamide, palmitoylethanolamide, and oleoylethanolamide: A pilot dose-escalation study in healthy young adult men

This pilot dose-escalation study evaluated the absorption and metabolism of a novel fasting mimetic formulation containing spermidine, nicotinamide, palmitoylethanolamide (PEA), and oleoylethanolamide (OEA) taken as oral supplements in young adults. Five healthy men consumed a standardized breakfast, followed by control (wheat flour) or low, medium, or high doses of supplements containing spermidine, nicotinamide, PEA, and OEA 2 hours later. Blood was drawn at 0, 1, 2, and 4 hours after the supplement (2, 3, 4, and 6 hours postprandial). Plasma concentrations of spermidine, 1-methylnicotinamide, PEA and OEA were quantified by liquid chromatography-mass spectrometry. The secretion of tumor necrosis factor alpha and production of reactive oxygen species by stimulated macrophages incubated with plasma, and cholesterol efflux capacity of plasma were analyzed. Plasma 1-methylnicotinamide, PEA, and OEA concentrations increased after supplement intake (P < .05). Spermidine concentrations decreased in the control arm (P < .05) but not the supplement arms. Net incremental area under the curve for tumor necrosis factor alpha and reactive oxygen species in stimulated macrophages decreased when incubated with plasma following supplement intake (P < .05). Intake of the combined supplements showed they were bioavailable and increased in plasma in a dose-dependent manner and provide preliminary data showing enhanced plasma anti-inflammatory and antioxidant functions. This trial was registered at clinicaltrials.gov (NCT05017428).

Human Supplementation with AM3, Spermidine, and Hesperidin Enhances Immune Function, Decreases Biological Age, and Improves Oxidative-Inflammatory State: A Randomized Controlled Trial

The positive effect of AM3, spermidine, and hesperidin, which have antioxidant and anti-inflammatory properties, on immunity is known, but their effect on the rate of aging, known as biological age (BA), is unclear. This work aims to test if the intake of a blend of AM3 (150 mg), spermidine (0.6 mg), and hesperidin (50 mg) for 2 months could decrease BA and improve immunity, redox, and inflammatory states. For this, 41 participants (30-63 years) were randomly divided into placebo and supplement groups. The supplement group took two capsules daily with AM3, spermidine, and hesperidin for two months, while the placebo group took capsules containing only calcium phosphate and talcum powder. Before and after the treatment, peripheral blood was collected. Immune function was assessed in leukocytes, redox state in whole-blood cells, erythrocytes, and plasma, and cytokine concentration in both mononuclear cell cultures and plasma. Finally, the Immunity Clock model was applied to determine BA. The results show that the intake of this blend improves the immune functions that constitute the Immunity Clock, decreasing BA by 11 years and reducing the oxidative-inflammatory state of the participants. Therefore, this supplement can be proposed as a strategy to rejuvenate BA and achieve healthy aging.

Impact of polyamine supplementation on GnRH expression, folliculogenesis, and puberty onset in young mice

BACKGROUND

The hypothalamic-pituitary-gonadal (HPG) axis is pivotal in regulating reproductive functions, with gonadotropin-releasing hormone (GnRH) acting as a central regulator. Recently, polyamines have been shown to regulate the HPG axis, including GnRH expression and ovarian biology in old and adult rodents. The present study firstly highlights the age-specific variation in the polyamine and their corresponding biosynthetic enzymes in the ovary during aging, and further, the study focuses on the effect of polyamines, putrescine, and agmatine, in young female mice.

METHOD AND RESULT

Immunofluorescence analysis revealed age-related differences in the expression of ornithine decarboxylase 1 (ODC1), spermine (SPM), and spermidine (SPD) in the ovaries, with adult mice exhibiting significantly higher expression levels compared to young and old mice. Likewise, qPCR analysis showed the mRNA levels of Odc1, Spermidine synthase (Srm), and Spermine synthase (Sms) show a significant increase in adult ovaries, which is then followed by a significant decline in old age. Histological examination demonstrated morphological alterations in the ovaries with age, including decreased follicle numbers and increased stromal cells in old mice. Furthermore, treatment with putrescine, a polyamine, in young mice resulted in larger ovaries and increased follicle numbers compared to controls. Additionally, serum levels of gonadotropin-releasing hormone (GnRH) and progesterone (P4) were measured, showing elevated levels in polyamine-treated mice. GnRH mRNA expression also increased significantly. Gene expression analysis revealed upregulation of genes associated with folliculogenesis such as Fshr, Bmp15, Gdf9, Amh, Star, Hsdb3, and Plaur in the ovaries and onset of puberty such as Tac2, and Kiss1, and a decrease in Mkrn3 in the hypothalamus of polyamine-treated mice.

CONCLUSION

This study investigates the effect of polyamines in young immature female mice, shedding light on their role in upregulating GnRH, and enhancing folliculogenesis. Overall, these findings suggest that polyamines play a crucial role in ovarian aging and HPG axis regulation, offering potential therapeutics to reinstate fertility in reproductively challenged individuals.

Fibre & fermented foods: differential effects on the microbiota-gut-brain axis

The ability to manipulate brain function through the communication between the microorganisms in the gastrointestinal tract and the brain along the gut-brain axis has emerged as a potential option to improve cognitive and emotional health. Dietary composition and patterns have demonstrated a robust capacity to modulate the microbiota-gut-brain axis. With their potential to possess pre-, pro-, post-, and synbiotic properties, dietary fibre and fermented foods stand out as potent shapers of the gut microbiota and subsequent signalling to the brain. Despite this potential, few studies have directly examined the mechanisms that might explain the beneficial action of dietary fibre and fermented foods on the microbiota-gut-brain axis, thus limiting insight and treatments for brain dysfunction. Herein, we evaluate the differential effects of dietary fibre and fermented foods from whole food sources on cognitive and emotional functioning. Potential mediating effects of dietary fibre and fermented foods on brain health via the microbiota-gut-brain axis are described. Although more multimodal research that combines psychological assessments and biological sampling to compare each food type is needed, the evidence accumulated to date suggests that dietary fibre, fermented foods, and/or their combination within a psychobiotic diet can be a cost-effective and convenient approach to improve cognitive and emotional functioning across the lifespan.

Supplementation of spermidine enhances the quality of postovulatory aged porcine oocytes

BACKGROUND

Spermidine (SPD) is an intermediate compound in the polyamine metabolism which takes critical part in a variety of cellular processes. In particular, it has been reported to exert anti-aging effects, suppress the age-related diseases, and extend lifespan across species. However, whether it has the favorable influence on the quality of postovulatory aged oocytes remains elusive.

METHODS

Immunostaining and fluorescence intensity measurement were used to evaluate the effects of postovulatory aging and SPD supplementation on the oocyte fragmentation, spindle/chromosome structure, actin polymerization, dynamics of cortical granules (CGs) and ovastacin, mitochondrial distribution and function, as well as autophagy levels. In addition, in vitro sperm binding assay and in vitro fertilization (IVF) experiment were applied to assess the impacts of postovulatory aging and SPD supplementation on the sperm binding ability and fertilization capacity of oocytes.

RESULTS

Here, we showed that supplementation of SPD during postovulatory aging could relieve the deterioration of porcine oocytes. Specifically, we found that postovulatory aging impaired the oocyte quality by damaging the morphological integrity of oocytes, maintenance of spindle/chromosome structure, and dynamics of actin cytoskeleton. Postovulatory aging also weakened the sperm binding ability and fertilization capacity of oocytes by compromising the distribution pattern of CGs and their content ovastacin. Notably, supplementation of SPD attenuated these defects in postovulatory aged porcine oocytes via strengthening mitochondrial function, eliminating excessive reactive oxygen species (ROS), inhibiting apoptosis, and enhancing autophagy levels.

CONCLUSION

Altogether, our findings demonstrate that SPD supplementation is a feasible approach to ameliorate the quality of postovulatory aged oocytes, which can be potentially applied to the human assisted reproductive technology (ART) and in vitro production of animal embryos.

Spermidine as an epigenetic regulator of autophagy in neurodegenerative disorders

Autophagy is an abnormal protein degradation and recycling process that is impaired in various neurological diseases like Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease. Spermidine is a natural polyamine found in various plant- and meat-based diets that can induce autophagy, and is decreased in various neurodegenerative diseases. It acts on epigenetic enzymes like E1A-binding protein p300, HAT enzymes like Iki3p and Sas3p, and α-tubulin acetyltransferase 1 that modulate autophagy. Histone modifications like acetylation, phosphorylation, and methylation could influence autophagy. Autophagy is epigenetically regulated in various neurodegenerative disorders with many epigenetic enzymes and miRNAs. Polyamine regulation plays an essential role in the disease pathogenesis of AD and PD. Therefore, in this review, we discuss various enzymes and miRNAs involved in the epigenetic regulation of autophagy in neurodegenerative disorders and the role of spermidine as an autophagy enhancer. The alterations in spermidine-mediated regulation of Beclin-1, LC3-II, and p62 genes in AD and other PD-associated enzymes could impact the process of autophagy in these neurodegenerative diseases. With the ever-growing data and such promising effects of spermidine in autophagy, we feel it could be a promising target in this area and worth further detailed studies.

The network of cardiac KIR2.1: its function, cellular regulation, electrical signaling, diseases and new drug avenues

The functioning of the human heart relies on complex electrical and communication systems that coordinate cardiac contractions and sustain rhythmicity. One of the key players contributing to this intricate system is the KIR2.1 potassium ion channel, which is encoded by the KCNJ2 gene. KIR2.1 channels exhibit abundant expression in both ventricular myocytes and Purkinje fibers, exerting an important role in maintaining the balance of intracellular potassium ion levels within the heart. And by stabilizing the resting membrane potential and contributing to action potential repolarization, these channels have an important role in cardiac excitability also. Either gain- or loss-of-function mutations, but also acquired impairments of their function, are implicated in the pathogenesis of diverse types of cardiac arrhythmias. In this review, we aim to elucidate the system functions of KIR2.1 channels related to cellular electrical signaling, communication, and their contributions to cardiovascular disease. Based on this knowledge, we will discuss existing and new pharmacological avenues to modulate their function.

The potential impact of a vegetarian diet on glaucoma

Treatment of primary open-angle glaucoma has centered on the lowering of intraocular pressure that damages the optic nerve; however, this strategy is not uniformly successful, especially in normal tension glaucoma, and there is interest in antioxidant, anti-inflammatory, and other neuroprotective strategies. Vegetarian diets are known to be rich in antioxidant and anti-inflammatory components and have a number of established health benefits. Thus, it would be reasonable to assume that vegetarian diets would be beneficial in glaucoma, but this approach has not been well studied. We examine the possible role of vegetarian diets and their components in the incidence and progression of glaucoma.

Association between dietary spermidine intake and depressive symptoms among US adults: National Health and Nutrition Examination Survey (NHANES) 2005-2014

BACKGROUND

Spermidine (SPD) has a number of advantageous effects, including life extension and neuroprotection. However, few observational studies have investigated the association of dietary SPD intake with depression.

METHODS

We used data from the 2005-2014 National Health and Nutrition Examination Survey (NHANES) and the corresponding Food Patterns Equivalents Database (FPED). SPD content of food groups from published data were merged with the appropriate FPED data to estimate the SPD intake for each subject. Patients with Patient Health Questionnaire-9 (PHQ-9) scores of 10 or above were thought to experience clinically relevant depression symptoms. Logistic regression, sensitivity analysis, and restricted cubic spline (RCS) were used.

RESULTS

Among the 19,306 participants, the overall prevalence of depression was 8.72 %. After controlling for relevant confounders, individuals in the highest tertile or quartile of total SPD and SPD derived from fruits, vegetables, cereals, nuts, eggs and seafood had a significantly lower prevalence of depression (OR total SPD = 0.77, 95 % CI: 0.63-0.93); OR fruit-sourced SPD = 0.81, 95 % CI: 0.68-0.95; OR vegetable-sourced SPD = 0.72, 95 % CI: 0.61-0.85; OR cereals-sourced SPD = 0.73,95 % CI:0.60-0.88; OR nuts- sourced SPD = 0.80, 95 % CI: 0.71-0.91; OR egg-sourced = 0.72, 95 % CI: 0.62-0.84 and OR seafood-sourced SPD = 0.65, 95 % CI: 0.55-0.77) comparing those in the lowest tertile or quartile.

CONCLOUSION

Our fndings reveal a negative association between dietary SPD intake and depression.

A Survey on Potentially Beneficial and Hazardous Bioactive Compounds in Cocoa Powder Samples Sourced from the European Market

Cocoa (Theobroma cacao, L.) represents an important market that gained relevance and became an esteemed commodity thanks to cocoa powder, chocolate, and other related products. This work analyzed 59 cocoa powder samples from the European market. Three distinct subgroups were identified: organic or conventional, alkalized or not alkalized, and raw or roasted processing. The impact of the technological process on their pH, color, and compositional traits, as well as their content of biogenic amines and salsolinol, was evaluated. The phenolic fraction was also investigated through both common and emerging methods. The results depict that the influence of the agronomical practices (organic/conventional) did not significantly (p < 0.05) affect the composition of the cocoa powders; similarly, the roasting process was not a determinant of the compounds traced. On the other hand, the alkalinization process greatly impacted color and pH, no matter the cocoa's provenience or obtention or other processes, also resulting in reducing the phenolic fraction of the treated samples. Principal component analysis confirmed that the alkali process acts on pH, color, and phenolic composition but not on the content of other bioactive molecules (biogenic amines and salsolinol). All the samples were safe, while the alkalized powders saw a great reduction in beneficial biocompounds. A novel strategy could be to emphasize on the label whether cocoa powder is non-alkalized to meet the demand for more beneficial products.

Longitudinal Plasma Metabolome Patterns and Relation to Kidney Function and Proteinuria in Pediatric CKD

Key Points

Longitudinal untargeted metabolomics. Children with CKD have a circulating metabolome that changes over time.

Background

Understanding plasma metabolome patterns in relation to changing kidney function in pediatric CKD is important for continued research for identifying novel biomarkers, characterizing biochemical pathophysiology, and developing targeted interventions. There are a limited number of studies of longitudinal metabolomics and virtually none in pediatric CKD.

Methods

The CKD in Children study is a multi-institutional, prospective cohort that enrolled children aged 6 months to 16 years with eGFR 30–90 ml/min per 1.73 m2. Untargeted metabolomics profiling was performed on plasma samples from the baseline, 2-, and 4-year study visits. There were technologic updates in the metabolomic profiling platform used between the baseline and follow-up assays. Statistical approaches were adopted to avoid direct comparison of baseline and follow-up measurements. To identify metabolite associations with eGFR or urine protein-creatinine ratio (UPCR) among all three time points, we applied linear mixed-effects (LME) models. To identify metabolites associated with time, we applied LME models to the 2- and 4-year follow-up data. We applied linear regression analysis to examine associations between change in metabolite level over time (∆level) and change in eGFR (∆eGFR) and UPCR (∆UPCR). We reported significance on the basis of both the false discovery rate (FDR) <0.05 and P < 0.05.

Results

There were 1156 person-visits (N : baseline=626, 2-year=254, 4-year=276) included. There were 622 metabolites with standardized measurements at all three time points. In LME modeling, 406 and 343 metabolites associated with eGFR and UPCR at FDR <0.05, respectively. Among 530 follow-up person-visits, 158 metabolites showed differences over time at FDR <0.05. For participants with complete data at both follow-up visits (n =123), we report 35 metabolites with ∆level–∆eGFR associations significant at FDR <0.05. There were no metabolites with significant ∆level–∆UPCR associations at FDR <0.05. We report 16 metabolites with ∆level–∆UPCR associations at P < 0.05 and associations with UPCR in LME modeling at FDR <0.05.

Conclusions

We characterized longitudinal plasma metabolomic patterns associated with eGFR and UPCR in a large pediatric CKD population. Many of these metabolite signals have been associated with CKD progression, etiology, and proteinuria in previous CKD Biomarkers Consortium studies. There were also novel metabolite associations with eGFR and proteinuria detected.

Interactions between diet and gut microbiota in cancer

Dietary patterns and specific dietary components, in concert with the gut microbiota, can jointly shape susceptibility, resistance and therapeutic response to cancer. Which diet-microbial interactions contribute to or mitigate carcinogenesis and how they work are important questions in this growing field. Here we interpret studies of diet-microbial interactions to assess dietary determinants of intestinal colonization by opportunistic and oncogenic bacteria. We explore how diet-induced expansion of specific gut bacteria might drive colonic epithelial tumorigenesis or create immuno-permissive tumour milieus and introduce recent findings that provide insight into these processes. Additionally, we describe available preclinical models that are widely used to study diet, microbiome and cancer interactions. Given the rising clinical interest in dietary modulations in cancer treatment, we highlight promising clinical trials that describe the effects of different dietary alterations on the microbiome and cancer outcomes.

Safety of Acheta domesticus powder as a Novel food pursuant to Regulation (EU) 2015/2283

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on Acheta (A.) domesticus powder as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The main components of the NF are protein, fat and dietary fibre (chitin). The Panel notes that the concentration of contaminants in the NF depends on the occurrence levels of these substances in the insect feed. The Panel further notes that there are no safety concerns regarding the stability of the NF if the NF complies with the proposed specification limits during its entire shelf-life. The NF has a high protein content, although the true protein content is overestimated when using the nitrogen-to-protein conversion factor of 6.25 due to the presence of non-protein nitrogen from chitin. The applicant proposed to use the NF as food ingredient in a number of food products. The target population proposed by the applicant is the general population. Considering the composition of the NF and the proposed conditions of use, the consumption of the NF is not nutritionally disadvantageous. The panel notes that no safety concerns arise from the toxicological information of A. domesticus. The panel considers that the consumption of the NF might trigger primary sensitisation to A. domesticus proteins and may cause allergic reactions in subjects allergic to crustaceans, mites and molluscs. Additionally, allergens from the feed may end up in the NF. The panel concludes that the NF is safe under the proposed uses and use levels.

Innovative Applications of Tenebrio molitor Larvae in the Production of Sustainable Meat Sausages: Quality and Safety Aspects

With the world's population continuing to grow, ensuring sustainable protein sources for everyone is becoming increasingly challenging. Despite meat being considered unsustainable, people find it challenging to abstain from consuming it. However, one solution to this dilemma could be the incorporation of mealworms into conventional meat products, i.e., sausages. The incorporation of mealworms into sausage formulations appears to shift the fatty acid profile towards higher levels of monounsaturated fats and polyunsaturated fatty acids (PUFAs), particularly omega-3s, potentially enhancing the nutritional value and offering health benefits. Therefore, our study aimed to improve the nutritional value and safety parameters of traditional sausages by enriching them with the flour of mealworm larvae. For this purpose, the larvae were reared on a sustainable substrate with brewery by-products, brewer's yeast, and carrots. They were used frozen and freeze-dried in sausage recipes, replacing pork in different proportions. The analysis of the product's chemical safety parameters (biogenic amines, nitrates and nitrites, volatile fatty acids (FA), and peroxide) and nutritional value (including collagen, cholesterol, amino acids, FA, and hydroxyproline) was carried out in an accredited laboratory. The results of our study have demonstrated that the incorporation of mealworms into sausages, particularly through freeze-drying, increased fat content and enhanced the profile of FA, including omega-3s while reducing protein and cholesterol levels, and altering collagen content, suggesting improved nutritional value and potential health benefits without compromising the safety of the product. Therefore, we are highlighting that the addition of mealworms influences the quality of amino acids positively and maintains biogenic amine levels within safe limits, alongside a negligible impact on nitrates and nitrites and a reduction in peroxide values. These findings indicate an overall improvement in sausage quality and safety without compromising safety.

Investigation of Biogenic Amine Levels and Microbiological Activity as Quality Markers in Some Dairy and Fish Products in Food Markets in the Kingdom of Saudi Arabia

This study aimed to verify the presence of biogenic amines (BAs) and evaluate the microbiological activity of some food samples collected from retail stores in the Kingdom of Saudi Arabia. A total of thirty-five dairy and fish products were collected and analyzed for BAs, including putrescine (PUT), cadaverine (CAD), spermidine (SPE), histamine (HIS), spermine (SPR), and tyramine (TYR), as well as for total colony count (TCC), lactic acid bacteria (LAB), Enterobacteriaceae, yeast and mold (Y and M), coliforms, and aerobic sporulation count (ASF). The thin layer chromatography (TLC) method was used in the analytical methodology to identify the BAs. The results showed the presence of BAs in all dairy products, but their concentration did not exceed the maximum permissible limit, which in contrast was established by the Food and Drug Administration (FDA) at 10 mg/100 g. The amounts of BAs in fish products varied significantly. All fish product samples contained levels of BAs below the permissible limit. Results of an independent study also indicated potential toxicity at levels of BAs (>10 mg/100 g) in Egyptian herring. Enterobacteriaceae and the coli group were present in higher concentrations in the Egyptian herring samples, whereas other samples (particularly frozen shrimp) showed increased TCC levels with a higher concentration of histamine-producing bacteria. From a consumer safety perspective, this study also indicated that food samples generally contained acceptable levels of BAs. In conclusion, there is a need to improve and standardize food quality and hygiene practices during production and storage to ensure human safety and prevent HIS formation.

The Roles of Polyamines in Intestinal Development and Function in Piglets

The gastrointestinal tract plays crucial roles in the digestion and absorption of nutrients, as well as in maintenance of a functional barrier. The development and maturation of the intestine is important for piglets to maintain optimal growth and health. Polyamines are necessary for the proliferation and growth of enterocytes, which play a key role in differentiation, migration, remodeling and integrity of the intestinal mucosa after injury. This review elaborates the development of the structure and function of the intestine of piglets during embryonic, suckling and weaning periods, the utilization and metabolism of polyamines in the intestine, as well as the role of polyamines in intestinal development and mucosal repair. The nutritional intervention to improve intestinal development and functions by modulating polyamine metabolism in piglets is also put forward. These results may help to promote the adaption to weaning in pigs and provide useful information for the development and health of piglets.

Electrostatic Repulsion Hydrophilic Interaction Liquid Chromatography (ERLIC) for the Quantitative Analysis of Polyamines

Highly polar low molecular weight organic molecules are still very challenging to analyze by liquid chromatography. Yet, with the steadily increasing application of metabolomics and similar approaches in chemical analysis, separating polar compounds might be even more important. However, almost all established liquid chromatography techniques (i.e., normal and reversed phase, hydrophilic interaction liquid chromatography (HILIC), ion chromatography) struggle with either carry-over, low sensitivity, or a lack of retention. For improving these shortcomings, electrostatic repulsion hydrophilic interaction chromatography (ERLIC) might be an alternative. By combining a HILIC mobile phase, that is highly organic with a low water content, and an ion exchange column, a distinct layer system develops. When the analyte's charge is of the same direction as the stationary phase, retention and elution are determined by two antagonistic forces: electrostatic repulsion and hydrophilicity. One prominent group of challenging polar analytes are the polyamines cadaverine, putrescine, spermidine, and spermine. Carrying charges from +2 to +4 at physiological pH, these compounds are essential cell constituents and found in all living organisms. However, they are still notoriously challenging to analyze via the established liquid chromatography methods. In the present work, an ERLIC tandem mass spectrometry method has been exemplarily developed, optimized, and validated for the quantitative determination of cadaverine, putrescine, spermidine, and spermine. This method enables symmetrical peak shapes and good separation of analytes with different charges while simultaneously selectively detecting the co-eluting diamines by MS/MS. Furthermore, high linearity (R > 0.998) and sensitivity (LODs ≤ 2 ng/mL) have been proven. Thus, ERLIC may be interesting for both targeted and untargeted analysis approaches of highly charged low molecular weight organic molecules.

Possible Role of Cellular Polyamine Metabolism in Neuronal Apoptosis

Recent studies have shown that cellular levels of polyamines (PAs) are significantly altered in neurodegenerative diseases. Evidence from in vivo animal and in vitro cell experiments suggests that the cellular levels of various PAs may play important roles in the central nervous system through the regulation of oxidative stress, mitochondrial metabolism, cellular immunity, and ion channel functions. Dysfunction of PA metabolism related enzymes also contributes to neuronal injury and cognitive impairment in many neurodegenerative diseases. Therefore, in the current work, evidence was collected to determine the possible associations between cellular levels of PAs, and related enzymes and the development of several neurodegenerative diseases, which could provide a new idea for the treatment of neurodegenerative diseases in the future.

Spermidine ameliorates osteoarthritis via altering macrophage polarization

OBJECTIVE

Spermidine (SPD) is an anti-aging natural substance, and it exerts effects through anti-apoptosis and anti-inflammation. However, the specific protective mechanism of SPD in osteoarthritis (OA) remains unclear. Here, we explored the role of SPD on the articular cartilage and the synovial tissue, and tested whether the drug would regulate the polarization of synovial macrophages by in vivo and in vitro experiments.

METHODS

By constructing an OA model in mice, we preliminarily explored the protective effect of SPD on the articular cartilage and the synovial tissue. Meanwhile, we isolated and cultured human primary chondrocytes and bone marrow-derived macrophages (BMDMs), and prepared a conditioned medium (CM) to explore the specific protective effect of SPD in vitro.

RESULTS

We found that SPD alleviated cartilage degeneration and synovitis, increased M2 polarization and decreased M1 polarization in synovial macrophages. In vitro experiments, SPD inhibited ERK MAPK and p65/NF-κB signaling in macrophages, and transformed macrophages from M1 to M2 subtypes. Interestingly, SPD had no direct protective effect on chondrocytes in vitro; however, the conditioned medium (CM) from M1 macrophages treated with SPD promoted the anabolism and inhibited the catabolism of chondrocytes. Moreover, this CM markedly suppressed IL-1β-induced p38/JNK MAPK signaling pathway activation in chondrocytes.

CONCLUSIONS

This work provides new perspectives on the role of SPD in OA. SPD does not directly target chondrocytes, but can ameliorate the degradation of articular cartilage through regulating M1/M2 polarization of synovial macrophages. Hence, SPD is expected to be the potential therapy for OA.

Polyamine-mediated ferroptosis amplification acts as a targetable vulnerability in cancer

Targeting ferroptosis, an iron-dependent form of regulated cell death triggered by the lethal overload of lipid peroxides, in cancer therapy is impeded by our limited understanding of the intersection of tumour's metabolic feature and ferroptosis vulnerability. In the present study, arginine is identified as a ferroptotic promoter using a metabolites library. This effect is mainly achieved through arginine's conversion to polyamines, which exerts their potent ferroptosis-promoting property in an H2O2-dependent manner. Notably, the expression of ornithine decarboxylase 1 (ODC1), the critical enzyme catalysing polyamine synthesis, is significantly activated by the ferroptosis signal--iron overload--through WNT/MYC signalling, as well as the subsequent elevated polyamine synthesis, thus forming a ferroptosis-iron overload-WNT/MYC-ODC1-polyamine-H2O2 positive feedback loop that amplifies ferroptosis. Meanwhile, we notice that ferroptotic cells release enhanced polyamine-containing extracellular vesicles into the microenvironment, thereby further sensitizing neighbouring cells to ferroptosis and accelerating the "spread" of ferroptosis in the tumour region. Besides, polyamine supplementation also sensitizes cancer cells or xenograft tumours to radiotherapy or chemotherapy through inducing ferroptosis. Considering that cancer cells are often characterized by elevated intracellular polyamine pools, our results indicate that polyamine metabolism exposes a targetable vulnerability to ferroptosis and represents an exciting opportunity for therapeutic strategies for cancer.

New Insights into Identification, Distribution, and Health Benefits of Polyamines and Their Derivatives

Polyamines and their derivatives are ubiquitously present in free or conjugated forms in various foods from animal, plant, and microbial origins. The current knowledge of free polyamines in foods and their contents is readily available; furthermore, conjugated polyamines generate considerable recent research interest due to their potential health benefits. The structural diversity of conjugated polyamines results in challenging their qualitative and quantitative analysis in food. Herein, we review and summarize the knowledge published on polyamines and their derivatives in foods, including their identification, sources, quantities, and health benefits. Particularly, facing the inherent challenges of isomer identification in conjugated polyamines, this paper provides a comprehensive overview of conjugated polyamines' structural characteristics, including the cleavage patterns and characteristic ion fragments of MS/MS for isomer identification. Free polyamines are present in all types of food, while conjugated polyamines are limited to plant-derived foods. Spermidine is renowned for antiaging properties, acclaimed as antiaging vitamins. Conjugated polyamines highlight their anti-inflammatory properties and have emerged as the mainstream drugs for antiprostatitis. This paper will likely help us gain better insight into polyamines and their derivatives to further develop functional foods and personalized nutraceuticals.

Dietary polyamines promote intestinal adaptation in an experimental model of short bowel syndrome

Intestinal adaptation does not necessarily recover absorptive capacity in short bowel syndrome (SBS), sometimes resulting in intestinal failure-associated liver disease (IFALD). Additionally, its therapeutic options remain limited. Polyamines (spermidine and spermine) are known as one of the autophagy inducers and play important roles in promoting the weaning process; however, their impact on intestinal adaptation is unknown. The aim of this study was to investigate the impact of polyamines ingestion on adaptation and hepatic lipid metabolism in SBS. We performed resection of two-thirds of the small intestine in male Lewis rats as an SBS model. They were allocated into three groups and fed different polyamine content diets (0%, 0.01%, 0.1%) for 30 days. Polyamines were confirmed to distribute to remnant intestine, whole blood, and liver. Villous height and number of Ki-67-positive cells in the crypt area increased with the high polyamine diet. Polyamines increased secretory IgA and mucin content in feces, and enhanced tissue Claudin-3 expression. In contrast, polyamines augmented albumin synthesis, mitochondrial DNA copy number, and ATP storage in the liver. Moreover, polyamines promoted autophagy flux and activated AMP-activated protein kinase with suppression of lipogenic gene expression. Polyamines ingestion may provide a new therapeutic option for SBS with IFALD.

Putrescine promotes MMP9-induced angiogenesis in skeletal muscle through hydrogen peroxide/METTL3 pathway

Blood vessels play a crucial role in the development of skeletal muscle, ensuring the supply of nutrients and oxygen. Putrescine, an essential polyamine for eukaryotic cells, has an unclear impact on skeletal muscle angiogenesis. In this study, we observed lower vessel density and reduced putrescine level in the muscle of low-birth-weight piglet models, and identified a positive correlation between putrescine content and muscle vessel density. Furthermore, putrescine was found to promote angiogenesis in skeletal muscle both in vitro and in vivo by targeting matrix metalloproteinase 9 (MMP9). On a mechanistic level, putrescine augmented the expression of methyltransferase like 3 (METTL3) by attenuating hydrogen peroxide production, thereby increasing the level of N6-methyladenosine (m6A)-modified MMP9 mRNA. This m6A-modified MMP9 mRNA was subsequently recognized and bound by the YTH N6-methyladenosine RNA binding protein 1 (YTHDF1), enhancing the stability of MMP9 mRNA and its protein expression, consequently accelerating angiogenesis in skeletal muscle. In summary, our findings suggest that putrescine enhances MMP9-mediated angiogenesis in skeletal muscle via the hydrogen peroxide/METTL3 pathway.

A toxicological assessment of spermidine trihydrochloride produced using an engineered strain of Saccharomyces cerevisiae

Spermidine is a polyamine consumed in the diet, endogenously biosynthesized in most cells, and produced by the intestinal microbiome. A variety of foods contribute to intake of spermidine along with other polyamines. Spermidine trihydrochloride (spermidine-3HCl) of high purity can be produced using an engineered strain of Saccharomyces cerevisiae. Spermidine has a demonstrated history of safe use in the diet; however, limited information is available in the public literature to assess the potential toxicity of spermidine-3HCl. To support a safety assessment for this spermidine-3HCl as a dietary source of spermidine, authoritative guideline and good laboratory practice (GLP) compliant in vitro genotoxicity assays (bacterial reverse mutation and mammalian micronucleus assays) and a 90-day oral (dietary) toxicity study in rats were conducted with spermidine-3HCl. Spermidine-3HCl was non-genotoxic in the in vitro assays, and no adverse effects were reported in the 90-day oral toxicity study up to the highest dose tested, 12500 ppm, equivalent to 728 mg/kg bw/day for males and 829 mg/kg bw/day for females. The subchronic no observed adverse effect level (NOAEL) is 728 mg/kg bw/day.

A cross talk between microbial metabolites and host immunity: Its relevance for allergic diseases

BACKGROUND

Allergic diseases, including respiratory and food allergies, as well as allergic skin conditions have surged in prevalence in recent decades. In allergic diseases, the gut microbiome is dysbiotic, with reduced diversity of beneficial bacteria and increased abundance of potential pathogens. Research findings suggest that the microbiome, which is highly influenced by environmental and dietary factors, plays a central role in the development, progression, and severity of allergic diseases. The microbiome generates metabolites, which can regulate many of the host's cellular metabolic processes and host immune responses.

AIMS AND METHODS

Our goal is to provide a narrative and comprehensive literature review of the mechanisms through which microbial metabolites regulate host immune function and immune metabolism both in homeostasis and in the context of allergic diseases.

RESULTS AND DISCUSSION

We describe key microbial metabolites such as short-chain fatty acids, amino acids, bile acids and polyamines, elucidating their mechanisms of action, cellular targets and their roles in regulating metabolism within innate and adaptive immune cells. Furthermore, we characterize the role of bacterial metabolites in the pathogenesis of allergic diseases including allergic asthma, atopic dermatitis and food allergy.

CONCLUSION

Future research efforts should focus on investigating the physiological functions of microbiota-derived metabolites to help develop new diagnostic and therapeutic interventions for allergic diseases.

Spermine enhances the activity of anti-tuberculosis drugs

IMPORTANCE

This is the first study that attempted to demonstrate the mechanisms of reactive oxygen species (ROS) generation by spermine (Spm) in Mycobacterium tuberculosis (M.tb). Furthermore, this is the first study to demonstrate that it is able to enhance the activity of currently available and World Health Organization (WHO)-approved tuberculosis (TB) drugs. Spermine can easily be obtained since it is already found in our diet. Moreover, as opposed to conventional antibiotics, it is less toxic to humans since it is found in millimolar concentrations in the body. Finally, with the difficulty of curing TB with conventional antibiotics, this study suggests that less toxic molecules, such as Spm, could in a long-term perspective be incorporated in a TB regimen to boost the treatment.

Natural Activators of Autophagy

Autophagy is the process by which cell contents, such as aggregated proteins, dysfunctional organelles, and cell structures are sequestered by autophagosome and delivered to lysosomes for degradation. As a process that allows the cell to get rid of non-functional components that tend to accumulate with age, autophagy has been associated with many human diseases. In this regard, the search for autophagy activators and the study of their mechanism of action is an important task for treatment of many diseases, as well as for increasing healthy life expectancy. Plants are rich sources of autophagy activators, containing large amounts of polyphenolic compounds in their composition, which can be autophagy activators in their original form, or can be metabolized by the intestinal microbiota to active compounds. This review is devoted to the plant-based autophagy activators with emphasis on the sources of their production, mechanism of action, and application in various diseases. The review also describes companies commercializing natural autophagy activators.

Exosome-mediated macrophage regulation for inflammatory bowel disease repair: a potential target of gut inflammation

Inflammatory bowel disease (IBD), which includes Crohn's disease (CD) and ulcerative colitis (UC), is a complex condition without a definite cause. During IBD, immune cells such as macrophages release proinflammatory cytokines and chemokines, contributing to intestinal barrier integrity dysfunction. IBD is largely influenced by macrophages, which are classified into subtypes M1 and M2. M1 macrophages have been found to contribute to the development of IBD, whereas M2 macrophages alleviate IBD. Hence, agents that cause increased polarization of the M2 phenotype could help repair IBD. Exosomes, as ubiquitous conveyors of intercellular messages, are involved in immune responses and immune-mediated disease processes. Exosomes and their microRNA (miRNA) from healthy cells have been found to polarize macrophages to M2 to repair IBD due to their anti-inflammatory properties; however, those from inflammatory-driven cells and disease cells promote M1 macrophages to perpetuate IBD. Here, we review the biogenesis, biochemical composition, and sources of exosomes, as well as the roles of exosomes as extracellular vesicles in regulation of macrophages to repair IBD.

Total and Free Hydrogen Cyanide Content and Profile of Bioactive Amines in Commercial Tucupi, a Traditionally Derived Cassava Product Widely Consumed in Northern Brazil

Tucupi is a broth derived from cassava roots which is produced after the spontaneous fermentation of manipueira (the liquid portion obtained by pressing cassava roots), followed by cooking. This product is widely consumed along with traditional dishes in the Brazilian Amazonia and is already used in different places worldwide. In this study, tucupi obtained from the markets of Belém (Pará, Brazil) and produced using agroindustrial (11 samples) and non-agroindustrial (11 samples) units were investigated to determine their physicochemical characteristics, total and free HCN contents, and free bioactive amine profiles. Most of the samples showed significant variations (p ≤ 0.05) in pH (2.82-4.67), total acidity (0.14-1.36 g lactic acid/100 mL), reducing sugars (up to 2.33 g/100 mL), and total sugars (up to 4.35 g/100 mL). Regarding the amines, four biogenic amines (0.5-4.2 mg/L tyramine, 1.0-23.1 mg/L putrescine, 0.5-66.8 mg/L histamine, and 0.6-2.9 mg/L tryptamine) and one polyamine (0.4-1.7 mg/L spermidine) were identified in the tucupi samples. Even in the tucupi produced using the agroindustrial units, which had quality seals provided by the local regulatory agency, high levels of biogenic amines (4.4-78.2 mg/L) were observed, as well as high dosages of total (8.87-114.66 mg/L) and free (0.80-38.38 mg/L) HCN. These facts highlight the need for better knowledge regarding the product manufacturing process to establish standardization and high-quality conditions for tucupi processing since high contents of biogenic amines and HCN are commonly associated with adverse health effects.

The Molecular Role of Polyamines in Age-Related Diseases: An Update

Polyamines (Pas) are short molecules that exhibit two or three amine groups that are positively charged at a physiological pH. These small molecules are present in high concentrations in a wide variety of organisms and tissues, suggesting that they play an important role in cellular physiology. Polyamines include spermine, spermidine, and putrescine, which play important roles in age-related diseases that have not been completely elucidated. Aging is a natural process, defined as the time-related deterioration of the physiological functions; it is considered a risk factor for degenerative diseases such as cardiovascular, neurodegenerative, and musculoskeletal diseases; arthritis; and even cancer. In this review, we provide a new perspective on the participation of Pas in the cellular and molecular processes related to age-related diseases, focusing our attention on important degenerative diseases such as Alzheimerߣs disease, Parkinsonߣs disease, osteoarthritis, sarcopenia, and osteoporosis. This new perspective leads us to propose that Pas function as novel biomarkers for age-related diseases, with the main purpose of achieving new molecular alternatives for healthier aging.

Difluoromethylornithine rebalances aberrant polyamine ratios in Snyder-Robinson syndrome

Snyder-Robinson syndrome (SRS) results from mutations in spermine synthase (SMS), which converts the polyamine spermidine into spermine. Affecting primarily males, common manifestations of SRS include intellectual disability, osteoporosis, hypotonia, and seizures. Symptom management is the only treatment. Reduced SMS activity causes spermidine accumulation while spermine levels are reduced. The resulting exaggerated spermidine:spermine ratio is a biochemical hallmark of SRS that tends to correlate with symptom severity. Our studies aim to pharmacologically manipulate polyamine metabolism to correct this imbalance as a therapeutic strategy for SRS. Here we report the repurposing of 2-difluoromethylornithine (DFMO), an FDA-approved inhibitor of polyamine biosynthesis, in rebalancing spermidine:spermine ratios in SRS patient cells. Mechanistic in vitro studies demonstrate that, while reducing spermidine biosynthesis, DFMO also stimulates the conversion of spermidine into spermine in hypomorphic SMS cells and induces uptake of exogenous spermine, altogether reducing the aberrant ratios. In a Drosophila SRS model characterized by reduced lifespan, DFMO improves longevity. As nearly all SRS patient mutations are hypomorphic, these studies form a strong foundation for translational studies with significant therapeutic potential.

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.

Who Cares about Biogenic Amines?

Biogenic amines (BAs) have been under study since the early 1970s [...].

Polyamines in Ovarian Aging and Disease

Ovarian aging and disease-related decline in fertility are challenging medical and economic issues with an increasing prevalence. Polyamines are a class of polycationic alkylamines widely distributed in mammals. They are small molecules essential for cell growth and development. Polyamines alleviate ovarian aging through various biological processes, including reproductive hormone synthesis, cell metabolism, programmed cell death, etc. However, an abnormal increase in polyamine levels can lead to ovarian damage and promote the development of ovarian disease. Therefore, polyamines have long been considered potential therapeutic targets for aging and disease, but their regulatory roles in the ovary deserve further investigation. This review discusses the mechanisms by which polyamines ameliorate human ovarian aging and disease through different biological processes, such as autophagy and oxidative stress, to develop safe and effective polyamine targeted therapy strategies for ovarian aging and the diseases.

Molecular mechanism of caloric restriction mimetics-mediated neuroprotection of age-related neurodegenerative diseases: an emerging therapeutic approach

Aging-induced neurodegenerative diseases (NDs) are significantly increasing health problem worldwide. It has been well documented that oxidative stress is one of the potential causes of aging and age-related NDs. There are no drugs for the treatment of NDs, therefore there is an immediate necessity for the development of strategies/treatments either to prevent or cure age-related NDs. Caloric restriction (CR) and intermittent fasting have been considered as effective strategies in increasing the healthspan and lifespan, but it is difficult to adhere to these routines strictly, which has led to the development of calorie restriction mimetics (CRMs). CRMs are natural compounds that provide similar molecular and biochemical effects of CR, and activate autophagy process. CRMs have been reported to regulate redox signaling by enhancing the antioxidant defense systems through activation of the Nrf2 pathway, and inhibiting ROS generation through attenuation of mitochondrial dysfunction. Moreover, CRMs also regulate redox-sensitive signaling pathways such as the PI3K/Akt and MAPK pathways to promote neuronal cell survival. Here, we discuss the neuroprotective effects of various CRMs at molecular and cellular levels during aging of the brain. The CRMs are envisaged to become a cornerstone of the pharmaceutical arsenal against aging and age-related pathologies.

Counteracting Immunosenescence-Which Therapeutic Strategies Are Promising?

Aging attenuates the overall responsiveness of the immune system to eradicate pathogens. The increased production of pro-inflammatory cytokines by innate immune cells under basal conditions, termed inflammaging, contributes to impaired innate immune responsiveness towards pathogen-mediated stimulation and limits antigen-presenting activity. Adaptive immune responses are attenuated as well due to lowered numbers of naïve lymphocytes and their impaired responsiveness towards antigen-specific stimulation. Additionally, the numbers of immunoregulatory cell types, comprising regulatory T cells and myeloid-derived suppressor cells, that inhibit the activity of innate and adaptive immune cells are elevated. This review aims to summarize our knowledge on the cellular and molecular causes of immunosenescence while also taking into account senescence effects that constitute immune evasion mechanisms in the case of chronic viral infections and cancer. For tumor therapy numerous nanoformulated drugs have been developed to overcome poor solubility of compounds and to enable cell-directed delivery in order to restore immune functions, e.g., by addressing dysregulated signaling pathways. Further, nanovaccines which efficiently address antigen-presenting cells to mount sustained anti-tumor immune responses have been clinically evaluated. Further, senolytics that selectively deplete senescent cells are being tested in a number of clinical trials. Here we discuss the potential use of such drugs to improve anti-aging therapy.

Nutrigenomics of inward rectifier potassium channels

Inwardly rectifying potassium (Kir) channels play a key role in maintaining the resting membrane potential and supporting potassium homeostasis. There are many variants of Kir channels, which are usually tetramers in which the main subunit has two trans-membrane helices attached to two N- and C-terminal cytoplasmic tails with a pore-forming loop in between that contains the selectivity filter. These channels have domains that are strongly modulated by molecules present in nutrients found in different diets, such as phosphoinositols, polyamines and Mg²⁺. These molecules can impact these channels directly or indirectly, either allosterically by modulation of enzymes or via the regulation of channel expression. A particular type of these channels is coupled to cell metabolism and inhibited by ATP (KATP channels, essential for insulin release and for the pathogenesis of metabolic diseases like diabetes mellitus). Genomic changes in Kir channels have a significant impact on metabolism, such as conditioning the nutrients and electrolytes that an individual can take. Thus, the nutrigenomics of ion channels is an important emerging field in which we are attempting to understand how nutrients and diets can affect the activity and expression of ion channels and how genomic changes in such channels may be the basis for pathological conditions that limit nutrition and electrolyte intake. In this contribution we briefly review Kir channels, discuss their nutrigenomics, characterize how different components in the diet affect their function and expression, and suggest how their genomic changes lead to pathological phenotypes that affect diet and electrolyte intake.

Toxicology of pharmaceutical and nutritional longevity compounds

Aging is the most prominent risk factor for many diseases, which is considered to be a complicated biological process. The rate of aging depends on the effectiveness of important mechanisms such as the protection of DNA from free radicals, which protects the structural and functional integrity of cells and tissues. In any organism, not all organs may age at the same rate. Slowing down primary aging and reaching maximum lifespan is the most basic necessity. In this process, it may be possible to slow down or stabilise some diseases by using the compounds for both dietary and pharmacological purposes. Natural compounds with antioxidant and anti-inflammatory effects, mostly plant-based nutraceuticals, are preferred in the treatment of age-related chronic diseases and can also be used for other diseases. An increasing number of long-term studies on synthetic and natural compounds aim to elucidate preclinically and clinically the mechanisms underlying being healthy and prolongation of life. To delay age-related diseases and prolong the lifespan, it is necessary to take these compounds with diet or pharmaceuticals, along with detailed toxicological results. In this review, the most promising and utilised compounds will be highlighted and it will be discussed whether they have toxic effects in short/long-term use, although they are thought to be used safely.

Gut microbiota and anti-aging: Focusing on spermidine

The human gut microbiota plays numerous roles in regulating host growth, the immune system, and metabolism. Age-related changes in the gut environment lead to chronic inflammation, metabolic dysfunction, and illness, which in turn affect aging and increase the risk of neurodegenerative disorders. Local immunity is also affected by changes in the gut environment. Polyamines are crucial for cell development, proliferation, and tissue regeneration. They regulate enzyme activity, bind to and stabilize DNA and RNA, have antioxidative properties, and are necessary for the control of translation. All living organisms contain the natural polyamine spermidine, which has anti-inflammatory and antioxidant properties. It can regulate protein expression, prolong life, and improve mitochondrial metabolic activity and respiration. Spermidine levels experience an age-related decrease, and the development of age-related diseases is correlated with decreased endogenous spermidine concentrations. As more than just a consequence, this review explores the connection between polyamine metabolism and aging and identifies advantageous bacteria for anti-aging and metabolites they produce. Further research is being conducted on probiotics and prebiotics that support the uptake and ingestion of spermidine from food extracts or stimulate the production of polyamines by gut microbiota. This provides a successful strategy to increase spermidine levels.

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.

Characterization and Mechanism of Tea Polyphenols Inhibiting Biogenic Amine Accumulation in Marinated Spanish Mackerel

Putrescine is a low-molecular-weight organic compound that is widely found in pickled foods. Although the intake of biogenic amines is beneficial to humans, an excessive intake can cause discomfort. In this study, the ornithine decarboxylase gene (ODC) was involved in putrescine biosynthesis. After cloning, expression and functional verification, it was induced and expressed in E. coli BL21 (DE3). The relative molecular mass of the recombinant soluble ODC protein was 14.87 kDa. The function of ornithine decarboxylase was analyzed by determining the amino acid and putrescine content. The results show that the ODC protein could catalyze the decarboxylation of ornithine to putrescine. Then, the three-dimensional structure of the enzyme was used as a receptor for the virtual screening of inhibitors. The binding energy of tea polyphenol ligands to the receptor was the highest at -7.2 kcal mol^-1. Therefore, tea polyphenols were added to marinated fish to monitor the changes in putrescine content and were found to significantly inhibit putrescine production (p < 0.05). This study lays the foundation for further research on the enzymatic properties of ODC and provides insight into an effective inhibitor for controlling the putrescine content in pickled fish.

Safety of UV-treated powder of whole yellow mealworm (Tenebrio molitor larva) as a novel food pursuant to Regulation (EU) 2015/2283

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on UV-treated powder of whole yellow mealworm (Tenebrio molitor larva) as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The term yellow mealworm refers to the larval form of the insect species T. molitor. The NF is the UV-treated powder of the whole, thermally dried yellow mealworm. The NF consists mainly of crude protein, fat, digestible carbohydrates and fibre (chitin). The Panel notes that the levels of contaminants in the NF highly depend on the occurrence levels of these substances in the insect feed. The Panel notes furthermore that there are no safety concerns regarding the stability of the NF if the NF complies with the proposed specification limits during its entire shelf life. The NF has a high protein content, although the true protein content in the NF is overestimated when using the nitrogen-to-protein conversion factor of 6.25, due to the presence of non-protein nitrogen. The applicant proposed to use the NF as an ingredient in various food products, such as bakery products, pasta, compotes of fruit/vegetables and cheese. The target population is the general population. The Panel notes that considering the composition of the NF, the proposed conditions of use and that the NF will not be the sole source of dietary protein, the consumption of the NF is not nutritionally disadvantageous. Despite the UV treatment, the Panel notes that the NF is not a significant dietary contributor of vitamin D3. The submitted toxicity studies from the literature did not raise safety concerns. The Panel considers that the consumption of the NF may induce primary sensitisation and allergic reactions to yellow mealworm proteins and may cause allergic reactions in subjects with allergies to crustaceans and dust mites. Additionally, allergens from the feed may end up in the NF. With the exception of possible allergenicity, the Panel concludes that the NF is safe under the proposed uses and use levels.

Changes in the Physicochemical Properties of Chia (Salvia hispanica L.) Seeds during Solid-State and Submerged Fermentation and Their Influence on Wheat Bread Quality and Sensory Profile

This study aimed at investigating the impacts of 24 h of either solid-state fermentation (SSF) or submerged fermentation (SMF) with Lactiplantibacillus plantarum strain No. 122 on the physico-chemical attributes of chia seeds (CS). Furthermore, this study examined how adding fermented chia seeds (10, 20, and 30% concentrations) affected the properties and sensory profile of wheat bread. Acidity, lactic acid bacteria (LAB) viable counts, biogenic amine (BA), and fatty acid (FA) profiles of fermented chia seeds were analysed. The main quality parameters, acrylamide concentration, FA and volatile compound (VC) profiles, sensory characteristics, and overall acceptability of the obtained breads, were analysed. A decline in the concentration of certain BA and saturated FA and an increase in polyunsaturated FA and omega-3 (ω-3) were found in fermented CS (FCS). The same tendency in the FA profile was observed in both breads, i.e., breads with non-fermented CS (NFCS) or FCS. The quality parameters, VC profile, and sensory attributes of wheat bread were significantly affected by the addition of NFCS or FCS to the main bread formula. All supplemented breads had reduced specific volume and porosity, but SSF chia seeds increased moisture and decreased mass loss after baking. The lowest acrylamide content was found in bread with a 30% concentration of SSF chia seeds (11.5 µg/kg). The overall acceptance of supplemented breads was lower than the control bread, but breads with 10 and 20% SMF chia seed concentrations were still well accepted (on average, 7.4 score). Obtained results highlight that fermentation with Lp. plantarum positively contributes to chia seed nutritional value, while incorporation of NFCS and FCS at certain levels results in an improved FA profile, certain sensory attributes, and reduced acrylamide content in wheat bread.

Alterations of the Gut Microbiota and Metabolomics Associated with the Different Growth Performances of Macrobrachium rosenbergii Families

To investigate the key gut microbiota and metabolites associated with the growth performance of Macrobrachium rosenbergii families, 16S rRNA sequencing and LC-MS metabolomic methods were used. In this study, 90 M. rosenbergii families were bred to evaluate growth performance. After 92 days of culture, high (H), medium (M), and low (L) experimental groups representing three levels of growth performance, respectively, were collected according to the weight gain and specific growth rate of families. The composition of gut microbiota showed that the relative abundance of Firmicutes, Lachnospiraceae, Lactobacillus, and Blautia were much higher in Group H than those in M and L groups. Meanwhile, compared to the M and L groups, Group H had significantly higher levels of spermidine, adenosine, and creatinine, and lower levels of L-citrulline. Correlation analysis showed that the abundances of Lactobacillus and Blautia were positively correlated with the levels of alpha-ketoglutaric acid and L-arginine. The abundance of Blautia was also positively correlated with the levels of adenosine, taurine, and spermidine. Notably, lots of metabolites related to the metabolism and biosynthesis of arginine, taurine, hypotaurine, and fatty acid were upregulated in Group H. This study contributes to figuring out the landscape of the gut microbiota and metabolites associated with prawn growth performance and provides a basis for selective breeding.

The Role of Microbiota-Derived Metabolites in Colorectal Cancer

The impact of bacterial members of the microbiota on the development of colorectal cancer (CRC) has become clear in recent years. However, exactly how bacteria contribute to the development of cancer is often still up for debate. The impact of bacteria-derived metabolites, which can influence the development of CRC either in a promoting or inhibiting manner, is undeniable. Here, we discuss the effects of the most well-studied bacteria-derived metabolites associated with CRC, including secondary bile acids, short-chain fatty acids, trimethylamine-N-oxide and indoles. We show that the effects of individual metabolites on CRC development are often nuanced and dose- and location-dependent. In the coming years, the array of metabolites involved in CRC development will undoubtedly increase further, which will emphasize the need to focus on causation and mechanisms and the clearly defined roles of bacterial species within the microbiota.

High-Dose Spermidine Supplementation Does Not Increase Spermidine Levels in Blood Plasma and Saliva of Healthy Adults: A Randomized Placebo-Controlled Pharmacokinetic and Metabolomic Study

(1) Background: Spermidine is a biogenic polyamine that plays a crucial role in mammalian metabolism. As spermidine levels decline with age, spermidine supplementation is suggested to prevent or delay age-related diseases. However, valid pharmacokinetic data regarding spermidine remains lacking. Therefore, for the first time, the present study investigated the pharmacokinetics of oral spermidine supplementation. (2) Methods: This study was designed as a randomized, placebo-controlled, triple-blinded, two-armed crossover trial with two 5-day intervention phases separated by a washout phase of 9 days. In 12 healthy volunteers, 15 mg/d of spermidine was administered orally, and blood and saliva samples were taken. Spermidine, spermine, and putrescine were quantified by liquid chromatography-mass spectrometry (LC-MS/MS). The plasma metabolome was investigated using nuclear magnetic resonance (NMR) metabolomics. (3) Results: Compared with a placebo, spermidine supplementation significantly increased spermine levels in the plasma, but it did not affect spermidine or putrescine levels. No effect on salivary polyamine concentrations was observed. (4) Conclusions: This study's results suggest that dietary spermidine is presystemically converted into spermine, which then enters systemic circulation. Presumably, the in vitro and clinical effects of spermidine are at least in part attributable to its metabolite, spermine. It is rather unlikely that spermidine supplements with doses <15 mg/d exert any short-term effects.