Search Results (149)

Impaired endothelial function, excessive oxidative stress, and persistent bacterial infection collectively contribute to delayed healing of diabetic chronic wounds. Methylglyoxal (MGO)-induced metabolic stress is a critical driver of endothelial injury; however, effective multifunctional strategies capable of restoring vascular function and maintaining cellular homeostasis remain limited. In this study, the endothelial protective potential of an amphibian-derived Bowman–Birk inhibitor (BBI)-type peptide, OSTI-1872, and its rationally designed structural analogues were investigated using an MGO-induced injury model in human umbilical vein endothelial cells (HUVECs). Among the tested peptides, the optimised analogue OSTI-2337 exhibited superior protective activity. OSTI-2337 markedly attenuated MGO-induced oxidative stress, restored nitric oxide bioavailability, enhanced VEGF expression, promoted endothelial migration and tube formation, and reduced oxidative DNA damage. Mechanistically, these effects were associated with coordinated regulation of MGO detoxification and redox homeostasis, as evidenced by enhanced GLO1 expression and modulation of the PI3K/AKT/GSK3β/Nrf2 axis, accompanied by increased expression of downstream antioxidant proteins HO-1 and NQO1. In addition, OSTI-1872 and OSTI-2337 displayed antibacterial activity against representative bacterial strains, suggesting their potential advantages for complex diabetic wound environments. Collectively, these findings demonstrate that structural optimisation significantly enhances the biological activity of amphibian BBI-type peptides and identify OSTI-2337 as a multifunctional peptide candidate capable of integrating endothelial protection, MGO detoxification, redox regulation, and antibacterial activity for the management of diabetes-associated vascular injury and chronic wound complications. Full article

Crohn’s disease (CD) is a chronic inflammatory bowel disease with a rising incidence and prevalence worldwide. It is associated with Mycobacterium avium subspecies paratuberculosis (MAP). Current CD treatment strategies are based on anti-inflammatory therapies, including anti-TNF-α drugs. These treatment options provide short-term benefits and are associated with numerous side effects in CD patients. Manuka honey is distinguished from other honey by its high content of methylglyoxal (MGO). MGO, a reactive metabolite, is also generated endogenously in macrophages during infection through glycolysis; however, the amount is insufficient to neutralize the ongoing infection and subsequent tissue damage. This study examined whether exogenous, low-dose MGO can modulate MAP-driven inflammatory and glycolysis- and lactate-associated markers in infected macrophages. THP-1 macrophages were infected with the CD-associated MAP strain and then treated with MGO doses at defined time intervals. We measured markers of M1-/M2-like phenotype polarization, monocarboxylate transporters, lactate export, antioxidant responses, cytokines, and selected glycolysis- and lactate-associated markers at both the mRNA and protein levels. MGO reduced M1 signaling markers CXCL10 (p < 0.05), TNF-α (p < 0.0001), IL-1β (p < 0.01), and IL-6 (p < 0.0001). Simultaneously, MGO promoted M2 shift, elevating CD206 by 1.20-fold and IL-10 by 7-fold. Low-dose MGO administration was associated with increases in Nrf-2 (1.4-fold), HO-1 (1.4-fold), and IL-1Ra (1.5-fold), while the pro-inflammatory cytokines decreased. Metabolically, MGO downregulated MCT4 (p < 0.01) and reduced lactate export by 30%. These changes were coupled with higher PHD2 (1.4-fold) and decreases in GLUT1 (0.9-fold), PKD1 (0.8-fold), and IL-1β, consistent with attenuated glycolysis- and lactate-associated inflammatory signaling. These results suggest that hormetic concentration of MGO mitigates MAP-induced inflammatory activation while altering glycolysis- and lactate-related signaling markers in infected macrophages. Most importantly, we unraveled the predicted molecular mechanism by which MGO suppresses inflammation and modulates oxidative damage. Full article

Ageing is characterized by progressive metabolic and inflammatory dysregulation, in which methylglyoxal (MGO), a highly reactive dicarbonyl by-product of glycolysis, is involved in the formation of advanced glycation end products (AGEs). This review provides an integrated overview of the bidirectional relationship between MGO-derived carbonyl stress and the gut microbiota, focusing on its implications for ageing and age-related diseases. We summarize current evidence on MGO production, clearance, tissue distribution, and reactivity, with particular attention to the intestinal lumen as a site where dietary compounds, host metabolism, and microbial activity converge. Age-related dysbiosis may impair intestinal barrier integrity, alter microbial metabolite production, and promote chronic low-grade inflammation, thereby reinforcing metabolic dysfunction and favoring free MGO accumulation. Conversely, MGO and AGEs can reshape microbial communities, compromise epithelial tight junctions, and amplify inflammatory signalling through receptor-dependent and independent mechanisms. Evidence from in vitro, animal, and clinical studies supports a role for the MGO–microbiota axis in metabolic, cardiovascular, gastrointestinal, neurodegenerative, and frailty-related conditions. Targeting microbiota composition, intestinal barrier function, and MGO scavenging pathways may therefore represent a promising strategy to mitigate carbonyl stress and preserve health during ageing. Full article

Methylglyoxal (MGO), a highly reactive 1,2-dicarbonyl, is generated by all three principal pathways of advanced glycation end product (AGE) synthesis in type 2 diabetes mellitus (T2DM)—the Hodge, Namiki, and Wolff pathways—and by the non-enzymatic degradation of glycolytic triose phosphates. It is the principal substrate of the glutathione-dependent GLO1/GLO2 glyoxalase system and the main source of the hydroimidazolone-1 (MG-H1) adduct, and it directly modifies intracellular proteins across multiple tissues. This clinically oriented narrative review synthesizes dicarbonyl chemistry, glyoxalase, and AGE adduct research to propose—as a hypothesis-generating schema rather than established biology—that MGO functions as a convergent biochemical node in diabetic complications. We examine MGO generation across the four input routes, its preferential modification of arginine and lysine residues, the correspondence between tissue MGO accumulation and complication distribution, glyoxalase-mediated clearance, and therapeutic strategies. We further propose that routine parameters such as gamma-glutamyl transferase and red cell distribution width may serve as accessible proxies for MGO burden, with the explicit caveat that these mappings require prospective validation and do not constitute a validated clinical instrument. Full article

Chronic hyperglycemia and excessive reactive oxygen species (ROS) production are defining features of endothelial dysfunction, a key driver of diabetic vascular complications such as diabetic nephropathy. Microvesicles (MV-enriched fraction), a subtype of extracellular vesicles, and the stress-responsive antioxidant protein Sestrin2 (SESN2) have emerged as important contributors to these processes. This study investigated the role of the MV-enriched fraction in endothelial cell communication under diabetic conditions, with a particular focus on oxidative stress signaling. To model diabetic injury, EA.hy926 endothelial cells were treated with methylglyoxal (MGO), and the resulting MV-enriched fraction was isolated and then applied to two recipient models: naïve endothelial cells and SESN2 knockdown (KD) cells. Protein expression of key antioxidant markers, including endothelial nitric oxide synthase (eNOS), was assessed by Western blot. Nitric oxide (NO) bioavailability was quantified via nitrite measurement using 2,3-diaminonaphthalene (DAN), while mitochondrial and cytosolic ROS levels were evaluated using MitoSOX and dihydroethidium (DHE), respectively. Results demonstrated that the MV-enriched fraction derived from diabetic conditions triggers a complex antioxidant response in healthy endothelial cells, characterized by upregulation of SESN2, superoxide dismutase 1 (SOD1), and heme oxygenase-1 (HO-1). This suggests a compensatory mechanism that mitigates oxidative stress. Notably, SESN2 KD cells exhibited increased ROS production and reduced NO levels upon MV treatment, underscoring the essential role of SESN2 in maintaining redox homeostasis. Overall, this study highlights the dual role of the MV-enriched fraction as a mediator of both protective and detrimental redox signaling in diabetic endothelial dysfunction and suggests potential therapeutic targets for managing diabetic vascular complications. Full article

This study characterises the polyphenol profile (LC–MS), antiglycation (BSA–GLU, BSA–FRU, BSA–MGO), and antioxidant potential (ABTS, DPPH) of A. arguta (‘Scarlet September Kiwi’) and A. kolomikta (‘Lande’) fruit before and after extract purification. A total of 48 polyphenols belonging to 11 chemical groups were identified. Crude Scarlet extract showed higher TPI (1079.51 µg/g dw) than the crude Lande (761.13 µg/g dw), with quercetin glucoside accounting for 71% of TPI. Crude Lande extract was dominated by caffeic acid glucoside (39% TPI). Purification markedly increased TPI values to 4082.13 µg/g dw (Scarlet) and 2550.51 µg/g dw (Lande). The crude extracts more effectively inhibited glucose- and fructose-induced protein glycation (IC₅₀ = 1.81–7.71 mg/mL) than methylglyoxal-mediated glycation (IC₅₀ = 14.33–24.26). Purification significantly enhanced antiglycation efficacy in all models (IC₅₀ = 0.47–1.78), as well as antioxidant capacity (IC₅₀ = 0.10–0.67 mg/mL). Statistical analyses revealed a strong alignment between the glycation-inhibitory activity and the tested antioxidant potential. These findings suggest that targeted purification enhances the functional potential of Actinidia species, making them promising sources of bioactive compounds against oxidative stress and protein glycation-related disorders. Full article

This study focused on the inhibitory effects of wheat bran feruloyl oligosaccharides (FOs) on the formation of AGEs in three bovine serum albumin (BSA)-based non-enzymatic glycation models, namely BSA-fructose, BSA-methylglyoxal (MGO), and BSA-glyoxal (GO). In the BSA-fructose model, FOs at 0.25 mg/mL achieved a 62% inhibition rate of fructosamine, equivalent to approximately 78% of the activity of the positive control aminoguanidine (AG), and reduced fluorescent AGEs by over 50% on day 12. Additionally, FOs suppressed the accumulation of α-dicarbonyl compounds, key intermediates in the glycation pathway. In the BSA-MGO and BSA-GO system, the decreased fluorescence intensity of tryptophan residues indicated that FOs bound to BSA, inducing conformational changes in the protein microenvironment; this binding also inhibited protein carbonyl formation and the loss of thiol groups, thereby modulating the protein glycation process. Compared with their precursors (ferulic acid, FA; xylooligosaccharides, XOS), FOs exhibited comparable or even superior inhibitory activity against specific AGE subtypes, suggesting a synergistic effect between the feruloyl and oligosaccharide moieties. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed that FOs reduced the band intensity of 90 kDa AGEs in the glycation system, indicating the inhibition of protein-fructose cross-linking. Fluorescence spectroscopy confirmed that FOs dynamically quenched BSA with a single binding site, and thermodynamic calculations demonstrated that the binding was spontaneous (ΔG < 0), primarily driven by hydrogen bonds and van der Waals forces (ΔH < 0, ΔS < 0). This study systematically investigated the anti-glycation activities of FOs and their precursors. The findings demonstrate that FOs are promising natural glycation inhibitors and provide important theoretical and experimental support for related research. Furthermore, this study establish a basis for the green and high-value utilization of agricultural by-products like wheat bran. Full article

Background/Objectives: Methylglyoxal (MGO) and subsequent activation of advanced glycation end products (AGEs)–RAGE receptor signaling has been implicated in the complications of diabetes mellitus (DM), such as bladder dysfunction. Chronic treatment with MGO leads to bladder overactivity, but the effects of acute MGO exposure have not yet been evaluated. Methods: In this study, we used female wild-type, endothelial nitric oxide (eNOS) knockout (eNOS^−/−), and triple (neuronal/endothelial/inducible) NOS^−/− mice to investigate the effects of incubation of MGO (10 to 300 µM) on bladder contractions induced by carbachol and electrical field stimulation (EFS). We also analyzed the activity of the MGO detoxification enzyme glyoxalase 1 (Glo1). Results: Incubation with MGO at 10 and 30 µM in urothelium-intact preparations produced marked detrusor hypercontractility to both carbachol and EFS that was abolished by urothelium removal. Detrusor hypercontractility was associated with the generation of reactive oxygen species (ROS), RAGE activation, Rho kinase sensitization, and activation of TRPA1 and TRPV4 channels. At higher concentrations (100 and 300 µM), MGO did not significantly affect the detrusor contractility to carbachol and EFS, but L-NAME pretreatment restored the hypercontractile state by MGO. Likewise, in bladder strips obtained from eNOS^−/− or triple NOS^−/− mice, MGO exposure (300 µM) significantly enhanced carbachol and EFS-induced contractions, indicating a major role for nitric oxide (NO) counteracting the hypercontractility. No concentration of MGO altered Glo1 activity in bladder tissues. Conclusions: In conclusion, progressive MGO accumulation may account for the transition from the initial hyperactive phase to the subsequent hypoactive decompensated phase of diabetic bladder dysfunction. Full article

Glycation of superoxide dismutase 1 (SOD1) has been shown to modulate the cytosolic levels of phosphorylated TAR DNA-binding protein 43 (TDP-43), a hallmark of amyotrophic lateral sclerosis (ALS) pathology. In this study, we investigated the interaction between TDP-43 and SOD1 and assessed how methylglyoxal (MGO)-induced glycation and the ALS-associated G93A SOD1 mutation affect this interplay in H4 cells. MGO exposure reduced SOD1 activity and TDP-43 phosphorylation in cells expressing WT SOD1, but not in those expressing G93A SOD1. Both WT and mutant SOD1 interacted with TDP-43 in the nucleus and cytosol; however, cytosolic interactions were more prevalent in G93A-expressing cells. Although MGO did not significantly alter the overall interaction between TDP-43 and WT SOD1, it induced cytosolic inclusion formation at 0.4 mM, a concentration associated with reduced cell viability. These inclusions did not colocalize with stress granules, indicating alternative aggregation pathways. Treatment with cyclosporin A, which inhibits the phosphatase calcineurin, decreased both TDP-43–WT SOD1 inclusions and cytosolic interactions between TDP-43 and G93A SOD1. Together, these findings suggest that SOD1 damage, induced by glycation or ALS-linked mutation, may affect TDP-43 phosphorylation status and promote its cytosolic mislocalization and aggregation, providing new insights into ALS-associated proteinopathy. Full article

Protein glycation and oxidation contribute to the pathogenesis of neurodegenerative diseases. This study evaluated the antiglycative and antioxidative effects of donepezil, rivastigmine, galantamine, memantine, lamotrigine, sodium valproate, and carbamazepine using bovine serum albumin (BSA) as a model protein. Glycation was induced with fructose, ribose, or methylglyoxal (MGO), and oxidation with chloramine T (ChT). Concentrations of glycation products—Amadori products (APs), amyloid cross-β structure (βA), argpyrimidine (ARG), crossline (CRO), vesperlysine (VES), pentosidine (PEN), total AGEs and glycoxidation products—dityrosine (DT), kynurenine (KN), N-formylkynurenine (NFK) as well as oxidation biomarkers, total thiols (TTs), protein carbonyls (PCs), and advanced oxidation protein products (AOPPs), were determined via spectrophotometric and spectrofluorimetric methods. Molecular docking and a systematic literature review (PRISMA) complemented the experimental data. Lamotrigine showed the strongest antiglycative and antioxidative effects, surpassing aminoguanidine in reducing ARG, PEN, DT, and NFK levels. In contrast, donepezil markedly increased APs, βA, ARG, VES, DT, and PEN, suggesting proglycative and pro-oxidative activity. Docking revealed a high affinity of donepezil for RAGE (–7.2 kcal/mol), possibly explaining its impact on carbonyl stress. Overall, anti-dementia drugs showed weak to moderate antiglycative potential, with lamotrigine being the most effective. Full article

Glyoxal (GO) and methylglyoxal (MGO) are highly toxic metabolic byproducts that induce carbonyl stress in bacteria and eukaryotes. Their accumulation in cells is linked to non-enzymatic glycosylation (glycation) of proteins, nucleic acids, and lipids, leading to the formation of advanced glycation end products (AGEs). In humans, AGEs are associated with several health problems, such as diabetes, Alzheimer’s disease, cancer, and aging. Recent studies indicate that, despite their short lifespan, bacteria are also affected by AGEs formation. In this review, we summarize the pathways and mechanisms that help bacteria cope with GO, MGO, and AGEs. We also discuss the impact of dietary AGEs on gut microbiota and the antibacterial activity of host-derived GO/MGO. Recent studies highlight three main areas for future research: the role of AGEs in dysbiosis, the regulation of protein activities by MGO/GO-dependent modifications, and the potential use of glyoxalase pathway inhibitors to combat pathogens. This last point is especially important due to the rising prevalence of multidrug-resistant strains and the failure of antibiotic therapies. Full article

Pasuchaca (Geranium dielsianum Knuth), a traditional Peruvian medicinal plant from the Geraniaceae family used for diabetes management, was investigated for its antiglycative properties. This study aimed to screen, isolate, and identify the active antiglycative compounds from its aerial parts. By coupling a methylglyoxal (MGO)-HPLC screening assay with high-speed counter-current chromatography (HSCCC), seven dihydroflavonol derivatives were separated and identified from the 80% methanol extract. The compounds were identified as 2,3-dihydromyricetin 3-O-α-rhamnopyranoside (1), (+)-taxifolin 3-O-β-D-xylopyranoside (2), astilbin (6), isoastilbin (8), 3″-acetyl astilbin (9), and 2″-acetyl astilbin (11). Astilbin was identified as the major constituent, with remarkably high contents of 252.41 mg/g in the 80% methanol extract and 541.04 mg/g in the partitioned upper layer fraction. Astilbin demonstrated potent antiglycation activity across all stages of protein glycation (early, middle, late, and whole stages), significantly surpassing the positive control aminoguanidine. Furthermore, the formation of MGO-astilbin adducts was confirmed by LC-ESI-MS, validating its role as an effective MGO scavenger. This report is the first to isolate these phytochemicals from Pasuchaca. The findings establish astilbin as the key antiglycative component of Pasuchaca, substantiating its traditional use and highlighting its potential as a source of functional food ingredients or natural therapeutics for mitigating glycative stress. Full article

Chronic wound infections associated with resistant polymicrobial biofilms are often refractory to conventional therapies with sustained healing time. This study evaluated the efficacy of non-antibiotic treatments including Methylglyoxal—MGO—Light-Emitting Diode—LED—and Complex Magnetic Fields—CMFs—alone/combined against the biofilms of two polymicrobial mixes (MIX 1, MIX 2) containing S. aureus, P. aeruginosa and C. albicans using the Lubbock chronic wound biofilm model. At 24 h after treatment, the effects were evaluated by (i) CFU/mg reduction, (ii) Confocal Laser Scanning Microscopy—CLSM—and (iii) Scanning Electron Microscopy—SEM. All treatments significantly reduced biofilms in terms of CFU/mg in both mixes versus the controls, 24 h after treatment. MGO showed remarkable activity, especially against P. aeruginosa. In MIX 1, LED/MGO + LED was highly effective against C. albicans. The combinations MGO + LED/MGO + CMFs enhanced the antibiofilm activity compared to each single treatment against S. aureus and P. aeruginosa, in both MIX1/MIX2. CLSM and SEM analysis showed biofilm disaggregation and reduction in cell viability with combined treatments, and Candida hyphal inhibition after CMFs application. In conclusion, the results demonstrate that MGO, alone or combined with LED or CMFs, shows high efficacy against resistant biofilms in the LCWB model 24 h after treatment, and encourage further studies on potential non-antibiotic and eco-friendly strategies as future alternative therapeutic approaches for chronic wound infections. Full article

Diabetes mellitus is prevalent worldwide, with vascular complications responsible for over 70% of deaths associated with the condition. Methylglyoxal (MGO), a by-product of glycolysis, is a significant modulator of vascular dysfunction in diabetes. Sestrin2 (SESN2) has been recognized as a vital regulator of cellular homeostasis and stress responses. Although SESN2’s role in cellular defense is gaining recognition, its precise function in endothelial cells under diabetic-like conditions remains poorly understood. This study examines the role of SESN2 in preserving endothelial cell angiogenic function under MGO-induced stress. The study reveals that SESN2 is a vital regulator of multiple protective pathways, as demonstrated by both loss-of-function and gain-of-function approaches in EA.hy926 endothelial cells. Our data showed that SESN2 overexpression significantly maintained tubular network formation, proliferation, and invasive capacity under MGO stress, whereas SESN2 silencing exacerbated MGO-induced impairment of angiogenic capacity. SESN2 was identified as orchestrating NRF2/HO-1 antioxidant pathway activation while simultaneously enhancing VEGF-C expression, offering a dual strategy for cellular protection and angiogenesis. Moreover, SESN2 facilitated a regulated equilibrium of the AKT/mTOR signaling pathway, ensuring synchronized activation during stress conditions. SESN2 also regulated stress-activated MAPK pathways, diminishing P38 and ERK1/2 activation upon MGO exposure. This study highlights SESN2 as a pivotal regulator of endothelial cell homeostasis and angiogenic activity under MGO-induced stress, indicating its potential as a therapeutic target for addressing diabetic vascular complications and improving patient outcomes. Full article

As the size of the elderly population increases, the need for an improved understanding of what leads to the age-related decline in physiological function continues to grow. SAMP8 mice were selected for their accelerated aging phenotype. The low levels of glyoxalase 1 (Glo1), the main enzyme that removes the reactive dicarbonyl methylglyoxal (MGO), in the cerebral cortex of SAMP8 mice prompted us to produce the first transgenic mice overexpressing Glo1 against the SAMP8 background, aimed at rescuing the accelerated aging phenotype. Selected health and biochemical endpoints were assessed in ten-month-old SAMP8 mice overexpressing Glo1. Glo1 overexpression increased median survival in males (21%) and females (4.6%), which was associated with better memory performance. Glo1 overexpression also increased synaptic markers (synaptophysin and SNAP25) as well as markers of mitochondrial function (NDUFB8, SDHB) and negative modulators of oxytosis/ferroptosis (NQO1, FTH1, and GPx4) in the cerebral cortex. For all parameters analyzed, the effect of Glo1 overexpression was more pronounced in males. Overall, the data support the beneficial effects of overexpressing Glo1 in multiple tissues, especially in SAMP8 males, suggesting a possible gender effect of MGO in aging. Both modulation of oxytosis/ferroptosis and mitochondrial metabolism warrant further investigation as potential mechanisms underlying the improved health span of Glo1 mice. Full article