Antioxidants

Mitochondrial morphology and function are critical determinants of neuronal function and survival, with disruptions in mitochondrial dynamics often preceding the overt neuronal dysfunction seen in neurodegenerative diseases such as Alzheimers disease, Huntingtons disease and Parkinsons disease. The kynurenine pathway accounts for 95% of dietary tryptophan catabolism and many of the metabolites are neuroactive, including redox-active 3-hydroxykynurenine (3-HK). 3-HK is present under normal physiological conditions in the central nervous system (CNS) and is elevated during inflammation. While supraphysiological levels of 3-HK have been associated with neurotoxicity, the effects of physiological concentrations on neuronal cells, and specifically their mitochondria, remain poorly understood. Here we assessed viability, ATP levels and redox status to determine cellular health and function in neuronal cells exposed to physiological levels of 3-HK, alongside confocal imaging and transcriptomic profiling, finding significant alterations in mitochondrial function and morphology. Interestingly, a biphasic influence of 3-HK on mitochondrial morphology was observed, with an elongated network as well as decreased surface area and volume being observed only at the lowest concentration of 3-HK, reflecting normal physiological levels. At the highest 3-HK concentration tested, reflecting an inflammatory situation, an increased number of mitochondria were present, accompanied by increased activation of caspase-3/7 and enhanced production of mitochondrial superoxide. These results highlight a previously unknown role for 3-HK in regulating mitochondrial function and structure, possibly through altered fission and fusion events, suggesting that subtle changes in kynurenine pathway metabolism may contribute to early mitochondrial dysfunction in neurological disease.

Rhodiola rosea is a traditional medicinal plant often classified as an adaptogen, with reported effects in supporting the bodys response to physical, environmental, and emotional stressors. The present study investigated the antioxidant properties of Rhodiola rosea extract and its major chemical constituents to provide insight into their potential mechanisms of action. Through in vitro biochemical assays, we demonstrated that Rhodiola rosea extract has the capacity to reduce hydrogen peroxide (H2O2) levels. Among its primary chemical components, rosavin significantly decreased H2O2, whereas salidroside had no effect. Neither compound affected superoxide levels. Structural analysis revealed that the intact phenylpropanoid glycoside architecture of rosavin is required for activity, as its individual components, arabinose and rosin, showed no inhibitory effect. Further investigation demonstrated that rosavin attenuates H2O2-mediated oxidation of thiol groups, supporting a role in cellular redox regulation. In cultured human cells, rosavin mitigated reductions in cell viability induced by exposure to H2O2, indicating cytoprotective effects under oxidative stress conditions. Finally, in an in vivo model, administration of SARS-CoV-2 spike protein increased circulating levels of H2O2, which were subsequently reduced following rosavin treatment. Collectively, these findings identify rosavin as a structurally dependent antioxidant component of Rhodiola rosea that modulates H2O2-associated oxidative stress and supports further investigation of phenylpropanoid glycosides as adaptogens.

The production of reactive oxygen species (ROS) in response to cadmium (Cd) has been extensively studied, demonstrating that they play a key role in the plants response to this heavy metal. While the role of enzymes like RBOHs has been thoroughly studied, the function of other ROS-producing enzymes, such as peroxisomal glycolate oxidase (GOX), remains largely overlooked. Peroxisomal GOX is a core metabolic enzyme of the photorespiratory pathway occurring in chloroplasts, mitochondria and peroxisomes. Using Arabidopsis (Arabidopsis thaliana) mutants lacking the main peroxisomal GOX genes, GOX1 (gox1-1) and GOX2 (gox2-1) we explored their function in plant response to Cd. Although photosynthetic capacity appears to be affected to the same extent in both mutants under control and Cd stress conditions, GOX2 seems to play a greater role in ROS production in response to the metal. Transcriptomic analyses on WT and gox2-1 pointed to the mitochondrial electron transport chain (mETC) as a target of Cd stress. We further investigated the individual GOX1 and GOX2 functions in mETC regulation and redox state. Although oxidative ratio of mitochondria was higher in both mutants, it was more pronounced in the absence of GOX1. Furthermore, the mETC is affected in both mutants but the regulation of its components differs in each mutant. These results point out the different functions of the two photorespiratory GOX isoforms in Arabidopsis, leading to a better understanding of the photorespiratory pathway.

Age-related macular degeneration (AMD) is a progressive complex eye disease and one of the leading causes of blindness. AMD progression is marked by molecular changes in the retinal pigmented epithelium (RPE) which include increased reactive oxygen species (ROS) accumulation, mitochondrial dysfunction - eventually leading to dysfunctional RPE. Mitophagy regulator, Pink1, is reduced in the RPE of AMD patients and Pink1 loss leads to a shift from mitochondrial respiration to glycolysis. Serine is a non-essential amino acid which is de novo synthesized from glycolytic intermediate 3-PG via the rate limiting enzyme PHGDH. Serine is tightly integrated into anabolic processes like glutathione (GSH) cycling, maintaining NADH/NADPH pools leading to changes in AMPK signaling. Here, we show that Pink1 loss leads to a reduction in PHGDH and serine levels in the RPE leading to impaired mitochondrial structure and function, increased ROS mediated damage, increased inflammation, and hampered retinal function. Serine supplementation rescued ROS accumulation, balanced GSH abundance, and increased retinal function. Overall, our study highlights the potential of dietary serine in ROS management in AMD.

RAP2.6, an AP2/ERF transcription factor (TF), regulates plant stress responses; however, its role in floral transition remains unexplored. Here, we evaluated RAP2.6s role in flowering and the associated transcriptional changes in Arabidopsis thaliana under long-day conditions. RAP2.6-overexpressing line showed early flowering with fewer rosette leaves, whereas rap2.6-1 mutant flowered later, had more rosette leaves, and higher expression of the floral repressor FLOWERING LOCUS C (FLC). Early flowering in the overexpressing line was accompanied by transcriptional activation of the floral integrators GIGANTEA (GI), FLOWERING LOCUS T (FT), and COSTANS (CO), potentially through RAP2.6 interaction with GCC/DRE cis-regulatory elements. RAP2.6-mediated floral transition depended on nitric oxide (NO), with flowering time largely varying based on NO bioactivity. RAP2.6 was found to be a downstream regulator of Arabidopsis S-NITROSOGLUTATHIONE REDUCTASE 1 (GSNOR1) in controlling S-nitrosothiol (SNO) levels, flowering time, and silique formation. The NITRIC OXIDE-ASSOCIATED 1 (NOA1)-dependent reduction in NO levels abolished early flowering in 35S::RAP2.6 plants without affecting silique formation. Furthermore, enhanced cytokinin sensitivity and upregulation of cytokinin biosynthetic genes suggest cytokinin involvement in RAP2.6-mediated flowering. Together, these findings highlight the crucial role of RAP2.6 in regulating flowering time by integrating redox and hormonal signaling to coordinate reproductive development in A. thaliana.

The tight regulation of iron homeostasis is of great importance for cellular health. An increase in intracellular iron levels results in the formation of free radicals, which damages macromolecules and membranes, eventually resulting in cell death by Ferroptosis. Recently, we showed that patients with mutations in VPS41 display a severe neurodegenerative phenotype with iron deposition in the brain. VPS41 is well known as subunit of the HOPS complex required for fusion of late endosomes and autophagosomes with lysosomes. However, VPS41 has also been identified as inhibitor of Ferroptosis and regulator of redox homeostasis. How VPS41 exerts these functions and if these are dependent on the HOPS complex is unknown. Here we show that depletion of VPS41 results in increased intracellular iron levels, ROS formation and mitochondrial fission. Our findings indicate an important role for VPS41 in the regulation of iron homeostasis and mitochondrial fission and suggest Ferroptosis as a possible cause for neurodegeneration in VPS41 patients.

Background/ObjectivesNeuroinflammation-driven iron dysregulation and neurotoxic astrocyte polarization are increasingly recognized as interconnected pathological mechanisms in neurodegenerative diseases. Systemic inflammation triggered by strenuous exercise or infection can engage the central nervous system and astrocytic inflammatory responses and perturb iron homeostasis; however, targeted nutritional strategies to counteract these processes remain limited. Inflamate(R) is a multi-component botanical supplement comprising boswellic acids, astilbin, xanthohumol, and cinnamaldehyde, each with documented anti-inflammatory properties. However, whether this combined formulation can modulate the inflammatory-iron metabolic axis and astrocyte phenotypic polarization remains unexplored. This study aimed to investigate the effects of Inflamate(R) on LPS-induced pro-inflammatory gene expression, iron metabolism-related gene regulation, and A1/A2 astrocyte phenotypic polarization in mouse astrocytes. MethodsMouse astrocytes (AWT) were pre-treated with Inflamate(R) (0.0375 g/mL) or DMSO vehicle for 24 h, followed by lipopolysaccharide (LPS; 1 g/mL) stimulation for an additional 24 h. The non-cytotoxic working concentration was determined by morphological assessment, CCK-8 cell viability, and LDH cytotoxicity assays. Expression of 14 target genes spanning pro-inflammatory mediators (NOS2, IL6, C3, COX2, PLA2g15, SOCS3), iron metabolism regulators (FTH1, Hepcidin, TFRC, SLC40A1, RGMa, RGMb), and astrocyte polarization markers (S100A10, GFAP) was quantified by qRT-PCR. ResultsUnder normal culture conditions, Inflamate(R) did not significantly alter the expression of any target gene except S100A10, confirming the absence of baseline cytotoxicity or transcriptional homeostatic perturbation. Upon LPS stimulation, Inflamate(R) selectively suppressed NOS2 (approximately 64% reduction, p < 0.0001), IL6 (approximately 37% reduction, p < 0.0001), and C3 (approximately 47% reduction, p < 0.0001), while COX2, PLA2g15, and SOCS3 remained unaffected. Concurrently, Inflamate(R) significantly reduced LPS-induced Hepcidin expression to approximately 17% of the control level (p < 0.05) and attenuated FTH1 upregulation (p < 0.01), without altering the expression of iron transporters (TFRC, SLC40A1) or BMP-SMAD pathway components (RGMa, RGMb). Furthermore, Inflamate(R) upregulated the neuroprotective A2 marker S100A10 under both basal (p < 0.05) and LPS-stimulated conditions (p < 0.01), while the general reactivity marker GFAP remained unchanged. ConclusionsInflamate(R) exerts a selective, multi-target modulatory effect at the transcriptional level in LPS-stimulated astrocytes, encompassing suppression of the iNOS-NO and IL-6 signaling axes, attenuation of inflammation-driven hepcidin-ferritin iron dysregulation via the IL-6-STAT3 pathway, and promotion of a phenotypic shift from neurotoxic A1 toward neuroprotective A2 astrocyte polarization. Given that the IL-6-JAK-STAT3-hepcidin axis is also activated during exercise-induced systemic inflammation, these findings suggest that Inflamate(R) may represent a targeted nutritional strategy for preserving CNS iron homeostasis and supporting neuroprotective astrocyte function in both neurodegenerative and exercise-related neuroinflammatory contexts. Further validation in in vivo neurodegenerative and exercise models, including protein-level analyses, is warranted to confirm these transcriptional findings.

Inflammation and oxidative stress (OS) are key to Parkinsons disease (PD). We performed a cross-dataset integrative transcriptomic analysis to identify OS- and inflammation-related hub genes persistently dysregulated in PD and to evaluate their response to nutrigenomic interventions using publicly available datasets. Four GEO datasets (GSE7621, GSE20141, GSE20146, GSE49036) were analysed to identify differentially expressed genes (DEGs), which were intersected with GeneCards OS-inflammation gene sets. Functional enrichment analyses, including gene ontology (GO), pathway over-representation analysis (ORA), and protein-protein interaction (PPI) analysis, were used to identify key pathways and hub genes. Gene-food bioactive compound (FBC) association was explored by integrating PD signatures with nutrigenomic profiles from NutriGenomeDB. We identified 183 DEGs in PD, enriched in synaptic, dopaminergic, OS, and inflammatory pathways. Intersection analysis yielded 26 OS-inflammation-related genes and 10 central regulators, including TH, DDC, SNCA, LRRK2, HSPB1, and HSPA1B. revealed opposing transcriptional patterns, with several FBCs suppressing stress-related genes and upregulating dopaminergic markers such as TH, GCH1, and DDC. Overall, this integrative analysis highlights OS-inflammation gene networks in PD and identifies candidate diet-gene interactions that warrant further experimental validation

Artemisinin is an effective antimalarial drug sourced from Artemisia annua, but its low and variable yields require enhancement either semi-synthetically or in-planta to meet the global demand for treatment. Though essential enzymes have been identified in the artemisinin biosynthetic pathway, including an essential Cytochrome P450 monooxygenase (CYP71AV1), there are still many unknowns. Cytochrome P450 reductase 1 (herein, AaCPR1), has been experimentally confirmed as an electron transfer partner for CYP71AV1 in its three step oxygenation of key artemisinin precursors. However, the recent discovery of a highly related CPR, herein AaCPR2, introduces the possibility that another, potentially more catalytically favourable interaction, could exist for CYP71AV1. Therefore, enzyme kinetics and differential scanning fluorimetry (DSF) were used in the characterisation of both AaCPR1 and AaCPR2 to determine the existence and source of their catalytic differences. Tested enzyme activity under cytochrome c and NADPH concentrations revealed that AaCPR1 had lower Km and higher kcat/Km values, while AaCPR2 had higher Vmax and kcat values. This suggests that AaCPR1 is more effective at reducing cytochrome c when substrate conditions are limiting, whereas AaCPR2 is more effective than AaCPR1 at reducing cytochrome c when substrate conditions are saturating. This implies a functional partitioning of the two enzymes on the basis of substrate availability. The DSF results provided deeper insight into the different protein-ligand interactions between the two enzymes. AaCPR2 reached lower maximum melting temperatures across all tested conditions, whereas AaCPR1 had higher maximum melting temperatures. Thus, AaCPR1 exhibits higher thermal stability and has a higher temperature threshold than AaCPR2. This contributes to the notion that the AaCPRs are functionally divergent also on the basis of temperature. The cumulative differences in melting behaviour between the two enzymes led to the hypothesis that AaCPR1 and AaCPR2 exhibit different domain motions that may lead to preferential catalysis for one redox partner over another. This was further supported by the prediction of a highly variable loop region between the two enzymes at the connecting domain just after the flexible hinge. If such loops are highly mobile, as predicted, then the residue differences therein could provide a bio-structural basis for the kinetic and thermal/biophysical differences observed between AaCPR1 and AaCPR2. These data support that AaCPR1 and AaCPR2 possess fundamental biophysical differences despite their high degree of relatedness. Ultimately, these differences suggest differential metabolic functions of the two enzyme in artemisinin biosynthesis and/or other important secondary metabolic processes.

Objective Fatty Acid esters of Hydroxy-Fatty Acids (FAHFAs) are anti-diabetic and anti-inflammatory lipokines produced mainly by adipose tissue (AT). As exercise training enhances FAHFA levels, we investigated the impact of acute exercise (AE) and exercise-mimicking conditions on circulating and adipocyte FAHFA levels. Methods Clinical trial (NCT05572905) in 60 women, grouped by BMI (lean vs. obese) and age (young vs. older), was combined with in vitro experiments on human adipocytes. Following baseline characterization (body composition, VO2max, insulin sensitivity, AT/plasma FAHFAs), women underwent a cross-over AE and control interventions with repeated blood sampling for FAHFA analysis. Results In AT, lean and older women exhibited higher FAHFA levels than obese and young women, respectively; older women also showed a shift toward higher levels of 13/12-carbon-branched FAHFAs. Circulating FAHFA levels were similar across all groups and were not positively associated with insulin sensitivity, VO2max or FAHFA levels in AT. Although AE increased circulating free fatty acids (FFA), plasma FAHFAs dropped in response to both AE and control interventions. In adipocytes, FAHFAs were unaffected by glucocorticoids but increased in response to lipolysis together with gene expression related to FFA oxidation (FAO). Nevertheless, blocking mitochondrial FAO partially mimicked the lipolytic effect, while peroxisomal inhibition synergistically boosted FAHFA lipolysis-driven production despite having no effect alone. Conclusions While adiposity and aging modulate FAHFA levels in AT, circulating levels remain stable and unaffected by AE, challenging subcutaneous AT as their primary systemic source. In vitro, FAHFA synthesis is driven by high FFA availability but limited by competing peroxisomal FAO.

ObjectiveN-acetylcysteine (NAC) is a clinically available antioxidant with potential applications in trauma-induced hypermetabolic states, including burn injury and crush syndrome. However, its effects on heat-stressed skeletal muscle cells remain incompletely characterized. This study conducted a secondary analysis of a publicly available dataset to quantify NACs protective effects against heat-stress-induced cellular damage. MethodsWe re-analyzed a publicly available dataset (Lu J, 2024, Mendeley Data, doi:10.17632/wffrtcgbnx.1) containing 21 observations across three conditions: Control (n=3), Heat Stress only (HS, n=3), and HS with NAC at five doses (0.5-8.0 mM, n=3 per dose). The primary outcome was the protective ratio [(HS+NAC - HS) / (Control - HS)], where 1.0 indicates complete protection. Statistical analyses included one-way ANOVA, post-hoc t-tests with Bonferroni correction, Cohens d effect sizes, and bootstrap confidence intervals. ResultsHeat stress significantly reduced cell viability by 56.3% (Control: 100.0 {+/-} 12.2 vs HS: 43.7 {+/-} 5.1; t(4)=7.37, p=0.002, Cohens d=6.02). NAC demonstrated a biphasic dose-response with maximal protection at 2.0 mM (66.7 {+/-} 14.4), yielding a protective ratio of 0.409 (95% CI: 0.146-0.675), representing 40.9% protection against heat stress damage. The comparison between HS and HS+NAC (2.0 mM) showed a large effect size (Cohens d = 2.12) but did not reach statistical significance (p = 0.060) due to the small sample size. One-way ANOVA confirmed overall group differences (F(2,18)=32.39, p<0.001, 2=0.783). ConclusionsNAC provides partial protection against heat stress-induced skeletal muscle cell damage at 2.0 mM, with a large effect size suggesting clinical relevance despite limited statistical power. These preliminary findings support further investigation of NAC as an adjunct therapy in trauma-induced hypermetabolic states. All analysis code is provided for reproducibility.

BackgroundAcute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are frequently associated with cardiac complications, including myocardial injury and right ventricular dysfunction. However, the mechanisms linking pulmonary injury to cardiac dysfunction remain incompletely understood. In this study, we investigated ventricular mitochondrial respiratory function during the acute phase of bleomycin-induced ALI. MethodsALI was induced in male and female rats by intratracheal bleomycin (2.5 mg/kg); saline served as a control. Circulating cardiac troponin I (cTnI) was measured as an indicator of myocardial injury. Mitochondrial respiration was assessed in permeabilized ventricular fibers using high-resolution respirometry (HRR). The mitochondrial respiration rate of the H9C2 cardiomyoblast cell line was performed using Seahorse Xfe96 Cell Mitochondrial Stress Test. Cells were treated with pro-inflammatory cytokine cocktails (PRO; IL1{beta} plus TNF plus IL6), anti-inflammatory cytokine cocktails (ANTI; IL4 plus IL10), a mixture of PRO and ANTI (BOTH), and (-)-norepinephrine (NE) in either hypoxic (1% oxygen) or normoxic conditions. ResultsBleomycin-induced ALI increased circulating cTnI levels in male rats, indicating early cardiac stress following lung injury. Mitochondrial respiration in the LV appeared to show modest alterations, with preserved oxidative phosphorylation (OXPHOS) and electron transport (ET) capacity. In contrast, the RV of male animals demonstrated marked reductions in absolute respiratory flux and substrate-supported OXPHOS capacity, indicating impaired mitochondrial oxidative capacity. Female animals exhibited greater preservation of mitochondrial respiratory function, particularly in the RV, with higher OXPHOS capacity and greater Complex I gain than males. H9C2 cells treated with PRO showed a significant increase in uncoupled respiration following 6- and 24-hour incubation periods, under normoxic conditions. Maximal respiration and spare respiratory capacity were increased following 24-hours under hypoxia. No significant changes were observed following treatment with NE alone and in combination with PRO under normoxia or hypoxia for 24 hours. ConclusionsALI induces ventricle-specific and sex-dependent alterations in cardiac mitochondrial bioenergetics, with pronounced impairment in males and relative mitochondrial resilience in females. In H9C2 cardiomyoblasts, short-term exposure (6-24 hours) to pro-inflammatory cytokines enhances uncoupled mitochondrial respiration under normoxic conditions, while short-term hypoxic exposure independently increases maximal respiration and spare respiratory capacity.

Conflicting roles have been proposed for the E. coli protein RatA. Initially described as a ribosome targeting toxin, a later report pronounced it the bacterial homologue to the inner mitochondrial membrane protein Coq10. Coq10 proteins are conserved from prokaryotes to human and implicated to serve a lipid chaperone role in the biosynthesis of ubiquinone, a crucial electron carrier during aerobic respiration. We recently identified that the contradictory results published for RatA can be attributed to a mis-annotation of the gene in the reference genome. Here, we further elucidate the molecular function of RatA. We clarify that RatA is not a toxin but serves as a lipid shuttle for ubiquinone from its cytosolic biosynthesis complex to the inner membrane. Furthermore, we show that the loss of RatA results in an impaired, but not abolished electron transport chain and demonstrate broad metabolic adaptations of the cells as a consequence. Therefore, we propose to rename RatA to UbiM to reflect its function and to be in accordance with the naming convention of other ubiquinone biosynthesis proteins.

Catechinopyranocyanidins (Cpcs) which consist of diastereomers A and B are pigments derived from adzuki beans and are compounds in which the catechin and cyanidin skeletons are condensed to a pyrano ring. While catechins and anthocyanidins possess high antioxidant capacity, the physiological functions of Cpcs remains unclear. In this study, the antioxidant capacity of Cpcs was evaluated by in vitro antioxidant assays and by assessing their cytoprotective activity against oxidative stress in normal human dermal fibroblasts (NHDFs). Antioxidant capacity based on the hydrogen atom transfer (HAT) mechanism, as assessed by the ORAC assay revealed that Cpcs exhibit 14.1 mol TE/mol (Trolox equivalent antioxidant capacity: TEAC). Meanwhile, capacity based on the single electron transfer (SET) mechanism, as assessed by the DPPH, ABTS and CUPRAC assays revealed, they exhibit 2.1-3.6 mol TE/mol. Since TEAC value of Cpcs demonstrated by the HAT based mechanism higher than its SET based oxidative capacity suggesting that the antioxidant capacity of Cpcs is driven by the HAT mechanism. In cell culture experiments, Cpcs ameliorate cell toxicity in rotenone-induced injury model, suggesting to cytoprotective activity against mitochondrial dysfunction-dependent apoptosis. These results reveal novel physiological functions of Cpcs which may serve as a design guideline for elucidating in vivo dynamics based on antioxidant mechanisms.

IntroductionThe mitochondrial citrate carrier (CiC), which mediates the transport of citrate across mitochondria, has been implicated in various diseases, but its role in kidney tubules is unclear. Here, we unraveled a novel role of CiC in tubular metabolism in the context of antibiotics-induced acute tubular injury (ATI). MethodsATI was induced by administration of vancomycin and gentamycin for 48 hours in mice (V+G-ATI). Tubular-specific CiC knockout (KO) was induced by adeno-associated virus (AAV) serotype 9 encoding Cre recombinase driven by KSP promoter (AAV9-Ksp-Cre) injection. Unbiased proteomic and metabolomic analyses were performed in CiC KO mouse kidneys. We performed in vivo 13C metabolic flux analysis to elucidate metabolic alterations in ATI and the effect of CiC KO. ResultsIn this study, V+G-induced ferroptosis, oxidative damage, and extensive ATI in mice were alleviated by CiC KO. Metabolic reprogramming induced by CiC KO increased mitochondrial TCA cycle intermediates, including alpha ketoglutarate (AKG), and elevated levels of the endogenous antioxidant glutathione (GSH). Supplementation with AKG or GSH attenuated V+G-ATI in mice. Tracking of the 13C pyruvate / lactate revealed an increased flux of glucose oxidation pathway in V+G-ATI. Interestingly, tubular-specific CiC KO expands the effective TCA cycle pool reserve space, which may contribute to mitigation of ROS. The beneficial metabolic alteration in CiC KO requires AKG and glutamate, as simultaneous inhibition of mitochondrial transporters of AKG and glutamate attenuated the cytoprotective effects of CiC KO against antibiotic-induced oxidative damage. ConclusionsThis is the first study to demonstrate the role of mitochondrial CiC in kidney tubular epithelial cells, showing that it induces metabolic alterations that protect against antibiotic-induced ATI.

The gut microbiome plays a central role in host metabolism, immune function, and overall health, with disruptions in microbial composition (dysbiosis) being associated with a range of metabolic, inflammatory, and infectious conditions [1,2]. Consequently, strategies aiming to modulate the microbiome require selective activity that preserves beneficial commensals while limiting pathogenic organisms [3]. In this context, ThymoQuin(R)--a cold-pressed, standardized black cumin (Nigella sativa) seed oil developed by TriNutra Ltd. and defined by [&ge;]3% thymoquinone (TQ), controlled p-cymene levels, and low free fatty acids ([&le;]1.25%)--was evaluated for its microbiome-relevant activity. In vitro minimum bactericidal concentration (MBC) assays across three independent batches demonstrated a biphasic, dose-dependent response. At intermediate concentrations (0.25-0.5%), Streptococcus thermophilus was strongly stimulated (up to 53-fold) and Lactiplantibacillus plantarum fully preserved, while Klebsiella pneumoniae was effectively reduced (>94%). Akkermansia muciniphila exhibited stable viability at concentrations below 1%, with reductions only observed at 1%. This is notable given its role as a mucin-degrading commensal that has been linked to metabolic health, but whose abundance may vary across physiological and disease contexts [4,5]. At concentrations [&ge;]1%, selective effects diminished, resulting in broader antimicrobial activity and reduced specificity. These findings indicate a defined concentration range in which selective microbiome modulation is maintained, whereas higher thymoquinone levels may increase the risk of non-selective detrimental effect on microbes.

Chilling stress induces photosystem I (PSI) photoinhibition in chilling-sensitive cucumber, in which insufficient activity of the chloroplast NADH dehydrogenase-like complex (NDH) leads to PSI over-reduction and damage. However, it is not yet clear whether these findings can be generalized to other species or what the molecular mechanism underlying impaired NDH function is. In this study, we first examined whether NDH is essential for PSI protection under chilling stress using an NDH-deficient rice mutant. Compared with wild-type plants, the NDH-deficient mutant exhibited enhanced PSI over-reduction and pronounced PSI photoinhibition under chilling stress. In contrast, rice plants expressing flavodiiron protein (FLV), which functions as an alternative electron acceptor downstream of PSI, did not exhibit PSI photoinhibition under chilling stress, demonstrating that electron sink capacity of NDH is important for PSI protection under chilling stress. Furthermore, analysis of the factors responsible for NDH dysfunction under chilling stress in cucumber revealed that chilling stress destabilizes the PSI-NDH supercomplex, leading to NDH monomerization and a consequent loss of NDH activity. This NDH monomerization is likely attributable to chilling-induced damage to the light-harvesting complex Lhca, which mediates the association between PSI and NDH. Together, these results indicate that NDH is essential for protecting PSI from photoinhibition under chilling stress in both rice and cucumber, and that chilling-induced destabilization of the PSI-NDH supercomplex represents a key molecular mechanism underlying PSI over-reduction and photoinhibition.

Since NO can modulate mesenchymal cell function, we posit that NO can modulate gene expression associated with excitation-contraction coupling. Our study shows that treating asthma-derived HASMCs with a low dose of NO plus sGC stimulator BAY-41, in most cases sensitized smooth muscle sGC towards activation via an elevated sGC heterodimer and in some cases also improved sGC{beta}1, catalase, Cyb5r3 or Trx1 expression (n=24 non-asthma and n=25 asthma). Interestingly we found that majority of asthma HASMCs showed a marked downregulation of G6PD expression inducing a low GSH/GSSG ratio in asthma, and these findings were replicated in murine lungs of allergic asthma (OVA and CFA/HDM). Studies with HEK/COS-7 cells showed G6PD synergizing with hsp90 in enabling sGC heme-maturation. G6PD overexpression in HASMCs enhanced the sGC heterodimerization while silencing of endogenous G6PD abrogated it. Complementation of these cellular results with whole animal models of G6PD deficiency or overexpression provided verification to our findings. Mouse lung tissue from the humanized variant of G6PD deficiency, V68M (G6PD A-deficiency) showed significant downregulation in the sGC heterodimer, with a concomitant reduction in its NO heme-dependent activity, thereby showing that G6PD deficiency lowers sGC heme. Conversely, G6PD overexpressing mouse lung tissue displayed an elevated sGC heterodimer and also showed a robust G6PD-sGC{beta}1 interaction, suggesting G6PD to be involved in the heme-maturation of sGC{beta}1. While G6PD maintains the cell redox by generating NADPH, its new role in regulating sGC maturation links sGC dysfunction in asthma to G6PD deficiency and may potentially uncover new targets for asthma treatment.

BackgroundLauric acid (LA) is a medium-chain saturated fatty acid found in several foods, including vegetable oils and seeds. Previous studies have demonstrated that LA exhibits neuroprotective, antioxidant, and anti-inflammatory properties in experimental models of neuropsychiatric disorders. Therefore, the present study aimed to investigate the behavioral and neurochemical effects of LA in a corticosterone-induced murine model of depression. MethodsMale Swiss mice received corticosterone (CORT; 20 mg/kg, subcutaneously) for 23 consecutive days, while the control group received vehicle only. During the last nine days of the experimental protocol, the animals received the respective treatments by oral gavage: LA (10 or 20 mg/kg), fluvoxamine (FLUV; 50 mg/kg), or vehicle, administered 1 hour after CORT injection. One hour after treatment administration, the animals were subjected to the behavioral tests: Forced Swimming Test (FST), Tail Suspension Test (TST), and Open Field Test (OFT). At the end of the experimental protocol, the animals were euthanized, and the prefrontal cortex (PFC), hippocampus (HPC), and striatum (STR) were collected for neurochemical analyses. ResultsChronic CORT treatment significantly increased immobility time in the FST and TST, characterizing depressive-like behavior. Treatment with LA reversed these behavioral alterations, showing an effect similar to that observed in the FLUV-treated group. In the OFT, LA did not promote significant changes in locomotor activity, suggesting the absence of psychostimulant effects. Regarding neurochemical analyses, LA treatment did not reduce malondialdehyde (MDA) or nitrite/nitrate (NO2-/NO3-) levels, nor did it alter reduced glutathione (GSH) levels in the evaluated brain regions. ConclusionThe results demonstrated that LA treatment was able to reverse corticosterone-induced behavioral alterations in mice, indicating a potential antidepressant-like effect. Furthermore, the observed effects were not associated with nonspecific locomotor alterations. Although LA did not promote significant changes in the evaluated neurochemical markers, these findings reinforce its potential as a therapeutic agent for depressive disorders and highlight the need for further studies to elucidate its mechanisms of action and possible clinical applicability.

One major aftermath of COVID-19 pandemic is cardiovascular consequences. SARS-CoV-2 binds to ACE2 and downregulates vasodilation. Dengue favors hypotension by weakening endothelial glycocalyx leading to plasma leakage. C1q levels, immune complexes (ICs), and proteomic profiles in serum samples from 52 COVID-19 and 19 pre-pandemic Dengue cases were studied. Unlike Dengue, COVID-19 serums showed elevated coagulation proteins promoting vaso-occlusion and peripheral artery diseases. The stress-induced chaperone and atherosclerosis marker, GRP78 (gene/ protein) was found upregulated upon SARS-CoV-2 spike expression in cardiac/ lung cell lines. Elevated GRP78 levels were also observed in serum samples from COVID-19-diagnosed individuals and subjects with myocardial infarction (MI) in post COVID-era. Surprisingly, spike antibodies (Abs) showed cross-binding to GRP78 and possibly contributed to the observed higher-level ICs in COVID-19 serums (cardiovascular embolism?). Co-localization studies showed that spike Abs (analogous to pro-atherosclerotic GRP78 auto-Abs) could directly bind to upregulated cellular GRP78 (type II hypersensitivity?). Both pathways could worsen vascular injury and atherosclerosis, leading to cardiac complications in COVID-19 cases with narrowed vessels.