Menadione

The Key Role of GSH in Keeping the Redox Balance in Mammalian Cells: Mechanisms and Significance of GSH in Detoxification via Formation of Conjugates

Glutathione (GSH) is a ubiquitous tripeptide that is biosynthesized in situ at high concentrations (1-5 mM) and involved in the regulation of cellular homeostasis via multiple mechanisms. The main known action of GSH is its antioxidant capacity, which aids in maintaining the redox cycle of cells. To this end, GSH peroxidases contribute to the scavenging of various forms of ROS and RNS. A generally underestimated mechanism of action of GSH is its direct nucleophilic interaction with electrophilic compounds yielding thioether GSH S-conjugates. Many compounds, including xenobiotics (such as NAPQI, simvastatin, cisplatin, and barbital) and intrinsic compounds (such as menadione, leukotrienes, prostaglandins, and dopamine), form covalent adducts with GSH leading mainly to their detoxification. In the present article, we wish to present the key role and significance of GSH in cellular redox biology. This includes an update on the formation of GSH-S conjugates or GSH adducts with emphasis given to the mechanism of reaction, the dependence on GST (GSH S-transferase), where this conjugation occurs in tissues, and its significance. The uncovering of the GSH adducts' formation enhances our knowledge of the human metabolome. GSH-hematin adducts were recently shown to have been formed spontaneously in multiples isomers at hemolysates, leading to structural destabilization of the endogenous toxin, hematin (free heme), which is derived from the released hemoglobin. Moreover, hemin (the form of oxidized heme) has been found to act through the Kelch-like ECH associated protein 1 (Keap1)-nuclear factor erythroid 2-related factor-2 (Nrf2) signaling pathway as an epigenetic modulator of GSH metabolism. Last but not least, the implications of the genetic defects in GSH metabolism, recorded in hemolytic syndromes, cancer and other pathologies, are presented and discussed under the framework of conceptualizing that GSH S-conjugates could be regarded as signatures of the cellular metabolism in the diseased state.

Nanoengineered lanthanum niobate nanocaviar anchored carbon nanofibers for trace level detection of menadione in environmental samples

An innovative sensor is prepared by electrode modification through a nano-ranged electrode modifier composed of LaNbO₄ nano caviars decorated on the enmeshed carbon nanofibers to identify excess vitamins in animal feed. Menadione (Vitamins K3) is a micronutrient fundamentally required in precise quantities for animal health upkeep. Still, its exploitation has recently resulted in water reservoir contamination through waste generated from animal husbandry. Sustainable prevention of water contamination makes menadione detection highly imperative and flickered the attention of researchers. Considering these aspects, a novel menadione sensing platform is designed by interdisciplinary incorporation of nanoscience and electrochemical engineering. The structural and crystallographic features and the electrode modifier's morphological insights were keenly investigated. The hierarchal arrangement of individual constituents in nanocomposite is benefited through hybrid heterojunction and quantum confinement that synchronously activate the menadione detection with a LOD of 68.5 nM and 67.49 nM for oxidation and reduction, respectively. The as-prepared sensor has a wide linear range (0.1-173.6 μM), high sensitivity, good selectivity, and stability. The application of this sensor is extended to a water sample to monitor the consistency of the proposed sensor.

A Study on the Planarian Model Confirms the Antioxidant Properties of Tameron against X-ray- and Menadione-Induced Oxidative Stress

Ionizing radiation and radiation-related oxidative stress are two important factors responsible for the death of actively proliferating cells, thus drastically reducing the regeneration capacity of living organisms. Planarian flatworms are freshwater invertebrates that are rich in stem cells called neoblasts and, therefore, present a well-established model for studies on regeneration and the testing of novel antioxidant and radioprotective substances. In this work, we tested an antiviral and antioxidant drug Tameron (Monosodium α-Luminol or 5-amino-2,3-dihydro-1,4-phthalazinedione sodium salt) for its ability to reduce the harm of X-ray- and chemically induced oxidative stress on a planarian model. Our study has revealed the ability of Tameron to effectively protect planarians from oxidative stress while enhancing their regenerative capacity by modulating the expression of neoblast marker genes and NRF-2-controlled oxidative stress response genes.

Enzymatic Recording of Local Hydrogen Peroxide Generation Using Genetically Encodable Enzyme

Reactive oxygen species (ROS) are endogenously generated in live cells and essential for cell signaling. However, excess ROS generation can cause oxidative damage to biomolecules, which are implicated in various human diseases, including aging. Here, we developed an in vivo hydrogen peroxide monitoring method using a genetically encodable peroxidase (APEX2)-based system. We confirmed that APEX2 is activated by endogenous H₂O₂ and generates phenoxyl radicals to produce biotinylated signals (i.e., biotin-phenol) and fluorescent signals (i.e., AmplexRed), which can be detected using a fluorescence microscope. We observed that all subcellular targeted APEX2s were activated by local H₂O₂ generation by menadione treatment. Among them, the endoplasmic reticulum lumen and lysosome-targeted APEX2 showed the highest response upon addition of menadione which implies that local H₂O₂ levels in those spaces are highly increased by menadione treatment. Using APEX2, we also found that a minimum amount of menadione (>10 μM) is required to generate detectable levels of H₂O₂ in all subcellular compartments. We also checked the local H₂O₂-quenching effect of N-acetylcysteine using our system. As APEX2 can be genetically expressed in diverse live organisms (e.g., cancer cell lines, mice, fly, worm, and yeast), our method can be effectively used to detect local generation of endogenously produced H₂O₂ in diverse live models.

Menadione: a platform and a target to valuable compounds synthesis

Naphthoquinones are important natural or synthetic compounds belonging to the general class of quinones. Many compounds in this class have become drugs that are on the pharmaceutical market for the treatment of various diseases. A special naphthoquinone derivative is menadione, a synthetic naphthoquinone belonging to the vitamin K group. This compound can be synthesized by different methods and it has a broad range of biological and synthetic applications, which will be highlighted in this review.

Nitroreductase Increases Menadione-Mediated Oxidative Stress in Aspergillus nidulans

Nitroreductases (NTRs) catalyze the reduction of a wide range of nitro-compounds and quinones using NAD(P)H. Although the physiological functions of these enzymes remain obscure, a tentative function of resistance to reactive oxygen species (ROS) via the detoxification of menadione has been proposed. This suggestion is based primarily on the transcriptional or translational induction of an NTR response to menadione rather than on convincing experimental evidence. We investigated the performance of a fungal NTR from Aspergillus nidulans (AnNTR) exposed to menadione to address the question of whether NTR is really an ROS defense enzyme. We confirmed that AnNTR was transcriptionally induced by external menadione. We observed that menadione treatment generated cytotoxic levels of O₂^•-, which requires well-known antioxidant enzymes such as superoxide dismutase, catalase, and peroxiredoxin to protect A. nidulans against menadione-derived ROS stress. However, AnNTR was counterproductive for ROS defense, since knocking out AnNTR decreased the intracellular O₂^•- levels, resulting in fungal viability higher than that of the wild type. This observation implies that AnNTR may accelerate the generation of O₂^•- from menadione. Our in vitro experiments indicated that AnNTR uses NADPH to reduce menadione in a single-electron reaction, and the subsequent semiquinone-quinone redox cycling resulted in O₂^•- generation. We demonstrated that A. nidulans nitroreductase should be an ROS generator, but not an ROS scavenger, in the presence of menadione. Our results clarified the relationship between nitroreductase and menadione-derived ROS stress, which has long been ambiguous. IMPORTANCE Menadione is commonly used as an O₂^•- generator in studies of oxidative stress responses. However, the precise mechanism through which menadione mediates cellular O₂^•- generation, as well as the way in which cells respond, remains unclear. Elucidating these events will have important implications for the use of menadione in biological and medical studies. Our results show that the production of Aspergillus nidulans nitroreductase (AnNTR) was induced by menadione. However, the accumulated AnNTR did not protect cells but instead increased the cytotoxic effect of menadione through a single-electron reduction reaction. Our finding that nitroreductase is involved in the menadione-mediated O₂^•- generation pathway has clarified the relationship between nitroreductase and menadione-derived ROS stress, which has long been ambiguous.

Synthetic vitamin K analogs inhibit inflammation by targeting the NLRP3 inflammasome

Vitamin K refers to a group of structurally similar vitamins that are essential for proper blood coagulation, as well as bone and cardiovascular health. Previous studies have indicated that vitamin K may also have anti-inflammatory properties, although the underlying mechanisms of its anti-inflammatory effects remain unclear. The NLRP3 inflammasome is a multiprotein complex, and its activation leads to IL-1β and IL-18 secretion and contributes to the pathogenesis of various human inflammatory diseases. Here, we show that synthetic vitamins K3 and K4 are selective, potent inhibitors of the NLRP3 inflammasome and specifically block the interaction between NLRP3 and ASC, thereby inhibiting NLRP3 inflammasome assembly. Moreover, we show that treatment with vitamin K3 or K4 attenuates the severity of inflammation in a mouse model of peritonitis. Our results demonstrate that vitamins K3 and K4 exert their anti-inflammatory effects by inhibiting NLRP3 inflammasome activation and indicate that vitamin K supplementation may be a treatment option for NLRP3-associated inflammatory diseases.

Antimutagenic, Cytoprotective and Antioxidant Properties of Ficus deltoidea Aqueous Extract In Vitro

Ficus deltoidea var. deltoidea is used as traditional medicine for diabetes, inflammation, and nociception. However, the antimutagenic potential and cytoprotective effects of this plant remain unknown. In this study, the mutagenic and antimutagenic activities of F. deltoidea aqueous extract (FDD) on both Salmonella typhimurium TA 98 and TA 100 strains were assessed using Salmonella mutagenicity assay (Ames test). Then, the cytoprotective potential of FDD on menadione-induced oxidative stress was determined in a V79 mouse lung fibroblast cell line. The ferric-reducing antioxidant power (FRAP) assay was conducted to evaluate FDD antioxidant capacity. Results showed that FDD (up to 50 mg/mL) did not exhibit a mutagenic effect on either TA 98 or TA 100 strains. Notably, FDD decreased the revertant colony count induced by 2-aminoanthracene in both strains in the presence of metabolic activation (p < 0.05). Additionally, pretreatment of FDD (50 and 100 µg/mL) demonstrated remarkable protection against menadione-induced oxidative stress in V79 cells significantly by decreasing superoxide anion level (p < 0.05). FDD at all concentrations tested (12.5–100 µg/mL) exhibited antioxidant power, suggesting the cytoprotective effect of FDD could be partly attributed to its antioxidant properties. This report highlights that F. deltoidea may provide a chemopreventive effect on mutagenic and oxidative stress inducers.

Effects of prolonged subchronic benzo(α)pyrene exposure on rat liver morphology and CYP1A expression during treatment with menadione, quercetin, or tocopherol

Arylamines and polycyclic aromatic hydrocarbons (PAHs) are hazardous anthropogenic pollutants in the environment. The toxicity of PAHs, which include benzo(α)pyrene (BP), is mediated by the activation of Р450 cytochromes of the 1А subfamily (CYP1A1 and CYP1A2). Previously, we have demonstrated that tocopherol, quercetin, and menadione inhibit the expression and activity of CYP1A in the liver of male Wistar rats after administration of a high BP dose to the rats for 3 days. Here, we confirmed the effects of tocopherol, quercetin, and menadione on the expression and activity of CYP1A and on rat liver morphology during prolonged administration (90 days) of a low BP dose. We revealed that subchronic oral administration of a low BP dose has no influence on CYP1A expression as compared to controls but can cause pathomorphological changes in rat liver tissue. These changes are abrogated by tocopherol, attenuated by quercetin, and enhanced by menadione.

Mechanisms of antimicrobial resistance in Stenotrophomonas maltophilia: a review of current knowledge

Introduction: Stenotrophomonas maltophilia is a prototype of bacteria intrinsically resistant to antibiotics. The reduced susceptibility of this microorganism to antimicrobials mainly relies on the presence in its chromosome of genes encoding efflux pumps and antibiotic inactivating enzymes. Consequently, the therapeutic options for treating S. maltophilia infections are limited.Areas covered: Known mechanisms of intrinsic, acquired and phenotypic resistance to antibiotics of S. maltophilia and the consequences of such resistance for treating S. maltophilia infections are discussed. Acquisition of some genes, mainly those involved in co-trimoxazole resistance, contributes to acquired resistance. Mutation, mainly in the regulators of chromosomally-encoded antibiotic resistance genes, is a major cause for S. maltophilia acquisition of resistance. The expression of some of these genes is triggered by specific signals or stressors, which can lead to transient phenotypic resistance.Expert opinion: Treatment of S. maltophilia infections is difficult because this organism presents low susceptibility to antibiotics. Besides, it can acquire resistance to antimicrobials currently in use. Particularly problematic is the selection of mutants overexpressing efflux pumps since they present a multidrug resistance phenotype. The use of novel antimicrobials alone or in combination, together with the development of efflux pumps' inhibitors may help in fighting S. maltophilia infections.

The Paradoxical Leishmanicidal Effects of Superoxide Dismutase (SOD)-Mimetic Tempol in Leishmania braziliensis Infection in vitro

Leishmaniasis is an infectious disease caused by protozoans of the genus Leishmania. The macrophage is the resident cell in which the parasite replicates and it is important to identify new compounds that can aid in parasite elimination since the drugs used to treat leishmaniasis are toxic and present side effects. We have previously shown that treatment of Leishmania braziliensis-infected macrophages with DETC (Diethyldithiocarbamate) induces parasite killing, in vivo. Thus, the objective of this study was to further evaluate the effect of oxidants and antioxidants in L. braziliensis-infected macrophages, following treatment with either oxidizing Hydrogen Peroxide, Menadione, DETC, or antioxidant [NAC (N-Acetyl-Cyteine), Apocynin, and Tempol] compounds. We determined the percentage of infected macrophages and number of amastigotes. Promastigote survival was also evaluated. Both DETC (SOD-inhibitor) and Tempol (SOD-mimetic) decreased the percentage of infected cells and parasite load. Hydrogen peroxide did not interfere with parasite burden, while superoxide-generator Menadione had a reducing effect. On the other hand, NAC (GSH-replenisher) and Apocynin (NADPH-oxidase inhibitor) increased parasite burden. Tempol surfaces as an interesting candidate for the chemotherapy of CL with an IC₅₀ of 0.66 ± 0.08 mM and selectivity index of 151. While it remains obscure how a SOD-mimetic may induce leishmanicidal effects, we suggest the possibility of developing Tempol-based topical applications for the treatment of cutaneous leishmaniasis caused by L. braziliensis.

Comparison of the Effect of Native 1,4-Naphthoquinones Plumbagin, Menadione, and Lawsone on Viability, Redox Status, and Mitochondrial Functions of C6 Glioblastoma Cells

Background: 1,4-naphthoquinones, especially juglone, are known for their anticancer activity. However, plumbagin, lawsone, and menadione have been less investigated for these properties. Therefore, we aimed to determine the effects of plumbagin, lawsone, and menadione on C6 glioblastoma cell viability, ROS production, and mitochondrial function. Methods: Cell viability was assessed spectrophotometrically using metabolic activity method, and by fluorescent Hoechst/propidium iodide nuclear staining. ROS generation was measured fluorometrically using DCFH-DA. Oxygen uptake rates were recorded by the high-resolution respirometer Oxygraph-2k. Results: Plumbagin and menadione displayed highly cytotoxic activity on C6 cells (IC₅₀ is 7.7 ± 0.28 μM and 9.6 ± 0.75 μM, respectively) and caused cell death by necrosis. Additionally, they increased the amount of intracellular ROS in a concentration-dependent manner. Moreover, even at very small concentrations (1–3 µM), these compounds significantly uncoupled mitochondrial oxidation from phosphorylation impairing energy production in cells. Lawsone had significantly lower viability decreasing and mitochondria-uncoupling effect, and exerted strong antioxidant activity. Conclusions: Plumbagin and menadione exhibit strong prooxidant, mitochondrial oxidative phosphorylation uncoupling and cytotoxic activity. In contrast, lawsone demonstrates a moderate effect on C6 cell viability and mitochondrial functions, and possesses strong antioxidant properties.

Inhibitory Effects of Menadione on Helicobacter pylori Growth and Helicobacter pylori-Induced Inflammation via NF-κB Inhibition

H. pylori is classified as a group I carcinogen by WHO because of its involvement in gastric cancer development. Several reports have suggested anti-bacterial effects of menadione, although the effect of menadione on major virulence factors of H. pylori and H. pylori-induced inflammation is yet to be elucidated. In this study, therefore, we demonstrated that menadione has anti-H. pylori and anti-inflammatory effects. Menadione inhibited growth of H. pylori reference strains and clinical isolates. Menadione reduced expression of vacA in H. pylori, and translocation of VacA protein into AGS (gastric adenocarcinoma cell) was also decreased by menadione treatment. This result was concordant with decreased apoptosis in AGS cells infected with H. pylori. Moreover, cytotoxin-associated protein A (CagA) translocation into H. pylori-infected AGS cells was also decreased by menadione. Menadione inhibited expression of several type IV secretion system (T4SS) components, including virB2, virB7, virB8, and virB10, that are responsible for translocation of CagA into host cells. In particular, menadione inhibited nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) activation and thereby reduced expression of the proinflammatory cytokines such as IL-1β, IL-6, IL-8, and TNF-α in AGS as well as in THP-1 (monocytic leukemia cell) cell lines. Collectively, these results suggest the anti-bacterial and anti-inflammatory effects of menadione against H. pylori.

Mitochondria as emerging targets for therapies against T cell acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) comprises a heterogeneous group of hematologic malignancies, arising from diverse genetic alterations in the early lymphocyte development. T-cell subtype of ALL (T-ALL) accounts for about 15% and 25% of ALL in children and adults, respectively. Being less frequent among ALL subtypes, T-ALL represents a high-risk factor for poor prognosis due to its aggressiveness and resistance to common antileukemic drugs. Mitochondria were widely explored recently as a target for anticancer treatment because they are involved in a metabolic reprogramming of a cancer cell and play key roles in reactive oxygen species generation, Ca²⁺ signaling, and cell death induction. Accordingly, a new class of anticancer compounds named mitocans has been developed, which target mitochondria at distinct crucial points to promote their dysfunction and subsequent cell death. The present review analyses the role of mitochondria in malignant reprogramming and emerging therapeutic strategies targeting mitochondria as an "Achilles' heel" in T-ALL, with an emphasis on BH3 mimetics, sequestering pro-survival BCL proteins and voltage-dependent anion channel (VDAC)1-directed drugs, which promote the suppression of aerobic glycolysis, VDAC1 closure, mitochondrial Ca²⁺ overload, stoppage of the oxidative phosphorylation, oxidative stress, and release of proapoptotic factors.

Vitamin K3 Induces the Expression of the Stenotrophomonas maltophilia SmeVWX Multidrug Efflux Pump

Stenotrophomonas maltophilia is an opportunistic pathogen with increasing prevalence, which is able to cause infections in immunocompromised patients or in those with a previous pathology. The treatment of the infections caused by this bacterium is often complicated due to the several intrinsic antibiotic resistance mechanisms that it presents. Multidrug efflux pumps are among the best-studied mechanisms of S. maltophilia antibiotic resistance. Some of these efflux pumps have a basal expression level but, in general, their expression is often low and only reaches high levels when the local regulator is mutated or bacteria are in the presence of an effector. In the current work, we have developed a yellow fluorescent protein (YFP)-based sensor with the aim to identify effectors able to trigger the expression of SmeVWX, an efflux pump that confers resistance to quinolones, chloramphenicol, and tetracycline when it is expressed at high levels. With this purpose in mind, we tested a variety of different compounds and analyzed the fluorescence signal given by the expression of YFP under the control of the smeVWX promoter. Among the tested compounds, vitamin K₃, which is a compound belonging to the 2-methyl-1,4-naphthoquinone family, is produced by plants in defense against infection, and has increasing importance in human therapy, was able to induce the expression of the SmeVWX efflux pump. In addition, a decrease in the susceptibility of S. maltophilia to ofloxacin and chloramphenicol was observed in the presence of vitamin K₃, in both wild-type and smeW-deficient strains.

Administration of Menadione, Vitamin K3, Ameliorates Off-Target Effects on Corneal Epithelial Wound Healing Due to Receptor Tyrosine Kinase Inhibition

PURPOSE

The antiangiogenic receptor tyrosine kinase inhibitor (RTKi), 3-[(4-bromo-2,6-difluorophenyl)methoxy]-5-[[[[4-(1-pyrrolidinyl) butyl] amino] carbonyl]amino]-4-isothiazolecarboxamide hydrochloride, targets VEGFR2 (half maximal inhibitory concentration [IC50] = 11 nM); however, off-target inhibition of epidermal growth factor receptor (EGFR) occurs at higher concentrations. (IC50 = 5.8 μM). This study was designed to determine the effect of topical RTKi treatment on EGF-mediated corneal epithelial wound healing and to develop new strategies to minimize off-target EGFR inhibition.

METHODS

In vitro corneal epithelial wound healing was measured in response to EGF using a transformed human cell line (hTCEpi cells). In vivo corneal wound healing was assessed using a murine model. In these complementary assays, wound healing was measured in the presence of varying RTKi concentrations. Immunoblot analysis was used to examine EGFR and VEGFR2 phosphorylation and the kinetics of EGFR degradation. An Alamar Blue assay measured VEGFR2-mediated cell biology.

RESULTS

Receptor tyrosine kinase inhibitor exposure caused dose-dependent inhibition of EGFR-mediated corneal epithelial wound healing in vitro and in vivo. Nanomolar concentrations of menadione, a vitamin K3 analog, when coadministered with the RTKi, slowed EGFR degradation and ameliorated the inhibitory effects on epithelial wound healing both in vitro and in vivo. Menadione did not alter the RTKi's IC50 against VEGFR2 phosphorylation or its inhibition of VEGF-induced retinal endothelial cell proliferation.

CONCLUSIONS

An antiangiogenic RTKi exhibited off-target effects on the corneal epithelium that can be minimized by menadione without deleteriously affecting its on-target VEGFR2 blockade. These data indicate that menadione has potential as a topical supplement for individuals suffering from perturbations in corneal epithelial homeostasis, especially as an untoward side effect of kinase inhibitors.

Vitamin K and hepatocellular carcinoma: The basic and clinic

Vitamin K (VK), which was originally identified as a cofactor involved in the production of functional coagulation factors in the liver, has been shown to be involved in various aspects of physiological and pathological events, including bone metabolism, cardiovascular diseases and tumor biology. The mechanisms and roles of VK are gradually becoming clear. Several novel enzymes involved in the VK cycle were identified and have been shown to be linked to tumorigenesis. The VKs have been shown to suppress liver cancer cell growth through multiple signaling pathways via the transcription factors and protein kinases. A VK2 analog was applied to the chemoprevention of hepatocellular carcinoma (HCC) recurrence after curative therapy and was shown to have beneficial effects, both in the suppression of HCC recurrence and in patient survival. Although a large scale randomized control study failed to demonstrate the suppression of HCC recurrence, a meta-analysis suggested a beneficial effect on the long-term survival of HCC patients. However, the beneficial effects of VK administration alone were not sufficient to prevent or treat HCC in clinical settings. Thus its combination with other anti-cancer reagents and the development of more potent novel VK derivatives are the focus of ongoing research which seeks to achieve satisfactory therapeutic effects against HCC.

Menadione (Vitamin K3) induces apoptosis of human oral cancer cells and reduces their metastatic potential by modulating the expression of epithelial to mesenchymal transition markers and inhibiting migration

Oral cancer is one of the most commonly occurring cancers worldwide, decreasing the patient's survival rate due to tumor recurrence and metastasis. Menadione (Vitamin K3) is known to exhibit cytotoxicity in various cancer cells but the present study focused on its effects on viability, apoptosis, epithelial to mesenchymal transition (EMT), anchorage independent growth and migration of oral cancer cells. The results show that menadione is more cytotoxic to SAS (oral squamous carcinoma) cells but not to non-tumorigenic HEK293 and HaCaT cells. Menadione treatment increased the expression of pro-apoptotic proteins, Bax and p53, with a concurrent decrease in anti-apoptotic proteins, Bcl-2 and p65. Menadione induced the expression of E-cadherin but reduced the expression of EMT markers, vimentin and fibronectin. Menadione also inhibited anchorage independent growth and migration in SAS cells. These findings reveal and confirm that menadione is a potential candidate in oral cancer therapy as it exhibits cytotoxic, antineoplastic and antimigratory effects besides effectively blocking EMT in oral cancer cells.