Regulation of NF-κB-induced inflammatory signaling by lipid peroxidation-derived aldehydes

Effects of triclosan on lipid metabolism and underlying mechanisms in the cyprinid fish Squalidus argentatus

The ubiquitous presence of the disinfectant triclosan (TCS) has raised global concerns regarding its potential threat to aquatic organisms. However, the effects of TCS on lipid metabolism in fish and its underlying mechanisms remain unclear. This study investigated the effect of environmentally relevant levels of TCS on the lipid metabolism in the cyprinid fish Squalidus argentatus. Our results showed that the lipid metabolism in the cyprinid fish S. argentatus was perturbed by 28-day exposure to TCS, as evidenced by higher levels of lipid accumulation in both the liver and blood. To elucidate the mechanisms underlying toxicity, we evaluated oxidative stress, inflammatory status, and lipase activity in the liver. Our findings indicated increased ROS-specific fluorescence intensity, superoxide dismutase (SOD) activity, and malondialdehyde (MDA) content in the livers of S. argentatus exposed to TCS, suggesting oxidative damage. Additionally, TCS treatment induced the production of proinflammatory cytokines in the liver of S. argentatus exposed to TCS, which suppressed hepatic lipase activity. Intestinal tissue morphology, inflammation, and blood lipopolysaccharide (LPS) levels were also examined. Significant increases in goblet cell count and MDA levels were observed in the intestinal tract. After 28 days of TCS exposure, the serum LPS levels were significantly elevated. 16S rRNA sequencing was conducted to analyze the effects of TCS on the diversity and composition of the intestinal microbiota. Transcriptomic analysis was performed to reveal global molecular alterations following TCS exposure. In conclusion, our results indicate that TCS may disrupt the lipid metabolism in S. argentatus by (i) inducing hepatic oxidative stress and inflammation, which suppress lipoprotein lipase activity, (ii) affecting the production of beneficial metabolites and endotoxins by dysregulating gut microbiota composition, and (iii) altering the expression levels of lipid metabolism-related pathways.

Insights into the bioactive potential of the Amazonian species Acmella oleracea leaves extract: A focus on wound healing applications

ETHNOPHARMACOLOGICAL RELEVANCE

Acmella oleracea is traditionally used by Amazonian folks to treat skin and mucous wounds, influenza, cough, toothache, bacterial and fungal infections. Its phytoconstituents, such as alkylamides, phenolic compounds, and terpenes, are reported to produce therapeutic effects, which justify the medicinal use of A. oleracea extracts. However, the scientific evidence supporting the application A. oleracea bioactive products for wound treatment of remains unexplored so far.

OBJECTIVE

This work aimed to characterize the phytochemical composition of methanolic extract of A. oleracea leaves (AOM) and to investigate their antioxidant, anti-inflammatory, antimicrobial and healing potential focusing on its application for wound healing.

MATERIAL AND METHODS

The dried leaves from A. oleracea submitted to static maceration in methanol for 40 days. The phytochemical constitution of AOM was analyzed based on the total phenolic dosage method and by UFLC-QTOF-MS analysis. Antioxidant activity was assessed by DPPH and NO scavenging activities, as well as MDA formation, evaluation of ROS levels, and phosphomolybdenum assays. In vitro anti-inflammatory activities were assessed by reduction of NO, IL-6, and TNF-α production and accumulation of LDs in peritoneal macrophages cells. Antimicrobial activity was evaluated by determining MIC and MBC/MFC values against P. aeruginosa, E. coli, S. epidermidis, S. aureus and C. albicans, bacterial killing assay, and biofilm adhesion assessment. In vitro wound healing activity was determined by means of the scratch assay with L929 fibroblasts.

RESULTS

Vanillic acid, quercetin, and seven other alkamides, including spilanthol, were detected in the UFLC-QTOF-MS spectrum of AOM. Regarding the biocompatibility, AOM did not induce cytotoxicity in L929 fibroblasts and murine macrophages. The strong anti-inflammatory activity was evidenced by the fact that AOM reduced the cellular production of inflammatory mediators IL-6, TNF-α, NO, and LDs in macrophages by 100%, 96.66 ± 1.95%, 99.21 ± 3.82%, and 67.51 ± 0.72%, respectively. The antioxidant effects were confirmed, since AOM showed IC50 values of 44.50 ± 4.46 and 127.60 ± 14.42 μg/mL in the DPPH and NO radical inhibition assays, respectively. Additionally, AOM phosphomolybdenium reducing power was 63.56 ± 13.01 (RAA% of quercetin) and 104.01 ± 21.29 (RAA% of rutin). Finally, in the MDA quantification assay, AOM showed 63,69 ± 3.47% of lipid peroxidation inhibition. It was also observed that the production of ROS decreased by 69.03 ± 3.85%. The MIC values of AOM ranged from 1000 to 125 μg/mL. Adhesion of S. aureus, P. Aeruginosa, and mixed biofilms was significantly reduced by 44.71 ± 4.44%, 95.50 ± 6.37 %, and 51.83 ± 1.50%, respectively. AOM also significantly inhibited the growth of S. aureus (77.17 ± 1.50 %) and P. aeruginosa (62.36 ± 1.01%). Furthermore, AOM significantly enhanced the in vitro migration of L929 fibroblasts by 97.86 ± 0.82% compared to the control (P < 0.05).

CONCLUSIONS

This study is the first to report total antioxidant capacity and intracellular LD reduction by AOM. The results clearly demonstrated that AOM exerts potent anti-inflammatory, antioxidant, antimicrobial, and wound healing effects, encouraging its further investigation and promising application in wound treatment.

Inflammasome activity regulation by PUFA metabolites

Oxidative stress and the accompanying chronic inflammation constitute an important metabolic problem that may lead to pathology, especially when the body is exposed to physicochemical and biological factors, including UV radiation, pathogens, drugs, as well as endogenous metabolic disorders. The cellular response is associated, among others, with changes in lipid metabolism, mainly due to the oxidation and the action of lipolytic enzymes. Products of oxidative fragmentation/cyclization of polyunsaturated fatty acids (PUFAs) [4-HNE, MDA, 8-isoprostanes, neuroprostanes] and eicosanoids generated as a result of the enzymatic metabolism of PUFAs significantly modify cellular metabolism, including inflammation and the functioning of the immune system by interfering with intracellular molecular signaling. The key regulators of inflammation, the effectiveness of which can be regulated by interacting with the products of lipid metabolism under oxidative stress, are inflammasome complexes. An example is both negative or positive regulation of NLRP3 inflammasome activity by 4-HNE depending on the severity of oxidative stress. 4-HNE modifies NLRP3 activity by both direct interaction with NLRP3 and alteration of NF-κB signaling. Furthermore, prostaglandin E2 is known to be positively correlated with both NLRP3 and NLRC4 activity, while its potential interference with AIM2 or NLRP1 activity is unproven. Therefore, the influence of PUFA metabolites on the activity of well-characterized inflammasome complexes is reviewed.

Renal protection after hemorrhagic shock in rats: Possible involvement of SUMOylation

Hemorrhagic shock (HS), a leading cause of preventable death, is characterized by severe blood loss and inadequate tissue perfusion. Reoxygenation of ischemic tissues exacerbates organ damage through ischemia-reperfusion injury. SUMOylation has been shown to protect neurons after stroke and is upregulated in response to cellular stress. However, the role of SUMOylation in organ protection after HS is unknown. This study aimed to investigate SUMOylation-mediated organ protection following HS. Male Wistar rats were subjected to HS (blood pressure of 40 ± 2 mmHg, for 90 min) followed by reperfusion. Blood, kidney, and liver samples were collected at various time points after reperfusion to assess organ damage and investigate the profile of SUMO1 and SUMO2/3 conjugation. In addition, human kidney cells (HK-2), treated with the SUMOylation inhibitor TAK-981 or overexpressing SUMO proteins, were subjected to oxygen and glucose deprivation to investigate the role of SUMOylation in hypoxia/reoxygenation injury. The animals presented progressive multiorgan dysfunction, except for the renal system, which showed improvement over time. Compared to the liver, the kidneys displayed distinct patterns in terms of oxidative stress, apoptosis activation, and tissue damage. The global level of SUMO2/3 in renal tissue was also distinct, suggesting a differential role. Pharmacological inhibition of SUMOylation reduced cell viability after hypoxia-reoxygenation damage, while overexpression of SUMO1 or SUMO2 protected the cells. These findings suggest that SUMOylation might play a critical role in cellular protection during ischemia-reperfusion injury in the kidneys, a role not observed in the liver. This difference potentially explains the renal resilience observed in HS animals when compared to other systems.

Cerium oxide nanoparticles (nanoceria) pretreatment attenuates cell death in the hippocampus and cognitive dysfunction due to repeated isoflurane anesthesia in newborn rats

General anesthetics exposure, particularly prolonged or repeated exposure, is a crucial cause of neurological injuries. Notably, isoflurane (ISO), used in pediatric anesthesia practice, is toxic to the developing brain. The relatively weak antioxidant system at early ages needs antioxidant support to protect the brain against anesthesia. Cerium oxide nanoparticles (CeO2-NPs, nanoceria) are nano-antioxidants and stand out due to their unique surface chemistry, high stability, and biocompatibility. Although CeO2-NPs have been shown to exhibit neuroprotective and cognitive function-facilitating effects, there are no reports on their protective effects against anesthesia-induced neurotoxicity and cognitive impairments. Herein, Wistar albino rat pups were exposed to ISO (1.5 %, 3-h) at postnatal day (P)7+P9+P11, and the protective properties of CeO2-NP pretreatment (0.5 mg/kg, intraperitoneal route) were investigated for the first time. The control group at P7+9+11 received 50 % O2 (3-h) instead of ISO. Exposure to nanoceria one-hour before ISO protected hippocampal neurons of the developing rat brain against apoptosis [determined by hematoxylin-eosin (HE) staining, immunohistochemistry (IHC) analysis with caspase-3, and immunoblotting with Bax/Bcl2, cleaved caspase-3 and PARP1] oxidative stress, and inflammation [determined by immunoblotting with 4-hydroxynonenal (4HNE), nuclear factor kappa-B (NF-κB), and tumor necrosis factor-alpha (TNF-α)]. CeO2-NP pretreatment also reduced ISO-induced learning (at P28-32) and memory (at P33) deficits evaluated by Morris Water Maze. However, memory deficits and thigmotactic behaviors were detected in the agent-control group; elimination of these harmful effects will be possible with dose studies, thus providing evidence supporting safer use. Overall, our findings support pretreatment with nanoceria application as a simple strategy that might be used for pediatric anesthesia practice to protect infants and children from ISO-induced cell death and learning and memory deficits.

Effects of ibuprofen in the ZDF rat model of type 2 diabetes

We aimed to investigate the therapeutic potential of ibuprofen against type 2 diabetes (T2D) using obese Zucker diabetic fatty (ZDF) rats as type 2 diabetes model. ZDF rats were hyperglycemic, dyslipidemic and expressed proinflammatory markers in contrast to lean controls, thus reflecting the relationship between obesity and chronic inflammation promoting T2D. Chronic treatment with ibuprofen (2-(4-Isobutylphenyl)propanoic acid) was used to study the impact on pathological T2D conditions as compared to metformin (1,1-dimethylbiguanide) treated ZDF as well as lean controls. Ibuprofen decreased A1c but induced a high insulin release with improved glucose tolerance only after early time points (i.g., 15 and 30 min) resulting in a non-significant decline of AUC values and translating into a high HOMA-IR. In addition, ibuprofen significantly lowered cholesterol, free fatty acids and HDL-C. Some of these effects by ibuprofen might be based on its anti-inflammatory effects through inhibition of cytokine/chemokine signaling (i.g., COX-2, ICAM-1 and TNF-α) as measured in whole blood and epididymal adipose tissue by TaqMan and/or upregulation of anti-inflammatory cytokines (i.g., IL-4 and IL-13) by ELISA analysis in blood. In conclusion, our ZDF animal study showed positive effects of ibuprofen against diabetic complications such as inflammation and dyslipidemia but also demonstrated the risk of causing insulin resistance.

Biochemical and histopathological evaluation of systemic and ocular toxicity of favipiravir in rats

Purpose: Favipiravir (FAV) used against COVID-19 is an antiviral drug that causes adverse reactions, such as hyperuricaemia, liver damage, and hematopoetic toxicity. The aim of the study was to investigate the systemic and ocular side-effects of FAV in rats, for the first time.Materials and methods: A total of 18 albino male Wistar rats were used in the study. The rats were divided into 3 groups as the healthy group (HG), the group given 50 mg/kg/day favipiravir (FAV50), and the group given 200 mg/kg/d favipiravir (FAV200). These doses were given to the experimental groups for one week. At the end of the experiment histopathological examinations were performed on the conjunctiva and sclera of the eye. In addition, malondialdehyde (MDA), total glutathione (tGSH), superoxide dismutase (SOD), interleukin-1β (IL-1β), and tumor necrosis factor alpha (TNF-α) levels were measured in blood samples taken from rats. Results: Compared to HG, the MDA (1.37 ± 0.61 vs. 4.82 ± 1.40 µmol/mL), IL-1β (2.52 ± 1.14 vs. 6.67 ± 1.99 pg/mL), and TNF-α levels (3.28 ± 1.42 vs. 8.53 ± 3.06 pg/mL) of the FAV200 group were higher. The levels of tGSH (7.58 ± 1.98 vs. 2.50 ± 0.98 nmol/mL) and SOD (13.63 ± 3.43 vs. 3.81 ± 1.43 U/mL) the FAV200 group were lower than the HG (p < 0.05, for all). The degree of damage to the cornea and sclera of the FAV200 group was quite high according to HG (p < 0.001). Conclusions: FAV can cause damage to rat conjunctiva and sclera by increasing oxidant stress and inflammation at high dose.

Antioxidant and anti-inflammatory potentials of Ammodaucus leucotrichus Coss. & Durieu seeds' extracts: In vitro and in vivo studies

ETHNOPHARMACOLOGICAL RELEVANCE

Ammodaucus leucotrichus Coss. & Durieu (Apiaceae) is traditionally used in southern Algeria as a remedy against a wide range of disease due to its health-promoting properties.

AIM OF THE STUDY

To investigate anti-oxidant and anti-inflammatory potentials of plant methanolic extract and its fractions in vitro and in vivo.

MATERIALS AND METHODS

Anti-radical activity was assessed in vitro using ABTS•+, superoxide anion (O2•-) and nitric oxide radical (•NO). Lipid peroxidation inhibition was also investigated in the linoleic acid system. Enzyme inhibition assay was performed against α-amylase and α-glucosidase. The anti-inflammatory effect of extracts was screened in vitro through thermal induction of human serum albumin, and in vivo on a skin acute inflammation model induced by λ-carrageenan paw injection, xylene and croton oil topical application. Analgesic effect was evaluated by acetic acid-induced writhing test.

RESULTS

The highest contents of polyphenols and flavonoids was recorded by the crude extract (77.14 ± 0.01 μg GAE/mg E and 19.59 ± 0.08 μg QE/mg E, respectively). Among the extracts, ethyl acetate extract showed a promising anti-radical activity of ABTS•+, O2•- and •NO, in addition to a remarkable inhibition activity of the tested enzymes. Meanwhile, all extracts effectively protected linoleic acid against lipid peroxidation and human serum albumin structure in thermal condition even at low concentration (0.31 mg/ml). Oral administration of 200 mg/kg of crude extract successfully inhibited acetic acid induced nociception and reduced edema formation induced by xylene and carrageenan. However, a dose-dependent manner was observed to decrease ear edema by a microscopic examination in croton oil induced acute inflammation. Nitrite and malondialdehyde levels together with catalase activity were modulated in the presence of plant-derived bioactive compounds.

CONCLUSIONS

This study showed that Ammodaucus leucotrichus is potentially rich source of anti-oxidant and anti-inflammatory bioactive compounds.

Porous Se@SiO2 nanospheres alleviate diabetic retinopathy by inhibiting excess lipid peroxidation and inflammation

BACKGROUND

Lipid peroxidation is a characteristic metabolic manifestation of diabetic retinopathy (DR) that causes inflammation, eventually leading to severe retinal vascular abnormalities. Selenium (Se) can directly or indirectly scavenge intracellular free radicals. Due to the narrow distinction between Se's effective and toxic doses, porous Se@SiO2 nanospheres have been developed to control the release of Se. They exert strong antioxidant and anti-inflammatory effects.

METHODS

The effect of anti-lipid peroxidation and anti-inflammatory effects of porous Se@SiO2 nanospheres on diabetic mice were assessed by detecting the level of Malondialdehyde (MDA), glutathione peroxidase 4 (GPX4), decreased reduced/oxidized glutathione (GSH/GSSG) ratio, tumor necrosis factor (TNF)-α, interferon (IFN)-γ, and interleukin (IL) -1β of the retina. To further examine the protective effect of porous Se@SiO2 nanospheres on the retinal vasculopathy of diabetic mice, retinal acellular capillary, the expression of tight junction proteins, and blood-retinal barrier destruction was observed. Finally, we validated the GPX4 as the target of porous Se@SiO2 nanospheres via decreased expression of GPX4 and detected the level of MDA, GSH/GSSG, TNF-α, IFN-γ, IL -1β, wound healing assay, and tube formation in high glucose (HG) cultured Human retinal microvascular endothelial cells (HRMECs).

RESULTS

The porous Se@SiO2 nanospheres reduced the level of MDA, TNF-α, IFN-γ, and IL -1β, while increasing the level of GPX4 and GSH/GSSG in diabetic mice. Therefore, porous Se@SiO2 nanospheres reduced the number of retinal acellular capillaries, depletion of tight junction proteins, and vascular leakage in diabetic mice. Further, we identified GPX4 as the target of porous Se@SiO2 nanospheres as GPX4 inhibition reduced the repression effect of anti-lipid peroxidation, anti-inflammatory, and protective effects of endothelial cell dysfunction of porous Se@SiO2 nanospheres in HG-cultured HRMECs.

CONCLUSION

Porous Se@SiO2 nanospheres effectively attenuated retinal vasculopathy in diabetic mice via inhibiting excess lipid peroxidation and inflammation by target GPX4, suggesting their potential as therapeutic agents for DR.

Marine bromophenols suppressed choroidal neovascularization by targeting HUWE1 through NF-κb signaling pathway

Inflammation plays a key role in the progression of choroidal neovascularization (CNV). Regular intravitreal injection of anti-VEGF medication is required for many patients to sustain eye condition as CNV always recurs due to persistent chronic inflammation in the retina and choroid. Marine bromophenols (BDB) have been widely studied due to their diverse bioactivities, including anti-inflammatory effect, though the mechanism of which remained unclear. Our study demonstrated that BDB could restricted endothelial cells' function and suppressed choroidal explants both in vitro and in vivo without out affecting the cells viability. BDB also significantly reduced numerous inflammatory cytokines in both raw cells and choroidal tissue, including IL-1β, IL-6, TNF-α, IL-4 and MMP-9. Moreover, we demonstrated that BDB down regulated phosphorylation of NF-κB p65 in the raw cells. By Co-IP assay, HUWE1 was found to be bound with BDB and the binding location was at sequences position 4214. When overexpressed HUWE1 in HUVECs, the suppression of endothelial cells' function by BDB became more significant. Taken together, the findings in this study showed that BDB suppressed endothelial cells' function and choroidal neovascularization by targeting HUWE1 through NF-κB pathway, which suggested that BDB could be a potential therapeutic candidate in treating chronic inflammation in choroidal neovascularization.

An integrated in vitro approach on the enzymatic and antioxidant mechanisms of four commercially available essential oils (Copaifera officinalis, Gaultheria fragrantissima, Helichrysum italicum, and Syzygium aromaticum) traditionally used topically for their anti-inflammatory effects

Introduction: Despite the increasing number of essential oils being reported on their potential therapeutic effects, some remain relatively unknown on their biological properties. That is the case of the essential oils obtained from copaiba (Copaifera officinalis L.), wintergreen (Gaultheria fragrantissima Wall.), everlasting (Helichrysum italicum (Roth) G.Don) and clove (Syzygium aromaticum (L.) Merr. & L.M.Perry), commonly labelled as being useful on the amelioration of conditions with an inflammatory background. Methods: To further broaden the current knowledge on the four essential oils, commercially available samples were approached on their effects upon a series of mediators that are involved on the inflammatory and oxidative response, both through in vitro cell-free and cell-based assays (5-lipoxygenase activity, lipid peroxidation, free radical and nitric oxide radical scavenging properties or tyrosinase inhibition). Results: The four oils proved to be active at some of the concentrations tested in most of the performed assays. Significant differences were found between the essential oils, S. aromaticum proving to tbe the most active, followed by G. fragrantissima against 5-lipoxygenase (5-LOX) and linoleic acid peroxidation, proving their potential use as antioxidants and anti-inflammatory agents. In fact, the IC50 value of S. aromaticum in the 5-LOX assay was 62.30 μg mL-1. Besides S. aromaticum efficiently scavenged superoxide radicals generated by xanthine/xanthine oxidase, displaying an IC50 value of 135.26 μg mL-1. The essential oil obtained from H. italicum exhibited a significant decrease in the nitric oxide levels on BV-2 cells, showing its potential as a cytoprotective agent against toxic damage. Copaiba oil ranked first as the most potent tyrosinase inhibitor, exhibiting an IC50 98.22 μg mL-1. Conclusion: More studies are needed to describe the essential oils properties, but these results confirm the potential of these essential oils as anti-inflammatory and antioxidant agents.

Deciphering Molecular Mechanisms of Carbon Tetrachloride- Induced Hepatotoxicity: A Brief Systematic Review

The liver plays a critical role in metabolic processes, making it vulnerable to injury. Researchers often study carbon tetrachloride (CCl4)-induced hepatotoxicity in model organisms because it closely resembles human liver damage. This toxicity occurs due to the activation of various cytochromes, including CYP2E1, CYP2B1, CYP2B2, and possibly CYP3A, which produce the trichloromethyl radical (CCl3*). CCl3* can attach to biological molecules such as lipids, proteins, and nucleic acids, impairing lipid metabolism and leading to fatty degeneration. It can also combine with DNA to initiate hepatic carcinogenesis. When exposed to oxygen, CCl3* generates more reactive CCl3OO*, which leads to lipid peroxidation and membrane damage. At the molecular level, CCl4 induces the release of several inflammatory cytokines, including TNF-α and NO, which can either help or harm hepatotoxicity through cellular apoptosis. TGF-β contributes to fibrogenesis, while IL-6 and IL-10 aid in recovery by minimizing anti-apoptotic activity and directing cells toward regeneration. To prevent liver damage, different interventions can be employed, such as antioxidants, mitogenic agents, and the maintenance of calcium sequestration. Drugs that prevent CCl4- induced cytotoxicity and proliferation or enhance CYP450 activity may offer a protective response against hepatic carcinoma.

Trichostatin A enhances the titanium rods osseointegration in osteoporotic rats by the inhibition of oxidative stress through activating the AKT/Nrf2 pathway

The use of titanium implants as fixed supports following fractures in patients with OP can often result in sterile loosening and poor osseointegration. Oxidative stress has been shown to play a particularly important role in this process. While TSA has been reported to facilitate in vivo osteogenesis, the underlying mechanisms remain to be clarified. It also remains unclear whether TSA can improve the osseointegration of titanium implants. This study investigated whether TSA could enhance the osseointegration of titanium rods by activating AKT/Nrf2 pathway signaling, thereby suppressing oxidative stress. MC3T3-E1 cells treated with CCCP to induce oxidative stress served as an in vitro model, while an OVX-induced OP rat model was employed for in vivo analysis of titanium rod implantation. In vitro, TSA treatment of CCCP-treated MC3T3-E1 cells resulted in the upregulation of osteogenic proteins together with increased AKT, total Nrf2, nuclear Nrf2, HO-1, and NQO1 expression, enhanced mitochondrial functionality, and decreased oxidative damage. Notably, the PI3K/AKT inhibitor LY294002 reversed these effects. In vivo, TSA effectively enhanced the microstructural characteristics of distal femur trabecular bone, increased BMSCs mineralization capacity, promoted bone formation, and improved the binding of titanium implants to the surrounding tissue. Finally, our results showed that TSA could reverse oxidative stress-induced cell damage while promoting bone healing and improving titanium rods' osseointegration through AKT/Nrf2 pathway activation.

Epoxides: an underestimated lipid oxidation product

Immense gains in understanding of mechanisms and effects of lipid oxidation have been achieved in the nearly 90 years over which lipid oxidation has been an active research focus. Even so, the substantial questions still being raised about lipid oxidation in this special issue show clearly that missing pieces remain and must be considered for full accounting of this important reaction in any system. In this context, epoxides are spotlighted as a critical overlooked product of lipid autoxidation - underestimated in analysis, underestimated in presence as a functionally active and competitive intermediate and product of lipid oxidation, and underestimated in potential contributions to impact of lipid oxidation on other molecules and cell functions. Logical reasons for ignoring or not finding epoxides are offered in historical development of lipid oxidation knowledge. Reactions generating lipid epoxides in autoxidation are reviewed, limitations in detecting and tracking epoxides are outlined to explain why epoxides may not be detected when they should be present, and justifications for increased research and analysis of epoxides are argued. The main goal is to provide a context for recognizing epoxides as critical products that must be accounted for in determining the state rather than extent of lipid oxidation and in tracking its consequences in oils, foods, personal care products, and tissues. A secondary goal is to stimulate new research using contemporary analyses to fill in the gaps of knowledge about epoxide formation, structure, and reactions in lipid autoxidation.

Association between Nfr2, HO-1, NF-kB Expression, Plasma ADMA, and Oxidative Stress in Metabolic Syndrome

Endothelial dysfunction is one of the major factors in the pathogenesis of metabolic syndrome (MetS), and its molecular mechanisms are not completely understood. The present study aimed to examine the connection between nuclear factor2-related factor2 (Nrf2), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), heme oxygenase 1 (HO-1), and plasma asymmetric dimethylarginine (ADMA) and malondialdehyde (MDA) in people with MetS. Participants in the study were as follows: with MetS (n = 30) and without MetS (Control) (n = 14). Expression of Nrf2, NF-kB, and HO-1 was measured in peripheral blood mononuclear cells (PBMCs). Plasma ADMA was determined using the ELISA technique and MDA via the thiobarbituric acid method. Our study showed that mRNA of NF-kB, Nrf2, and HO-1 levels in PBMCs in the MetS group were significantly higher than in the controls by 53%, 130%, and 185% (p < 0.05), respectively. Similarly, elevated levels of MDA (by 78%, p < 0.001) and ADMA (by 18.7%, p < 0.001) were established in the MetS group. Our findings show the importance of transcription factor Nrf2, playing an integral role in the protection of the endothelium, and of NF-κB, a transcription factor mediating the inflammatory response in MetS. Knowledge of complex cellular-molecular mechanisms would allow the use of biomarkers such as Nrf2, NF-kB, HO-1, and ADMA for the assessment of endothelial dysfunction in clinical practice.

The Roles of NFR2-Regulated Oxidative Stress and Mitochondrial Quality Control in Chronic Liver Diseases

Chronic liver disease (CLD) affects a significant portion of the global population, leading to a substantial number of deaths each year. Distinct forms like non-alcoholic fatty liver disease (NAFLD) and alcoholic fatty liver disease (ALD), though they have different etiologies, highlight shared pathologies rooted in oxidative stress. Central to liver metabolism, mitochondria are essential for ATP production, gluconeogenesis, fatty acid oxidation, and heme synthesis. However, in diseases like NAFLD, ALD, and liver fibrosis, mitochondrial function is compromised by inflammatory cytokines, hepatotoxins, and metabolic irregularities. This dysfunction, especially electron leakage, exacerbates the production of reactive oxygen species (ROS), augmenting liver damage. Amidst this, nuclear factor erythroid 2-related factor 2 (NRF2) emerges as a cellular protector. It not only counters oxidative stress by regulating antioxidant genes but also maintains mitochondrial health by overseeing autophagy and biogenesis. The synergy between NRF2 modulation and mitochondrial function introduces new therapeutic potentials for CLD, focusing on preserving mitochondrial integrity against oxidative threats. This review delves into the intricate role of oxidative stress in CLD, shedding light on innovative strategies for its prevention and treatment, especially through the modulation of the NRF2 and mitochondrial pathways.

Emerging Alzheimer's disease therapeutics: promising insights from lipid metabolism and microglia-focused interventions

More than 55 million people suffer from dementia, with this number projected to double every 20 years. In the United States, 1 in 3 aged individuals dies from Alzheimer's disease (AD) or another type of dementia and AD kills more individuals than breast cancer and prostate cancer combined. AD is a complex and multifactorial disease involving amyloid plaque and neurofibrillary tangle formation, glial cell dysfunction, and lipid droplet accumulation (among other pathologies), ultimately leading to neurodegeneration and neuronal death. Unfortunately, the current FDA-approved therapeutics do not reverse nor halt AD. While recently approved amyloid-targeting antibodies can slow AD progression to improve outcomes for some patients, they are associated with adverse side effects, may have a narrow therapeutic window, and are expensive. In this review, we evaluate current and emerging AD therapeutics in preclinical and clinical development and provide insight into emerging strategies that target brain lipid metabolism and microglial function - an approach that may synergistically target multiple mechanisms that drive AD neuropathogenesis. Overall, we evaluate whether these disease-modifying emerging therapeutics hold promise as interventions that may be able to reverse or halt AD progression.

Cellular stress in the pathogenesis of nonalcoholic steatohepatitis and liver fibrosis

The burden of chronic liver disease is rising substantially worldwide. Fibrosis, characterized by excessive deposition of extracellular matrix proteins, is the common pathway leading to cirrhosis, and limited treatment options are available. There is increasing evidence suggesting the role of cellular stress responses contributing to fibrogenesis. This Review provides an overview of studies that analyse the role of cellular stress in different cell types involved in fibrogenesis, including hepatocytes, hepatic stellate cells, liver sinusoidal endothelial cells and macrophages.

Short Survey on the Protein Modifications in Plasma during SARS-CoV-2 Infection

Although the COVID-19 pandemic has ended, it is important to understand the pathology of severe SARS-CoV-2 infection associated with respiratory failure and high mortality. The plasma proteome, including protein modification by lipid peroxidation products in COVID-19 survivors (COVID-19; n = 10) and deceased individuals (CovDeath; n = 10) was compared in samples collected upon admission to the hospital, when there was no difference in their status, with that of healthy individuals (Ctr; n = 10). The obtained results show that COVID-19 development strongly alters the expression of proteins involved in the regulation of exocytosis and platelet degranulation (top 20 altered proteins indicated by analysis of variance; p-value (False Discovery Rate) cutoff at 5%). These changes were most pronounced in the CovDeath group. In addition, the levels of 4-hydroxynonenal (4-HNE) adducts increased 2- and 3-fold, whereas malondialdehyde (MDA) adducts increased 7- and 2.5-fold, respectively, in COVID-19 and CovDeath groups. Kinases and proinflammatory proteins were particularly affected by these modifications. Protein adducts with 15-deoxy-12,14-prostaglandin J2 (15d-PGJ2) were increased 2.5-fold in COVID-19 patients, including modifications of proteins such as p53 and STAT3, whereas CovDeath showed a decrease of approximately 60% compared with Ctr. This study for the first time demonstrates the formation of lipid metabolism products-protein adducts in plasma from survived and deceased COVID-19 patients, significantly distinguishing them, which may be a predictor of the course of SARS-CoV-2 infection.

Blueberry Supplementation and Skin Health

Environmental stressors such as air pollutants, ozone, and UV radiation are among the most noxious outdoor stressors affecting human skin and leading to premature skin aging. To prevent the extrinsic aging, the skin is equipped with an effective defensive system. However, cutaneous defense mechanisms can be overwhelmed through chronic exposure to environmental pollutants. Recent studies have suggested that the topical usage of natural compounds, such as blueberries, could be a good strategy to prevent skin damage from the environment. Indeed, blueberries contain bioactive compounds found to induce an active skin response against the environmental noxious effects. In this review, results from recent studies on this topic are discussed in order to build the argument for blueberries to possibly be an effective agent for skin health. In addition, we hope to highlight the need for further research to elucidate the mechanisms behind the use of both topical application and dietary supplementation with blueberries to bolster cutaneous systems and defensive mechanisms.

An Adverse Outcome Pathway Network for Chemically Induced Oxidative Stress Leading to (Non)genotoxic Carcinogenesis

Nongenotoxic (NGTX) carcinogens induce cancer via other mechanisms than direct DNA damage. A recognized mode of action for NGTX carcinogens is induction of oxidative stress, a state in which the amount of oxidants in a cell exceeds its antioxidant capacity, leading to regenerative proliferation. Currently, carcinogenicity assessment of environmental chemicals primarily relies on genetic toxicity end points. Since NGTX carcinogens lack genotoxic potential, these chemicals may remain undetected in such evaluations. To enhance the predictivity of test strategies for carcinogenicity assessment, a shift toward mechanism-based approaches is required. Here, we present an adverse outcome pathway (AOP) network for chemically induced oxidative stress leading to (NGTX) carcinogenesis. To develop this AOP network, we first investigated the role of oxidative stress in the various cancer hallmarks. Next, possible mechanisms for chemical induction of oxidative stress and the biological effects of oxidative damage to macromolecules were considered. This resulted in an AOP network, of which associated uncertainties were explored. Ultimately, development of AOP networks relevant for carcinogenesis in humans will aid the transition to a mechanism-based, human relevant carcinogenicity assessment that involves a substantially lower number of laboratory animals.

Evolving Diagnostic and Treatment Strategies for Pediatric CNS Tumors: The Impact of Lipid Metabolism

Pediatric neurological tumors are a heterogeneous group of cancers, many of which carry a poor prognosis and lack a "standard of care" therapy. While they have similar anatomic locations, pediatric neurological tumors harbor specific molecular signatures that distinguish them from adult brain and other neurological cancers. Recent advances through the application of genetics and imaging tools have reshaped the molecular classification and treatment of pediatric neurological tumors, specifically considering the molecular alterations involved. A multidisciplinary effort is ongoing to develop new therapeutic strategies for these tumors, employing innovative and established approaches. Strikingly, there is increasing evidence that lipid metabolism is altered during the development of these types of tumors. Thus, in addition to targeted therapies focusing on classical oncogenes, new treatments are being developed based on a broad spectrum of strategies, ranging from vaccines to viral vectors, and melitherapy. This work reviews the current therapeutic landscape for pediatric brain tumors, considering new emerging treatments and ongoing clinical trials. In addition, the role of lipid metabolism in these neoplasms and its relevance for the development of novel therapies are discussed.

Ferroptosis mediates decabromodiphenyl ether-induced liver damage and inflammation

Decabromodiphenyl ether (BDE-209) is an environmental toxin. Increasing evidence showed that BDE-209 exposure induced liver injury, but the mechanism still remains unknown. The present study explored the effect and mechanism of ferroptosis on hepatotoxicity triggered by BDE-209 in vivo and in vitro. In vivo experiment, ICR mice were exposed to BDE-209 for 50 days, and then recovered for 50 days; HepG2 and L02 cells were treated with BDE-209 or/and ferrostatin-1 (Fer-1) for establishing in vitro model. In vivo, the results showed that BDE-209 accumulated in liver and induced liver damage, increased Fe²⁺ and MDA contents, and blocked the activation of SLC7A11/GSH/GPX4 pathway in liver; BDE-209 also activated IKK/IκB/NF-κB pathway and elevated inflammatory cytokines levels in liver after exposure for 50 days. After BDE-209 stopping exposure 50 days, the severity of liver damage, ferroptosis and inflammatory response were still higher than the corresponding control group. In vitro, ferroptosis inhibitor Fer-1 rescued ferroptotic damage and attenuated cell death in BDE-209-treated HepG2 and L02 cells. In addition, Fer-1 reversed the activation of IKK/IκB/NF-κB pathway and the increase of pro-inflammatory cytokines levels in BDE-209-treated HepG2 and L02 cells. Together, the above results suggested that BDE-209 induced tissue damage and inflammatory response by activating ferroptosis through increasing iron-dependent lipid peroxidation and blocking the activation of SLC7A11/GSH/GPX4 pathway in liver, indicating that ferroptosis is a potential mechanism for BDE-209-induced hepatotoxicity.

Molecular dissection of anti-colon cancer activity of NARI-29: special focus on H2O2 modulated NF-κB and death receptor signaling

Accumulating evidence attributes the role of aldose reductase (AR) in modulating ROS and inflammation which are the main factor responsible for cancer progression and drug resistance. Epalrestat is the only AR inhibitor being used in Asian countries. It did not make it to the markets of the USA and Europe due to marginal efficacy as an antioxidant and anti-inflammatory agent owing to difficulty reaching intracellular targets. In our previous studies, we attempted to synthesize the epalrestat analogs and reported that the compound 4-((Z)-5-((Z)-2-Cyano-3-phenylallylidene)-4-oxo-2-thioxothiazolidin-3-yl) benzoic acid named as NARI-29 has potent AR inhibition compared to epalrestat. In the current study, we aimed to find the effect of NARI-29 on ROS-induced cancer progression and TRAIL resistance in colon cancer in vitro models. In the first part of the study, we demonstrated that the NARI-29 has specific AKR1B1 inhibition and superior drug-like properties than epalrestat using bioinformatics tools. In the second part of the study, it was proven that NARI-29 has induced the hydrogen peroxide-triggered TRAIL-induced apoptosis in the colon cancer cells via modulating the AKR1B1/4HNE/FOXO3a/DR axis. The selective cytotoxicity of NARI-29 (10-fold) compared to epalrestat (4-fold) toward cancer cells is due to its differential ROS regulation and anti-inflammatory activities. Altogether, these data show that NARI-29 may be a potential candidate for AR inhibitors, which will be used to prevent colon cancer progression and as adjuvant therapy for preventing TRAIL resistance.

Aldose reductase and cancer metabolism: The master regulator in the limelight

It is strongly established that metabolic reprogramming mediates the initiation, progression, and metastasis of a variety of cancers. However, there is no common biomarker identified to link the dysregulated metabolism and cancer progression. Recent studies strongly advise the involvement of aldose reductase (AR) in cancer metabolism. AR-mediated glucose metabolism creates a Warburg-like effect and an acidic tumour microenvironment in cancer cells. Moreover, AR overexpression is associated with the impairment of mitochondria and the accumulation of free fatty acids in cancer cells. Further, AR-mediated reduction of lipid aldehydes and chemotherapeutics are involved in the activation of factors promoting proliferation and chemo-resistance. In this review, we have delineated the possible mechanisms by which AR modulates cellular metabolism for cancer proliferation and survival. An in-depth understanding of cancer metabolism and the role of AR might lead to the use of AR inhibitors as metabolic modulating agents for the therapy of cancer.

Oxylipins and Reactive Carbonyls as Regulators of the Plant Redox and Reactive Oxygen Species Network under Stress

Reactive oxygen species (ROS), and in particular H2O2, serve as essential second messengers at low concentrations. However, excessive ROS accumulation leads to severe and irreversible cell damage. Hence, control of ROS levels is needed, especially under non-optimal growth conditions caused by abiotic or biotic stresses, which at least initially stimulate ROS synthesis. A complex network of thiol-sensitive proteins is instrumental in realizing tight ROS control; this is called the redox regulatory network. It consists of sensors, input elements, transmitters, and targets. Recent evidence revealed that the interplay of the redox network and oxylipins–molecules derived from oxygenation of polyunsaturated fatty acids, especially under high ROS levels–plays a decisive role in coupling ROS generation and subsequent stress defense signaling pathways in plants. This review aims to provide a broad overview of the current knowledge on the interaction of distinct oxylipins generated enzymatically (12-OPDA, 4-HNE, phytoprostanes) or non-enzymatically (MDA, acrolein) and components of the redox network. Further, recent findings on the contribution of oxylipins to environmental acclimatization will be discussed using flooding, herbivory, and establishment of thermotolerance as prime examples of relevant biotic and abiotic stresses.

Association between mixed aldehydes and bone mineral density based on four statistical models

Aldehydes as an environmental pollutant may lead to oxidative stress, which is an important mechanism in the development of osteoporosis. This suggests a possible link between aldehyde exposure and osteoporosis. Considering the mixed nature of aldehyde exposure and the interactions between different aldehydes, we explored for the first time the associations between mixed six aldehydes (benzaldehyde, butyraldehyde, heptanal, hexanal, isovaleraldehyde, and propionaldehyde) and BMD in three populations (men, premenopausal women, and postmenopausal women) by applying four statistical models: quantile g-computation (qgcomp) model, Bayesian kernel machine regression (BKMR) model, generalized linear regression model (GLM), and generalized additive model (GAM), based on the National Health and Nutrition Examination Survey (NHANES) 2013-2014. We found that mixed aldehydes could significantly reduce BMD in men, with hexanaldehyde and propanaldehyde having the greatest negative qgcomp model and BKMR model weights, also confirmed by GLM. The associations between isopentanaldehyde and propanaldehyde and femoral BMD in men were non-linear and had threshold effects as derived from the BKMR model and GAM. The associations turned positive when the concentrations of isopentanaldehyde and propanaldehyde exceeded their respective inflection points. To conclude, our study might provide new ideas for the prevention and treatment of osteoporosis, and hexanaldehyde and propanaldehyde should be more regulated to prevent osteoporosis.

Isolation and Chemical Characterization of Antifungal, Antioxidant, and Anti-Inflammatory Compounds from Centrosema coriaceum using GC/MS, UFLC-QTOF-MS, and FACE

In recent years, natural products with biological activities have been increasingly researched. The elucidation of phytoconstituents is necessary for the development of drugs as a natural alternative for the treatment of various diseases. The work aimed to evaluate in vitro and in silico bioactivities of hexane (CCHE) and methanol (CCME) fractions of ethanolic extract from Centrosema coriaceum Benth (Fabaceae) leaves and elucidate their phytoconstituents. CCHE and CCME showed antifungal activity for Candida glabrata (MIC of 1000 μg/mL) with fungistatic effect and action in cell envelope by sorbitol and ergosterol assays. CCHE and CCME presented promising antioxidant activity against the DPPH radical with IC₅₀ of 13.61±0.50 and 6.31±0.40 μg/mL, respectively, and relative antioxidant activity (RAA%) of 45.77±3.61/ 28.53±2.25 % for CCHE and 82.18±2.25/51.99±3.23 % for CCME when compared to rutin and quercetin, respectively. Moreover, these fractions demonstrated promising results for the inhibition of lipid peroxidation by β-carotene/linoleic acid assay. For anti-inflammatory and cytotoxicity activities, CCHE and CCME significantly inhibited the production of nitric oxide and TNF-α, without toxicity on murine intraperitoneal macrophages, respectively. Esters, alkanes, steroids, tocopherols, and terpenes were identified in CCHE by GC/MS. Flavonoids, phenolic acids, and disaccharides were detected in CCME by UFLC-QTOF-MS and FACE. Furthermore, rutin was purified from CCME. In silico predictions evidenced that compounds present in both fractions have high affinity to the fungal membrane besides antioxidant and anti-inflammatory activities. Based on these observations, CCHE and CCME have a noteworthy potential for the design of novel antifungal and anti-inflammatory agents that should be explored in future studies.

Silver nanoparticles synthesized by Euphorbia hirta exhibited antibacterial activity and induced apoptosis through downregulation of PI3Kγ mediated PI3K/Akt/mTOR/p70S6K in human lung adenocarcinoma A549 cells

Plant extracts were successfully applied to synthesize nanoparticles, and expected such biological processes of effective for chemotherapeutic applications and safe for human use. Our study planned to evaluate the anticancer efficacy of silver nanoparticles (AgNPs) synthesized by Euphorbia hirta on human lung adenocarcinoma A549 cells. The E. hirta synthesized Eh-AgNPs was investigated by UV-spectroscopy, X-ray diffraction, transmission electron microscopy, and Fourier-transform infrared spectroscopy examination. The bactericidal efficacy of Eh-AgNPs was studied by the agar well method, and the cytotoxicity on A549 cells was assessed by MTT assay. Results showed that Eh-AgNPs exhibited effective antibacterial activity against bacterial pathogens, established dose-dependent cytotoxicity on A549 cells, and persuaded apoptosis, as evidenced by increased lipid peroxidation and decreased levels of antioxidants. Eh-AgNPs significantly increased the early apoptosis in A549 cells in a concentration-dependent way. The Eh-AgNPs administration reduced the Bcl-2 expression; however, it increased the expression of p53, Bax, cleaved caspase-3 and -9 apoptotic members. Eh-AgNPs treatment reduced PI3Kγ, phospho-PI3K, phospho-Akt, phospho-mTOR, and p70S6K levels. The obtained results demonstrated that the Eh-AgNPs induce reactive oxygen species-mediated apoptosis by expressing p53, Bax, and inhibiting PI3K/Akt/mTOR/p70S6K signaling pathway.

Energy substrate metabolism and oxidative stress in metabolic cardiomyopathy

Metabolic cardiomyopathy is an emerging cause of heart failure in patients with obesity, insulin resistance, and diabetes. It is characterized by impaired myocardial metabolic flexibility, intramyocardial triglyceride accumulation, and lipotoxic damage in association with structural and functional alterations of the heart, unrelated to hypertension, coronary artery disease, and other cardiovascular diseases. Oxidative stress plays an important role in the development and progression of metabolic cardiomyopathy. Mitochondria are the most significant sources of reactive oxygen species (ROS) in cardiomyocytes. Disturbances in myocardial substrate metabolism induce mitochondrial adaptation and dysfunction, manifested as a mismatch between mitochondrial fatty acid oxidation and the electron transport chain (ETC) activity, which facilitates ROS production within the ETC components. In addition, non-ETC sources of mitochondrial ROS, such as β-oxidation of fatty acids, may also produce a considerable quantity of ROS in metabolic cardiomyopathy. Augmented ROS production in cardiomyocytes can induce a variety of effects, including the programming of myocardial energy substrate metabolism, modulation of metabolic inflammation, redox modification of ion channels and transporters, and cardiomyocyte apoptosis, ultimately leading to the structural and functional alterations of the heart. Based on the above mechanistic views, the present review summarizes the current understanding of the mechanisms underlying metabolic cardiomyopathy, focusing on the role of oxidative stress.

Vicious cycle of lipid peroxidation and iron accumulation in neurodegeneration

Lipid peroxidation and iron accumulation are closely associated with neurodegenerative diseases, such as Alzheimer's, Parkinson's, and Huntington's diseases, or neurodegeneration with brain iron accumulation disorders. Mitochondrial dysfunction, lipofuscin accumulation, autophagy disruption, and ferroptosis have been implicated as the critical pathomechanisms of lipid peroxidation and iron accumulation in these disorders. Currently, the connection between lipid peroxidation and iron accumulation and the initial cause or consequence in neurodegeneration processes is unclear. In this review, we have compiled the known mechanisms by which lipid peroxidation triggers iron accumulation and lipofuscin formation, and the effect of iron overload on lipid peroxidation and cellular function. The vicious cycle established between both pathological alterations may lead to the development of neurodegeneration. Therefore, the investigation of these mechanisms is essential for exploring therapeutic strategies to restrict neurodegeneration. In addition, we discuss the interplay between lipid peroxidation and iron accumulation in neurodegeneration, particularly in PLA2G6-associated neurodegeneration, a rare neurodegenerative disease with autosomal recessive inheritance, which belongs to the group of neurodegeneration with brain iron accumulation disorders.

Acutely increased aquaporin-4 exhibits more potent protective effects in the cortex against single and repeated isoflurane-induced neurotoxicity in the developing rat brain

Damage to hippocampus, cerebellum, and cortex associated with cognitive functions due to anesthetic-induced toxicity early in life may cause cognitive decline later. Aquaporin 4 (AQP4), a key protein in waste clearance pathway of brain, is involved in synaptic plasticity and neurocognition. We investigated the effects of single and repeated isoflurane (Iso) anesthesia on AQP4 levels and brain damage. Postnatal-day (P)7 Wistar albino rats were randomly assigned to Iso or Control (C) groups. For single-exposure, pups were exposed to 1.5% Iso in 30% oxygenated-air for 3-h at P7 (Iso₁). For repeated-exposure, pups were exposed to Iso for 3 days, 3-h each day, at 1-day intervals (P7 + 9+11) starting at P7 (Iso₃). C₁ and C₃ groups received only 30% oxygenated-air. Based on HE-staining and immunoblotting (Bax/Bcl-2, cleaved-caspase3 and PARP1) analyses, Iso exposures caused a higher degree of apoptosis in hippocampus. Anesthesia increased 4HNE, oxidative stress marker; the highest ROS accumulation was determined in cerebellum. Increased inflammation (TNF-α, NF-κB) was detected. Multiple Iso-exposures caused more significant damage than single exposure. Moreover, 4HNE and TNF-α contributed synergistically to Iso-induced neurotoxicity. After anesthesia, higher expression of AQP4 was detected in cortex than hippocampus and cerebellum. There was an inverse correlation between increased AQP4 levels and apoptosis/ROS/inflammation. Correlation analysis indicated that AQP4 had a more substantial protective profile against oxidative stress than apoptosis. Remarkably, acutely increased AQP4 against Iso exhibited a more potent neuroprotective effect in cortex, especially frontal cortex. These findings promote further research to understand better the mechanisms underlying anesthesia-induced toxicity in the developing brain.

Chemical priming enhances plant tolerance to salt stress

Salt stress severely limits the productivity of crop plants worldwide and its detrimental effects are aggravated by climate change. Due to a significant world population growth, agriculture has expanded to marginal and salinized regions, which usually render low crop yield. In this context, finding methods and strategies to improve plant tolerance against salt stress is of utmost importance to fulfill food security challenges under the scenario of the ever-increasing human population. Plant priming, at different stages of plant development, such as seed or seedling, has gained significant attention for its marked implication in crop salt-stress management. It is a promising field relying on the applications of specific chemical agents which could effectively improve plant salt-stress tolerance. Currently, a variety of chemicals, both inorganic and organic, which can efficiently promote plant growth and crop yield are available in the market. This review summarizes our current knowledge of the promising roles of diverse molecules/compounds, such as hydrogen sulfide (H2S), molecular hydrogen, nitric oxide (NO), hydrogen peroxide (H2O2), melatonin, chitosan, silicon, ascorbic acid (AsA), tocopherols, and trehalose (Tre) as potential primers that enhance the salinity tolerance of crop plants.

Phthalate Exposure and Oxidative/Nitrosative Stress in Childhood Asthma: A Nested Case-Control Study with Propensity Score Matching

Whether low-dose phthalate exposure triggers asthma among children, and its underlying mechanisms, remain debatable. Here, we evaluated the individual and mixed effects of low-dose phthalate exposure on children with asthma and five (oxidative/nitrosative stress/lipid peroxidation) mechanistic biomarkers—8-hydroxy-2′-deoxyguanosine (8-OHdG), 8-nitroguanine (8-NO₂Gua), 4-hydroxy-2-nonenal-mercapturic acid (HNE-MA), 8-isoprostaglandin F2α (8-isoPF2α), and malondialdehyde (MDA)—using a propensity score-matched case-control study (case vs. control = 41 vs. 111). The median monobenzyl phthalate (MBzP) concentrations in the case group were significantly higher than those in the control group (3.94 vs. 2.52 ng/mL, p = 0.02), indicating that dust could be an important source. After adjustment for confounders, the associations of high monomethyl phthalate (MMP) (75th percentile) with 8-NO₂Gua (adjusted odds ratio (aOR): 2.66, 95% confidence interval (CI): 1.03–6.92) and 8-isoPF2α (aOR: 4.04, 95% CI: 1.51–10.8) and the associations of mono-iso-butyl phthalate (MiBP) with 8-isoPF2α (aOR: 2.96, 95% CI: 1.13–7.79) were observed. Weighted quantile sum regression revealed that MBzP contributed more than half of the association (56.8%), followed by MiBP (26.6%) and mono-iso-nonyl phthalate (MiNP) (8.77%). Our findings supported the adjuvant effect of phthalates in enhancing the immune system response.

Deltamethrin and Its Nanoformulations Induce Behavioral Alteration and Toxicity in Rat Brain through Oxidative Stress and JAK2/STAT3 Signaling Pathway

Deltamethrin (DM) is the most powerful synthetic pyrethroid that has toxicity to the central nervous system and results in behavioral changes in both animals and humans. This effect is mediated by inducing alterations in the action of neurotransmitters and brain pathological changes. Nanocarrier encapsulated pesticides may decrease the toxicity of pesticides. Thus, this study aimed to determine the effect of an inorganic metal carrier (silica Nps) and polymeric capsule (chitosan Nps) of deltamethrin nano-formulations on antioxidant levels and oxidative stress in the brain and on behavior of the male albino rat. Sixty male albino rats were equally divided into four groups. Group I: control group; group II given DM liquefied in corn oil at 3.855 mg/kg BW; group III receiving silica-loaded deltamethrin (S/DM Nps) at 8.795 mg/kg BW; and group IV: given chitosan encapsulated deltamethrin (CS/DM Nps) at 30.44 mg/kg BW. All treatments were given orally for four weeks. Following this, behavioral tests were conducted to record locomotor activity, anxiety like behaviors, exploration, and the short memory of rats. In addition, brain antioxidant/oxidant, serum neurotransmitters such as acetylcholine esterase (AchE) and monoamine oxidase (MAO), JAK2 and STAT3 gene and proteins expression were measured. The DM group showed a highly significant elevation in malondialdehyde content, MAO, AchE, vascular endothelial growth factor (VEGF) levels, and the expression level of neurogenic genes, JAK2 and STAT3, in comparison with the control group. Both S/DM Nps and CS/DM Nps significantly decreased MAO, AchE, and VEGF compared with the DM group. Moreover, both S/DM Nps and CS/DM Nps significantly decreased the gene and proteins expression of JAK2 and STAT3 compared with the DM group. These alterations were evidenced by the deficiency in memory and learning behaviors that were accompanied by histopathological findings of the hippocampus and the cortex. It was concluded that the nano formulations containing DM induced less neurobehavioral toxicity than free DM. Additionally, the use of nanocarriers reduced the damage to health and the environment.

Curcumin and Wnt/β‑catenin signaling in exudative age‑related macular degeneration (Review)

Curcumin is a natural product widely used due to its pharmacological effects. Nevertheless, only a limited number of studies concerning the effects of curcumin on exudative age‑related macular degeneration (AMD) is currently available. Since ophthalmic diseases, including exudative AMD, have a marked impact on public health, the prevention and therapy of ophthalmic disorders remain of increasing concern. Exudative AMD is characterized by choroidal neovascularization (CNV) invading the subretinal space, ultimately enhancing exudation and hemorrhaging. The exudative AMD subtype corresponds to 10 to 15% of cases of macular degeneration; however, the occurrence of this subtype has been reported as the major cause of vision loss and blindness, with the occurrence of CNV being responsible for 80% of the cases with vision loss. In CNV increased expression of VEGF has been observed, stimulated by the overactivation of Wnt/β‑catenin signaling pathway. The stimulation of the Wnt/β‑catenin signaling pathway is responsible for the activation of several cellular mechanisms, simultaneously enhancing inflammation, oxidative stress and angiogenesis in numerous diseases, including ophthalmic disorders. Some studies have previously demonstrated the possible advantage of the use of curcumin for the inhibition of Wnt/β‑catenin signaling. In the present review article, the different mechanisms of curcumin are described concerning its effects on oxidative stress, inflammation and angiogenesis in exudative AMD, by interacting with Wnt/β‑catenin signaling.

Livogrit Prevents Methionine-Cystine Deficiency Induced Nonalcoholic Steatohepatitis by Modulation of Steatosis and Oxidative Stress in Human Hepatocyte-Derived Spheroid and in Primary Rat Hepatocytes

The prevalence of nonalcoholic steatohepatitis (NASH), characterized by fatty liver, oxidative injury, and inflammation, has considerably increased in the recent years. Due to the complexity of NASH pathogenesis, compounds which can target different mechanisms and stages of NASH development are required. A robust screening model with translational capability is also required to develop therapies targeting NASH. In this study, we used HepG2 spheroids and rat primary hepatocytes to evaluate the potency of Livogrit, a tri-herbal Ayurvedic prescription medicine, as a hepatoprotective agent. NASH was developed in the cells via methionine and cystine-deficient cell culture media. Livogrit at concentration of 30 µg/mL was able to prevent NASH development by decreasing lipid accumulation, ROS production, AST release, NFκB activation and increasing lipolysis, GSH (reduced glutathione), and mitochondrial membrane potential. This study suggests that Livogrit might reduce the lipotoxicity-mediated ROS generation and subsequent production of inflammatory mediators as evident from the increased gene expression of FXR, FGF21, CHOP, CXCL5, and their normalization due to Livogrit treatment. Taken together, Livogrit showed the potential as a multimodal therapeutic formulation capable of attenuating the development of NASH. Our study highlights the potential of Livogrit as a hepatoprotective agent with translational possibilities.

Atractylodin induces oxidative stress-mediated apoptosis and autophagy in human breast cancer MCF-7 cells through inhibition of the P13K/Akt/mTOR pathway

This study aimed to determine the apoptosis and autophagy-inducing mechanism of atractylodin in human breast cancer MCF-7 cells. The molecular mechanism of anticancer activity of atractylodin was confirmed by assessing the levels of reactive oxygen species (ROS) level, lipid peroxidation (LPO), antioxidants activity, dual staining, and comet assay. Moreover, cleaved caspases 3, 8, and 9, and signaling proteins, such as p53, Bcl-2, and Bax, phosphatidylinositol-3-kinase/protein kinase B/mammalian target of rapamycin(P13K/Akt/mTOR), LC3I and LC3II, and beclin-1 were analyzed. In MCF-7 cells treated with atractylodin, the concentration-dependent toxicity, increased LPO, increased production of ROS, and decreased activity of superoxide dismutase, catalase, and glutathione peroxidasewere observed. In MCF-7 cells, atractylodin administration decreased Bcl-2 expression while activating the expression of p53, Bax, cleaved caspase-3, caspase-8, and caspase-9 apoptotic members. Furthermore, atractylodin blocked the P13K/Akt/mTOR signaling pathway, increased the conversion of LC3I to its lipidated form of LC3II, and increased beclin-1 expression, whereas downregulated the p62 expression in MCF-7 cells. As a result, altering apoptotic and autophagy-related biomarkers, atractylodin triggered apoptosis and autophagy in MCF-7 cells. As a result, atractylodin could be utilized to treat human breast cancer after the proper clinical trial.

Methionine strengthens anti-inflammation of rice protein via depressing NF-κB activation and stimulating Msr expression in rats fed cholesterol-enriched diets

Oxidized low-density lipoprotein (ox-LDL) is an inducer of inflammation. To elucidate the link of depression of ox-LDL accumulation and anti-inflammatory function of rice protein (RP) whether dependent on methionine availability, growing and adult rats were fed RP and methionine-supplemented RP (RM) under cholesterol-enriched dietary condition. After two weeks feeding, RP and RMs exerted the anti-inflammatory effects through up-regulating IL-10, while RP and RMs significantly reduced ox-LDL levels and effectively suppressed the expressions of inflammatory mediators (COX-2, IL-1β, IL-6, TNF-α, iNOS). The anti-inflammatory molecular mechanism was to inhibit NF-κB activation and to simulate methionine sulfoxide reductase expression. Results showed, under cholesterol-enriched dietary condition, the anti-inflammatory action can be induced by RP and enhanced by methionine in growing and adult rats. The present study reveals a link of the decreased ox-LDL accumulation with the anti-inflammatory function of RP, which is dependent on methionine availability and independent of dietary cholesterol.

Rice protein suppresses 4-hydroxy-2-nonenal-induced inflammation owing to methionine availability

4-Hydroxy-2-nonenal (HNE) is one of the most important products of lipid peroxidation which induces inflammation. In order to investigate the effect of rice protein (RP) on suppressing HNE-induced inflammation and the role of methionine in regulating the anti-inflammatory function of RP, Wistar rats (male, weighing180-200 g) were ad libitum fed either a pellet diet with oral administration of methionine or ad libitum fed RP for two weeks. RP and methionine significantly reduced HNE levels and effectively suppressed the expressions of cyclooxygenase-2, tumor necrosis factor alpha, interleukin (IL)-1β, IL-6, and inducible nitric oxide synthase. The anti-inflammatory action of RP was evident from the upregulation of IL-10 and glutathione S-transferase, which played a role in the detoxification of HNE. The results show that the molecular mechanism responsible for the anti-inflammatory function of RP is the inhibition of nuclear factor-κB activation by the downregulation of protein kinase B/phosphoinositide 3 kinase. Further, this study demonstrates that methionine availability contributes to the suppression of HNE-induced inflammation through up-regulating IL-10 and GST in rats fed RP. Novelty: RP suppresses HNE-induced inflammation. Met plays a role in up-regulating IL-10 and GST. Met availability regulates the inhibition of NF-κB by RP.

Flavonoids: The Innocuous Agents Offering Protection Against Alzheimer's Disease Through Modulation Of Proinflammatory And Apoptotic Pathways

BACKGROUND

Beginning from mild cognitive impairment in patients suffering from Alzheimer's disease (AD), dementia sets in with the progress of the disease. The pathological changes in the brain begin fifteen to twenty years before AD related dementia develops. Presence of senile plaques and neurofibrillary tangles are considered the hallmarks of AD brain. Chronic inflammation resulting from the disruption of equilibrium between anti-inflammatory and pro-inflammatory signalling emerges as another important feature of AD and also other neurodegenerative diseases. Substantial studies demonstrate that this sustained immune response in the brain is associated with neuronal loss, along with facilitation and aggravation of Aβ and NFT pathologies. Although it is well accepted that neuroinflammation and oxidative stress have both detrimental and beneficial influences on the brain tissues, the involvement of microglia and astrocytes in the onset and progress of the neurodegenerative process in AD is becoming increasingly recognized. The cause of neuronal loss, although, is known to be apoptosis, the mechanism of promotion of neuronal death remains undisclosed.

OBJECTIVE

Controlling the activation of the resident immune cells and/or the excessive production of pro-inflammatory and pro-oxidant factors could be effective as therapeutics. Among the phytonutrients, the neuroprotective role of flavonoids is beyond doubt. This review is an exploration of literature on the role of flavonoids in these aspects.

CONCLUSION

Flavonoids are not only effective in ameliorating the adverse consequences of oxidative stress but also impede the development of late onset Alzheimer's disease by modulating affected signalling pathways and boosting signalling crosstalk.

Acrolein inhalation acutely affects the regulation of mitochondrial metabolism in rat lung

Exposure of the airways to cigarette smoke (CS) is the primary risk factor for developing several lung diseases such as Chronic Obstructive Pulmonary Disease (COPD). CS consists of a complex mixture of over 6000 chemicals including the highly reactive α,β-unsaturated aldehyde acrolein. Acrolein is thought to be responsible for a large proportion of the non-cancer disease risk associated with smoking. Emerging evidence suggest a key role for CS-induced abnormalities in mitochondrial morphology and function in airway epithelial cells in COPD pathogenesis. Although in vitro studies suggest acrolein-induced mitochondrial dysfunction in airway epithelial cells, it is unknown if in vivo inhalation of acrolein affects mitochondrial content or the pathways controlling this. In this study, rats were acutely exposed to acrolein by inhalation (nose-only; 0-4 ppm), 4 h/day for 1 or 2 consecutive days (n = 6/group). Subsequently, the activity and abundance of key constituents of mitochondrial metabolic pathways as well as expression of critical proteins and genes controlling mitochondrial biogenesis and mitophagy were investigated in lung homogenates. A transient decreasing response in protein and transcript abundance of subunits of the electron transport chain complexes was observed following acrolein inhalation. Moreover, acrolein inhalation caused a decreased abundance of key regulators associated with mitochondrial biogenesis, respectively a differential response on day 1 versus day 2. Abundance of components of the mitophagy machinery was in general unaltered in response to acrolein exposure in rat lung. Collectively, this study demonstrates that acrolein inhalation acutely and dose-dependently disrupts the molecular regulation of mitochondrial metabolism in rat lung. Hence, understanding the effect of acrolein on mitochondrial function will provide a scientifically supported reasoning to shortlist aldehydes regulation in tobacco smoke.

Natural and Synthetic Agents Targeting Reactive Carbonyl Species against Metabolic Syndrome

Reactive carbonyl species (RCS) may originate from the oxidation of unsaturated fatty acids and sugar in conditions of pathology. They are known to have high reactivity towards DNA as well as nucleophilic sites of proteins, resulting in cellular dysfunction. It has been considered that various pathological conditions are associated with an increased level of RCS and their reaction products. Thus, regulating the levels of RCS may be associated with the mitigation of various metabolic and neurodegenerative disorders. In order to perform a comprehensive review, various literature databases, including MEDLINE, EMBASE, along with Google Scholar, were utilized to obtain relevant articles. The voluminous review concluded that various synthetic and natural agents are available or in pipeline research that hold tremendous potential to be used as a drug of choice in the therapeutic management of metabolic syndrome, including obesity, dyslipidemia, diabetes, and diabetes-associated complications of atherosclerosis, neuropathy, and nephropathy. From the available data, it may be emphasized that various synthetic agents, such as carnosine and simvastatin, and natural agents, such as polyphenols and terpenoids, can become a drug of choice in the therapeutic management for combating metabolic syndromes that involve RCS in their pathophysiology. Since the RCS are known to regulate the biological processes, future research warrants detailed investigations to decipher the precise mechanism.

Phthalates mixture on allergies and oxidative stress biomarkers among children: The Hokkaido study

BACKGROUND

Exposure to individual phthalates and the mediation effect of oxidative stress in association with asthma and allergic symptoms have been studied previously. Little is known about the mixture effect of phthalates on health outcomes. Thus, we investigated the effect of a mixture of ten phthalate metabolites in association with wheeze, rhino-conjunctivitis, and eczema. The mediating effect of three oxidative stress biomarkers was also assessed.

METHODS

Levels of 10 phthalate metabolites and 3 oxidative stress biomarkers were measured in 386 urine samples from 7-year-old children. Parents reported demographic and allergic symptoms using ISAAC questionnaires. Logistic regression for individual metabolites and mixture analysis weighted quantile sum (WQS) and Bayesian kernel machine regression (BKMR) were fitted to examine the association between phthalate metabolite exposure and health outcomes. Baron and Kenny's regression approach was used for mediation analysis.

RESULTS

In logistic regression model showed mono (2-ethyl-5-carboxypentyl) phthalate (MECPP) (OR = 1.41, 95% CI 1.02-1.97) and mono carboxy-isononyl phthalate (cx-MINP) (OR = 1.40, 95% CI 1.07-1.86) were associated with wheeze. The WQS index had a significant association (OR = 1.46, 95% CI 1.09-1.96) with wheeze and (OR = 1.40, 95% CI 1.07-1.82) with eczema. Mono-isononyl phthalate (MINP) and mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP) were the most highly weighted metabolites. In the BKMR model, diisononyl phthalate (DINP) metabolites showed the highest group posterior inclusion probability (PIP). Among DINP metabolites, MINP in wheeze, cx-MINP in rhino-conjunctivitis and OH-MINP in eczema showed the highest conditional PIPs. The overall metabolites mixture effect was associated with eczema. We did not find any mediation of oxidative stress in the association between phthalates and symptoms. No significant association between phthalate metabolites and oxidative stress was observed in this study.

CONCLUSION

Mixture of phthalate metabolites were associated with wheeze and eczema. The main contributors to the association were DEHP and DINP metabolites. No mediation of oxidative stress was observed.

Apiaceous vegetables protect against acrolein-induced pulmonary injuries through modulating hepatic detoxification and inflammation in C57BL/6 male mice

Acrolein (Acr) is a reactive aldehyde in the environment. Acr causes oxidative stress and a cascade of catalytic events and has, thereby, been associated with increased risk of pulmonary diseases. Whether apiaceous vegetables (API) consumption can prevent Acr-induced pulmonary toxicity has not yet been explored hence, we investigated the effects of API on Acr-induced pulmonary damages in C57BL/6J mice. The mice were assigned into either negative control [NEG group; American Institute of Nutrition (AIN)-93G diet only], positive control (POS group; AIN-93G+Acr) or API intervention group (API group; AIN-93G+21% API+Acr). After 1 week of dietary intervention, the POS and API mice were exposed to Acr (10 µmol/kg body weight/day) for 5 days. During the exposure period, assigned diets remained the same. Prominent indicators lung of toxicity of POS mice were found, including mucus accumulation, macrophage infiltration, and hemorrhage, all of which were ameliorated by the API. Serum and lung inflammation markers, such as a tumor necrosis factor alpha were also increased by Acr while reduced by API. In the liver, API upregulated expression of glutathione S-transferases, which enhanced the metabolism of Acr into water-soluble 3-hydroxypropyl mercapturic acid for excretion. This is consistent with observed reductions in serum Acr-protein adducts. Taken together, our results suggest that API may provide protection against Acr-induced pulmonary damages and inflammation via enhancement of the hepatic detoxification of Acr.

Pharmacological investigation of antioxidant and anti-inflammatory activities of leaves and branches extracts from Plinia cauliflora (Jaboticaba)

ETHNOPHARMACOLOGICAL RELEVANCE

Among all native Brazilian plant species, Plinia cauliflora (DC.) Kausel (Jaboticaba), is well known for producing "superfruits", due to their high phenolic content and antioxidant property. The fruit has astringent characteristics, and it is popularly known for the treatment of diarrhea, rash, and intestinal inflammation. However, there are only a few studies on the use of leaves and branches of this species in the literature, mainly to treat oxidative stress and inflammation.

AIM OF THE STUDY

The present study aimed to investigate the antioxidant and anti-inflammatory potential of leaves and branches extracts from P. cauliflora.

MATERIAL AND METHODS

The phytochemical analysis of P. cauliflora extracts was performed by the total phenolic, flavonoid, and tannin dosage method. Moreover, the compounds were identified by HPLC-MS-Q-TOF. Antioxidant capacity was determined by DPPH, β-carotene/linoleic acid system, MDA formation, and phosphomolybdenum assays. In vitro and in vivo anti-inflammatory activities of P. cauliflora were evaluated by the reduction of nitric oxide in the J774A.1 cell line and inhibition of ear edema in mice, respectively.

RESULTS

The ethanolic extract of the leaves exhibited greater flavonoid content whereas the ethanolic extract of the branches showed higher tannins content. Twenty-two and seventeen compounds were identified by HPLC-MS-Q-TOF in the leaves and branches, respectively, being tellimagrandin I, castalagin, and valoneic acid dilactone reported for the first time in P. cauliflora. The antioxidant potential of extracts was confirmed through different oxidation pathways from oxidizing radicals, which might be related to the presence of phenolic compounds. For the anti-inflammatory assay, the leaves and branches extracts showed promising results, with a reduction of nitric oxide ear edema inhibition around 95% and 80%, respectively.

CONCLUSIONS

Herein, the great biological potential of leaves and branches extracts from P. cauliflora was highlighted. These parts of the plant are underused and poorly reported in the literature, especially for the antioxidant and anti-inflammatory activities.

New facets of nanozyme activity of ceria: lipo- and phospholipoperoxidase-like behaviour of CeO2 nanoparticles

Cerium dioxide nanoparticles have a special place among engineered nanomaterials due to the wide range of their enzyme-like activities. They possess SOD-, catalase- and peroxidase-like properties, as well as recently discovered phosphatase-, photolyase-, phospholipase- and nuclease-like properties. Advancing biomedical applications of CeO₂-based nanozymes requires an understanding of the features and mechanisms of the redox activity of CeO₂ nanoparticles when entering the vascular bed, especially when interacting with lipid-protein supramolecular complexes (biomembranes and lipoproteins). In this paper, CeO₂ nanoparticles are shown to possess two further types of nanozyme activity, namely lipo- and phospholipoperoxidase-like activities. Compared to a strong blood prooxidant, hemoglobin, CeO₂ nanoparticles act as a mild oxidising agent, since they exhibit a 10⁶ times lower, and 20 times lower, prooxidant capacity towards linoleic acid and phosphatidylcholine hydroperoxides, respectively. Compared to the widespread pharmacological preparation of iron, Fe(iii) carboxymaltose (antianemic preparation Ferinject®), the prooxidant capacity of CeO₂ nanoparticles towards lipid and phospholipid substrates has been shown to be 10² times lower, and 4 times higher, respectively. The data obtained on the mechanism of the interaction of nanodisperse CeO₂ with the main components of biological membranes, lipids and phospholipids enable the substantial expansion of the scope of biomedical applications of CeO₂ nanozymes.

CeO₂ nanoparticles were shown to possess two novel types of enzyme-like activity, namely lipoperoxidase and phospholipoperoxidase activity.

Neuronal Death, Glial Reactivity, Microglia Activation, Oxidative Stress and Bioenergetics Impairment Caused by Intracerebroventricular Administration of D-2-hydroxyglutaric Acid to Neonatal Rats

D-2-hydroxyglutaric acid (D-2-HG) accumulates and is the biochemical hallmark of D-2-hydroxyglutaric acidurias (D-2-HGA) types I and II, which comprehend two inherited neurometabolic diseases with severe cerebral abnormalities. Since the pathogenesis of these diseases is poorly established, we tested whether D-2-HG could be neurotoxic to neonatal rats. D-2-HG intracerebroventricular administration caused marked vacuolation in cerebral cortex and striatum. In addition, glial fibrillary acidic protein (GFAP), S-100 calcium binding protein B (S100B) and ionized calcium-binding adapter molecule 1 (Iba-1) staining was increased in both brain structures, suggesting glial reactivity and microglial activation. D-2-HG also provoked a reduction of NeuN-positive cells in cerebral cortex, signaling neuronal death. Considering that disturbances in redox homeostasis and energy metabolism may be involved in neuronal damage and glial reactivity, we assessed whether D-2-HG could induce oxidative stress and bioenergetics impairment. D-2-HG treatment significantly augmented reactive oxygen and nitrogen species generation, provoked lipid peroxidation and protein oxidative damage, diminished glutathione concentrations and augmented superoxide dismutase and catalase activities in cerebral cortex. Increased reactive oxygen species generation, lipoperoxidation and protein oxidation were also found in striatum. Furthermore, the antagonist of NMDA glutamate receptor MK-801 and the antioxidant melatonin were able to prevent most of D-2-HG-induced pro-oxidant effects, implying the participation of these receptors in D-2-HG-elicited oxidative damage. Our results also demonstrated that D-2-HG markedly reduced the respiratory chain complex IV and creatine kinase activities. It is presumed that these deleterious pathomechanisms caused by D-2-HGA may be involved in the brain abnormalities characteristic of early-infantile onset D-2-HGA.