Dual Antioxidant Research Articles

Unique antioxidant and sulfur corrosion retardant properties of transformer oil blended with turmerone extract

One of the most detrimental effects associated with transformer insulating materials (paper and oil) and copper windings is the corrosive action of certain sulfur components found in transformer oil. Consequently, transformer oil is typically blended with both antioxidant and anti-corrosive agents in an attempt to prolong ageing effects and hinder copper sulfide deposition respectively. This study focusses on the effect antioxidants have on corrosive sulfur deposition on copper metal surfaces. To this end transformer oil was blended with a natural extract from turmeric powder and tested for its ability to act as an antioxidant and to retard copper sulfide deposition. The efficacy of this blended oil was compared with that of oil blended with either of two commonly used antioxidants, namely, 2,6-di-tert-butyl- 4-methylphenol or 2,6-di-tert-butylphenol. Tests for corrosive sulfur showed that for the turmerone oil blend there was a substantial delay in the onset of copper sulfide deposition on the surface of copper metal. Open circuit potential studies showed that the turmerone fraction that was blended into the transformer oil was adsorbed onto the copper surface. This unique property was not observed for the other two antioxidants in this study and can account for the retardation of copper sulfide deposition. In addition, the turmerone-virgin oil blend did not alter the thermal stability of the Kraft insulation paper in direct contact with the oil. The performance of the turmerone oil blend as a dual antioxidant and retardant of copper sulfide deposition renders it eminently suitable for extending the lifetime of insulation in fluid-filled transformers.

Cysteine-independent Catalase-like Activity of Vertebrate Peroxiredoxin 1 (Prx1)

Peroxiredoxins (Prxs) are a ubiquitous family of antioxidant proteins that are known as thioredoxin peroxidases. Here we report that Prx1 proteins from Tetraodon nigroviridis and humans also possess a previously unknown catalase-like activity that is independent of Cys residues and reductants but dependent on iron. We identified that the GVL motif was essential to the catalase (CAT)-like activity of Prx1 but not to the Cys-dependent thioredoxin peroxidase (POX) activity, and we generated mutants lacking POX and/or CAT activities for individually delineating their functional features. We discovered that the TnPrx1 POX and CAT activities possessed different kinetic features in reducing H2O2. The overexpression of wild-type TnPrx1 and mutants differentially regulated the intracellular levels of reactive oxygen species and p38 phosphorylation in HEK-293T cells treated with H2O2. These observations suggest that the dual antioxidant activities of Prx1 may be crucial for organisms to mediate intracellular redox homeostasis.

Hydrogen-bonded multilayers of tannic acid as mediators of T-cell immunity.

Type 1 diabetes is an autoimmune-mediated disease resulting in the destruction of insulin-secreting pancreatic β-cells. Transplantation of insulin-producing islets is a viable treatment to restore euglycemia in Type 1 diabetics; however, the clinical application remains limited due to the use of toxic immunosuppressive therapies to prevent immune-mediated rejection. A nanothin polymer material with dual antioxidant and immunosuppressive properties capable of modulating both innate and adaptive immune responses crucial for transplantation outcome is presented. Through the use of hollow microparticles (capsules) composed of hydrogen-bonded multilayers of natural polyphenol (tannic acid) with poly(N-vinylpyrrolidone) (TA/PVPON) and with poly(N-vinylcaprolactam) (TA/PVCL), proinflammatory reactive oxygen and nitrogen species are efficiently dissipated and the production of interferon (IFN)-γ and tumor necrosis factor (TNF)-α proinflammatory cytokines is attenuated by cognate antigen-stimulated autoreactive CD4+ T cells. These results provide evidence that TA-containing capsules are efficacious in immunomodulation and may provide physical transplant protection and prevent diabetogenic autoreactive T-cell responses. Future studies will determine if xeno- and allotransplantation with (TA/PVPON)- or (TA/PVCL)-coated pancreatic islets will decrease the risk of graft rejection due to attenuation of oxidative stress and IFN-γ, and restore euglycemia in Type 1 diabetics.

Shogaol–huprine hybrids: Dual antioxidant and anticholinesterase agents with β-amyloid and tau anti-aggregating properties

Multitarget compounds are increasingly being pursued for the effective treatment of complex diseases. Herein, we describe the design and synthesis of a novel class of shogaol–huprine hybrids, purported to hit several key targets involved in Alzheimer’s disease. The hybrids have been tested in vitro for their inhibitory activity against human acetylcholinesterase and butyrylcholinesterase and antioxidant activity (ABTS+, DPPH and Folin–Ciocalteu assays), and in intact Escherichia coli cells for their Aβ42 and tau anti-aggregating activity. Also, their brain penetration has been assessed (PAMPA-BBB assay). Even though the hybrids are not as potent AChE inhibitors or antioxidant agents as the parent huprine Y and [4]-shogaol, respectively, they still exhibit very potent anticholinesterase and antioxidant activities and are much more potent Aβ42 and tau anti-aggregating agents than the parent compounds. Overall, the shogaol–huprine hybrids emerge as interesting brain permeable multitarget anti-Alzheimer leads.

Nucleoside—2′,3′/3′,5′-Bis(thio)phosphate Analogues Are Promising Antioxidants Acting Mainly via Cu+/Fe2+ Ion Chelation

We synthesized a series of adenine/guanine 2',3'- or 3',5'-bisphosphate and -bisphosphorothioate analogues, 1-6, as potential Cu(+)/Fe(2+) chelators, with a view to apply them as biocompatible and water-soluble antioxidants. We found that electron paramagnetic resonance (EPR)-monitored inhibition of OH radicals production from H2O2, in an Fe(2+)-H2O2 system, by bisphosphate derivatives 1, 3, and 5 (IC50 = 36, 24, and 40 μM, respectively), was more effective than it was by ethylenediaminetetraacetic acid (EDTA), by a factor of 1.5, 2, and 1.4, respectively. Moreover, 2'-deoxyadenosine-3',5'-bisphosphate, 1, was 1.8- and 4.7-times more potent than adenosine 5'-monophosphate (AMP) and adenosine 5'-diphosphate (ADP), respectively. The bisphosphorothioate derivatives 2, 4, and 6 (IC50 = 92, 50, and 80 μM, respectively), exhibited a dual antioxidant activity, acting as both metal-ion chelators and radical scavengers [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assay data indicates IC50 = 50, 70, and 108 μM vs 27 μM for Trolox]. Only 2'-deoxyadenosine-3',5'-bisphosphorothioate, 2, exhibited good inhibition of Cu(+)-induced H2O2 decomposition (IC50 = 78 vs 224 μM for EDTA). Nucleoside-bisphosphorothioate analogues (2, 4, and 6) were weaker inhibitors than the corresponding bisphosphate analogues (1, 3, and 5), due to intramolecular oxidation under Fenton reaction conditions. (1)H- and (31)P NMR monitored Cu(+) titration of 2, showed that Cu(+) was coordinated by both 3',5'-bisphosphorothioate groups, as well as N7-nitrogen atom, while adenosine-2',3'-bisphosphorothioate, 6, coordinated Cu(+) only by 2',3'-bisphosphorothioate groups. In conclusion, an additional terminal phosphate group on AMP/guanosine 5'-monophosphate (GMP) resulted in Fe(2+)-selective chelators highly potent as Fenton reaction inhibitors.

Berberine, a natural antidiabetes drug, attenuates glucose neurotoxicity and promotes Nrf2-related neurite outgrowth

Reactive oxygen intermediates production and apoptotic damage induced by high glucose are major causes of neuronal damage in diabetic neuropathy. Berberine (BBR), a natural antidiabetes drug with PI3K-activating activity, holds promise for diabetes because of its dual antioxidant and anti-apoptotic activities. We have previously reported that BBR attenuated H2O2 neurotoxicity via activating the PI3K/Akt/Nrf2-dependent pathway. In this study, we further explored the novel protective mechanism of BBR on high glucose-induced apoptotic death and neurite damage of SH-SY5Y cells. Results indicated BBR (0.1–10nM) significantly attenuated reactive oxygen species (ROS) production, nucleus condensation, and apoptotic death in high glucose-treated cells. However, AG1024, an inhibitor of insulin growth factor-1 (IGF-1) receptor, significantly abolished BBR protection against high glucose-induced neuronal death. BBR also increased Bcl-2 expression and decreased cytochrome c release. High glucose down-regulated IGF-1 receptor and phosphorylation of Akt and GSK-3β, the effects of which were attenuated by BBR treatment. BBR also activated nuclear erythroid 2-related factor 2 (Nrf2), the key antioxidative transcription factor, which is accompanied with up-regulation of hemeoxygenase-1 (HO-1). Furthermore, BBR markedly enhanced nerve growth factor (NGF) expression and promoted neurite outgrowth in high glucose-treated cells. To further determine the role of the Nrf2 in BBR neuroprotection, RNA interference directed against Nrf2 was used. Results indicated Nrf2 siRNA abolished BBR-induced HO-1, NGF, neurite outgrowth and ROS decrease. In conclusion, BBR attenuated high glucose-induced neurotoxicity, and we are the first to reveal this novel mechanism of BBR as an Nrf2 activator against glucose neurotoxicity, providing another potential therapeutic use of BBR on the treatment of diabetic complications.

Sweet and Sour β-Cells: ROS and Hif1α Induce Warburg-Like Lactate Production During Type 2 Diabetes

β-Cell dysfunction is a hallmark of type 2 diabetes (T2DM) and comprises insulin secretory dysfunction and/or reduced β-cell mass (1). Normal β-cell function requires tight coupling of glucose metabolism with insulin secretion via a well-defined pathway utilizing oxidative metabolism and ATP production (2). Moreover, β-cell gene expression and metabolism are tuned to suppress pathways that would otherwise disrupt glucose-stimulated insulin secretion (GSIS), such as lactate production (3,4). Oversupply of glucose during T2DM can disrupt GSIS (glucotoxicity) via excessive generation of reactive oxygen species (ROS) causing oxidative stress: β-cells are particularly susceptible due to relatively low expression of antioxidant enzymes (5). Therefore, understanding the mechanisms by which ROS contribute to β-cell dysfunction during T2DM is an important research goal. The new study by Sasaki et al. (6) identifies a novel mechanism by which ROS impair β-cell function during T2DM: by activating hypoxia-inducible factor 1α (Hif1α), switching on lactate production and impairing glucose oxidation and insulin secretion (Fig. 1). The authors studied Goto-Kakizaki (GK) rats, an inbred, polygenic model of nonobese T2DM with β-cell dysfunction, originally derived from Wistar rats, and found that dual antioxidant treatment significantly improved GSIS in vivo and in vitro, consistent with previous studies using the GK rat and other diabetic models such as Zucker diabetic fatty rats and db / db mice (5). Taken together, these findings reinforce the role of glucotoxicity and oxidative stress in β-cell dysfunction during T2DM. Furthermore, …

Modulation of Nrf2 and NF‐κB Counteracts Multiple Manifestations of Experimental Diabetic Neuropathy: Potential of Sulforaphane and Melatonin

In the recent years Nrf2 and NF‐κB have surfaced as two transcription factors orchestrating antioxidant defense and inflammation, respectively. Since oxidative stress and inflammation play a pivotal role in nerve dysfunction and damage in diabetic neuropathy, Nrf2 and NF‐κB could be major players here too. For in vitro experiments neuro2a cells were incubated with sulforaphane and melatonin (both possess dual antioxidant and anti‐inflammatory activities) in the presence of normal (5.5 mM) and high glucose (30 mM). For in vivo studies, sulforaphane and melatonin were administered to rats 6 weeks post diabetes induction for 14 days. Motor nerve conduction velocity, nerve blood flow and pain behavior were improved and malondialdehyde level was reduced by treatment. Antioxidant effect of both agents was derived from Nrf2 as demonstrated by increased expression of Nrf2 and downstream targets HO‐1 and NQO‐1 in neuro2a cells and sciatic nerve of diabetic animals. NF‐κB inhibition may be responsible for their antiinflammatory activity as there was reduction in its expression and IκB kinase (IKK) phosphorylation along with abrogation of proinflammatory mediators. This study supports the defensive role of Nrf2 under conditions of oxidative stress and also suggests that NF‐κB is an important modulator of inflammatory damage in diabetic neuropathy. Funded by Ministry of Chemicals and Fertilizers, Government of India.

Nrf2 and NF-κB Modulation by Sulforaphane Counteracts Multiple Manifestations of Diabetic Neuropathy in Rats and High Glucose-Induced Changes

High glucose driven reactive oxygen intermediates production and inflammatory damage are recognized contributors of nerve dysfunction and subsequent damage in diabetic neuropathy. Sulforaphane, a known chemotherapeutic agent holds a promise for diabetic neuropathy because of its dual antioxidant and anti-inflammatory activities. The present study investigated the effect of sulforaphane in streptozotocin (STZ) induced diabetic neuropathy in rats. For in vitro experiments neuro2a cells were incubated with sulforaphane in the presence of normal (5.5 mM) and high glucose (30 mM). For in vivo studies, sulforaphane (0.5 and 1 mg/kg) was administered six weeks post diabetes induction for two weeks. Motor nerve conduction velocity (MNCV), nerve blood flow (NBF) and pain behavior were improved and malondialdehyde (MDA) level was reduced by sulforaphane. Antioxidant effect of sulforaphane is derived from nuclear erythroid 2-related factor 2 (Nrf2) activation as demonstrated by increased expression of Nrf2 and downstream targets hemeoxygenase-1 (HO-1) and NAD(P)H:quinone oxidoreductase 1 (NQO-1) in neuro2a cells and sciatic nerve of diabetic animals. Nuclear factor-kappa B (NF-κB) inhibition seemed to be responsible for antiinflammatory activity of sulforaphane as there was reduction in NF-κB expression and IκB kinase (IKK) phosphorylation along with abrogation of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression and tumor necrosis factor-α (TNF-α) and interleukine-6 (IL-6) levels. Here in this study we provide an evidence that sulforaphane is effective in reversing the various deficits in experimental diabetic neuropathy. This study supports the defensive role of Nrf2 in neurons under conditions of oxidative stress and also suggests that the NF-κB pathway is an important modulator of inflammatory damage in diabetic neuropathy.

G.P.6.02 In vitro activities and in vivo pharmacokinetics of dual cysteine proteases inhibitors and antioxidant

G.P.6.02 In vitro activities and in vivo pharmacokinetics of dual cysteine proteases inhibitors and antioxidant

Alpha lipoic acid posses dual antioxidant and lipid lowering properties in atherosclerotic-induced New Zealand White rabbit

There is accumulating data demonstrated hypercholesterolemia and oxidative stress play an important role in the development of atherosclerosis. In the present study, a protective activity of alpha-lipoic acid; a metabolic antioxidant in hypercholesterolemic-induced animals was investigated. Eighteen adult male New Zealand White (NZW) rabbit were segregated into three groups labelled as group K, AT and ALA ( n = 6). While group K was fed with normal chow and acted as a control, the rest fed with 100 g/head/day with 1% high cholesterol diet to induce hypercholesterolemia. 4.2 mg/body weight of alpha lipoic acid was supplemented daily to the ALA group. Drinking water was given ad-libitum. The study was designed for 10 weeks. Blood sampling was taken from the ear lobe vein at the beginning of the study, week 5 and week 10 and plasma was prepared for lipid profile estimation and microsomal lipid peroxidation index indicated with malondialdehyde (MDA) formation. Animals were sacrificed at the end of the study and the aortas were excised for intimal lesion analysis. The results showed a significant reduction of lipid peroxidation index indicated with low MDA level ( p < 0.05) in ALA group compared to that of the AT group. The blood total cholesterol (TCHOL) and low density lipoprotein (LDL) levels were found to be significantly low in ALA group compared to that of the AT group ( p < 0.05). Histomorphometric intimal lesion analysis of the aorta showing less of atheromatous plaque formation in alpha lipoic acid supplemented group ( p < 0.05) compared to that of AT group. These findings suggested that apart from its antioxidant activity, alpha lipoic acid may also posses a lipid lowering effect indicated with low plasma TCHOL and LDL levels and reduced the athero-lesion formation in rabbits fed a high cholesterol diet.

Antioxidative Effects of Plant Polyphenols

The antioxidant potency of three natural polyphenols, resveratrol, curcumin, and genistein, was compared by using the two human models: oxymodified with H(2)O(2) and homocysteine (Hcy) G proteins in the postmortem frontal cortex (FC) membranes of age-matched control and Alzheimer's disease (AD) subjects; and Cu(2+)-induced oxidation of plasma low-density lipoproteins (LDL). In Co, 3-10 microM polyphenols dose-dependently depressed the G protein 25% stimulation induced by 10 microM H(2)O(2) or 500 microM Hcy. Resveratrol revealed significantly higher antioxidativity than curcumin or genistein. In AD, the antioxidativity of polyphenols showed no significant differences. Polyphenols (1 microM) significantly increased the LDL oxidation lag time (oxyresistance) as compared with control, the effect of resveratrol being most potent. Due to the dual antioxidant mechanism, the investigated polyphenols, particularly resveratrol, should have preferences for the preventive-therapeutic use in age-related oxidative stress-based pathologies.

Hydrophilic Dual Vitamin E-Like Antioxidants as Modulators of Inflammatory Response in Low-Flow States and Impaired Wound Healing

Hydrophilic Dual Vitamin E-Like Antioxidants as Modulators of Inflammatory Response in Low-Flow States and Impaired Wound Healing

Direct superoxide anion scavenging by a disodium disuccinate astaxanthin derivative: relative efficacy of individual stereoisomers versus the statistical mixture of stereoisomers by electron paramagnetic resonance imaging

Carotenoids are a related group of greater than 600 natural compounds, irrespective of geometric- and stereoisomers, with demonstrated antioxidant efficacy. The carotenoids are broadly divided into “carotenes,” or non-oxygen substituted hydrocarbon carotenoids, and “xanthophylls,” oxygen-substituted carotenoids. The natural compounds are excellent singlet oxygen quenchers as well as lipid peroxidation chain-breakers; this dual antioxidant capacity is generally attributed to the activity of the polyene chain, and increases with the number of conjugated double bonds along the polyene chain length. However, the poor aqueous solubility of most carotenes and the vast majority of xanthophylls limits their use as aqueous-phase singlet oxygen quenchers and direct radical scavengers. A variety of introduction vehicles (e.g., organic solvents, cyclodextrins) have been used to introduce the insoluble carotenoids into aqueous test systems. Hawaii Biotech, Inc. (HBI) successfully synthesized a novel carotenoid derivative, the disodium disuccinate derivative of astaxanthin (3,3 ′-dihydroxy-β,β-carotene-4,4 ′-dione) in all- trans (all- E) form. The novel derivative is a water-dispersible symmetric chiral molecule with two chiral centers, yielding four stereoisomeric forms: 3 R,3 ′ R and 3 S,3 ′ S (enantiomers), and the diastereomeric meso forms (3 R,3 ′ S and 3 ′ R,3 S). The individual stereoisomers were synthesized at high purity (>90% by HPLC) and compared directly for efficacy with the statistical mixture of stereoisomers obtained from the synthesis from the commercial source of astaxanthin (1:2:1 ratio of 3 S,3 ′ S, meso, and 3 R,3 ′ R, respectively). Direct scavenging of superoxide anion was evaluated in a standard in vitro isolated human neutrophil assay by electron paramagnetic resonance (EPR) imaging, employing the spin-trap DEPMPO. Each novel derivative was tested in pure aqueous formulation and in ethanolic formulation shown to completely disaggregate the compounds in solution. In each case, the ethanolic formulation was a more potent scavenging vehicle. No significant differences in scavenging efficiency were noted among the individual stereoisomers and the statistical mixture of stereoisomers, suggesting that the polyene chain alone was responsible for superoxide scavenging. Dose-ranging revealed that the statistical mixture of stereoisomers of the novel derivative, at millimolar (mM) concentrations, could nearly completely eliminate the superoxide anion signal generated in the activated human neutrophil assay. All ethanolic formulations of the novel derivatives exhibited increased scavenging efficiency over equimolar concentrations of non-esterified astaxanthin delivered in a dimethyl sulfoxide (DMSO) vehicle. These novel compounds will likely find utility in applications requiring aqueous delivery of a highly potent direct radical scavenger.

Oxidative stress, chromatin remodeling and gene transcription in inflammation and chronic lung diseases.

Inflammatory lung diseases are characterized by chronic inflammation and oxidant/antioxidant imbalance. The sources of the increased oxidative stress in patients with chronic inflammatory lung diseases such as asthma and chronic obstructive pulmonary disease (COPD) derive from the increased burden of inhaled oxidants, and from the increased amounts of reactive oxygen species (ROS) generated by several inflammatory, immune and various structural cells of the airways. Increased levels of ROS produced in the airways is reflected by increased markers of oxidative stress in the airspaces, sputum, breath, lungs and blood in patients with lung diseases. ROS, either directly or via the formation of lipid peroxidation products such as 4-hydroxy-2-nonenal may play a role in enhancing the inflammation through the activation of stress kinases (JNK, MAPK, p38) and redox sensitive transcription factors such as NF-capital KJE, MacedonianB and AP-1. Recent evidences have indicated that oxidative stress and pro-inflammatory mediators can alter nuclear histone acetylation/deacetylation allowing access for transcription factor DNA binding leading to enhanced pro-inflammatory gene expression in various lung cells. Understanding of the mechanisms of redox signaling, NF-kappaB/AP-1 regulation, the balance between histone acetylation and deacetylation and the release and expression of pro- and antiinflammatory mediators may lead to the development of novel therapies based on the pharmacological manipulation of antioxidants in lung inflammation and injury. Antioxidants that have effective wide spectrum activity and good bioavailability, thiols or molecules which have dual antioxidant and anti-inflammatory activity, may be potential therapeutic agents which not only protect against the direct injurious effects of oxidants, but may fundamentally alter the underlying inflammatory processes which play an important role in the pathogenesis of chronic inflammatory lung diseases.

Reduction of carbon tetrachloride-induced rat liver injury by IRFI 042, a novel dual vitamin E-like antioxidant

Carbon tetrachloride (CCl4)-induced hepatotoxicity is likely the result of a CCl4-induced free radical production which causes membrane lipid peroxidation and activation of transcription factors regulating both the TNF-α gene and the early-immediate genes involved in tissue regeneration. IRFI 042 is a novel vitamin E-like compound having a masked sulphydryl group in the aliphatic side chain. We studied the effect of IRFI 042 on CCl4-induced liver injury. Liver damage was induced in male rats by an intraperitoneal injection of CCl4 (1 ml/kg in vegetal oil). Serum alanine aminotransferase (ALT) activity, liver malondialdehyde (MAL), hydroxyl radical formation (OH·), calculated indirectly by a trapping agent, hepatic reduced glutathione (GSH) concentration, plasma TNF-α, liver histology and hepatic mRNA levels for TNF-α were evaluated 48 h after CCl4 administration. Hepatic vitamin E (VE) levels were evaluated, in a separate group of animals, 2 h after CCl4 injection. A control group with vitamin E (100 mg/kg) was also treated in order to evaluate the differences versus the analogue treated groups.Intraperitoneal injection of carbon tetrachloride produced a marked increase in serum ALT activity (CCl4= 404.61 ± 10.33 U/L; Controls= 28.54 ± 4.25 U/L), liver MAL (CCl4= 0.67 ± 0.16 nmol/mg protein; Controls= 0.13 ± 0.06 nmol/mg protein), OH· levels assayed as 2,3-DHBA (CCl4= 8.73 ± 1.46 μM; Controls= 0.45 ± 0.15 μM) and 2,5-DHBA (CCl4= 24.61 ± 3.32 μM; Controls= 2.75 ± 0.93 μM), induced a severe depletion of GSH (CCl4= 3.26 ± 1.85 μmol/g protein; Controls= 17.82 ± 3.13 μmol/g protein) and a marked decrease in VE levels (CCl4= 5.67 ± 1.22 nmol/g tissue; Controls= 13.47 ± 3.21 nmol/g tissue), caused liver necrosis, increased plasma TNF-α levels (CCl4= 57.36 ± 13.24 IU/ml; Controls= 7.26 ± 2.31 IU/ml) and enhanced hepatic mRNA for TNF-α (CCl4= 19.22 ± 4.38 a.u.; Controls= 0.76 ± 0.36 a.u.).IRFI 042 (100 mg/kg, 30 min after CCl4 injection) blunted liver MAL (0.32 ± 0.17 nmol/mg protein), decreased the serum levels of ALT (128.71 ± 13.23 U/L), and restored the hepatic concentrations of VE (9.52 ± 3.21 nmol/g tissue), inhibited OH· production (2,3-DHBA= 3.54 ± 1.31 μM; 2,5-DHBA= 7.37 ± 2.46 μM), restored the endogenous antioxidant GSH (12.77 ± 3.73 mmol/g protein) and improved histology. Furthermore IRFI 042 treatment suppressed plasma TNF-α concentrations (31.47 ± 18.25 IU/ml) and hepatic TNF-α mRNA levels (11.65 ± 3.21 a.u.). The acute treatment with vitamin E failed to exert any protective effect against CCl4-induced hepatotoxicity.These investigations suggest that IRFI 042 treatment may be of benefit during free radical-mediated liver injury.