Advanced lipid peroxidation end products in oxidative damage to proteins. Potential role in diseases and therapeutic prospects for the inhibitors

Lipid-Derived Electrophiles Modify Proteins and Alter Their Interfacial Behavior: The Distinct Mediating Role of the Interface

In interface-dominated systems (IDSs), lipid peroxidation (LPO) and interfacial protein arrangement commonly coexist. Although lipid-derived electrophiles (LDEs), especially α,β-unsaturated aldehydes, extensively modify proteins, the specific role of interfaces in promoting such modification and its effect on protein behavior remains unclear. Here, we synthesized a yne-ACR probe to simulate LDEs and investigated its modification effect on whey protein (WP) in an IDS model comprising n-hexadecane (Hex) and water. Interface hydromechanics results reveal that the interface distinctly mediates protein modification by yne-ACR in the IDS model. Both the yne-ACR concentration and interfacial properties significantly affect protein interfacial behavior. The interface offers a unique environment for protein modification by yne-ACR, differing from homogeneous systems and producing varied aggregation behaviors between interfacial and nonadsorbed proteins. Chemical proteomic profiling identified 209 modified proteins at the interface compared to 156 in nonadsorbed systems, highlighting increased susceptibility of interfacial proteins to yne-ACR modification and subsequent changes in aggregation patterns. All-atom molecular dynamics (MD) simulations indicate that yne-ACR modification disrupts the stability of protein aggregates at interfaces, promoting redistribution between the interface and the bulk phases and modifying interfacial activity. These findings clarify how LDEs modify proteins in IDSs and their subsequent effects on interfacial behavior.

Leptin and Insulin in COPD: Unveiling the Metabolic-Inflammatory Axis-A Narrative Review

Chronic obstructive pulmonary disease (COPD) is a progressive and debilitating condition characterized by airflow limitations and systemic inflammation. The interaction between the metabolic and inflammatory pathways plays a key role in disease progression, with leptin and insulin emerging as pivotal metabolic regulators. Leptin, an adipokine that regulates energy homeostasis, and insulin, the primary regulator of glucose metabolism, are both altered in COPD patients. This narrative review provides an in-depth examination of the roles of leptin and insulin in COPD pathogenesis, focusing on the molecular mechanisms through which these metabolic regulators interact with inflammatory pathways and how their dysregulation contributes to a spectrum of extrapulmonary manifestations. These disturbances not only exacerbate COPD symptoms but also increase the risk of comorbidities such as metabolic syndrome, diabetes, cardiovascular disease, or muscle wasting. By exploring the underlying mechanisms of leptin and insulin dysregulation in COPD, this review underscores the significance of the metabolic-inflammatory axis, suggesting that restoring metabolic balance through leptin and insulin modulation could offer novel therapeutic strategies for improving clinical outcomes.

Air Pollution and Skin Diseases

Air pollution is a widespread environmental issue, with substantial global implications for human health. Recent epidemiological studies have shown that exposure to air pollution exacerbates various inflammatory skin conditions, including atopic dermatitis, psoriasis, or acne. Furthermore, air pollutants are associated with accelerated skin aging, hair loss, and skin cancer. The aim of this review is to elucidate the current understanding of the impact of air pollution on skin health, emphasizing the underlying mechanisms involved and existing therapeutic and cosmetic interventions available to prevent or mitigate these effects. A pivotal factor in the harmful effects of air pollution is the formation of reactive oxygen species and the resulting oxidative stress. The aryl hydrocarbon receptor signaling pathway also substantially contributes to mediating the effects of air pollutants on various skin conditions. Moreover, air pollutants can disrupt the skin barrier function and trigger inflammation. Consequently, antioxidant and anti-inflammatory therapies, along with treatments designed to restore the skin barrier function, have the potential to mitigate the adverse effects of air pollutants on skin health.

A Mathematical Model of Statin Anti-Hyperlipidemic Drug Reactivity and Diverse Concentrations of Risk Toxicity

Background/Objectives: Statins decrease the risk of cardiovascular events by lowering low-density lipoproteins (LDLs). Despite this, statins induce toxic effects by a mechanism of action that has not yet been elucidated. The aim of the present work was to create a mathematical simulation model to evaluate the effect of statins on LDL concentration reduction and the threshold value of toxic reversible concentrations. Methods: Fifteen calcified coronary artery biopsies from non-diabetic hyperlipidemic patients treated with statins were used. For this study, an advanced modified model including the Caputo Fractional Operator and molecular dynamics was employed. Results: The new characteristic absorption bands in the FTIR spectral region frequencies near 1744 and 976 cm-1, assigned to the chemical functional groups of aldehydes (vCHO) and phosphates V(PO43-) of the atheromatic plaques, respectively, were used for mathematical model development. The energy of the functional chemical bonds caused by redox modifications during atheromatic plaque progression was used to show the effects of statin concentrations numerically. The model provides the anti-atheromatic effects of statins by the inhibition of LDL formation. Furthermore, the mathematical model highlights the dose medication-statin dependence on the reverse point of the statins' protective role. Conclusions: The new mathematical model shows both the beneficial and harmful actions of statins, which are associated with critical dose-dependent treatments with statins. The model also indicates that, upon increasing the statin dose, excessive secondary oxidation products were obtained. These products control the upregulation of the biological response by triggering other new pathways of redox homeostasis reactions.

Methylglyoxal mutagenizes single-stranded DNA via Rev1-associated slippage and mispairing

Methylglyoxal (MG) is a highly reactive aldehyde that is produced endogenously during metabolism and is derived from exogenous sources such as sugary food items and cigarette smoke. Unless detoxified by glyoxalases (Glo1 and Glo2), MG can readily react with all major biomolecules, including DNA and proteins, generating characteristic lesions and glycation-derived by- products. As a result, MG exposure has been linked to a variety of human diseases, including cancers. Prior studies show that MG can glycate DNA, preferentially on guanine residues, and cause DNA damage. However, the mutagenicity of MG is poorly understood in vivo. In the context of cancer, it is essential to comprehend the true contribution of MG to genome instability and global mutational burden. In the present study, we show that MG can robustly mutagenize induced single-stranded DNA (ssDNA) in yeast, within a guanine centered mutable motif. We demonstrate that genome-wide MG mutagenesis in ssDNA is greatly elevated throughout the genome in the absence of Glo1, and abrogated in the presence of the aldehyde quencher aminoguanidine. We uncovered strand slippage and mispairing as the predominant mechanism for generation of all MG-associated mutations, and demonstrate that the translesion polymerase Rev1 is necessary in this pathway. Finally, we find that the primary MG-associated mutation is enriched in a variety of sequenced tumor datasets. We discuss the genomic impact of methylglyoxal exposure in the context of mutagenesis, DNA damage, and carcinogenesis.

Lipid metabolic reprograming: the unsung hero in breast cancer progression and tumor microenvironment

Aberrant lipid metabolism is a well-recognized hallmark of cancer. Notably, breast cancer (BC) arises from a lipid-rich microenvironment and depends significantly on lipid metabolic reprogramming to fulfill its developmental requirements. In this review, we revisit the pivotal role of lipid metabolism in BC, underscoring its impact on the progression and tumor microenvironment. Firstly, we delineate the overall landscape of lipid metabolism in BC, highlighting its roles in tumor progression and patient prognosis. Given that lipids can also act as signaling molecules, we next describe the lipid signaling exchanges between BC cells and other cellular components in the tumor microenvironment. Additionally, we summarize the therapeutic potential of targeting lipid metabolism from the aspects of lipid metabolism processes, lipid-related transcription factors and immunotherapy in BC. Finally, we discuss the possibilities and problems associated with clinical applications of lipid‑targeted therapy in BC, and propose new research directions with advances in spatiotemporal multi-omics.

Metabolomics to Identify Unclassified Uremic Toxins: A Comprehensive Literature Review

A comprehensive review of known uremic retention molecules goes back to more than 10 years ago and did not consider metabolomic analyses. The present analysis searches for as of yet unclassified solutes retained in chronic kidney disease (CKD) by analyzing metabolites associated with relevant outcomes of CKD. This untargeted metabolomics-based approach is compared with a conventional targeted literature search. For the selected molecules, the literature was screened for arguments regarding toxic (harmful), beneficial, or neutral effects in experimental or clinical studies. Findings were independently crosschecked. In total, 103 molecules were selected. No literature on any effect was found for 55 substances, 3 molecules had no significant effect, and 13 others showed beneficial effects. For the remaining 32 compounds, we found at least one report of a toxic effect. Whereas 62.5% of the compounds with at least one study on a toxic effect was retrieved via the bottom-up approach, 69.2% of the substances originating from metabolomics-based approaches showed a beneficial effect. Our results suggest that untargeted metabolomics offer a more balanced view of uremic retention than the targeted approaches, with higher chances of revealing the beneficial potential of some of the metabolites.

Auto-antibodies against carbonyl-modified vimentin in COPD: potential role as a biomarker

COPD has many hallmarks of autoimmune dysfunction. Driving this autoimmune response are self-antigens, such as highly abundant structural proteins and cellular proteins, which can lead to the production of auto-antibodies. However, controversy surrounds the detection of some of these auto-antibodies as they have often been screened against native, unmodified proteins. Autoantigens arise as a result of a conformational change in the native protein exposing hidden epitopes or by the creation of neo-epitopes through chemical or enzymatic modifications, often caused by oxidative/carbonyl stress. In this study, we screened for auto-antibodies targeting key structural proteins modified by oxidative/carbonyl stress in peripheral blood from stable COPD patients versus control subjects using ELISA. We found an auto-antibody response against unmodified, carbonyl-modified and citrinylated vimentin, with the highest response observed against carbonyl-modified vimentin. Both the IgG and IgM antibody titres against carbonyl-modified were significantly increased in COPD patients compared to healthy non-smokers. Smokers also displayed increased antibody levels against carbonyl-modified vimentin, but only for the IgG isotype. Selectivity analysis indicated that 70% and 63% of COPD patients had higher IgM and IgG titres, respectively, compared to non-smokers. In contrast only 26% and 48% of smokers had higher IgM and IgG titres, respectively, than non-smokers. ROC analysis gave AUC values of 0.78 (p < 0.01) and 0.84 (p < 0.001) for IgM and IgG, respectively, for COPD versus non-smokers, which fell to 0.70 (p < 0.01) and 0.64 (NS), respectively, when asymptomatic smokers were included. No significant increase in antibody titre against carbonyl-modified elastin or collagen was observed in COPD patients or asymptomatic smokers. We conclude that IgM autoantibody responses against carbonyl modified vimentin could serve as a simple blood-based biomarker for COPD, reflecting the disease's pathophysiology, and could help in patient stratification and diagnosis.

The unique reactivity of EKODE lipid peroxidation products allows in vivo detection of inflammation

Lipid peroxidation is a complex biochemical process associated with oxidative stress, and its products play crucial roles in cellular signaling and the pathophysiology of many diseases. Among the diverse array of lipid peroxidation (LPO) products, epoxyketooctadecenoic acids (EKODEs) have emerged as intriguing molecules with potential impacts on inflammatory diseases. EKODEs arise from linoleic acid reacting with reactive oxygen and nitrogen species present during inflammation. A hallmark of many LPO products is an electrophilic chemical functionality that can react with different biological nucleophiles to form adducts that impact a broad swath of physiologic processes. Here, we present the identification of reactivity patterns exhibited by the EKODE class of LPO products that arise due to the unique chemistry of the EKODE electrophiles, namely α, β-unsaturated epoxyketones of variable regiochemistry. Our initial investigations with models of the EKODE reactive core showed that surrogates of lysine did not react, and histidine nucleophiles formed reversible Michael adducts. However, when models of cysteine nucleophiles were tested, a unique reactivity profile emerged where rapid Michael addition was followed by slow rearrangement and epoxide opening at an unpredicted electrophilic site, affording what we postulated to be an advanced lipoxidation end product (ALE). After confirming the EKODE reactivity in model systems, we produced polyclonal antibodies of a stable epitope of the EKODE-based ALE and used these antibodies to investigate an approach for in vivo monitoring of inflammatory disease progression.

Pharmacological reduction of lipid hydroperoxides as a potential modulator of sarcopenia

We previously reported that elevated expression of phospholipid hydroperoxide glutathione peroxidase 4, an enzyme that regulates membrane lipid hydroperoxides, can mitigate sarcopenia in mice. However, it is still unknown whether a pharmacological intervention designed to modulate lipid hydroperoxides might be an effective strategy to reduce sarcopenia in aged mice. Here we asked whether a newly developed compound, CMD-35647 (CMD), can reduce muscle atrophy induced by sciatic nerve transection. We treated mice daily with vehicle or CMD (15 mg/kg, i.p. injection) starting 1 day prior to denervation. CMD treatment reduced hydroperoxide generation and blunted muscle atrophy by over 17% in denervated muscle. To test whether CMD can reduce ageing-induced muscle atrophy and weakness, we treated mice with either vehicle or CMD (15 mg/kg, i.p. injection) 3 days per week for 8 months, starting at 18 months of age until 26 months of age. We measured muscle mass, functional status of neuromuscular junctions, muscle contractile function and mitochondrial function in control and CMD-treated 26-month-old female mice. Treatment with CMD conferred protection against muscle atrophy in both tibialis anterior and extensor digitorum longus that was associated with maintenance of fibre size of MHC 2b and 2x fibres. Mitochondrial respiration was also protected in CMD-treated mice. We also found that muscle force generation was protected with CMD treatment despite denervation in ∼25% of the muscle fibres. Overall, this study shows that pharmacological interventions designed to reduce lipid hydroperoxides might be effective for preventing sarcopenia. KEY POINTS: Sarcopenia in aged mice is associated with muscle loss, contractile dysfunction, denervation, and reduced mitochondrial respiration. CMD-35647 is a pharmocological compound that can neutralize lipid hydroperoxides. 8 month treatment of CMD-35647 mitigated muscle atrophy in tibialis anterior and extensor digitorum longus. 8 month treatment of CMD-35647 improved muscle function in aged mice independent of the neuromuscular junction. Aged mice treated with CMD-35647 had greater respiration in red gastrocnemius muscle when compared to vehicle treated mice.

Fish Oil's Preventive Effect on Two-Stage Skin Carcinogenesis in Swiss Albino Mice: Involvement of NF-ҝB Pathways and Oxidative Stress in a Dose- and Route Dependent Manner

This study investigated the chemopreventive mechanisms of fish oil (FO) at different doses and administration routes in skin carcinogenesis induced by 7,12-dimethylbenz[a]anthracene (DMBA) and croton oil (CO) in Swiss albino mice. Seventy mice were divided into 10 groups, including controls and those receiving FO either orally or topically, with or without the carcinogenesis protocol. Warts were morphologically analyzed. Anatomopathological analysis, qRT-PCR of nuclear factor kappa B (NF-қB) subunits' gene expression, and evaluation of oxidative parameters were conducted. Anatomopathological analysis revealed a presence of invasive squamous cell carcinoma (SCC) in DMBA group. Both oral (500 mg/kg/day) and topical FO treatment showed no signs of cancer, while oral administration at 50 mg/kg/day had no therapeutic effect, and 250 mg/kg/day resulted in low-grade malignancy. Both oral (250 and 500 mg/kg/day) and topical FO significantly reduced NF-кB1 gene expression, alleviated oxidative stress markers, and restored antioxidant enzyme activities compared to the DMBA group. FO shows dose-dependent chemopreventive effects, with oral administration potentially as effective as topical application when using an appropriate dosage. The development of SCC is linked to the stress status and the upregulation of the canonical NF-κB pathway, while FO's chemoprotective effects likely result from its downregulation.

Enalomics: A Mass Spectrometry-Based Approach for Profiling, Identifying, and Semiquantifying Enals in Biological Samples

Human cells generate a bulk of aldehydes during lipid peroxidation (LPO), influencing critical cellular processes, such as oxidative stress, protein modification, and DNA damage. Enals, highly reactive α,β-unsaturated aldehydic metabolites, are implicated in various human pathologies, especially neurodegenerative disorders, cancer, and cardiovascular diseases. Despite their importance, endogenous enals remain poorly characterized, primarily due to their instability and low abundance. Herein, we introduced "enalomics," a mass spectrometry (MS)-based approach for profiling, identifying, and semiquantifying enals in biological samples. Derivatization with 2,4-dinitrophenylhydrazine and treatment with ascorbic acid stabilized enals in biological matrices and provided a unique MS fragment ([M-H-47]-) for reliable enal identification. Utilizing precursor ion scanning, dynamic multiple reaction monitoring, high-resolution MS, and mathematical correlations between retention times and carbon numbers of enals, we identified 157 enals (127 newly reported) with tissue-specific profiles in rats and 29 enals (24 newly reported) in human plasma. To the best of our knowledge, this represents the comprehensive analysis of enals, i.e., "enalomics," in biological samples. Enalomics demonstrated significant alterations in enal metabolism in rats with myocardial injury, highlighting the potential of medium- and short-chain plasma enals as sensitive diagnostic biomarkers. Further application of enalomics in patients with myocardial infarction (MI) identified 14 plasma diagnostic biomarkers. Receiver operating characteristic curves showed good discrimination (area under curve ≥ 0.8603, p ≤ 0.0043). This research advances the understanding of LPO products and emphasizes the roles of enals in human diseases, offering good prospects for early screening, diagnosis, and clinical interventions targeting LPO products in MI patients.

Delayed cutaneous wound healing in young and old female mice is associated with differential growth factor release but not inflammatory cytokine secretion

The capacity for tissue repair during wound healing declines with age. A chronic low but systemic inflammatory status, often called "inflammaging", is considered a key factor that contributes to impaired tissue regeneration. This phenomenon has been substantiated by an increased number of immune cells in wound-tissue of old mice. Although immune cells coordinate an inflammatory response by their secretome the composition of the wound milieu has not been examined. In young (2 months) and old (18 months) female mice, excision wounds were induced using a punch biopsy device, i.e., the healing progress occurred through secondary intention. The closure rate was analyzed for 7 days. At days 1, 3 and 7 post-surgery, wound specimen were investigated for immunohistochemical detection of granulocytes, M1-macrophages and mesenchymal stem cells of the skin. The concentrations of inflammatory cytokines and regenerative growth factors were determined in tissue homogenates by ELISA. The carbonyl assay was used to determine protein oxidation. In old mice, the wound closure was delayed between days 1 and 3 post-surgery, as was the peak of immune cell infiltration. There was no age effect on the concentration of inflammatory cytokines, but wounds of young animals contained higher number of mesenchymal stem cells and increased levels of growth factors. Protein oxidation was increased with age. The present study suggests that a reduced regenerative capacity rather than an enhanced inflammatory score affected the tissue regeneration process in old mice.

Elucidating the effect of levothyroxine and triiodothyronine on methylglyoxal derived stress

PURPOSE

Methylglyoxal (MG) is the most potent precursor during the formation of the advanced glycation end products (AGEs). MG-dependent glycative stress contributes to pathogenesis of diabetes, age-related disorders, and cancer. There is a great need to study the reduction process of glycative stress for effective management of metabolic disorders. From natural compounds to synthetic drugs, each element contributes to the reduction of glycative stress. Previously, it was established that the lowering of uric acid, low-density lipoprotein cholesterol, and urine albumin excretion rate, as well as reducing total oxidative stress, were all achieved more effectively with a levothyroxine regimen. Still, there is no such study found that supports the MG-dependent glycative stress reduction with thyroid hormone compound. Our study aims to investigate the effects of T3 and T4 on MG-dependent glycative stress.

METHODS

The antiglycation effect was assayed through NBT assay, DNPH assay, ELISA, and fluorescence spectrophotometer. The intracellular reduction in reactive oxygen species (ROS) has been estimated through confocal microscopy.

RESULTS

The results revealed an effective reduction in the formation of AGEs adducts and intracellular ROS formation.

CONCLUSION

The investigation concludes AGEs formation was suppressed using these compounds, although in vivo and rigorous clinical trials are required in order to verify these findings.

Attenuation of Chronic Oxidative Stress-Induced Testicular and Epididymal Dysfunction by Oral Intake of Lepidium meyenii in New Zealand Rabbits

Lepidium meyenii (Maca) is a plant that has nutritional benefits and increases the effectiveness of male reproduction. In this study, oxidative stress-exposed New Zealand rabbits were used to assess the ameliorative effects of daily Maca ingestion on testicular and epididymal tissues as well as the quality of fresh and frozen/thawed sperm. Twenty-four 40-week-old, healthy New Zealand white male rabbits were divided into four groups. The first group consumed tap water and served as a control. The second group was given 300 mg of Maca daily in capsules. The third group drank water containing hydrogen peroxide (H2O2) at a concentration of 1%. Finally, the fourth group consumed H2O2 and Maca daily. The ejaculate volume, sperm concentration, vitality, motility and velocity of the H2O2 group were considerably lower than those of the other groups. Frozen/thawed spermatozoa showed more dramatic decreases in motility and velocity as a result of H2O2 consumption. The plasma concentrations of testosterone and total antioxidant capacity were also lowest in the H2O2-treated rabbits, while malondialdehyde levels were highest. Exposure to H2O2 increased collagen deposition between ST and epididymal ducts which induced testicular and epididymis fibrosis. In addition, the spermatogenic and epididymal epithelial cells exhibited signs of apoptosis, degeneration, vacuolation and a reduction in height. Maca intake attenuated most of the damaging effects of H2O2 ingestion-induced oxidative stress. Furthermore, H2O2-treated rabbits had modest nuclear androgen receptor positivity, unlike those in the Maca group. The number of Leydig cells significantly increased with daily Maca intake. In conclusion, daily intake of Maca improved reproductive performance and mitigated the damaging effects of oxidative stress on testicular and epididymal functions in New Zealand rabbits.

Long-term exposure to advanced lipid peroxidation end products impairs cognitive function through microbiota-gut-brain axis

The frequent intake of ultra-processed, heat-processed, and fat-enriched foods rich in dietary advanced lipoxidation end-products (ALEs) has been correlated with cognitive decline; however, the underlying mechanisms of action remain unexplored. This study investigated the impact of a 12-month dietary exposure to ALEs on learning, memory, and Aβ1-42 accumulation in mice, with a focus on the AMPK/SIRT1 signaling pathway and ADAM10 expression. The gut microbiota and metabolomic profiles revealed ALEs-induced gut dysbiosis and cognitive impairment, highlighting modulation through the microbiota-gut-brain axis. Key findings include increased pathogenic bacteria and decreased beneficial bacteria, linked to metabolite profile changes that affect neurotoxic Aβ1-42 peptide accumulation. This long-term comprehensive study underscores the need for dietary guidelines to reduce ALE intake and mitigate neurodegenerative disease risk, highlighting the intricate interplay between diet, gut microbiota, and cognitive health.

Role of oxidative stress in diabetes-induced complications and their management with antioxidants

Diabetes mellitus (DM) is a huge global health issue and one of the most studied diseases, with a large global prevalence. Oxidative stress is a cytotoxic consequence of the excessive development of ROS and suppression of the antioxidant defense system for ROS elimination, which accelerates the progression of diabetes complications such as diabetic neuropathy, retinopathy, and nephropathy. Hyperglycaemia induced oxidative stress causes the activation of seven major pathways implicated in the pathogenesis of diabetic complications. These pathways increase the production of ROS and RNS, which contributes to dysregulated autophagy, gene expression changes, and the development of numerous pro-inflammatory mediators which may eventually lead to diabetic complications. This review will illustrate that oxidative stress plays a vital role in the pathogenesis of diabetic complications, and the use of antioxidants will help to reduce oxidative stress and thus may alleviate diabetic complications.

Role of ferroptosis in mitochondrial damage in diabetic retinopathy

Diabetic retinopathy is driven by oxidative stress-mitochondrial damage. Activation of ROS producing cytosolic NADPH oxidase 2 (Nox2) in diabetes precedes retinal mitochondrial damage, initiating a vicious cycle of free radicals. Elevated ROS levels peroxidize membrane lipids increasing damaging lipid peroxides (LPOs). While glutathione peroxidase 4 (GPx4) neutralizes LPOs, an imbalance in its generation-neutralization leads to ferroptosis, which is characterized by increased LPOs, free iron and decreased GPx4 activity. Mitochondria are rich in polyunsaturated fatty acids and iron and have mitochondrial isoform of GPx4. Our aim was to investigate mitochondrial ferroptosis in diabetic retinopathy, focusing on Nox2 mediated ROS production. Using human retinal endothelial cells, incubated in 5 mM or 20 mM D-glucose for 12-96 h, with or without Nox2 inhibitors (100 μM apocynin, 5 μM EHop-016 or 5 μM Gp91 ds-tat), or ferroptosis inhibitors (1 μM ferrostatin-1, 50 μM deferoxamine) or activator (0.1 μM RSL3), cytosolic and mitochondrial ROS, LPOs, iron, GPx4 activity, mitochondrial integrity (membrane permeability, oxygen consumption rate, mtDNA copy numbers) and cell death were quantified. High glucose significantly increased ROS, LPOs and iron levels and inhibited GPx4 activity in cytosol, and while Nox2 and ferroptosis inhibitors prevented glucose-induced increase in ferroptosis markers, mitochondrial damage and cell death, RSL3, further worsened them. Furthermore, high glucose also increased ferroptosis markers in the mitochondria, which followed their increase in the cytosol, suggesting a role of cytosolic ROS in mitochondrial ferroptosis. Thus, targeting Nox2-ferroptosis should help break down the self-perpetuating vicious cycle of free radicals, initiated by the damaged mitochondria, and could provide novel therapeutics to prevent/retard the development of diabetic retinopathy.

Apigeninidin chloride disrupts Toxoplasma gondii Mitochondrial membrane potential and induce reactive oxygen species and metabolites production

Introduction

Apigeninidin chloride (APi) is a form of 3-deoxyanthrocyanidins (3-DAs) abundantly produced by the red Sorghum bicolor plant. It has been previously reported to be effective against Toxoplasma gondii (T. gondii) tachyzoites grown in vitro with less cytotoxic effect. However, its possible mechanism(s) of action has not been elucidated. Biochemically, we discovered that APi induced high reactive oxygen species (ROS) and mitochondria superoxide (MitoSOX) productions in tachyzoites, leading to mitochondrial membrane potential (MMP) disruption in vitro.

Methods

To confirm our biochemical results at the molecular level, we performed a liquid chromatography-mass spectrometry (LC-MS) analysis on APi-treated parasites to assess any metabolite and lipid alterations often associated with high ROS/MitoSOX production in cells.

Results

Noteworthy is that we detected several important oxidative stress-induced metabolites such as hexanal, aldehydes, methyl undeo10-enoate, butadiynyl phenyl ketone, 16-hydroxyhexadecanoic acid (16-OH, 16:0), 2-hydroxytricosanoic acid (C23:0; O), 3-oxodecanosanoic acid (C22:1; O), 2-hydroxypropylsterate, and furan fatty acids F6 (19FU-FA).

Discussion

These metabolites are associated with lipid, protein, and nucleic acid disruptions. Using atovaquone (Atov) as a control, we observed that it disrupted intracellular tachyzoites' mitochondrial membrane potential, increased ROS and MitoSOX production, and altered metabolite and lipid production similar to what was observed with our experimental compound APi. Overall, our results indicated that APi targets T. gondii tachyzoite growth through inducing oxidative stress, mitochondrial dysfunction, and eventually parasite death.

The Effect of Environmental Enrichment on Selected Physiological and Immunological Stress-Related Markers in Dairy Goats

Homeostasis preservation is essential for animal survival, and any event that causes a disturbance in homeostasis is defined as a stressor. Here, we aimed to evaluate the effect of scratch brushes and stages as an environmental enrichment to alleviate stress in dairy goats. Twenty-four mixed-breed goats were divided into two groups according to common physiological conditions in breeding farms: milking and dry (milk-producing and non-milk-producing, respectively). Ten days after exposure to environmental enrichment treatment or not (control), blood was sampled. Following the enrichment, we observed a reduction in reactive oxidative stress metabolites, advanced glycation end products (AGEs), and their binding protein (transferrin) in the dry goats, as determined by an ELISA. In contrast, no change in AGEs, along with an increase in transferrin levels, was observed in the milking goats. Moreover, oxytocin levels decreased in the dry and increased in the milking goats, while serotonin levels increased in the dry and remained unchanged in the milking goats. Additionally, gene expression of the cytokines, IL-6 and IL-1ß, and anti-oxidative proteins, lysozyme and transferrin (in peripheral blood leukocytes), as determined by qPCR, presented the same pattern: down-regulation in the dry or up-regulation in the milking goats. In conclusion, a reliable methodology was developed for measuring husbandry stress in goats and to improve dairy goats' husbandry practice. Current environmental enrichment produced different responsiveness in goats correlated to their physiological status: beneficial effect in dry goats, detrimental effect in milking goats.

Association of dietary inflammatory index and dietary oxidative balance score with gastrointestinal cancers in NHANES 2005-2018

BACKGROUND&AIMS

Gastrointestinal (GI) cancers, including gastric, liver, esophageal, pancreatic, and colorectal cancers, represent significant global health burdens. Emerging evidence suggests that dietary patterns, particularly their inflammatory and oxidative properties, may influence cancer risk. The Dietary Inflammatory Index (DII) and Dietary Oxidative Balance Score (DOBS) assess the inflammatory and oxidative effects of diets, respectively. This study aims to explore the association between DII, DOBS, and the combined risk of GI cancers, and investigates the potential mediating roles of serum albumin and red cell distribution width (RDW).

METHODS

Data from 26,320 participants in the NHANES 2005-2018 cycles were analyzed. DII was calculated based on 28 dietary components, and DOBS included 17 nutrients (3 pro-oxidants and 14 antioxidants). Logistic regression models assessed the associations between DII, DOBS, and GI cancers. Restricted cubic spline (RCS) models examined dose-response relationships. Mediation analysis evaluated the roles of serum albumin and RDW. Subgroup analyses explored interactions with demographic and health-related factors.

RESULTS

Higher DII was associated with increased GI cancer risk (OR: 1.26, 95% CI: 1.07-1.49 per unit increase), while higher DOBS was associated with reduced risk (OR: 0.90, 95% CI: 0.76-0.99 per unit increase). RCS analysis indicated a significant nonlinear relationship between DII and GI cancer risk. Serum albumin and RDW partially mediated the associations between DII, DOBS, and GI cancers. Subgroup analyses showed stronger associations for DII among certain demographics, and significant interactions were found between DII and BMI. For DOBS, significant interactions were observed with age and BMI.

CONCLUSION

This study reveals significant associations between dietary inflammatory and oxidative balance scores and GI cancer risk. Higher DII is linked to increased risk, while higher DOBS is protective. The mediating roles of serum albumin and RDW provide insights into underlying mechanisms. These findings underscore the potential of dietary modifications in GI cancer prevention and management, emphasizing the importance of anti-inflammatory and antioxidant-rich diets.

Monoamine oxidase and neurodegeneration: Mechanisms, inhibitors and natural compounds for therapeutic intervention

Mammalian flavoenzyme Monoamine oxidase (MAO) resides on the outer mitochondrial membrane (OMM) and it is involved in the metabolism of different monoamine neurotransmitters in brain. During MAO mediated oxidative deamination of relevant substrates, H2O2 is released as a catalytic by-product, thus serving as a major source of reactive oxygen species (ROS). Under normal conditions, MAO mediated ROS is reported to propel the functioning of mitochondrial electron transport chain and phasic dopamine release. However, due to its localization onto mitochondria, sudden elevation in its enzymatic activity could directly impact the form and function of the organelle. For instance, in the case of Parkinson's disease (PD) patients who are on l-dopa therapy, the enzyme could be a concurrent source of extensive ROS production in the presence of uncontrolled substrate (dopamine) availability, thus further impacting the health of surviving neurons. It is worth mentioning that the expression of the enzyme in different brain compartments increases with age. Moreover, the involvement of MAO in the progression of neurological disorders such as PD, Alzheimer's disease and depression has been extensively studied in recent times. Although the usage of available synthetic MAO inhibitors has been instrumental in managing these conditions, the associated complications have raised significant concerns lately. Natural products have served as a major source of lead molecules in modern-day drug discovery; however, there is still no FDA-approved MAO inhibitor which is derived from natural sources. In this review, we have provided a comprehensive overview of MAO and how the enzyme system is involved in the pathogenesis of different age-associated neuropathologic conditions. We further discussed the applications and drawbacks of the long-term usage of presently available synthetic MAO inhibitors. Additionally, we have highlighted the prospect and worth of natural product derived molecules in addressing MAO associated complications.

Effective-Component Compatibility of Bufei Yishen Formula III Suppresses Mitochondrial Oxidative Damage in COPD: Via Pkm2/Nrf2 Pathway

Purpose

The main objective of this study was to explore the mechanism of effective component compatibility of Bufei Yishen formula III (ECC-BYF III) in inhibiting mitochondrial oxidative stress in a rat model of chronic obstructive pulmonary disease (COPD).

Methods

A549 cells exposed to cigarette smoke extract (CSE) were used to establish a model of mitochondrial oxidative damage. The cells were treated with the plasmid encoding Pkm2 and the enzymes and proteins involved in oxidative stress and mitochondrial function were measured. A rat model of COPD was established using CS and bacteria. Two different treatments were established, ECC-BYF III (5.5 mg/kg/d) and N-acetylcysteine (54 mg/kg/day). Animals were tested for pulmonary function (Vt, PEF, FVC, FEV0.1s and Cdyn) after eight weeks of therapy and were sacrificed. Pulmonary H&E staining was performed, and the total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC), and malondialdehyde (MDA) content were measured. The mitochondrial function was also examined. Furthermore, the Pkm2/Nrf2 signaling pathway was evaluated.

Results

Overexpression of Pkm2 dramatically ameliorated the CS-induced mitochondrial oxidative damage. Further studies indicated that ECC-BYF III significantly improved mitochondrial function and inhibited oxidative stress in the lung tissues of COPD rats. Moreover, it can upregulate mitochondrial respiratory chain enzyme activity. ECC-BYF III also decreased the MDA content and increased T-SOD, GSH-Px, and T-AOC expression to facilitate oxidative homeostasis. Finally, our results indicated that the Pkm2/Nrf2 pathway is regulated by ECC-BYF III in A549 cells and lung tissue.

Conclusion

These results indicate that ECC-BYF III exerts a strong effective therapeutic effect against cigarette smoke combined with bacteria-induced COPD in rats by activating the Pkm2/Nrf2 signaling pathway and restoring mitochondrial oxidative stress. Although more in vivo animal model research is needed to confirm these findings, this study contributes new data to support the conventional usage of ECC-BYF III.

Protein Haptenation and Its Role in Allergy

Humans are exposed to numerous electrophilic chemicals either as medicines, in the workplace, in nature, or through use of many common cosmetic and household products. Covalent modification of human proteins by such chemicals, or protein haptenation, is a common occurrence in cells and may result in generation of antigenic species, leading to development of hypersensitivity reactions. Ranging in severity of symptoms from local cutaneous reactions and rhinitis to potentially life-threatening anaphylaxis and severe hypersensitivity reactions such as Stephen-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), all these reactions have the same Molecular Initiating Event (MIE), i.e. haptenation. However, not all individuals who are exposed to electrophilic chemicals develop symptoms of hypersensitivity. In the present review, we examine common chemistry behind the haptenation reactions leading to formation of neoantigens. We explore simple reactions involving single molecule additions to a nucleophilic side chain of proteins and complex reactions involving multiple electrophilic centers on a single molecule or involving more than one electrophilic molecule as well as the generation of reactive molecules from the interaction with cellular detoxification mechanisms. Besides generation of antigenic species and enabling activation of the immune system, we explore additional events which result directly from the presence of electrophilic chemicals in cells, including activation of key defense mechanisms and immediate consequences of those reactions, and explore their potential effects. We discuss the factors that work in concert with haptenation leading to the development of hypersensitivity reactions and those that may act to prevent it from developing. We also review the potential harnessing of the specificity of haptenation in the design of potent covalent therapeutic inhibitors.

Molecular dynamics of structural effects of reactive carbonyl species derivate of lipid peroxidation on bovine serum albumin

BACKGROUND

Serum albumin is the most abundant protein in the Mammalia blood plasma at where plays a decisive role in the transport wide variety of hydrophobic ligands. BSA undergoes oxidative modifications like the carbonylation by the reactive carbonyl species (RCSs) 4-hydroxy-2-nonenal (HNE), 4 hydroxy-2-hexenal (HHE), malondialdehyde (MDA) and 4-oxo-2-nonenal (ONE), among others. The structural and functional changes induced by protein carbonylation have been associated with the advancement of neurodegenerative, cardiovascular, metabolic and cancer diseases.

METHODS

To elucidate structural effects of protein carbonylation with RCSs on BSA, parameters for six new non-standard amino acids were designated and molecular dynamics simulations of its mono‑carbonylated-BSA systems were conducted in the AMBER force field. Trajectories were evaluated by RMSD, RMSF, PCA, RoG and SASA analysis.

RESULTS

An increase in the conformational instability for all proteins modified with local changes were observed, without significant changes on the BSA global three-dimensional folding. A more relaxed compaction level and major solvent accessible surface area for modified systems was found. Four regions of high molecular fluctuation were identified in all modified systems, being the subdomains IA and IIIB those with the most remarkable local conformational changes. Regarding essential modes of domain movements, it was evidenced that the most representatives were those related to IA subdomain, while IIIB subdomain presented discrete changes.

CONCLUSIONS

RCSs induces local structural changes on mono‑carbonylated BSA. Also, this study extends our knowledge on how carbonylation by RCSs induce structural effects on proteins.

Lipid Oxidation Products and the Risk of Cardiovascular Diseases: Role of Lipoprotein Transport

Cholesterol has for decades ruled the history of atherosclerotic cardiovascular diseases (CVDs), and the present view of the etiology of the disease is based on the transport of cholesterol by plasma lipoproteins. The new knowledge of the lipoprotein-specific transport of lipid oxidation products (LOPs) has introduced another direction to the research of CVD, revealing strong associations between lipoprotein transport functions, atherogenic LOP, and CVD. The aim of this review is to present the evidence of the lipoprotein-specific transport of LOP and to evaluate the potential consequences of the proposed role of the LOP transport as a risk factor. The associations of cholesterol and lipoprotein LOP with the known risk factors of CVD are mostly parallel, and because of the common transport and cellular intake mechanisms it is difficult to ascertain the independent effects of either cholesterol or LOP. While cholesterol is known to have important physiological functions, LOPs are merely regarded as metabolic residues and able to initiate and boost atherogenic processes. It is therefore likely that with the increased knowledge of the lipoprotein-specific transport of LOP, the role of cholesterol as a risk factor of CVD will be challenged.

Effect of advanced glycation end-products in a wide range of medical problems including COVID-19

Glycation is a physiological process that determines the aging of the organism, while in states of metabolic disorders it is significantly intensified. High concentrations of compounds such as reducing sugars or reactive aldehydes derived from lipid oxidation, occurring for example in diabetes, atherosclerosis, dyslipidemia, obesity or metabolic syndrome, lead to increased glycation of proteins, lipids and nucleic acids. The level of advanced glycation end-products (AGEs) in the body depends on rapidity of their production and the rate of their removal by the urinary system. AGEs, accumulated in the extracellular matrix of the blood vessels and other organs, cause irreversible changes in the biochemical and biomechanical properties of tissues. As a consequence, micro- and macroangiopathies appear in the system, and may contribute to the organ failure, like kidneys and heart. Elevated levels of AGEs also increase the risk of Alzheimer's disease and various cancers. In this paper, we propose a new classification due to modified amino acid residues: arginyl-AGEs, monolysyl-AGEs and lysyl-arginyl-AGEs and dilysyl-AGEs. Furthermore, we describe in detail the effect of AGEs on the pathogenesis of metabolic and old age diseases, such as diabetic complications, atherosclerosis and neurodegenerative diseases. We summarize the currently available data on the diagnostic value of AGEs and present the AGEs as a therapeutic goal in a wide range of medical problems, including SARS-CoV-2 infection and so-called long COVID.

Reactive Carbonyl Species and Protein Lipoxidation in Atherogenesis

Atherosclerosis is a multifactorial disease of medium and large arteries, characterized by the presence of lipid-rich plaques lining the intima over time. It is the main cause of cardiovascular diseases and death worldwide. Redox imbalance and lipid peroxidation could play key roles in atherosclerosis by promoting a bundle of responses, including endothelial activation, inflammation, and foam cell formation. The oxidation of polyunsaturated fatty acids generates various lipid oxidation products such as reactive carbonyl species (RCS), including 4-hydroxy alkenals, malondialdehyde, and acrolein. RCS covalently bind to nucleophilic groups of nucleic acids, phospholipids, and proteins, modifying their structure and activity and leading to their progressive dysfunction. Protein lipoxidation is the non-enzymatic post-translational modification of proteins by RCS. Low-density lipoprotein (LDL) oxidation and apolipoprotein B (apoB) modification by RCS play a major role in foam cell formation. Moreover, oxidized LDLs are a source of RCS, which form adducts on a huge number of proteins, depending on oxidative stress intensity, the nature of targets, and the availability of detoxifying systems. Many systems are affected by lipoxidation, including extracellular matrix components, membranes, cytoplasmic and cytoskeletal proteins, transcription factors, and other components. The mechanisms involved in lipoxidation-induced vascular dysfunction are not fully elucidated. In this review, we focus on protein lipoxidation during atherogenesis.

The skin sensitization adverse outcome pathway: exploring the role of mechanistic understanding for higher tier risk assessment

For over a decade, the skin sensitization Adverse Outcome Pathway (AOP) has served as a useful framework for development of novel in chemico and in vitro assays for use in skin sensitization hazard and risk assessment. Since its establishment, the AOP framework further fueled the existing efforts in new assay development and stimulated a plethora of activities with particular focus on validation, reproducibility and interpretation of individual assays and combination of assay outputs for use in hazard/risk assessment. In parallel, research efforts have also accelerated in pace, providing new molecular and dynamic insight into key events leading to sensitization. In light of novel hypotheses emerging from over a decade of focused research effort, mechanistic evidence relating to the key events in the skin sensitization AOP may complement the tools currently used in risk assessment. We reviewed the recent advances unraveling the complexity of molecular events in sensitization and signpost the most promising avenues for further exploration and development of useful assays.

Lipid droplets, autophagy, and ageing: A cell-specific tale

Lipid droplets are the essential organelle for storing lipids in a cell. Within the variety of the human body, different cells store, utilize and release lipids in different ways, depending on their intrinsic function. However, these differences are not well characterized and, especially in the context of ageing, represent a key factor for cardiometabolic diseases. Whole body lipid homeostasis is a central interest in the field of cardiometabolic diseases. In this review we characterize lipid droplets and their utilization via autophagy and describe their diverse fate in three cells types central in cardiometabolic dysfunctions: adipocytes, hepatocytes, and macrophages.

Extraction, purification, structural characteristics and biological properties of the polysaccharides from Armillaria mellea (Vahl) P. Kumm.: A review

Armillaria mellea (Vahl) P. Kumm. is a well-known homoeopathic plant with medicinal and culinary uses. Modern phytochemical researchers have successfully extracted and purified over 40 types of A. mellea polysaccharides (AMPs) from the fruiting bodies, hyphae and fermentation broth of A. mellea, and some of them have been analyzed and identified by their chemical structures. The impressive biological activity of these polysaccharides has been recognized by scientists worldwide. Many studies show that AMPs have remarkable antioxidant, anti-diabetic, anti-tumor, anti-inflammatory, immunoregulatory, hypolipidemic, thrombectomy, anti-aging, pulmonary protective, hepatic protective, anti-Alzheimer's properties, etc. However, the current understanding of the relationships between their chemical structure and biological activity, toxicological effects and pharmacokinetics remains limited. This article provides a systematic review of the research conducted over the past decades on the extraction and purification methods, structural characteristics, biological activity and mechanism of action of AMPs. The aim is to provide a research base that will benefit the future application of AMPs as therapeutic drugs and functional foods, and also provide insights for the further development of AMPs.

Plantago asiatica L. polysaccharides: Physiochemical properties, structural characteristics, biological activity and application prospects: A review

Plantago asiatica L. (PAL), a traditional herb, has been used in East Asia for thousands of years. In recent years, polysaccharides extracted from PAL have garnered increased attention due to their outstanding pharmacological and biological properties. Previous research has established that PAL-derived polysaccharides exhibit antioxidant, anti-inflammatory, antidiabetic, antitumor, antimicrobial, immune-regulatory, intestinal health-promoting, antiviral, and other effects. Nevertheless, a comprehensive summary of the research related to Plantago asiatica L. polysaccharides (PALP) has not been reported to date. In this paper, we review the methods for isolation and purification, physiochemical properties, structural features, and biological activities of PALP. To provide a foundation for research and application in the fields of medicine and food, this review also outlines the future development prospects of plantain polysaccharides.

Brazilin-7-acetate, a novel potential drug of Parkinson's disease, hinders the formation of α-synuclein fibril, mitigates cytotoxicity, and decreases oxidative stress

Parkinson's disease (PD) is a prevalent neurodegenerative disorder characterized by the accumulation of α-synuclein (α-Syn) aggregates. However, there are currently no effective therapies for PD. Brazilin, an inhibitor of α-Syn aggregation, is unstable and toxic. Therefore, we have developed and synthesized derivatives of brazilin. One of these derivatives, called brazilin-7-acetate (B-7-A), has shown reduced toxicity and a stronger effect on inhibiting α-Syn aggregation. It showed that B-7-A prevented the formation of α-Syn fibers and disrupted existing fibers in a dosage-dependent manner. Additionally, B-7-A significantly reduced the cytotoxicity of α-Syn aggregates and alleviated oxidative stress in PC12 cells. The beneficial effects of B-7-A were also confirmed using the Caenorhabditis elegans model. These effects included preventing the accumulation of α-Syn clumps, improving behavior disorder, increasing lifespan, reducing oxidative stress, and protecting against lipid oxidation and loss. Finally, B-7-A showed good ADMET properties in silico. Based on these findings, B-7-A exhibits potential as a prospective treatment for PD.

Iron scavenging and suppression of collagen cross-linking underlie antifibrotic effects of carnosine in the heart with obesity

Oral consumption of histidyl dipeptides such as l-carnosine has been suggested to promote cardiometabolic health, although therapeutic mechanisms remain incompletely understood. We recently reported that oral consumption of a carnosine analog suppressed markers of fibrosis in liver of obese mice, but whether antifibrotic effects of carnosine extend to the heart is not known, nor are the mechanisms by which carnosine is acting. Here, we investigated whether oral carnosine was able to mitigate the adverse cardiac remodeling associated with diet induced obesity in a mouse model of enhanced lipid peroxidation (i.e., glutathione peroxidase 4 deficient mice, GPx4+/-), a model which mimics many of the pathophysiological aspects of metabolic syndrome and T2 diabetes in humans. Wild-type (WT) and GPx4+/-male mice were randomly fed a standard (CNTL) or high fat high sucrose diet (HFHS) for 16 weeks. Seven weeks after starting the diet, a subset of the HFHS mice received carnosine (80 mM) in their drinking water for duration of the study. Carnosine treatment led to a moderate improvement in glycemic control in WT and GPx4+/-mice on HFHS diet, although insulin sensitivity was not significantly affected. Interestingly, while our transcriptomic analysis revealed that carnosine therapy had only modest impact on global gene expression in the heart, carnosine substantially upregulated cardiac GPx4 expression in both WT and GPx4+/-mice on HFHS diet. Carnosine also significantly reduced protein carbonyls and iron levels in myocardial tissue from both genotypes on HFHS diet. Importantly, we observed a robust antifibrotic effect of carnosine therapy in hearts from mice on HFHS diet, which further in vitro experiments suggest is due to carnosine's ability to suppress collagen-cross-linking. Collectively, this study reveals antifibrotic potential of carnosine in the heart with obesity and illustrates key mechanisms by which it may be acting.

Acute Toxicity, Anti-diabetic, and Anti-cancerous Potential of Trillium Govanianum-conjugated Silver Nanoparticles in Balb/c Mice

BACKGROUND

The current study aimed to develop an economic plant-based therapeutic agent to improve the treatment strategies for diseases at the nano-scale because Cancer and Diabetes mellitus are major concerns in developing countries. Therefore, in vitro and in vivo antidiabetic and anti-cancerous activities of Trillium govanianum conjugated silver nanoparticles were assessed.

METHODS

In the current study synthesis of silver nanoparticles using Trillium govanianum and characterization were done using a scanning electron microscope, UV-visible spectrophotometer, and FTIR analysis. The in vitro and in vivo anti-diabetic and anti-cancerous potential (200 mg/kg and 400 mg/kg) were carried out.

RESULTS

It was discovered that Balb/c mice did not show any major alterations during observation of acute oral toxicity when administered orally both TGaqu (1000 mg/kg) and TGAgNPs (1000 mg/kg), and results revealed that 1000 mg/kg is not lethal dose as did not find any abnormalities in epidermal and dermal layers when exposed to TGAgNPs. In vitro studies showed that TGAgNPs could not only inhibit alpha-glucosidase and protein kinases but were also potent against the brine shrimp. Though, a significant reduction in blood glucose levels and significant anti-cancerous effects was recorded when alloxan-treated and CCl4-induced mice were treated with TGAgNPs and TGaqu.

CONCLUSION

Both in vivo and in vitro studies revealed that TGaqu and TGAgNPs are not toxic at 200 mg/kg, 400 mg/kg, and 1000 mg/kg doses and possess strong anti-diabetic and anti-cancerous effects due to the presence of phyto-constituents. Further, suggesting that green synthesized silver nanoparticles could be used in pharmaceutical industries to develop potent therapeutic agents.

Role of methylglyoxal and redox homeostasis in microbe-mediated stress mitigation in plants

One of the general consequences of stress in plants is the accumulation of reactive oxygen (ROS) and carbonyl species (like methylglyoxal) to levels that are detrimental for plant growth. These reactive species are inherently produced in all organisms and serve different physiological functions but their excessive accumulation results in cellular toxicity. It is, therefore, essential to restore equilibrium between their synthesis and breakdown to ensure normal cellular functioning. Detoxification mechanisms that scavenge these reactive species are considered important for stress mitigation as they maintain redox balance by restricting the levels of ROS, methylglyoxal and other reactive species in the cellular milieu. Stress tolerance imparted to plants by root-associated microbes involves a multitude of mechanisms, including maintenance of redox homeostasis. By improving the overall antioxidant response in plants, microbes can strengthen defense pathways and hence, the adaptive abilities of plants to sustain growth under stress. Hence, through this review we wish to highlight the contribution of root microbiota in modulating the levels of reactive species and thereby, maintaining redox homeostasis in plants as one of the important mechanisms of stress alleviation. Further, we also examine the microbial mechanisms of resistance to oxidative stress and their role in combating plant stress.

Oxidative modification of carbonic anhydrase by peroxynitrite trigger immune response in mice and rheumatic disease patients

BACKGROUND

Carbonic anhydrases (CA) are metalloenzymes with wide tissue distribution, involved in many important physiological processes, and in some rheumatic diseases, autoantibodies are formed against these enzymes. Recent studies have suggested that oxidative stress triggers anti-CA antibody formation. In this study, we aimed to investigate the effects of modification with oxidative/nitrosative stress end products on CA antigenicity in mice and the relationship between the modified CA autoantibodies and oxidant-antioxidant status in patients with rheumatoid arthritis (RA) and Sjögren's syndrome (SjS).

METHODS

CA I and CA II isoenzymes were isolated from human erythrocytes and modified with 4-hydroxynonenal (4-HNE), malondialdehyde (MDA), and peroxynitrite (PN). Balb-c mice were immunized with these agents to determine the effects of modification on CA antigenicity. The autoantibody titers of modified CA isoenzymes were detected in patients. In addition MDA, 4-HNE, 3-nitrotyrosine (3-NT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activities were measured to assess the oxidant-antioxidant status in patients.

RESULTS

Modifications of carbonic anhydrase with oxidative stress end products, HNE, MDA and PN, lead to alterations in the immune response to these enzymes in mice. It was found that HNE and MDA decreased the antigenicity while PN increased. In addition, PN-modified CA autoantibody levels were found to be significantly different in both RA and SjS patients compared to their controls (p<0.05).

CONCLUSIONS

PN modifications can also trigger an immune response against CA isoenzymes in mice, and PN-modified CA I and CA II autoantibody titers were found at a significantly high level in both RA and SjS patients.

Multiple ammonia-induced episodes of hepatic encephalopathy provoke neuronal cell loss in bile-duct ligated rats

Background & Aims

Hepatic encephalopathy (HE) is defined as a reversible syndrome and therefore should resolve following liver transplantation (LT). However, neurological complications have been reported in up to 47% of LT recipients, which have been documented to be associated with a history of overt HE pre-LT. We hypothesise that multiple episodes of HE lead to permanent cell injury and exacerbate neurological dysfunction. Our goal was to evaluate the impact of cumulative HE episodes on neurological status and brain integrity in rats with chronic liver disease.

Methods

Episodes of overt HE (loss of righting reflex) were induced following injection of ammonium acetate in bile duct ligation (BDL) rats (BDL-Ammonia) every 4 days starting at week 3 post-BDL. Neurobehaviour was evaluated after the last episode. Upon sacrifice, plasma ammonia, systemic oxidative stress, and inflammation markers were assessed. Neuronal markers including neuron-specific nuclear antigen and SMI311 (anti-neurofilament marker) and apoptotic markers (cleaved caspase-3, Bax, and Bcl2) were measured. Total antioxidant capacity, oxidative stress marker (4-hydroxynonenal), and proinflammatory cytokines (tumour necrosis factor-alpha and interleukin-1β) were measured in brain (hippocampus, frontal cortex, and cerebellum). Proteomic analysis was conducted in the hippocampus.

Results

In hippocampus of BDL-Ammonia rats, cleaved caspase-3 and Bax/Bcl2 ratio were significantly increased, whereas NeuN and SMI311 were significantly decreased compared with BDL-Vehicle rats. Higher levels of oxidative stress-induced post-translational modified proteins were found in hippocampus of BDL-Ammonia group which were associated with a lower total antioxidant capacity.

Conclusions

Ammonia-induced episodes of overt HE caused neuronal cell injury/death in BDL rats. These results suggest that multiple bouts of HE can be detrimental on the integrity of the brain, translating to irreversibility and hence neurological complications post-LT.

Impact and implications

Hepatic encephalopathy (HE) is defined as a reversible neuropsychiatric syndrome resolving following liver transplantation (LT); however, ∼47% of patients demonstrate neurological impairments after LT, which are associated with a previous history of overt HE pre-LT. Our study indicates that multiple episodes of overt HE can cause permanent neuronal damage which may lead to neurological complications after LT. Nevertheless, preventing the occurrence of overt HE episodes is critical for reducing the risk of irreversible neuronal injury in patients with cirrhosis.

OP2113, a new drug for chronic hypoxia-induced pulmonary hypertension treatment in rat

BACKGROUND AND PURPOSE

Pulmonary hypertension (PH) is a cardiovascular disease characterised by an increase in pulmonary arterial (PA) resistance leading to right ventricular (RV) failure. Reactive oxygen species (ROS) play a major role in PH. OP2113 is a drug with beneficial effects on cardiac injuries that targets mitochondrial ROS. The aim of the study was to address the in vivo therapeutic effect of OP2113 in PH.

EXPERIMENTAL APPROACH

PH was induced by 3 weeks of chronic hypoxia (CH-PH) in rats treated with OP2113 or its vehicle via subcutaneous osmotic mini-pumps. Haemodynamic parameters and both PA and heart remodelling were assessed. Reactivity was quantified in PA rings and in RV or left ventricular (LV) cardiomyocytes. Oxidative stress was detected by electron paramagnetic resonance and western blotting. Mitochondrial mass and respiration were measured by western blotting and oxygraphy, respectively.

KEY RESULTS

In CH-PH rats, OP2113 reduced the mean PA pressure, PA remodelling, PA hyperreactivity in response to 5-HT, the contraction slowdown in RV and LV and increased the mitochondrial mass in RV. Interestingly, OP2113 had no effect on haemodynamic parameters, both PA and RV wall thickness and PA reactivity, in control rats. Whereas oxidative stress was evidenced by an increase in protein carbonylation in CH-PH, this was not affected by OP2113.

CONCLUSION AND IMPLICATIONS

Our study provides evidence for a selective protective effect of OP2113 in vivo on alterations in both PA and RV from CH-PH rats without side effects in control rats.

A review of the characteristic properties of selected tobacco chemicals and their associated etiological risks

OBJECTIVES

Despite the quantum of research findings on tobacco epidemic, a review on the formation characteristics of nicotine, aldehydes and phenols, and their associated etiological risks is still limited in literature. Accordingly, knowledge on the chemical properties and free radical formation during tobacco burning is an important subject towards unravelling the relationship between smoking behaviour and disease. This review investigates how scientific efforts have been advanced towards understanding the release of molecular products from the thermal degradation of tobacco, and harm reduction strategies among cigarette smokers in general. The mechanistic characteristics of nicotine and selected aldehydes are critically examined in this review. For the purpose of this work, articles published during the period 2004-2021 and archived in PubMed, Google Scholar, Medley, Cochrane, and Web of Science were used. The articles were selected based on the health impacts of cigarette smoking, tobacco burning kinetics, tobacco cessation and tobacco as a precursor for emerging diseases such as Covid-19.

CONTENT

The toxicity of cigarette smoke is directly correlated with its chemical composition derived from the pyrolysis of tobacco stem and leaves. Most of the harmful toxic substances are generated by pyrolysis during smoking and depends on pyrolysis conditions. Detailed studies have been conducted on the kinetics of nicotine by use of robust theoretical models in order to determine the rate constants of reactions in nicotine and those of nicotine dissociation via C-C and C-N scission, yielding pyridinyl and methyl radicals, respectively. Research has suggested that acetaldehyde enhances the effect of nicotine, which in turn reinforces addiction characteristics whereas acrolein and crotonaldehyde are ciliatoxic, and can inhibit lung clearance. On the other hand, phenol affects liver enzymes, lungs, kidneys, and the cardiovascular system while m-cresol attacks the nervous system.

SUMMARY AND OUTLOOK

The characteristics of chemical release during tobacco burning are very important in the tobacco industry and the cigarette smoking community. Understanding individual chemical formation from cigarette smoking will provide the necessary information needed to formulate sound tobacco reform policies from a chemical standpoint. Nonetheless, intense research is needed in this field in order to prescribe possible measures to deter cigarette smoking addiction and ameliorate the grave miseries bedevilling the tobacco smoking community.

Advance in Morchella sp. polysaccharides: Isolation, structural characterization and structure-activity relationship: A review

Morchella sp. is a kind of precious medicinal and edible fungus with a unique flavor and is rich in various amino acids and organic germanium needed by the human body. Most notably, Morchella sp. polysaccharides have attracted widespread attention due to their significant bioactivity in recent years. At present, extensive studies have been carried out on the extraction methods, structural characterization and activity evaluation of Morchella sp. polysaccharides, which provides a good theoretical basis for its further development and application. However, the systematic summary of the related research of Morchella sp. polysaccharides has not been reported yet. Therefore, this review mainly focused on the isolation and purification methods, structural characterization, biological activities and structure-activity relationship of Morchella sp. polysaccharides. This work will help to have a better in-depth understanding of Morchella sp. polysaccharides and provide a scientific basis and direct reference for more scientific and rational applications.

Potential antidepressant effects of a dietary supplement from Huáng qí and its complex in aged senescence-accelerated mouse prone-8 mice

Healthcare is an emerging industry with significant market potential in the 21st century. Therefore, this study aimed to evaluate the benefits of tube feeding Huáng qí and its complexes for 8 weeks on 3-month-old senescence-accelerated mouse prone-8 (SAMP8) mice, 48 in total, randomly divided into 3 groups including control, Huáng qí extract [820 mg/kg Body weight (BW)/day], and Huáng qí complexes (6.2 mL /kg BW/day), where each group consisted of males (n = 8) and females (n = 8). Behavioral tests (locomotion test and aging score assessment on week 6, the single-trial passive avoidance test on week 7, and the active shuttle avoidance test on week 8) were conducted to evaluate the ability of the mice to learn and remember. In addition, after sacrificing the animals, the blood and organs were measured for antioxidant and aging bioactivities, including malondialdehyde (MDA) content and superoxide dismutase (SOD) activity and catalase activities (CAT), and the effects on promoting aging in SAMP8 mice were investigated. The findings showed that Huáng qí enhanced locomotor performance and had anti-aging effects, with positive effects on health, learning, and memory in SAMP-8 mice (p < 0.05), whether applied as a single agent (820 mg/kg BW/day) or as a complex (6.2 mL/kg BW/day) (p < 0.05). Based on existing strengths, a more compelling platform for clinical validation of human clinical evidence will be established to enhance the development and value-added of astragalus-related products while meeting the diversified needs of the functional food market.

Aldehyde Dehydrogenase and Aldo-Keto Reductase Enzymes: Basic Concepts and Emerging Roles in Diabetic Retinopathy

Diabetic retinopathy (DR) is a complication of diabetes mellitus that can lead to vision loss and blindness. It is driven by various biochemical processes and molecular mechanisms, including lipid peroxidation and disrupted aldehyde metabolism, which contributes to retinal tissue damage and the progression of the disease. The elimination and processing of aldehydes in the retina rely on the crucial role played by aldehyde dehydrogenase (ALDH) and aldo-keto reductase (AKR) enzymes. This review article investigates the impact of oxidative stress, lipid-derived aldehydes, and advanced lipoxidation end products (ALEs) on the advancement of DR. It also provides an overview of the ALDH and AKR enzymes expressed in the retina, emphasizing their growing importance in DR. Understanding the relationship between aldehyde metabolism and DR could guide innovative therapeutic strategies to protect the retina and preserve vision in diabetic patients. This review, therefore, also explores various approaches, such as gene therapy and pharmacological compounds that have the potential to augment the expression and activity of ALDH and AKR enzymes, underscoring their potential as effective treatment options for DR.

The impact of e-cigarette exposure on different organ systems: A review of recent evidence and future perspectives

The use of electronic cigarettes (e-cigs) is rapidly increasing worldwide and is promoted as a smoking cessation tool. The impact of traditional cigs on human health has been well-defined in both animal and human studies. In contrast, little is known about the adverse effects of e-cigs exposure on human health. This review summarizes the impact of e-cigs exposure on different organ systems based on the rapidly expanding recent evidence from experimental and human studies. A number of growing studies have shown the adverse effects of e-cigs exposure on various organ systems. The summarized data in this review indicate that while e-cigs use causes less adverse effects on different organs compared to traditional cigs, its long-term exposure may lead to serious health effects. Data on short-term organ effects are limited and there is no sufficient evidence on long-term organ effects. Moreover, the adverse effects of secondhand and third hand e-cigs vapour exposure have not been thoroughly investigated in previous studies. Although some studies demonstrated e-cigs used as a smoking cessation tool, there is a lack of strong evidence to support it. While some researchers suggested e-cigs as a safer alternative to tobacco smoking, their long-term exposure health effects remain largely unknown. Therefore, more epidemiological and prospective studies including mechanistic studies are needed to address the potential adverse health effects of e-cigs to draw a firm conclusion about their safe use. A wide variation in e-cigs products and the lack of standardized testing methods are the major barriers to evaluating the existing data. Specific regulatory guidelines for both e-cigs components and the manufacturing process may be effective to protect consumer health.

The Janus-Faced Role of Lipid Droplets in Aging: Insights from the Cellular Perspective

It is widely accepted that nine hallmarks-including mitochondrial dysfunction, epigenetic alterations, and loss of proteostasis-exist that describe the cellular aging process. Adding to this, a well-described cell organelle in the metabolic context, namely, lipid droplets, also accumulates with increasing age, which can be regarded as a further aging-associated process. Independently of their essential role as fat stores, lipid droplets are also able to control cell integrity by mitigating lipotoxic and proteotoxic insults. As we will show in this review, numerous longevity interventions (such as mTOR inhibition) also lead to strong accumulation of lipid droplets in Saccharomyces cerevisiae, Caenorhabditis elegans, Drosophila melanogaster, and mammalian cells, just to name a few examples. In mammals, due to the variety of different cell types and tissues, the role of lipid droplets during the aging process is much more complex. Using selected diseases associated with aging, such as Alzheimer's disease, Parkinson's disease, type II diabetes, and cardiovascular disease, we show that lipid droplets are "Janus"-faced. In an early phase of the disease, lipid droplets mitigate the toxicity of lipid peroxidation and protein aggregates, but in a later phase of the disease, a strong accumulation of lipid droplets can cause problems for cells and tissues.

Protein adducts with lipid peroxidation products in patients with psoriasis

Psoriasis, one of the most frequent immune-mediated skin diseases, is manifested by numerous psoriatic lessons on the skin caused by excessive proliferation and keratinization of epidermal cells. These disorders of keratinocyte metabolism are caused by a pathological interaction with the cells of the immune system, including lymphocytes, which in psoriasis are also responsible for systemic inflammation. This is accompanied by oxidative stress, which promotes the formation of lipid peroxidation products, including reactive aldehydes and isoprostanes, which are additional pro-inflammatory signaling molecules. Therefore, the presented review is focused on highlighting changes that occur during psoriasis development at the level of lipid peroxidation products, including 4-hydroxynonenal, 4-oxononenal, malondialdehyde, and acrolein, and their influence on protein structures. Furthermore, we will examine inducing agents of cellular functioning, as well as intercellular signaling. These lipid peroxidation products can form adducts with a variety of proteins with different functions in the body, including proteins within skin cells and cells of the immune system. This is especially true in autoimmune diseases such as psoriasis. For example, these changes concern proteins involved in maintaining redox homeostasis or pro-inflammatory signaling. Therefore, the formation of such adducts should attract attention, especially during the design of preventive cosmetics or anti-psoriasis therapies.

Reuse of treated urban wastewater on the growth and physiology of Medicago sativa L. cv. Gea and Petroselinum crispum L. cv. Commun: correlation with oxydative stress and DNA damage

The freshwater scarcity is one of the major environmental problems, which is why the water reuse has become a possible remedy to cope with the shortage of water needed for agriculture irrigation. This study focuses on the evaluation of the irrigation effect with treated effluent from wastewater treatment plant in Tunisia on parsley (Petroselinum crispum L. cv. Commun) used as human food and alfalfa (Medicago sativa L. cv. Gea) as animal food. In vitro germination test was conducted at different dilution levels of wastewater as rejected into the environment (25, 50, and 100%) and wastewater with further treatment (TWW). Results have shown that wastewater with dilution of 25% as well as TWW positively affected the physiological parameters in comparison with the dilutions 50 and 100%. However, the tap water (TW) applied as control treatment has shown the best effects. Oxidative stress evaluated by malondialdehyde (MDA) content was in agreement with the physiological results and showed that the most stressed seeds were those treated with the dilutions 50 and 100%. A pot trial was also conducted to evaluate the suitability of WW and TWW in comparison to TW. Results have shown that TWW is more adapted than WW for irrigation as an improvement of growth and physiological parameters was recorded. Oxidative stress assessed with MDA and proline content has shown that plants irrigated with WW significantly accumulate MDA and proline compared to TWW. The TW has shown the lowest values. DNA damage was evaluated by extraction and agarose gel electrophoresis. It has revealed degradation of DNA for plants irrigated with WW. According to these results, it can be concluded that TWW can be used for irrigation of plants destined for human or animal foods. So, it can be a hydric alternative to resolve the problem of water deficit in semi-arid countries.

Lipid Aldehydes 4-Hydroxynonenal and 4-Hydroxyhexenal Exposure Differentially Impact Lipogenic Pathways in Human Placenta

Long chain polyunsaturated fatty acids (LCPUFAs), such as the omega-6 (n-6) arachidonic acid (AA) and n-3 docosahexanoic acid (DHA), have a vital role in normal fetal development and placental function. Optimal supply of these LCPUFAs to the fetus is critical for improving birth outcomes and preventing programming of metabolic diseases in later life. Although not explicitly required/recommended, many pregnant women take n-3 LCPUFA supplements. Oxidative stress can cause these LCPUFAs to undergo lipid peroxidation, creating toxic compounds called lipid aldehydes. These by-products can lead to an inflammatory state and negatively impact tissue function, though little is known about their effects on the placenta. Placental exposure to two major lipid aldehydes, 4-hydroxynonenal (4-HNE) and 4-hydroxyhexenal (4-HHE), caused by peroxidation of the AA and DHA, respectively, was examined in the context of lipid metabolism. We assessed the impact of exposure to 25 μM, 50 μM and 100 μM of 4-HNE or 4-HHE on 40 lipid metabolism genes in full-term human placenta. 4-HNE increased gene expression associated with lipogenesis and lipid uptake (ACC, FASN, ACAT1, FATP4), and 4-HHE decreased gene expression associated with lipogenesis and lipid uptake (SREBP1, SREBP2, LDLR, SCD1, MFSD2a). These results demonstrate that these lipid aldehydes differentially affect expression of placental FA metabolism genes in the human placenta and may have implications for the impact of LCPUFA supplementation in environments of oxidative stress.

The Role of Potential Oxidative Biomarkers in the Prognosis of Acute Ischemic Stroke and the Exploration of Antioxidants as Possible Preventive and Treatment Options

Ischemic strokes occur when the blood supply to a part of the brain is interrupted or reduced due to arterial blockage, and it often leads to damage to brain cells or death. According to a myriad of experimental studies, oxidative stress is an important pathophysiological mechanism of ischemic stroke. In this narrative review, we aimed to identify how the alterations of oxidative stress biomarkers could suggest a severity-reflecting diagnosis of ischemic stroke and how these interactions may provide new molecular targets for neuroprotective therapies. We performed an eligibility criteria-based search on three main scientific databases. We found that patients with acute ischemic stroke are characterized by increased oxidative stress markers levels, such as the total antioxidant capacity, F2-isoprostanes, hydroxynonenal, total and perchloric acid oxygen radical absorbance capacity (ORACTOT and ORACPCA), malondialdehyde (MDA), myeloperoxidase, and urinary 8-oxo-7,8-dihydro-2′-deoxyguanosine. Thus, acute ischemic stroke is causing significant oxidative stress and associated molecular and cellular damage. The assessment of these molecular markers could be useful in diagnosing ischemic stroke, finding its causes, predicting its severity and outcomes, reducing its impact on the cellular structures of the brain, and guiding preventive treatment towards antioxidant-based therapy as novel therapeutic alternatives.

Emerging Therapy for Diabetic Cardiomyopathy: From Molecular Mechanism to Clinical Practice

Diabetic cardiomyopathy is characterized by abnormal myocardial structure or performance in the absence of coronary artery disease or significant valvular heart disease in patients with diabetes mellitus. The spectrum of diabetic cardiomyopathy ranges from subtle myocardial changes to myocardial fibrosis and diastolic function and finally to symptomatic heart failure. Except for sodium–glucose transport protein 2 inhibitors and possibly bariatric and metabolic surgery, there is currently no specific treatment for this distinct disease entity in patients with diabetes. The molecular mechanism of diabetic cardiomyopathy includes impaired nutrient-sensing signaling, dysregulated autophagy, impaired mitochondrial energetics, altered fuel utilization, oxidative stress and lipid peroxidation, advanced glycation end-products, inflammation, impaired calcium homeostasis, abnormal endothelial function and nitric oxide production, aberrant epidermal growth factor receptor signaling, the activation of the renin–angiotensin–aldosterone system and sympathetic hyperactivity, and extracellular matrix accumulation and fibrosis. Here, we summarize several important emerging treatments for diabetic cardiomyopathy targeting specific molecular mechanisms, with evidence from preclinical studies and clinical trials.