Mitochondrial oxidative damage contributes to a wide range of pathologies. One therapeutic strategy to treat these disorders is targeting antioxidants to mitochondria by conjugation to the lipophilic triphenylphosphonium (TPP) cation. To date only hydrophobic antioxidants have been targeted to mitochondria; however, extending this approach to hydrophilic antioxidants offers new therapeutic and research opportunities. Here we report the development and characterization of MitoC, a mitochondria-targeted version of the hydrophilic antioxidant ascorbate. We show that MitoC can be taken up by mitochondria, despite the polarity and acidity of ascorbate, by using a sufficiently hydrophobic link to the TPP moiety. MitoC reacts with a range of reactive species, and within mitochondria is rapidly recycled back to the active ascorbate moiety by the glutathione and thioredoxin systems. Because of this accumulation and recycling MitoC is an effective antioxidant against mitochondrial lipid peroxidation and also decreases aconitase inactivation by superoxide. These findings show that the incorporation of TPP function can be used to target polar and acidic compounds to mitochondria, opening up the delivery of a wide range of bioactive compounds. Furthermore, MitoC has therapeutic potential as a new mitochondria-targeted antioxidant, and is a useful tool to explore the role(s) of ascorbate within mitochondria.

• Klíčová slova
• Ascorbic acid, Lipid peroxidation, Lipophilic cation, MitoC, MitoPerox, Mitochondria, Mitochondrial targeting,
• MeSH
• antioxidancia chemie   farmakologie   MeSH
• jaterní mitochondrie účinky léků   metabolismus   MeSH
• krysa rodu Rattus MeSH
• kyselina askorbová chemie   farmakologie   MeSH
• oxidace-redukce MeSH
• oxidační stres účinky léků   MeSH
• potkani Wistar MeSH
• systémy cílené aplikace léků metody   MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antioxidancia MeSH
• kyselina askorbová MeSH

In this work, we studied the biochemical properties and evolutionary histories of catalase (CAT) and ascorbate peroxidase (APX), two central enzymes of reactive oxygen species detoxification, across the highly diverse clade Eugenozoa. This clade encompasses free-living phototrophic and heterotrophic flagellates, as well as obligate parasites of insects, vertebrates, and plants. We present evidence of several independent acquisitions of CAT by horizontal gene transfers and evolutionary novelties associated with the APX presence. We posit that Euglenozoa recruit these detoxifying enzymes for specific molecular tasks, such as photosynthesis in euglenids and membrane-bound peroxidase activity in kinetoplastids and some diplonemids.

• Klíčová slova
• Euglenozoa, ascorbate peroxidase, catalase, enzymatic activity, phylogeny,
• Publikační typ
• časopisecké články MeSH

The modulation of hormone and metabolite levels by ascorbate (ASA) and hydrogen peroxide (H2 O2 ) was compared during post-germination growth in shoots of wheat. Treatment with ASA resulted in a greater reduction of growth than the addition of H2 O2 . ASA also had a larger effect on the redox state of the shoot tissues as shown by the higher ASA and glutathione (GSH) levels, lower glutathione disulfide (GSSG) content and GSSG/GSH ratio compared to the H2 O2 treatment. Apart from common responses (i.e., increase of cis-zeatin and its O-glucosides), the contents of several compounds related to cytokinin (CK) and abscisic acid (ABA) metabolism were greater after ASA application. These differences in the redox state and hormone metabolism following the two treatments may be responsible for their distinct influence on various metabolic pathways. Namely, the glycolysis and citrate cycle were inhibited by ASA and they were not affected by H2 O2 , while the amino acid metabolism was induced by ASA and repressed by H2 O2 based on the changes in the level of the related carbohydrates, organic and amino acids. The first two pathways produce reducing power, while the last one needs it; therefore ASA, as a reductant may suppress and induce them, respectively. H2 O2 as an oxidant had different effect, namely it did not alter glycolysis and citrate cycle, and inhibited the formation of amino acids.

• MeSH
• aminokyseliny metabolismus   MeSH
• glutathion metabolismus   MeSH
• glutathiondisulfid metabolismus   MeSH
• hormony metabolismus   MeSH
• klíčení * MeSH
• kyselina askorbová metabolismus   MeSH
• peroxid vodíku * metabolismus   MeSH
• pšenice metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aminokyseliny MeSH
• glutathion MeSH
• glutathiondisulfid MeSH
• hormony MeSH
• kyselina askorbová MeSH
• peroxid vodíku * MeSH

Two isoforms of NAD(P)(+)-dependent malic enzyme (EC 1.1.1.39) were isolated from hydrogenosomes of Trichomonas vaginalis. A positively charged isoform at pH 7 was obtained in a single purification step using cation-exchange chromatography. The second isoform, negatively charged at pH 7.5, was partially purified using a combination of anion-exchange and affinity chromatography. Both isoforms displayed similar physical and kinetic properties. Molecular weight determination of the native enzyme suggested a homotetrameric arrangement of the 60 kDa subunits. The enzyme utilized NAD+ (Km, 6-6.3 microM) preferentially to NADP+ (Km, 125-145 microM). The NAD(+)-dependent activity showed a broad pH optimum with maximum under alkaline conditions (pH 9) likely to be present inside hydrogenosomes. Immunocytochemical studies using a polyclonal rabbit antibody raised against purified T. vaginalis malic enzyme proved hydrogenosomal localization of the enzyme. Subfractionation of hydrogenosomes suggested an association of the malic enzyme with the hydrogenosomal membranes. The 60 kDa malic enzyme subunit was highly sensitive to non-enzymatic cleavage by an iron-ascorbate system resulting in two enzymatically inactive fragments of about 31 kDa. Microsequencing of the fragments revealed that the 60 kDa subunit was cleaved at the metal-binding site between Asp279-Ile280. The enzyme inactivation was inhibited by an excess of manganese. Iron-dependent posttranslational modification might contribute to the regulation of malic enzyme activity in vivo.

• MeSH
• chloridy farmakologie   MeSH
• frakcionace buněk MeSH
• intracelulární membrány enzymologie   MeSH
• izoenzymy chemie   izolace a purifikace   metabolismus   MeSH
• kinetika MeSH
• koncentrace vodíkových iontů MeSH
• kyselina askorbová farmakologie   MeSH
• malátdehydrogenasa analýza   chemie   izolace a purifikace   metabolismus   MeSH
• molekulární sekvence - údaje MeSH
• molekulová hmotnost MeSH
• NAD metabolismus   MeSH
• organely enzymologie   MeSH
• sekvence aminokyselin MeSH
• sekvenční analýza MeSH
• sloučeniny manganu farmakologie   MeSH
• Trichomonas vaginalis enzymologie   MeSH
• železnaté sloučeniny farmakologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chloridy MeSH
• ferrous sulfate MeSH Prohlížeč
• izoenzymy MeSH
• kyselina askorbová MeSH
• malátdehydrogenasa MeSH
• malate dehydrogenase (decarboxylating) MeSH Prohlížeč
• manganese chloride MeSH Prohlížeč
• NAD MeSH
• sloučeniny manganu MeSH
• železnaté sloučeniny MeSH

L eishmaniasis is a prevalent disease that impacts 98 countries and territories, mainly in Africa, Asia, and South America. It can cause substantial illness and death, particularly in its visceral manifestation that can be specifically targeted in the development of medications to combat leishmaniasis. This study has found natural compounds with possible inhibitory activity against APX using a reliable and accurate QSAR model. Despite the severe side effects of current treatments and the absence of an effective vaccination, these compounds show promise as a potential treatment for the disease. Nine hit compounds were found, and subsequent molecular docking was performed. Estradiol cypionate showed the lowest binding energy (- 10.5 kcal/mol), thus showing the strongest binding, and also had the strongest binding affinity, with a ΔGTotal of - 26.31 ± 3.01 kcal/mol, second only to the control molecule. Additionally, three hits viz. cloxacillin-sodium (- 16.57 ± 2.89 kcal/mol), cinchonidine (- 16.04 ± 3.27 kcal/mol), and quinine hydrochloride dihydrate (13.38 ± 1.06 kcal/mol) also showed significant binding affinity. Multiple interactions between drugs and active site residues demonstrated a substantial binding affinity with the target protein. The identified compounds exhibited drug-like effects and were orally bioavailable based on their ADME-toxicology features. Overall, estradiol cypionate, cloxacillin sodium, cinchonidine, and quinine hydrochloride dihydrate all exhibited inhibitory effects on the APX enzyme of Leishmania donovani. These results suggest that further investigation is needed to explore the potential of developing novel anti-leishmaniasis drugs using these compounds.

• Klíčová slova
• Anti-leishmaniasis drugs, Ascorbate peroxidase, Leishmaniasis, Natural compounds, QSAR model,
• Publikační typ
• časopisecké články MeSH

Antioxidant and pro-oxidant effects of 14 naturally occurring polyphenols (PP) on rat liver microsomal lipid peroxidation (LP) and hydroxyl radical (*OH) production were studied in NADPH-dependent, 50 microM Fe(2+)-500 microM ascorbate (Fe-AA) or 50 microM Fe(2+) system, respectively. LP determined by the thiobarbituric acid method was inhibited in the NADPH system by flavonols and trans-resveratrol that were more effective than other flavonoids and derivatives of benzoic and cinnamic acid and were mostly more efficient than in the Fe-AA system. Inhibition of LP in the Fe system was higher by one order of magnitude than in the Fe-AA system. *OH production in the NADPH system, measured by formaldehyde production, was decreased by myricetin, fisetin and quercetin, but increased by kaempferol, morin and trans-resveratrol, indicating that z.rad;OH played a minor role in LP, which all of these PP inhibited. None of these PP at up to 40 microM concentration quenched *OH in the Fe-AA system. All tested PP, except trans-resveratrol and gentisic acid, spectrally interacted with Fe(2+) or Fe(3+), indicating formation of complexes or oxidation of PP. In contrast to the NADPH system we found no correlation between Fe(2+) chelation and inhibition of Fe-AA- or Fe-dependent LP indicating that iron chelation did not play a significant role in the two latter systems. It is concluded that the inhibition of LP by PP was apparently due to their hydrogen donating properties rather than chelation of iron.

• MeSH
• antioxidancia farmakologie   MeSH
• fenoly farmakologie   MeSH
• flavonoidy * MeSH
• hydroxylový radikál metabolismus   MeSH
• jaterní mikrozomy účinky léků   metabolismus   MeSH
• krysa rodu Rattus MeSH
• kyselina askorbová metabolismus   MeSH
• NADP metabolismus   MeSH
• oxidace-redukce MeSH
• peroxidace lipidů účinky léků   MeSH
• polyfenoly MeSH
• polymery farmakologie   MeSH
• železo metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antioxidancia MeSH
• fenoly MeSH
• flavonoidy * MeSH
• hydroxylový radikál MeSH
• kyselina askorbová MeSH
• NADP MeSH
• polyfenoly MeSH
• polymery MeSH
• železo MeSH

INTRODUCTION: Pain is the most common reason for seeking medical treatment. Despite extensive research efforts and effective analgesics modulating pain, there is still a major therapeutic gap in addressing the root causes of pain. Pain is associated with tissue damage induced by oxidative stress and induction of inflammatory mediators following high consumption of antioxidants. The role of antioxidants in general, and the administration of L-ascorbate in particular, is still controversially discussed and underestimated in the daily clinical practice. METHODS: The current literature on the therapeutic effect of L-ascorbate, ascorbic acid, and vitamin C on various pain conditions was evaluated against the background of evidence-based medicine. Those articles, obtained from systematic search in PubMed, were critically assessed and rated in terms of evidence level and methodological quality by two independent experts. The primary purpose of this work was to establish specific pain therapy guidance for intravenous L-ascorbate. RESULTS: A PubMed search revealed 14 suitable articles comprising controlled clinical trials and meta-analyses. An additional ten publications could be identified via secondary literature. There is supporting evidence for the efficacy of ascorbate treatment in inflammatory pain conditions, in the complex regional pain syndrome, in post zoster neuralgia, in neuropathic pain, in post-operative pain conditions, and in tumor-related pain. However, the considered studies differ in the type of administration, in dosage, in duration of treatment, as well as in quality of research. Despite all study heterogeneity, it became evident that research of high scientific quality is in support of the efficacy of L-ascorbate in pain treatment. DISCUSSION: Oxidative stress is present in almost all pain conditions. Because oral administration of most magistral formulas of vitamin C does not provide biological availability, parenteral administration should be preferred and can be supported by an oral dose with high bioavailability on days without intravenous treatment. L-ascorbate should be preferred for parenteral high dosage, rather than ascorbic acid, as it does not release acid valences under physiological conditions. CONCLUSIONS: L-ascorbate is an effective, safe, and economically favorable integrative treatment option for various pain conditions, addressing the root cause of tissue damage and inflammatory mediator burst.

• Klíčová slova
• l-ascorbate, Ascorbic acid, Complex regional pain syndrome, Critical assessment, Intravenous vitamin C, Neuralgia, Oxidative stress, Postoperative pain, Tumor pain,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

The antioxidant properties of flavonoids are mediated by their functional hydroxyl groups, which are capable of both chelating redox active metals such as iron, copper and scavenging free radicals. In this paper, the antioxidant vs. prooxidant and DNA protecting properties of baicalein and Cu(II)-baicalein complexes were studied under the conditions of the Copper-Fenton reaction and of the Copper-Ascorbate system. From the relevant EPR spectra, the interaction of baicalein with Cu(II) ions was confirmed, while UV-vis spectroscopy demonstrated a greater stability over time of Cu(II)-baicalein complexes in DMSO than in methanol and PBS and Phosphate buffers. An ABTS study confirmed a moderate ROS scavenging efficiency, at around 37%, for both free baicalein and Cu(II)-baicalein complexes (in the ratios 1:1 and 1:2). The results from absorption titrations are in agreement with those from viscometric studies and confirmed that the binding mode between DNA and both free baicalein and Cu-baicalein complexes, involves hydrogen bonds and van der Waals interactions. The DNA protective effect of baicalein has been investigated by means of gel electrophoresis under the conditions of the Cu-catalyzed Fenton reaction and of the Cu-Ascorbate system. In both cases, it was found that, at sufficiently high concentrations, baicalein offers some protection to cells from DNA damage caused by ROS (singlet oxygen, hydroxyl radicals and superoxide radical anions). Accordingly, baicalein may be useful as a therapeutic agent in diseases with a disturbed metabolism of redox metals such as copper, for example Alzheimer's disease, Wilson's disease and various cancers. While therapeutically sufficient concentrations of baicalein may protect neuronal cells from Cu-Fenton-induced DNA damage in regard to neurological conditions, conversely, in the case of cancers, low concentrations of baicalein do not inhibit the pro-oxidant effect of copper ions and ascorbate, which can, in turn, deliver an effective damage to DNA in tumour cells.

• Klíčová slova
• Antioxidant, Baicalein, Copper(II), DNA damage, Gel electrophoresis, Prooxidant, Radical scavenging, Spectroscopy,
• MeSH
• antioxidancia * chemie   MeSH
• DNA metabolismus   MeSH
• flavonoidy MeSH
• hydroxylový radikál metabolismus   MeSH
• kovy MeSH
• kyselina askorbová MeSH
• měď * chemie   MeSH
• oxidace-redukce MeSH
• poškození DNA MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antioxidancia * MeSH
• baicalein MeSH Prohlížeč
• DNA MeSH
• flavonoidy MeSH
• hydroxylový radikál MeSH
• kovy MeSH
• kyselina askorbová MeSH
• měď * MeSH
• reaktivní formy kyslíku MeSH

A seed's ability to properly germinate largely depends on its oxidative poise. The level of reactive oxygen species (ROS) in Arabidopsis (Arabidopsis thaliana) is controlled by a large gene network, which includes the gene coding for the hydrogen peroxide-scavenging enzyme, cytosolic ASCORBATE PEROXIDASE6 (APX6), yet its specific function has remained unknown. In this study, we show that seeds lacking APX6 accumulate higher levels of ROS, exhibit increased oxidative damage, and display reduced germination on soil under control conditions and that these effects are further exacerbated under osmotic, salt, or heat stress. In addition, ripening APX6-deficient seeds exposed to heat stress displayed reduced germination vigor. This, together with the increased abundance of APX6 during late stages of maturation, indicates that APX6 activity is critical for the maturation-drying phase. Metabolic profiling revealed an altered activity of the tricarboxylic acid cycle, changes in amino acid levels, and elevated metabolism of abscisic acid (ABA) and auxin in drying apx6 mutant seeds. Further germination assays showed an impaired response of the apx6 mutants to ABA and to indole-3-acetic acid. Relative suppression of abscisic acid insensitive3 (ABI3) and ABI5 expression, two of the major ABA signaling downstream components controlling dormancy, suggested that an alternative signaling route inhibiting germination was activated. Thus, our study uncovered a new role for APX6, in protecting mature desiccating and germinating seeds from excessive oxidative damage, and suggested that APX6 modulate the ROS signal cross talk with hormone signals to properly execute the germination program in Arabidopsis.

• MeSH
• Arabidopsis fyziologie   MeSH
• askorbátperoxidasa metabolismus   MeSH
• exprese genu MeSH
• interakce mezi receptory a ligandy MeSH
• klíčení * MeSH
• kyselina abscisová metabolismus   MeSH
• kyseliny indoloctové metabolismus   MeSH
• mutace MeSH
• oxidační stres * MeSH
• proteiny huseníčku metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• voda fyziologie   MeSH
• vysoká teplota MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• APX6 protein, Arabidopsis MeSH Prohlížeč
• askorbátperoxidasa MeSH
• kyselina abscisová MeSH
• kyseliny indoloctové MeSH
• proteiny huseníčku MeSH
• reaktivní formy kyslíku MeSH
• voda MeSH

• MeSH
• defekty srdečního septa diagnóza   MeSH
• dítě MeSH
• indikátorové diluční techniky * MeSH
• kyselina askorbová * MeSH
• lidé MeSH
• metody MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• kyselina askorbová * MeSH