Search Results (146)

Oxysterols such as 7-ketocholesterol (7KCh) contribute to the pathogenesis of autoimmune and chronic inflammatory diseases by inducing oxidative stress and promoting pro-inflammatory immune cell activation. Dendritic cells (DCs) play a central role in maintaining immune tolerance, and their dysregulation is a key driver of autoimmunity. Targeting DCs by using natural compounds offers a promising strategy to restore redox balance and suppress aberrant immune responses. This study investigated the immunomodulatory and antioxidant properties of Lupeol, a natural triterpenoid, in human monocyte-derived DCs exposed to 7KCh. Flow cytometry and cytokine profiling demonstrated that Lupeol preserved the immature, tolerogenic phenotype of DCs by promoting a dose-dependent increase in the anti-inflammatory cytokine IL-10. Lupeol also inhibited the 7KCh-induced upregulation of maturation markers (CD83, CD86) and suppressed the release of pro-inflammatory cytokines IL-1β and IL-12p70. Functionally, Lupeol-treated DCs directed T cell polarization toward an anti-inflammatory and regulatory profile while dampening the inflammatory responses triggered by 7KCh. This immunoregulatory effect was further supported by the decreased secretion of the pro-inflammatory cytokines IL-1β and IL-12p70 in DC culture supernatants. Mechanistic analyses using immunofluorescence showed that Lupeol alone significantly increased nuclear NRF2 levels and upregulated HO-1 expression. Western blot analysis further confirmed Lupeol’s ability to activate the KEAP1-NRF2 signaling pathway, as evidenced by increased expression of NRF2 and its downstream target, NQO1. The use of ML385, a selective NRF2 inhibitor, in ROS and cytokine assays supported the involvement of NRF2 in mediating the Lupeol antioxidant and anti-inflammatory effects in DCs. Notably, the oxidative burden induced by 7KCh limited the full activation of NRF2 signaling triggered by Lupeol. Furthermore, docking and MM/PBSA analyses revealed the specific interactions of Lupeol with the kelch domain of KEAP1. These findings suggest that Lupeol may serve as a promising orally available immunomodulatory agent capable of promoting tolerogenic DCs, offering potential applications in autoimmune and other chronic inflammatory diseases. Full article

Liver injury caused by the irrational use of acetaminophen (APAP) represents a significant challenge in the field of public health. In clinical treatment, apart from N—acetylcysteine (NAC), the only approved antidote, there are extremely limited effective intervention measures for APAP-induced hepatotoxicity. Therefore, exploring novel liver-protecting drugs and elucidating their mechanisms of action is of great scientific significance and clinical value. Rosmarinic acid (RA), as a natural polyphenolic compound, has been proven to have significant antioxidant activity. Previous studies have shown that it has a protective effect against drug-induced liver injury. Nevertheless, the precise protective mechanism of RA in APAP-induced acute liver injury (AILI) has not been fully defined. This study was based on an AILI mouse model to systematically explore the liver-protecting effect of RA and its underlying molecular mechanisms. The research results showed that pretreatment with RA could notably mitigate liver pathological injury. It could decrease the activities of ALT and AST in the serum, suppress the liver inflammatory reaction, and reverse the decline in the levels of CAT, T-AOC, SOD, and GSH caused by APAP. Meanwhile, RA could enhance antioxidant defense capabilities by activating the Keap1/Nrf2/HO-1 signaling pathway, regulate the xCT/GPX4 axis to inhibit lipid peroxidation, and thus block the process of ferroptosis. In conclusion, this study confirmed that RA exerts a protective effect against AILI by regulating the Keap1/Nrf2/HO-1 axis to enhance antioxidant capacity and inhibit ferroptosis through the xCT/GPX4 pathway. Our research provides a theoretical basis for RA as a potential therapeutic agent for APAP-induced liver injury. Full article

Liver fibrosis remains a critical health concern with limited therapeutic options. Kaempferol (Kae) is a natural flavonoid widely present in natural plants, yet its role in modulating gut–liver axis interactions during fibrosis is unexplored. This study investigates the hepatoprotective effects of Kae on alleviating carbon tetrachloride (CCl₄)-induced liver fibrosis, and its underlying mechanisms, focusing on oxidative stress, gut microbiota, and short-chain fatty acids (SCFAs), are revealed. A mouse model of hepatic fibrosis was built by the subcutaneous injection of CCl₄. Meanwhile, Kae was administered by gavage at doses of 25, 50, and 100 mg/kg body weight. Serum biomarkers, liver histopathology, oxidative damage markers, and nuclear factor erythroid 2-related factor 2 (Nrf2)/kelch-like ECH-associated protein 1 (Keap1)/heme oxygenase 1 (HO-1) signaling were analyzed. AML12 hepatocytes were pretreated with Kae or SCFAs (acetate, propionate, butyrate) before H₂O₂-induced oxidative injury. The changes in gut microbiota and the levels of SCFAs were assessed via 16S rRNA sequencing and GC-MS, respectively. Kae effectively alleviated the destruction of the liver morphology and tissue structure, reduced the infiltration of inflammatory cells, collagen deposition in the liver, and the expression of fibrotic factors, and downregulated the oxidative stress level in the liver of mice with liver fibrosis by activating the Nrf2/Keap1/HO-1 pathway (p < 0.05 or 0.01). In vitro, Kae significantly mitigated H₂O₂-induced cytotoxicity and oxidative damage (p < 0.05 or 0.01). Furthermore, Kae restored gut microbiota diversity, increased beneficial genera (e.g., Lactobacillus), and elevated both intestinal and hepatic SCFA levels (p < 0.01). The discrepant SCFA pretreatment similarly protected AML12 cells by activating Nrf2 signaling (p < 0.05 or 0.01). Our research suggests that Kae could inhibit CCl₄-induced liver fibrosis by restoring the levels of intestinal metabolite SCFAs to reduce oxidative damage. Full article

Background: Under oxidative stress conditions, the increased levels of reactive oxygen species (ROS) within cells disrupt the intracellular homeostasis. Tartary buckwheat peptides exert their effects by scavenging oxidative free radicals, such as superoxide anion and hydrogen peroxide, thereby reducing oxidative damage within cells. Meanwhile, these peptides safeguard mitochondria by maintaining the mitochondrial membrane potential, decreasing the production of mitochondrial oxygen free radicals, and regulating mitochondrial biogenesis and autophagy to preserve mitochondrial homeostasis. Through these mechanisms, Tartary buckwheat peptides restore the intracellular redox balance, sustain cellular energy metabolism and biosynthesis, and ensure normal cellular physiological functions, which is of great significance for cell survival and adaptation under oxidative stress conditions. Objectives: In this experiment, a classical cellular oxidative stress model was established. Indicators related to antioxidant capacity and mitochondrial membrane potential changes, as well as pathways associated with oxidative stress, were selected for detection. The aim was to elucidate the effects of Tartary buckwheat oligopeptides on the metabolism of cells in response to oxidative stress. Methods: In this study, we established an oxidative damage model of mouse skeletal muscle myoblast (SOL8) cells using hydrogen peroxide (H₂O₂), investigated the pre-protective effects of Tartary buckwheat oligopeptides on H₂O₂-induced oxidative stress damage in SOL8 cells at the cellular level, and explored the possible mechanisms. The CCK-8 method is a colorimetric assay based on WST-8-[2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodiumsalt], which is used to detect cell proliferation and cytotoxicity. Results: The value of CCK-8 showed that, when the cells were exposed to 0.01 mmol/L H₂O₂ for 1 h and 10 mg/mL Tartary buckwheat oligopeptides intervention for 48 h, these were the optimal conditions. Compared with the H₂O₂ group, the intervention group (KB/H₂O₂ group) showed that the production of ROS was significantly reduced (p < 0.001), the malondialdehyde (MDA) content was significantly decreased (p < 0.05), and the activity of catalase (CAT) was significantly increased (p < 0.01); the mitochondrial membrane potential in the KB/H₂O₂ group tended to return to the level of the control group, and they all showed dose-dependent effects. Compared with the H₂O₂ group, the mRNA expression of KEAP1 in the KB/H₂O₂ group decreased, while the mRNA expression of NRF2α, HO-1, nrf1, PGC-1, P62, and PINK increased. Conclusions: Therefore, Tartary buckwheat oligopeptides have a significant pre-protective effect on H₂O₂-induced SOL8 cells, possibly by enhancing the activity of superoxide dismutase, reducing ROS attack, balancing mitochondrial membrane potential, and maintaining intracellular homeostasis. Full article

This study aimed to investigate the preventive effects of isostrictiniin (ITN) from Nymphaea candida against acute lung injury (ALI) through lipopolysaccharide (LPS)-induced ALI mice and LPS-induced A549 cells. Compared with the model group, ITN (50 and 100 mg/kg) significantly reduced the lung indexes, W/D rates, BALF WBC counts, and total protein contents in ALI mice (p < 0.05), as well as the blood neu counts (p < 0.01), while increasing the blood lym counts (p < 0.01). ITN (50 and 100 mg/kg) also markedly decreased the lung tissue TNF-α, IL-6, IL-1β, MDA, and MPO activities in ALI mice (p < 0.01) and enhanced the SOD and GSH levels (p < 0.01). Additionally, ITN (50 and 100 mg/kg) significantly improved lung histopathological damage in ALI mice. Moreover, ITN (10 and 25 µM) significantly reduced the NO, PGE2, IL-1β, IL-6, TNF-α, and MDA levels in LPS-induced A549 cells (p < 0.01) while significantly increasing the SOD and GSH activities (p < 0.01). After LPS-induced A549 cells, the Keap1, p-JNK/JNK, p-ERK1/2/ERK1/2, p-P38/P38, p-IκBα/IκBα, and p-NF-κBp65/NF-κB p65 levels were significantly upregulated (p < 0.05), whereas the Nrf2 and HO-1 protein expressions were downregulated (p < 0.05). After treatment with ITN (25 μM), the changes in these relative protein expressions in LPS-induced A549 cells were significantly reversed (p < 0.05). The above results indicate that ITN has a better preventive effect against ALI, and its mechanisms are related to the regulation of the Keap1-Nrf2/HO-1 and MAPK/NF-κB signaling pathways. Full article

: Negative energy balance (NEB) in dairy cows induces excessive lipolysis, leading to elevated levels of β-hydroxybutyric acid (BHBA), which, when accumulated, can cause liver damage. Rutin (RT), a natural flavonoid with antioxidant and anti-inflammatory properties, has demonstrated potential hepatoprotective effects; however, its ability to mitigate BHBA-induced hepatocellular injury in calves remains unclear. This study first assessed the impact of various BHBA concentrations on oxidative stress in calf hepatocytes, then explored the protective effects and underlying mechanisms of RT, and finally employed untargeted metabolomics to further elucidate RT’s mode of action. The results showed that exposure to 1.2 mM BHBA significantly increased malondialdehyde (MDA), nitric oxide (NO) contents, and reactive oxygen species (ROS) levels, while markedly decreasing glutathione (GSH) content and catalase (CAT) activity compared with the blank control. Notably, pretreatment with 100 μg/mL RT resulted in the greatest increase in GSH contents (180%) compared to BHBA treatment alone, while 150 μg/mL RT led to the most pronounced reduction in MDA contents (220%). Furthermore, BHBA treatment significantly upregulated the expression of Kelch-like ECH-associated protein 1 (Keap1) and downregulated nuclear factor erythroid 2-related factor 2 (Nrf2), NAD(P)H quinone dehydrogenase 1 (NQO1), and heme oxygenase-1 (HO-1) at both the mRNA and protein levels. These alterations were effectively reversed by pretreatment with 100 μg/mL RT. Non-targeted metabolomics identified 1525 metabolites in total. Based on OPLS-DA, metabolites with a variable importance in projection (VIP) > 1 and p < 0.05 were considered significantly altered. Compared with the blank control, BHBA treatment upregulated 47 metabolites—including 8-hydroxy-2′-deoxyguanosine, 3-hydroxyisovaleric acid, and N-palmitoyl-sphingosine—and downregulated 58 metabolites, such as betaine, linolenic acid, and arachidonic acid. In contrast, RT pretreatment upregulated 207 metabolites relative to the BHBA treatment, including linolenic acid, taurocholic acid, and 4-hydroxybenzoic acid, and downregulated 126 metabolites, including 3-hydroxyisovaleric acid, 8-hydroxy-2′-deoxyguanosine, and pyruvaldehyde. Pathway enrichment analysis indicated that RT alleviated BHBA-induced hepatocyte injury primarily by modulating the fatty acid degradation pathway. In summary, RT mitigated BHBA-induced oxidative stress in calf hepatocytes by regulating the Keap1/Nrf2 signaling pathway and further exerted protective effects through metabolic reprogramming. Full article

Suk-SaiYasna (SSY) is a well-documented traditional Thai herbal formula in the Royal Scripture of King Narai’s Traditional Medicine. SSY contains Cannabis sativa leaves as a key ingredient and has traditionally been used to promote sleep, alleviate stress-related symptoms, and stimulate appetite. This study aimed to investigate the neuroprotective effects of SSY in a mouse model of unpredictable chronic mild stress (UCMS)-induced cognitive impairment and explore the underlying mechanisms, particularly antioxidant enzyme pathways. Behavioral tests, including the Y-maze test, novel object recognition test, and Morris water maze test, demonstrated that UCMS-exposed mice exhibited cognitive impairment compared to non-stress mice. However, SSY treatment significantly improved learning and memory performance in UCMS-exposed mice. Mechanistic studies revealed that SSY reduced lipid peroxidation in the hippocampus and frontal cortex, key brain regions affected by chronic stress. Furthermore, UCMS significantly reduced the activity of antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), whereas SSY treatment restored their activity, indicating antioxidative and neuroprotective effects in vivo. Gene expression analysis further revealed that SSY regulates oxidative stress via the Nrf2/Keap1 signaling pathway. In vitro studies using 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay confirmed the radical scavenging activities of SSY and its herbal components, demonstrating significant antioxidant potential. Phytochemical analysis identified delta-9-tetrahydrocannabinol, delta-9-tetrahydrocannabinolic acid A, and cannabinoids as bioactive compounds in SSY, along with potent antioxidants such as gallic acid, myricetin, myristicin, piperine, costunolide, and gingerol. These findings suggest that the SSY formula mitigates UCMS-induced cognitive function through its antioxidant properties via multiple pathways, including radical scavenging activities, modulating the Nrf2-Keap1 pathway, inducing the expression of HO-1, NQO1 mRNAs, and other antioxidant enzymes. This work bridges traditional Thai medicine with modern neuropharmacology. Full article

As the primary active component of Astragalus membranaceus, Astragaloside IV (AS-IV) is widely recognized in pharmacological research for its multifaceted therapeutic potential, particularly its antioxidative, immunostimulatory, and cardioprotective properties. Oxidative stress is an important mechanism in the induction of many diseases. The present study investigates the antioxidative mechanism of Astragaloside IV in zebrafish, using menaquinone exposure to induce oxidative stress conditions. The findings revealed that AS-IV effectively attenuated oxidative stress-induced mortality and morphological abnormalities in zebrafish. AS-IV exhibited a concentration-dependent protective effect against developmental abnormalities, with progressive reduction in pericardial effusion, body curvature, and growth retardation observed at higher doses. Moreover, AS-IV treatment not only effectively reduced reactive oxygen species (ROS) accumulation and attenuated oxidative DNA damage but also significantly decreased apoptosis in the cardiac region of zebrafish embryos under oxidative stress conditions. Western blot analysis revealed that AS-IV treatment significantly reduced the protein levels of both Cleaved Caspase-3 and γ-H2AX, indicating its ability to inhibit DNA damage-induced apoptosis. AS-IV mediates its antioxidant defense mechanisms through the activation of the nuclear factor erythroid 2-related factor 2 (NRF2) signaling pathway, inducing the significant upregulation of cytoprotective enzymes. This molecular mechanism underlies the observed phenotypic improvements in oxidative stress-related damage. Upstream analysis demonstrated that AS-IV activates NRF2 primarily through protein kinase B (AKT/PKB) pathway modulation, independent of KEAP1 regulation. Comprehensive mechanistic analysis reveals that Astragaloside IV mitigates oxidative stress-induced apoptosis in zebrafish through coordinated regulation of the AKT/NRF2/HO-1/Caspase-3 signaling axis. Full article

Diesel exhaust particulate (DEP) is widely recognized to weaken lung function and skin diseases. When the skin, which defends against external factors, is exposed to PM2.5, various chronic inflammatory diseases occur. When keratinocytes recognize harmful signals, they synthesize the NOD-like receptor protein 1 (NLRP1) inflammasome. DEP enhances NF-κB signaling and NLRP1 inflammasome expression through the interaction of TXNIP with NLRP1 in keratinocytes. Although many studies have reported the anti-inflammatory and antioxidant characteristics of Impressic acid (IPA), the umbrella consequences of IPA for PM2.5-influenced inflammasomes and the associated mechanisms remain unknown. Therefore, this study aimed to examine the protective function of IPA against inflammation in human keratinocytes. IPA attenuated the NLRP1 expression, caspase-1, IL-1β actuation, and NF-κB and IκB phosphorylation induction by DEP. IPA upregulated the Nrf2, HO-1, and NQO1 expression through CaMKKβ, AMPK, and GSK3β phosphorylation. Also, IPA led to the elevation of p62 and the degradation of the Keap1 protein. ML385 reversed the suppressive effect of IPA on the NLRP1 inflammasome, which was enhanced by DEP, and NAC counteracted the effect of ML385. These findings indicate that IPA can suppress inflammation induced by PM2.5 by expressing antioxidant enzymes through the Keap1/p62/Nrf2-signaling pathway in human keratinocytes. Full article

This study investigated the preventive effects and mechanisms of Paeonia lactiflora pall stem and leaf extract (PLE) on oxidative stress-induced diarrhea in broilers, using a Diquat (DQ)-induced model. Results indicated that PLE significantly improved growth performance, increased average daily gain (ADG), reduced feed-to-gain ratio (F/G), and enhanced liver and kidney indices. PLE alleviated DQ-induced oxidative stress diarrhea by reducing the diarrhea rate by 63.84%, upregulating mRNA expression of MUC2, Claudin-1, ZO-1, and Occludin, and decreasing AST and ALT activities in serum. Additionally, PLE increased levels of CAT, SOD, GSH-Px, and GSH while reducing PCO and MDA levels in serum, intestine, and liver tissues. Furthermore, PLE increased acetic acid content and decreased propionic acid, butyric acid, and isobutyric acid contents. PLE also altered gut microbiota by up-regulated Bacteroidetes and Barnesiella and down-regulated Firmicutes and unclassified_o__Eubacteriales. Network pharmacology suggested that PLE acts via the PI3K-Akt-Nrf2 pathway, confirmed by up-regulated mRNA expression of PI3K, AKT, Nrf2, NQO1, and HO-1, and down-regulated Keap1 in intestinal and liver tissues. Correlation analysis revealed significant associations between Barnesiella and unclassified_o__Eubacteriales with short-chain fatty acids and PI3K-Akt-Nrf2 pathway-related genes. Thus, PLE prevents and alleviates oxidative stress-induced diarrhea in broilers by modulating the PI3K-Akt-Nrf2 pathway, regulating gut microbiota, and influencing short-chain fatty acids. Full article

Depression is associated with bidirectional interactions between inflammatory responses and behavioral dysfunction. Paeoniflorin (PF), a monoterpene glycoside derived from Paeonia lactiflora, exhibits potent anti-inflammatory properties. This study investigates the therapeutic effects of PF on lipopolysaccharide (LPS)-induced depression-like behaviors in mice and neuroinflammation in BV2 microglial cells. Mice were co-administered PF (20, 40, or 80 mg/kg/day) and LPS (2 mg/kg) for 7 days. Behavioral tests; Nissl staining; and Golgi, Iba1, DLG4, and cytokine assays were conducted. Additionally, hippocampal NF-κB, Nrf2, and BDNF signaling pathways were analyzed using Western blots. In BV2 cells, oxidative stress and the Nrf2/HO-1 pathway were assessed using CCK-8, flow cytometry, and Western blotting after 24 h of LPS and PF treatment. PF significantly alleviated LPS-induced depression-like behaviors, increased hippocampal neuron and dendritic spine density, and upregulated synaptic proteins (PSD95, SNAP25, and BDNF). Mechanistically, PF suppressed NLRP3 inflammasome activation via the Akt/GSK3β pathway, reduced pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6), and enhanced the Nrf2/HO-1 antioxidant axis. In BV2 cells, PF restored mitochondrial membrane potential, inhibited apoptosis, and decreased cytokine levels (TNF-α, IL-1β, and IL-6) by inhibiting TLR4/NF-κB signaling. In conclusion, PF significantly improved LPS-induced depression-like behaviors and attenuated neuroinflammation in BV2 microglial cells, highlighting its potential as a therapeutic agent for inflammation-associated depression. Full article

Background: Methylglyoxal (MGO), a reactive dicarbonyl compound, has been implicated in the formation of advanced glycation end-products (AGEs) and neuronal dysfunction. This study investigated the neuroprotective effects of the combination of trans-resveratrol and hesperidin (tRES-HESP) against MGO-induced neurotoxicity, focusing on memory dysfunction and depression-like behavior. Methods: Neuroblastoma 2a (N2a) cells were treated with MGO to induce neurotoxicity. The effects of tRES-HESP on cell viability, reactive oxygen species (ROS) production, apoptotic markers (BAX/Bcl 2 ratio, caspase 3 activity, and poly [ADP ribose] polymerase cleavage), and components of the glyoxalase system (glyoxalase-1, glyoxalase- 2, and receptors for AGEs) were assessed. The activation of the Kelch-like ECH-associated protein 1/Nuclear factor erythroid-2-related factor 2/Heme oxygenase-1 (Keap1/Nrf2/HO-1) pathway was also evaluated. In vivo, mice with MGO-induced depressive amnesia were treated with tRES-HESP (200 mg/kg) for eight weeks, and behavioral, biochemical, and histological assessments were performed. Results: tRES-HESP significantly reduced MGO-induced cytotoxicity, ROS production, and apoptosis in N2a cells. In addition, it restored the glyoxalase system and activated the Keap1/Nrf2/HO-1 pathway. In an in vivo model, tRES-HESP improved memory and depression-like behaviors, reduced cortisol and interleukin (IL)-6 levels, increased IL-10 levels, and lowered the expression of amyloid precursor protein and amyloid beta. Furthermore, tRES-HESP protected CA2/3 hippocampal subregions from MGO-induced damage. tRES-HESP exhibited neuroprotective effects through antioxidant, anti-apoptotic, and anti-inflammatory mechanisms. Conclusions: Our results suggest that tRES-HESP is a potential dietary supplement for preventing cognitive decline and depression, particularly in neurodegenerative conditions such as Alzheimer’s disease. Further studies are required to assess its clinical relevance and efficacy in the human population. Full article

This study explores the antioxidant activity and antioxidant mechanism of phenolic compounds (including free (FP), esterified (EP), and bound phenolic (BP)) from Dendrobium fimbriatum Hook (DFH) stems, before and after ultra-high pressure (UHP) treatment. A total of 374 compounds were identified, with 149 showing significant differences in DFH phenolic extracts before and after UHP treatment. UHP treatment significantly increased the total phenolic content (TPC) and total flavonoid content (TFC) and enhanced antioxidant activity in vitro. Particularly, the UEP-DFH, IC₅₀ values in ABTS and DPPH were reduced by 49.6% and 64.1%, respectively. In H₂O₂-treated HepG2 cells, the extracts demonstrated significant cytoprotective effects, including increased cell viability, ROS reduction, and enhanced GSH levels by 17.8% (UFP-DFH) and 12.5% (UEP-DFH). The activities of GS, GCL, GR, GSH-Px, SOD, CAT, NQO1, and HO-1 were also elevated in UHP-treated extracts. DAPI staining indicated that the extracts promoted nuclear Nrf2 expression, particularly UFP-DFH and UEP-DFH. Molecular docking indicated that vanillic acid could competitively bind to the Keap1-Kelch domain, facilitating activation of the antioxidant pathway. Overall, UHP treatment enhanced both extraction efficiency and antioxidant activity, making it a promising method for improving the bioactivity of DFH in the food and functional food industries. Full article

Oxidative stress, a pivotal driver of neurodegenerative diseases, results from an imbalance between the generation of reactive oxygen species (ROS) and cellular antioxidant defenses. This review provides a comprehensive analysis of key oxidative stress sources, focusing on NADPH oxidase (NOX) hyperactivity and mitochondrial Uncoupling Protein (UCP) downregulation. Critically, we examine the therapeutic potential of phytochemicals in mitigating NOX-mediated ROS generation through direct enzyme inhibition, including impacts on NOX subunit assembly and gene expression. Furthermore, we explore the ability of phytochemicals to bolster cellular antioxidant defenses by activating the Kelch-like ECH-associated protein 1 (KEAP1)/nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathway, elucidating the upregulation of antioxidant genes, such as GPx, SOD, CAT, and HO-1. This review expands beyond confined overviews; emphasizes specific molecular interactions between phytochemicals and target proteins, including NOX isoforms; and provides an in-depth analysis of the specific antioxidant genes upregulated via Nrf2. This approach aims to pave the way for targeted and translatable therapeutic strategies in neurodegenerative diseases. Ultimately, this review illuminates the intricate molecular dynamics of oxidative stress in neurodegenerative diseases; underscores the potential of phytochemicals to restore redox homeostasis and reverse pathological conditions through precise modulation of key signaling pathways. Full article

Objectives: Ischemic stroke is a severe neurological disorder with high morbidity, mortality, and disability rates, posing a substantial burden on patients, families, and healthcare systems. Soy isoflavone (SI), a naturally occurring phytoestrogen, has demonstrated promising neuroprotective effects. This study aimed to evaluate the anti-stroke efficacy of SI and elucidate its underlying mechanisms through integrated phytochemical profiling, network pharmacology, and both in vitro and in vivo experimental validation. Methods: Active constituents of SI were extracted via reflux and identified using liquid chromatography–mass spectrometry (LC-MS). Network pharmacology was employed to predict therapeutic targets and signaling pathways. The neuroprotective effects of SI were first assessed in PC12 cells subjected to oxygen–glucose deprivation/reoxygenation (OGD/R) injury in vitro. For in vivo evaluation, transient cerebral ischemia–reperfusion injury was induced using the bilateral common carotid artery occlusion (BCCAO) model in adult male ICR rats (27.3 ± 1.8 g; 6–8 weeks old), obtained from the Shanghai Experimental Animal Center, Chinese Academy of Sciences. Forty-eight rats were randomly assigned into four groups (n = 12): sham, model (BCCAO), SI-treated (100 mg/kg, oral gavage for 5 days), and edaravone (EDA)-treated (10 mg/kg, i.p., positive control). All procedures were approved by the Institutional Animal Care and Use Committee of Changchun Normal University (Approval No. 2024003, 13 March 2024) and conducted in accordance with the NIH guidelines and ARRIVE 2.0 reporting standards. Results: In vitro, SI significantly enhanced PC12 cell viability from 57.23 ± 2.88% to 80.76 ± 4.43% following OGD/R. It also reduced intracellular Ca²⁺ by 58.42%, lactate dehydrogenase (LDH) release by 37.67%, caspase-3 activity by 55.05%, and reactive oxygen species (ROS) levels by 74.13% (p < 0.05). A flow cytometry analysis revealed that OGD/R increased the apoptosis rate from 5.34% (control) to 30.85% (model group), which was significantly attenuated by SI treatment, especially in the 560 µg/mL group (20.00%), followed by the 140 and 280 µg/mL groups. In vivo, SI improved neurological scores from 8.3 ± 1.09 to 6.8 ± 1.68, reduced cerebral infarction volume by 18.49%, and alleviated brain edema by 10.42% (p < 0.05). SI also decreased malondialdehyde (MDA) and LDH levels by 31.15% and 39.46%, respectively, while increasing the activity of antioxidant enzymes: superoxide dismutase (SOD) by 11.70%, catalase (CAT) by 26.09%, and glutathione peroxidase (GSH-px) by 27.55% (p < 0.01). Scratch assay results showed that SI restored the impaired migratory ability of the OGD/R-treated PC12 cells, further supporting its role in cellular repair. A Western blot analysis demonstrated the upregulation of nuclear factor erythroid 2–related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and NAD(P)H:quinone oxidoreductase 1 (NQO1) and the downregulation of Kelch-like, ECH-associated protein 1 (Keap1) in the cerebral ischemia–reperfusion model. Conclusions: These findings indicate that soy isoflavone confers significant neuroprotective effects against cerebral ischemia–reperfusion injury by enhancing endogenous antioxidant defense mechanisms, reducing oxidative stress, inhibiting apoptosis, and promoting cell migration. The protective effects are likely mediated through the activation of the Nrf2/Keap1 signaling pathway, supporting the therapeutic potential of SI in ischemic stroke treatment. Full article