Oxidative Stress-induced Damage Research Articles

Mefenamic Acid-Upregulated Nrf2/SQSTM1 Protects Hepatocytes against Oxidative Stress-Induced Cell Damage.

Mefenamic acid (MFA) is a commonly prescribed non-steroidal anti-inflammatory drug (NSAID) with anti-inflammatory and analgesic properties. MFA is known to have potent antioxidant properties and a neuroprotective effect against oxidative stress. However, its impact on the liver is unclear. This study aimed to elucidate the antioxidative effects of MFA and their underlying mechanisms. We observed that MFA treatment upregulated the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. Treatment with various anthranilic acid derivative-class NSAIDs, including MFA, increased the expression of sequestosome 1 (SQSTM1) in HepG2 cells. MFA disrupted the interaction between Kelch-like ECH-associated protein 1 (Keap1) and Nrf2, activating the Nrf2 signaling pathway. SQTM1 knockdown experiments revealed that the effect of MFA on the Nrf2 pathway was masked in the absence of SQSTM1. To assess the cytoprotective effect of MFA, we employed tert-Butyl hydroperoxide (tBHP) as a ROS inducer. Notably, MFA exhibited a protective effect against tBHP-induced cytotoxicity in HepG2 cells. This cytoprotective effect was abolished when SQSTM1 was knocked down, suggesting the involvement of SQSTM1 in mediating the protective effect of MFA against tBHP-induced toxicity. In conclusion, this study demonstrated that MFA exhibits cytoprotective effects by upregulating SQSTM1 and activating the Nrf2 pathway. These findings improve our understanding of the pharmacological actions of MFA and highlight its potential as a therapeutic agent for oxidative stress-related conditions.

New Insight into the Potential Protective Function of Sulforaphene against ROS-Mediated Oxidative Stress Damage In Vitro and In Vivo.

Sulforaphene (SFE) is a kind of isothiocyanate isolated from radish seeds that can prevent free-radical-induced diseases. In this study, we investigated the protective effect of SFE on oxidative-stress-induced damage and its molecular mechanism in vitro and in vivo. The results of cell experiments show that SFE can alleviate D-gal-induced cytotoxicity, promote cell cycle transformation by inhibiting the production of reactive oxygen species (ROS) and cell apoptosis, and show a protective effect on cells with H2O2-induced oxidative damage. Furthermore, the results of mice experiments show that SFE can alleviate D-galactose-induced kidney damage by inhibiting ROS, malondialdehyde (MDA), and 4-hydroxyalkenals (4-HNE) production; protect the kidney against oxidative stress-induced damage by increasing antioxidant enzyme activity and upregulating the Nrf2 signaling pathway; and inhibit the activity of pro-inflammatory factors by downregulating the expression of Toll-like receptor 4 (TLR4)-mediated inflammatory response. In conclusion, this research shows that SFE has antioxidant effects, providing a new perspective for studying the anti-aging properties of natural compounds.

Caffeic acid's role in mitigating polycystic ovary syndrome by countering apoptosis and ER stress triggered by oxidative stress

Polycystic ovary syndrome (PCOS) is a complex endocrine disorder that affects women of reproductive age, characterized by androgen-induced oxidative stress leading to several metabolic disorders. In this study, we investigated the potential therapeutic effect of caffeic acid on PCOS and its underlying molecular mechanism. We used a human ovarian granulosa cell line (KGN cells) induced by hydrogen peroxide (H2O2) to examine how caffeic acid influences the protein expression of oxidative stress-induced apoptosis-related markers. Our results indicate that caffeic acid significantly inhibits intracellular reactive oxygen species (ROS) generation and safeguards KGN cells against oxidative stress. For the in vivo aspect of our study, female Sprague-Dawley (SD) rats were utilized to induce the PCOS model using dehydroepiandrosterone (DHEA). Caffeic acid was then administered to the rats for a duration of 6 weeks. The outcomes revealed that caffeic acid effectively improved irregular estrous cycles, fasting blood glucose levels, liver function, and lipid profiles in DHEA-induced PCOS rats. Additionally, it mitigated hyperandrogenism, enhanced steroidogenesis enzyme expression, and modulated apoptosis-related protein expression. Our findings strongly suggest that caffeic acid holds promising potential in reducing oxidative stress-induced damage and ameliorating PCOS-related complications by modulating ER stress.

Oxidative Stress in Type 2 Diabetes: Impacts from Pathogenesis to Lifestyle Modifications.

Oxidative stress is a critical factor in the pathogenesis and progression of diabetes and its associated complications. The imbalance between reactive oxygen species (ROS) production and the body's antioxidant defence mechanisms leads to cellular damage and dysfunction. In diabetes, chronic hyperglycaemia and mitochondrial dysfunction contribute to increased ROS production, further exacerbating oxidative stress. This oxidative burden adversely affects various aspects of diabetes, including impaired beta-cell function and insulin resistance, leading to disrupted glucose regulation. Additionally, oxidative stress-induced damage to blood vessels and impaired endothelial function contribute to the development of diabetic vascular complications such as retinopathy, nephropathy, and cardiovascular diseases. Moreover, organs and tissues throughout the body, including the kidneys, nerves, and eyes, are vulnerable to oxidative stress, resulting in diabetic nephropathy, neuropathy, and retinopathy. Strategies to mitigate oxidative stress in diabetes include antioxidant therapy, lifestyle modifications, and effective management of hyperglycaemia. However, further research is necessary to comprehensively understand the underlying mechanisms of oxidative stress in diabetes and to evaluate the efficacy of antioxidant interventions in preventing and treating diabetic complications. By addressing oxidative stress, it might be possible to alleviate the burden of diabetes and improve patient outcomes.

Novel Therapeutic Approaches to Liver Fibrosis Based on Targeting Oxidative Stress.

Chronic liver disease (CLD) constitutes a growing global health issue, with no effective treatments currently available. Oxidative stress closely interacts with other cellular and molecular processes to trigger stress pathways in different hepatic cells and fuel the development of liver fibrosis. Therefore, inhibition of reactive oxygen species (ROS)-mediated effects and modulation of major antioxidant responses to counteract oxidative stress-induced damage have emerged as interesting targets to prevent or ameliorate liver injury. Although many preclinical studies have shown that dietary supplements with antioxidant properties can significantly prevent CLD progression in animal models, this strategy has not proved effective to significantly reduce fibrosis when translated into clinical trials. Novel and more specific therapeutic approaches are thus required to alleviate oxidative stress and reduce liver fibrosis. We have reviewed the relevant literature concerning the crucial role of alterations in redox homeostasis in different hepatic cell types during the progression of CLD and discussed current pharmacological approaches to ameliorate fibrosis by reducing oxidative stress focusing on selective modulation of enzymatic oxidant sources, antioxidant systems and ROS-mediated pathogenic processes.

Protective Effects and Mechanisms of Pectolinarin against H2O2-Induced Oxidative Stress in SH-SY5Y Neuronal Cells.

This study aims to investigate the protective effects and mechanisms of pectolinarin against oxidative stress-induced cell damage in SH-SY5Y cells. Neurodegenerative diseases-such as Alzheimer's disease-are potentially associated with oxidative stress, which causes excessive production of reactive oxygen species (ROS) that damage DNA and proteins in neuronal cells. The results of this study demonstrate that pectolinarin can scavenge hydroxyl and nitric oxide radicals in a concentration-dependent manner. Moreover, pectolinarin significantly increased cell viability while reducing ROS production and LDH release in the hydrogen peroxide (H2O2)-induced control group. Additionally, Pectolinarin recovered protein expression from H2O2-altered levels back to close-to-normal SH-SY5Y cell levels for components of the oxidative stress, inflammation, and apoptosis pathways-such as nuclear factor erythroid 2-related factor 2 (Nrf2), kelch-like ECH-associated protein (Keap1), anti-heme oxygenase 1 (HO-1), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin-1β (IL-1β), B-cell lympho-ma-2 (Bcl-2) protein, and Bcl-2-associated X protein (Bax). These findings suggest that pectolinarin has the potential to be used as a plant material for functional foods to be applied in the treatment of neurodegenerative diseases, such as Alzheimer's disease, by mitigating oxidative stress-induced damage to neuronal cells.

The protective effects of hyperoxic pre-treatment in human-derived adipose tissue mesenchymal stem cells against in vitro oxidative stress and a rat model of renal ischaemia-reperfusion

Objective: Improvement of cell survival is essential for achieving better clinical outcomes in stem cell therapy. We investigated the effects of hyperoxic pre-treatment (HP) on the viability of human adipose stromal stem cells (ASCs).Materials and Methods: MTT and Western blot tests were used to assess cell viability and the expression of apoptosis-related proteins, respectively. For the in-vivo trial, the rats were subjected to renal ischaemia-reperfusion (IR).Results: The results showed that HP could significantly increase the viability of ASCs and decrease apoptotic markers (Bax/BCL-2 ratio and Caspase-3) compared with control cells. There were some additional effects with regard to the improvement of renal structure and function in the animal model. However, the difference between the treated and non-treated transplanted ASCs failed to reach significance.Conclusion: These results suggested that HP could increase the survival of ASCs against oxidative stress-induced damages in the in-vitro condition, but this strategy was not highly effective in renal IR.

Molecular dynamics and simulation analysis against superoxide dismutase (SOD) target of Micrococcus luteus with secondary metabolites from Bacillus licheniformis recognized by genome mining approach

Micrococcus luteus, also known as M. luteus, is a bacterium that inhabits mucous membranes, human skin, and various environmental sources. It is commonly linked to infections, especially among individuals who have compromised immune systems. M. luteus is capable of synthesizing the enzyme superoxide dismutase (SOD) as a component of its protective response to reactive oxygen species (ROS). This enzyme serves as a promising target for drug development in various diseases. The current study utilized a subtractive genomics approach to identify potential therapeutic targets from M. luteus. Additionally, genome mining was employed to identify and characterize the biosynthetic gene clusters (BGCs) responsible for the production of secondary metabolites in Bacillus licheniformis (B. licheniformis), a bacterium known for its production of therapeutically relevant secondary metabolites. Subtractive genomics resulted in identification of important extracellular protein SOD as a drug target that plays a crucial role in shielding cells from damage caused by ROS. Genome mining resulted in identification of five potential ligands (secondary metabolites) from B. licheniformis such as, Bacillibactin (BAC), Paenibactin (PAE), Fengycin (FEN), Surfactin (SUR) and Lichenysin (LIC). Molecular docking was used to predict and analyze the binding interactions between these five ligands and target protein SOD. The resulting protein–ligand complexes were further analyzed for their motions and interactions of atoms and molecules over 250 ns using molecular dynamics (MD) simulation analysis. The analysis of MD simulations suggests, Bacillibactin as the probable candidate to arrest the activities of SOD. All the five compounds reported in this study were found to act by directly/indirectly interacting with ROS molecules, such as superoxide radicals (O2–) and hydrogen peroxide (H2O2), and transforming them into less reactive species. This antioxidant activity contributes to its protective effects against oxidative stress-induced damage in cells making them likely candidate for various applications, including in the development of antioxidant-based therapies, nutraceuticals, and functional foods.

Neuroprotective effects of bavachin against neuroinflammation and oxidative stress-induced neuronal damage via activation of Sirt1/Nrf2 pathway and inhibition of NF-κB pathway

Neuroprotective effects of bavachin against neuroinflammation and oxidative stress-induced neuronal damage via activation of Sirt1/Nrf2 pathway and inhibition of NF-κB pathway

Isolation, identification and in silico analysis of two novel cytoprotective peptides from tilapia skin against oxidative stress-induced ovarian granulosa cell damage

Isolation, identification and in silico analysis of two novel cytoprotective peptides from tilapia skin against oxidative stress-induced ovarian granulosa cell damage

AKBA alleviates experimental pancreatitis by inhibiting oxidative stress in Macrophages through the Nrf2/HO-1 pathway.

Acute pancreatitis (AP) is an inflammatory condition of the pancreas characterized by oxidative stress and inflammation in its pathophysiology. Acetyl-11-keto-β-boswellic acid (AKBA) is an active triterpenoid with antioxidant activity. This article seeks to assess the impact of AKBA on AP and investigate its underlying mechanisms. AP was induced in wild-type, Lyz2+/cre Nrf2fl/fl mice and Pdx1+/cre Nrf2fl/fl mice by caerulein. Serum amylase and lipase levels, along with histological grading, were utilized to evaluate the severity of AP. Murine bone marrow-derived macrophages (BMDMs) were isolated, cultured, and polarized to the M1 subtype. Flow cytometry and ELISA were utilized to identify the macrophage phenotype. Alterations in oxidative stress damage and intracellular ROS were observed. Nrf2/HO-1 signaling pathways were also evaluated. In a caerulein-induced mouse model of AP, treatment with AKBA reduced blood amylase and lipase activity and ameliorated pancreatic tissue histological and pathological features. Furthermore, AKBA significantly mitigated oxidative stress-induced damage and induced the expression of Nrf2 and HO-1 protein. Additionally, by using conditional knockout mice (Lyz2+/cre Nrf2fl/fl and Pdx1+/cre Nrf2fl/fl mice), we verified that Nrf2 primarily functions in macrophages rather than acinar cells. In vitro, AKBA inhibits pro-inflammatory M1-subtype macrophage polarization and reduces ROS generation through Nrf2/HO-1 oxidative stress pathway. Moreover, the protective effects of AKBA against AP were abolished in myeloid-specific Nrf2-deficient mice and BMDMs. Molecular docking results revealed interactions between AKBA and Nrf2. Our results confirm that AKBA exerts protective effects against AP in mice by inhibiting oxidative stress in macrophages through the Nrf2/HO-1 Pathway.

High molecular weight hyaluronic acid drastically reduces chemotherapy-induced mucositis and apoptotic cell death

Oral and intestinal mucositis (OIM) are debilitating inflammatory diseases initiated by oxidative stress, resulting in epithelial cell death and are frequently observed in cancer patients undergoing chemo-radiotherapy. There are currently few preventative strategies for this debilitating condition. Therefore, the development of a safe and effective mucositis mitigating strategy is an unmet medical need. Hyaluronic acid (HA) preparations have been tentatively used in oral mucositis. However, the protective effects of HA in chemotherapy-induced mucositis and their underlying mechanisms remain to be fully elucidated. This study aimed to assess these mechanisms using multiple formulations of enriched HA (Mucosamin®), cross-linked (xl-), and non-crosslinked high molecular weight HA (H-MW-HA) in an oxidative stress-induced model of human oral mucosal injury in vitro and an in vivo murine model of 5-flurouracil (5-FU)-induced oral/intestinal mucositis. All tested HA formulations protected against oxidative stress-induced damage in vitro without inducing cytotoxicity, with H-MW-HA also significantly reducing ROS production. Daily supplementation with H-MW-HA in vivo drastically reduced the severity of 5-FU-induced OIM, prevented apoptotic damage and reduced COX-2 enzyme activity in both the oral and intestinal epithelium. In 5-FU-injected mice, HA supplementation also significantly reduced serum levels of IL-6 and the chemokine CXCL1/KC, while the serum antioxidant activity of superoxide dismutase was elevated. Our data suggest that H-MW-HA attenuates 5-FU-induced OIM, at least partly, by impeding apoptosis, inhibiting of oxidative stress and suppressing inflammatory cytokines. This study supports the development of H-MW-HA preparations for preventing OIM in patients receiving chemotherapy.

HDAC6 inhibition: a significant potential regulator and therapeutic option to translate into clinical practice in renal transplantation.

Histone deacetylase 6 (HDAC6), an almost exclusively cytoplasmic enzyme, plays an essential role in many biological processes and exerts its deacetylation-dependent/independent effects on a variety of target molecules, which has contributed to the flourishing growth of relatively isoform-specific enzyme inhibitors. Renal transplantation (RT) is one of the alternatively preferred treatments and the most cost-effective treatment approaches for the great majority of patients with end-stage renal disease (ESRD). HDAC6 expression and activity have recently been shown to be increased in kidney disease in a number of studies. To date, a substantial amount of validated studies has identified HDAC6 as a pivotal modulator of innate and adaptive immunity, and HDAC6 inhibitors (HDAC6i) are being developed and investigated for use in arrays of immune-related diseases, making HDAC6i a promising therapeutic candidate for the management of a variety of renal diseases. Based on accumulating evidence, HDAC6i markedly open up new avenues for therapeutic intervention to protect against oxidative stress-induced damage, tip the balance in favor of the generation of tolerance-related immune cells, and attenuate fibrosis by inhibiting multiple activations of cell profibrotic signaling pathways. Taken together, we have a point of view that targeting HDAC6 may be a novel approach for the therapeutic strategy of RT-related complications, including consequences of ischemia-reperfusion injury, induction of immune tolerance in transplantation, equilibrium of rejection, and improvement of chronic renal graft interstitial fibrosis after transplantation in patients. Herein, we will elaborate on the unique function of HDAC6, which focuses on therapeutical mechanism of action related to immunological events with a general account of the tantalizing potential to the clinic.

Reactive oxygen/nitrogen species scavenging multi-enzyme mimetic ultrasmall calcium hexacyanoferrate (Ⅲ) nanozyme for hypertension remedy

Oxidative stress in the rostral ventrolateral medulla plays a pivotal role in the pathogenesis and progression of neurogenic hypertension, but limited strategy is currently available to maintain blood pressure and improve the life quality of patients with hypertension. The development of biocompatible nanomaterials with intrinsic antioxidative enzyme-mimicking activities is a promising approach to treat hypertension. Herein, we develop an ultrasmall calcium hexacyanoferrate (Ⅲ) nanoparticles (CaHF NPs) with the robust broad-spectrum reactive oxygen/nitrogen species (RONS) scavenging and anti-inflammation abilities for the treatment of hypertension. Specifically, CaHF NPs are simultaneously featured with superoxide dismutase-, peroxidase-, glutathione peroxidase- and catalase-like activities, protecting cell from oxidative stress-induced damage. Importantly, CaHF NPs alleviate hypertension through restoring endogenous redox homeostasis and reducing the secretion of proinflammatory cytokines. Our work not only provides a feasible therapeutic method for remedying hypertension, but also expands the biomedical applications of nanomaterials in treating oxidative stress-related central nervous system diseases.

Fangchinoline, an Extract of the Stephania tetrandra S. Moore Root, Promoted Oxidative Stress-induced DNA Damage and Apoptosis and Inhibited Akt Signaling in Jurkat T Cells.

Fangchinoline (Fan) is extracted from traditional Chinese medicine (called Fangji), or the root of Stephania tetrandra Moore. Fangji is well-known in Chinese medical literature for treating rheumatic diseases. Sjogren's syndrome (SS) is a rheumatic disease whose progression can be mediated via CD4+ T cell infiltration. This study identifies the potential role of Fan in inducing apoptosis in Jurkat T cells. First, we explored the biological process (BP) associated with SS development by performing a gene ontology analysis of SS salivary gland-related mRNA microarray data. The effect of Fan on Jurkat cells was investigated by analyzing the viability, proliferation, apoptosis, reactive oxygen species (ROS) production, and DNA damage. Biological process analysis showed that T cells played a role in salivary gland lesions in patients with SS, indicating the significance of T cell inhibition in SS treatment. Viability assays revealed that the half-maximal inhibitory concentration of Fan was 2.49 μM in Jurkat T cells, while the proliferation assay revealed that Fan had an inhibitory effect on the proliferation of Jurkat T cells. The results of the apoptotic, ROS, agarose gel electrophoresis, and immunofluorescence assays showed that Fan induced oxidative stress-induced apoptosis and DNA damage in a dosedependent manner. These results indicate that Fan could significantly induce oxidative stress-induced apoptosis and DNA damage and inhibit the proliferation of Jurkat T cells. Moreover, Fan further enhanced the inhibitory effect on DNA damage and apoptosis by inhibiting the pro-survival Akt signal.

Overexpression of 2-Cys Peroxiredoxin alleviates the NaHCO3 stress-induced photoinhibition and reactive oxygen species damage of tobacco

Plant 2-cysteine peroxiredoxin (2-Cys Prx) is a mercaptan peroxidase localized in chloroplasts and has unique catalytic properties. To explore the salt stress tolerance mechanisms of 2-Cys Prx in plants, we analyzed the effects of overexpressing the 2-CysPrx gene on the physiological and biochemical metabolic processes of tobacco under NaHCO3 stress through joint physiological and transcriptomic analysis. These parameters included growth phenotype, chlorophyll, photosynthesis, and antioxidant system. After NaHCO3 stress treatment, a total of 5360 differentially expressed genes (DEGs) were identified in 2-Cysprx overexpressed (OE) plants, and the number of DEGs was significantly lower than 14558 in wild-type (WT) plants. KEGG enrichment analysis showed that DEGs were mainly enriched in photosynthetic pathways, photosynthetic antenna proteins, and porphyrin and chlorophyll metabolism. Overexpressing 2-CysPrx significantly reduced the growth inhibition of tobacco induced by NaHCO3 stress, alleviating the down-regulation of the DEGs related to chlorophyll synthesis, photosynthetic electron transport and the Calvin cycle and the up-regulation of those related to chlorophyll degradation. In addition, it also interacted with other redox systems such as thioredoxins (Trxs) and the NADPH-dependent Trx reductase C (NTRC), and mediated the positive regulation of the activities of antioxidant enzymes such as peroxidase (POD) and catalase (CAT) and the expression of related genes, thereby reducing the accumulation of superoxide anion (O2·-), hydrogen peroxide (H2O2) and malondialdehyde (MDA). In conclusion, 2-CysPrx overexpression could alleviate the NaHCO3 stress-induced photoinhibition and oxidative damage by regulating chlorophyll metabolism, promoting photosynthesis and participating in the regulation of antioxidant enzymes, and thus improve the ability of plants to resist salt stress damage.

Role of endogenous and exogenous antioxidants in risk of six cancers: evidence from the Mendelian randomization study.

Background: Although oxidative stress is known to contribute to cancer, and endogenous and exogenous antioxidants are thought to prevent tumorigenesis by suppressing oxidative stress-induced DNA damage, antioxidants have also been reported to show negative effects on tumor formation, necessitating characterization of the causal associations between antioxidants and cancer risk. Methods: In this study, Mendelian randomization (MR) analysis, primarily inverse-variance weighted MR, was used to assess the causal effect of six endogenous and five exogenous diet-derived antioxidants on the risk of six cancers. MR-Egger intercept test and Cochran's Q statistic were utilized to assess pleiotropy and heterogeneity, respectively. Results: For endogenous antioxidants, a bidirectional two-sample MR analysis was conducted. Our findings suggested that serum albumin has a negative causal association with the risk of prostate cancer [odds ratio (OR) = 0.78, 95% confidence interval (CI): 0.68-0.91, p = 0.001]. The risks of the six cancers showed no significant associations with endogenous antioxidants in the converse MR analysis. For exogenous antioxidants, the unidirectional two-sample MR analysis exhibited a nominal relationship between the serum retinol level and non-small-cell lung cancer risk (OR = 0.29, 95% CI: 0.11-0.76, p = 0.011). Conclusions: Thus, our study revealed the protective effects of genetic susceptibility to high circulating albumin levels on prostate cancer, providing potential targeted interventions for prostate cancer prevention.

Evaluating the role of cytokinesis-block micronucleus assay as a biomarker for oxidative stress-inducing DNA damage in type 2 diabetes mellitus patients

BackgroundType 2 Diabetes Miletus (T2DM) is a common metabolic and lifestyle disorder leading to increased oxidative stress and DNA damage. The present study aims to evaluate the feasibility of utilizing the cytokinesis-block micronucleus assay (CBMN) as a biomarker for assessing the DNA damage induced due to variations in oxidative stress.MethodologyThe study group includes diabetic (n = 50) and non-diabetic (n = 50) subjects. The assays for the diabetes-like fasting blood sugar, postprandial glucose and hemoglobin A1c (HbA1c), lipid profiling, and serum ferritin level along with c-reactive protein (CRP) were applied. Further, the CBMN assay was performed to evaluate the micronuclei present in the lymphocytes of control and T2DM groups.ResultsSignificant imbalance in the glycaemic index, dyslipidemia, increased ferritin levels, and CRP levels, with a significant increase of micronucleus frequency, was found in T2DM patients compared with the control group. Results suggest a trend of positive correlation between HbA1c and the micronuclei, indicating the assay’s potential importance as a biomarker for T2DM-induced risk assessment.ConclusionFrom the observed results, it can be suggested that the CBMN assay could be used to assess the risk of oxidative stress-induced DNA damage in high glycaemic index diabetic patients.

Au Nanoparticles on 4-Thiophenol-Electrodeposited Carbon Surfaces for the Simultaneous Detection of 8-Hydroxyguanine and Guanine

In this proof-of-concept study, gold nanoparticles (AuNPs) were immobilized on glassy carbon electrode (GCE) surfaces using a surface-anchored diazonium salt of 4-aminothiophenol (GCE-Ph-S-AuNPs). X-ray photoelectron spectroscopy (XPS) studies confirmed the attachment of the AuNPs via 4-thiophenol onto the surface of the modified electrode. Differential pulse voltammetry (DPV) was performed for the simultaneous determination of guanine (G) and 8-hydroxyguanine (8-OH-G). The calibration curves were linear up to 140 µM and 60 µM with a limit of detection of 0.02 µM and 0.021 µM for G and 8-OH-G, respectively. Moreover, chronoamperometric studies were carried out for the determination of diffusion coefficients of 8-OH-G and G. The GCE-Ph-S-AuNPs were also applied in genomic DNA-spiked samples for the determination of G and 8-OH-G with recovery rates between 98.5% and 103.3%. The novel electrochemical surface provided a potential platform for the sensitive detection of 8-OH-G related to oxidative stress-induced DNA damage in clinical studies.

Leonurine alleviates acetaminophen-induced acute liver injury by regulating the PI3K/AKT signaling pathway in mice

Leonurine (Leo) is a natural alkaloid isolated from the herb Leonurus japonicus Houtt. (Leonuri) that has been shown to inhibit oxidative stress and inflammation. However, the role and mechanism of Leo in acetaminophen (APAP)-induced acute liver injury (ALI) remain unknown. In this study, we investigated the protective effect of Leo against APAP-induced ALI and elucidated the molecular mechanism. Here, we showed that the damage to mouse primary hepatocytes (MPHs) induced by APAP was attenuated by treatment with Leo, which promoted proliferation and inhibited oxidative stress injury, and Leo significantly improved APAP-induced ALI in mice. Leo could protect against APAP-induced ALI by reducing serum aspartate aminotransferase (AST) and alanine transaminase (ALT) levels, hepatic histopathological damage, liver cell necrosis, inflammation, and oxidative stress-induced damage in vivo and in vitro. Moreover, the results indicated that Leo relieved APAP-induced liver cell necrosis by reducing the expression of Bax and cleaved caspase-3 and increasing Bcl-2 expression. Leo alleviated APAP-induced oxidative stress-induced damage by activating the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, which facilitated Nrf2 nuclear translocation and upregulated oxidative stress-related protein expression in liver tissues. Moreover, the results suggested that APAP-induced inflammation in the liver was suppressed by Leo by suppressing the Toll-like receptor 4 (TLR4) and NLR family pyrin domain containing 3 (NLRP3) pathways. In addition, Leo facilitated the activation of the phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway in the liver tissue of ALI mice. Network pharmacology, molecular docking, and western blotting showed that PI3K was a potential target of Leo in the treatment of ALI. Molecular docking and cellular thermal shift assay (CETSA) indicated that Leo could stably bind to the PI3K protein. In conclusion, Leo attenuated ALI, and reversed liver cell necrosis, the inflammatory response and oxidative stress-induced damage by regulating the PI3K/AKT signaling pathway.