Naringenin complexed with hydroxypropyl-ß-cyclodextrin improves the sciatic nerve regeneration through inhibition of p75NTR and JNK pathway.

Peripheral nerve injuries are common conditions that often lead to dysfunctions. Although much knowledge exists on the several factors that mediate the complex biological process involved in peripheral nerve regeneration, there is a lack of effective treatments that ensure full functional recovery. Naringenin (NA) is the most abundant flavanone found in citrus fruits and it has promising neuroprotective, anti-inflammatory and antioxidant effects. This study aimed to enhance peripheral nerve regeneration using an inclusion complex containing NA and hydroxypropyl-ß-cyclodextrin (HPßCD), named NA/HPßCD. A mouse sciatic nerve crush model was used to evaluate the effects of NA/HPßCD on nerve regeneration. Sensory and motor parameters, hyperalgesic behavior and the sciatic functional index (SFI), respectively, improved with NA treatment. Western blot analysis revealed that the levels of p75NTR ICD and p75NTR full length as well phospho-JNK/total JNK ratios were preserved by NA treatment. In addition, NA treatment was able to decrease levels of caspase 3. The concentrations of TNF-α and IL-1ß were decreased in the lumbar spine, on the other hand there was an increase in IL-10. NA/HPßCD presented a better overall morphological profile but it was not able to increase the number of myelinated fibers. Thus, NA was able to enhance nerve regeneration, and NA/HPßCD decreased effective drug doses while maintaining the effect of the pure drug, demonstrating the advantage of using the complex over the pure compound.

Characterization of a novel antioxidant peptide from feather keratin hydrolysates.

Feather hydrolysates were obtained through submerged cultivation of 50 g/L feathers with Chryseobacterium sp. kr6. Culture supernatants, displaying antioxidant properties, as evaluated by the 2,2'-azino-bis-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) radical scavenging method, were partially purified by gel-filtration chromatography. Fractions showing scavenging activity were pooled, lyophilized and tested at different concentrations (0.1-1.0 mg/mL) by the total reactive antioxidant potential (TRAP) method, showing promising antioxidant capacities. Antioxidant activities of the partially purified feather hydrolysate (PPFH; 24.5 µg) were demonstrated by its ability to scavenge hydroxyl radicals and to inhibit lipid peroxidation. In addition, PPFH (0.24-24.5 µg) was found to reduce ferric ion (Fe3+), but did not display Fe2+-chelating activity. Thus, the main antioxidant activities could be related to the donation of hydrogen atoms, electron transfer and scavenging of hydroxyl radicals. PPFH was analyzed by mass spectrometry and five peptides were identified and chemically synthesized. The antioxidant activity of one peptide LPGPILSSFPQ was confirmed by ABTS and TRAP. The structure of this keratin-derived bioactive peptide has not been previously described.

Comparison of the effects of two antioxidant diets on oxidative stress markers in triathletes.

Intense exercise generates an imbalance in the redox system. However, chronic exercise can yield antioxidant adaptations. A few studies with humans have investigated the effects of antioxidant diets on athletes. Therefore we compared the effects of two dietary interventions on oxidative stress in competitive triathletes. Thirteen male triathletes were selected and divided into 2 groups: one that had a regular antioxidant diet (RE-diet) and the other that had a high antioxidant diet (AO-diet). The diet period was 14 days and blood samples were collected before and after this period. The AO-diet provided twice the dietary reference intake (DRI) of α-tocopherol (30 mg), five times the DRI of ascorbic acid (450 mg), and twice the DRI of vitamin A (1800 g), while the RE-diet provided the DRI of α-tocopherol (15 mg), twice the DRI of ascorbic acid (180 mg) and the DRI of vitamin A (900 µg). The oxidative stress parameters evaluated were: thiobarbituric acid reactive substances (TBARS), total reactive antioxidant potential (TRAP), total sulfhydryl, carbonyl, superoxide dismutase (SOD) activity, hydrogen peroxide consumption and glutathione peroxidase (GPx) activity. We observed, after the diet period, an increase in sulfhydryl, TRAP, TBARS and SOD activity, and a decrease in carbonyl levels. However, no changes were found in hydrogen peroxide consumption or GPx activity. We concluded that antioxidant-enriched diets can improve the redox status of triathletes.

Apoptotic signaling pathways induced by acute administration of branched-chain amino acids in an animal model of maple syrup urine disease.

Maple Syrup Urine Disease (MSUD) is an inborn error of metabolism caused by a deficiency of the branched-chain α-keto acid dehydrogenase complex activity. This blockage leads to accumulation of the branched-chain amino acids leucine, isoleucine and valine, as well as their corresponding α-keto acids and α-hydroxy acids. The affected patients present severe neurological symptoms, such as coma and seizures, as well as edema and cerebral atrophy. Considering that the mechanisms of the neurological symptoms presented by MSUD patients are still poorly understood, in this study, protein levels of apoptotic factors are measured, such as Bcl-2, Bcl-xL, Bax, caspase-3 and -8 in hippocampus and cerebral cortex of rats submitted to acute administration of branched-chain amino acids during their development. The results in this study demonstrated that BCAA acute exposure during the early postnatal period did not significantly change Bcl-2, Bcl-xL, Bax and caspase-8 protein levels. However, the Bax/Bcl-2 ratio and procaspase-3 protein levels were decreased in hippocampus. On the other hand, acute administration of BCAA in 30-day-old rats increase in Bax/Bcl-2 ratio followed by an increased caspase-3 activity in cerebral cortex, whereas BCAA induces apoptosis in hippocampus through activation and cleavage of caspase-3 and -8 without changing the Bax/Bcl-2 ratio. In conclusion, the results suggest that apoptosis could be of pivotal importance in the developmental neurotoxic effects of BCAA. In addition, the current studies also suggest that multiple mechanisms may be involved in BCAA-induced apoptosis in the cerebral cortex and hippocampus.

pH-dependent cytotoxic effects of extracts of the marine sponge Polymastia janeirensis on cancer cell lines.

The purpose of this work was to study the cytotoxic effects of marine sponge Polymastia janeirensis, which has been observed in the field to release an orange substance that is toxic to fish. The result showed that aqueous extract (pH 7.0) was highly cytotoxic to glioma (U87) and neuroblastoma (SHSY5Y) cancer cell lines (IC50 < 1.0 µg/mL). In addition, this extract showed potent antioxidant and procoagulant (decreased the clotting time by 1.7-fold) activities. Interestingly, the cytotoxic effects were pH-dependent since the viability of the cancer cells was not affected with the extract (pH 5.5). The close similarity between the aqueous extract (pH 7.0) and the orange liquid that is released by the sponge indicates that this potential chemical defence of P. janeirensis deserves further investigation.

Sphingosines Derived from Marine Sponge as Potential Multi-Target Drug Related to Disorders in Cancer Development.

Haliclona tubifera, marine sponge species abundant in Brazilian coastline, presents only a few papers published in the literature. Recently, we have reported the isolation of two modified C18 sphingoid bases: (2R,3R,6R,7Z)-2-aminooctadec-7-ene-1,3, 6-triol and and (2R,3R,6R)-2-aminooctadec-1,3,6-triol. In order to continue our research, in this work aimed at the biological investigation of fractions that led to the isolation of these compounds. We evaluated the cytotoxic effect of marine sponge H. tubifera fractions in glioma (U87) and neuroblastoma (SH-SY5Y) human cell lines. In addition, considering the link between cancer, imbalance of reactive oxygen species and coagulation disorders, we also investigated the in vitro effects on blood coagulation and their redox properties. We showed that the ethyl acetate (EtOAc) fraction, rich in sphingoid bases, had important cytotoxic effects in both cancer cell lines with an IC50 < 15 µg/mL and also can inhibit the production of peroxyl radicals. Interestingly, this fraction increased the recalcification time of human blood, showing anticoagulant properties. The present study indicates the sphingosines fraction as a promising source of chemical prototypes, especially multifunctional drugs in cancer therapy.

Redox-Active Profile Characterization of Remirea maritima Extracts and Its Cytotoxic Effect in Mouse Fibroblasts (L929) and Melanoma (B16F10) Cells.

Remirea maritima is a tropical plant with a reticulated root system belonging to the family Cyperaceae, also known to have biologically active secondary metabolites. However, very few data on R. maritima's biological actions are available and there are no reports regarding the redox-active profile of this plant. In this study, we examined the total phenolic content of Remirea maritima hydroalcoholic (RMHA) extracts, redox properties against different reactive species generated in vitro and their cytotoxic effect against fibroblasts (L929) and melanoma (B16F10) cells. Total reactive antioxidant potential index (TRAP) and total antioxidant reactivity (TAR) results revealed that RMHA at all concentrations tested showed significant antioxidant capacity. RMHA was also effective against hydroxyl radical formation, reduction of Fe3+ to Fe2+ and in scavenging nitric oxide (NO) radicals. In vitro, the level of lipid peroxidation was reduced by RMHA extract and the data showed significant oxidative damage protection. The RMHA cytotoxicity was evaluated by a neutral red assay in fibroblast (L929) and melanome (B16F10) cells. The obtained results showed that the RMHA (40 and 80 µg/mL, respectively) reduced 70% of the viable cells. In conclusion, this study represents the first report regarding the antioxidant and anti-proliferative potential of R. maritima against B16F10 melanoma cells.

Acute brain inflammation and oxidative damage are related to long-term cognitive deficits and markers of neurodegeneration in sepsis-survivor rats.

Survivors from sepsis present long-term cognitive deficits and some of these alterations resemble the pathophysiological mechanisms of neurodegenerative diseases. For this reason, we analyzed beta-amyloid peptide (Aß) and synaptophysin levels in the brain of rats that survived from sepsis and their relation to cognitive dysfunction and to acute brain inflammation. Sepsis was induced in rats by cecal ligation and puncture, and 30 days after surgery, the hippocampus and prefrontal cortex were isolated just after cognitive evaluation by the inhibitory avoidance test. The immunocontent of Aß and synaptophysin were analyzed by Western blot analysis. Aß increased and synaptophysin decreased in septic animals both in the hippocampus and prefrontal cortex concurrent with the presence of cognitive deficits. Prefrontal levels of synaptophysin correlated to the performance in the inhibitory avoidance. Two different treatments known to decrease brain inflammation and oxidative stress when administered at the acute phase of sepsis decreased Aß levels both in the prefrontal cortex and hippocampus, increased synaptophysin levels only in the prefrontal cortex, and improved cognitive deficit in sepsis-survivor animals. In conclusion, we demonstrated that brain from sepsis-survivor animals presented an increase in Aß content and a decrease in synaptophysin levels and cognitive impairment. These alterations can be prevented by treatments aimed to decrease acute brain inflammation and oxidative stress.

Resveratrol-loaded lipid-core nanocapsules treatment reduces in vitro and in vivo glioma growth.

The development of novel therapeutic strategies to treat gliomas remains critical as a result of the poor prognoses, inef-. ficient therapies and recurrence associated with these tumors. In this context, biodegradable nanoparticles are emerging as efficient drug delivery systems for the treatment of difficult-to-treat diseases such as brain tumors. In the current study, we evaluated the antiglioma effect of trans-resveratrol-loaded lipid-core nanocapsules (RSV-LNC) based on in vitro (C6 glioma cell line) and in vivo (brain-implanted C6 cells) models of the disease. In vitro, RSV-LNC decreased the viability of C6 glioma cells to a higher extent than resveratrol in solution. Interestingly, RSV-LNC treatment was not cytotoxic to hippocampal organotypic cultures, a model of healthy neural cells, suggesting selectivity for cancer cells. RSV-LNC induced losses in glioma cell viability through induction of apoptotic cell death, as assessed by Annexin-FITC/PI assay, which was preceded by an early arrest in the S and G1 phases of the cell cycle. In brain-implanted C6 tumors, treatment with RSV-LNC (5 mg/kg/day, i.p.) for 10 days promoted a marked decrease in tumor size and also reduced the incidence of some malignant tumor-associated characteristics, such as intratumoral hemorrhaging, intratumoral edema and pseudopalisading, compared to resveratrol in solution. Taken together, the results presented herein suggest that nanoencapsulation of resveratrol improves its antiglioma activity, thus providing a provocative foundation for testing the clinical usefulness of nanoformulations of this natural compound as a new chemotherapeutic strategy for the treatment of gliomas.

Exploring the multifactorial nature of autism through computational systems biology: calcium and the Rho GTPase RAC1 under the spotlight.

Autism is a neurodevelopmental disorder characterized by impaired social interaction and communication accompanied with repetitive behavioral patterns and unusual stereotyped interests. Autism is considered a highly heterogeneous disorder with diverse putative causes and associated factors giving rise to variable ranges of symptomatology. Incidence seems to be increasing with time, while the underlying pathophysiological mechanisms remain virtually uncharacterized (or unknown). By systematic review of the literature and a systems biology approach, our aims were to examine the multifactorial nature of autism with its broad range of severity, to ascertain the predominant biological processes, cellular components, and molecular functions integral to the disorder, and finally, to elucidate the most central contributions (genetic and/or environmental) in silico. With this goal, we developed an integrative network model for gene-environment interactions (GENVI model) where calcium (Ca(2+)) was shown to be its most relevant node. Moreover, considering the present data from our systems biology approach together with the results from the differential gene expression analysis of cerebellar samples from autistic patients, we believe that RAC1, in particular, and the RHO family of GTPases, in general, could play a critical role in the neuropathological events associated with autism.

Chronic administration of branched-chain amino acids impairs spatial memory and increases brain-derived neurotrophic factor in a rat model.

Maple syrup urine disease (MSUD) is a neurometabolic disorder that leads to the accumulation of branched-chain amino acids (BCAAs) and their α-keto branched-chain by-products. Because the neurotoxic mechanisms of MSUD are poorly understood, this study aimed to evaluate the effects of chronic administration of a BCAA pool (leucine, isoleucine and valine). This study examined the effects of BCAA administration on spatial memory and the levels of brain-derived neurotrophic factor (BNDF). We examined both pro-BDNF and bdnf mRNA expression levels after administration of BCAAs. Furthermore, this study examined whether antioxidant treatment prevented the alterations induced by BCAA administration. Our results demonstrated an increase in BDNF in the hippocampus and cerebral cortex, accompanied by memory impairment in spatial memory tasks. Additionally, chronic administration of BCAAs did not induce a detectable change in pro-BDNF levels. Treatment with N-acetylcysteine and deferoxamine prevented both the memory deficit and the increase in the BDNF levels induced by BCAA administration. In conclusion, these results suggest that when the brain is chronically exposed to high concentrations of BCAA (at millimolar concentrations) an increase in BDNF levels occurs. This increase in BDNF may be related to the impairment of spatial memory. In addition, we demonstrated that antioxidant treatment prevented the negative consequences related to BCAA administration, suggesting that oxidative stress might be involved in the pathophysiological mechanism(s) underlying the brain damage observed in MSUD.

Participation of 47C>T SNP (Ala-9Val polymorphism) of the SOD2 gene in the intracellular environment of human peripheral blood mononuclear cells with and without lipopolysaccharides.

The outcome of sepsis occurs due to influence of environmental and genetic factors besides genes variants whose expression support its outcome or not. Oxidative stress is associated to the pathogenicity of sepsis, occurring when there is a reactive species overproduction associated with inflammation. The aim of this study was to characterize the cellular redox status of human peripheral blood mononuclear cells (PBMCs) with either -9Ala (AA) or -9Val (VV) SOD2 genotypes and evaluate their response to oxidative stress induced by lipopolysaccharide (LPS). The PBMCs were isolated from the blood of 30 healthy human volunteers (15 volunteers for each allele) and the following assays were performed: antioxidant enzyme activities (superoxide dismutase; catalase; glutathione peroxidase), total radical-trapping antioxidant parameter, non-enzymatic antioxidant capacity (total antioxidant reactivity), and quantification of conjugated dienes (lipid peroxidation). At basal conditions (i.e., not stimulated by LPS), cells from 47C allele carriers showed higher activities of CAT and SOD, as well as higher TAR compared to 47T allele. However, when 47CC cells were challenged with LPS, we observed a higher shift toward a pro-oxidant state compared to 47TT cells. The CAT activity and lipid peroxidation were increased in cells with both alleles, but SOD activity increased significantly only in 47TT cells. These results demonstrate that SOD2 polymorphisms are associated with different cellular redox environments at both basal and LPS-stimulated states, and identification of this polymorphism may be important for a better understanding of pro-inflammatory conditions.

Similarities in serum oxidative stress markers and inflammatory cytokines in patients with overt schizophrenia at early and late stages of chronicity.

Schizophrenia (SZ) is a debilitating neurodevelopmental disorder that strikes at a critical period of a young person's life. Its pathophysiology could be the result of deregulation of synaptic plasticity, with downstream alterations of inflammatory immune processes regulate by cytokines, impaired antioxidant defense and increased lipid peroxidation. The aim of this study was to examine serum oxidative stress markers and inflammatory cytokines in early and late phases of chronic SZ. Twenty-two patients at early stage (within first 10 years of a psychotic episode), 39 at late stage (minimum 10 years after diagnosis of SZ) and their respective matched controls were included. Each subject had 5 ml blood samples collected by venipuncture to examined thiobarbituric acid-reactive substances (TBARS), total reactive antioxidant potential (TRAP), protein carbonyl content (PCC), Interleukins 6 and 10 (IL-6, IL-10) and tumor necrosis factor alpha (TNF-alpha). TBARS, IL-6 and PCC levels were significantly higher in patients with SZ at early and late stages than in controls. There were no differences for TRAP and TNF-alpha levels in patients with SZ at early and late stages than in controls. IL-10 levels were decreased in patients at late stage and a decrease trend in early stage was found. Results provided evidence consistent with comparable biological markers across chronic SZ. The concept of biochemical staging proposed by others for bipolar disorder is not seen in this cohort of patients with SZ, at least for cytokines and oxidative stress markers. Our findings reinforce the need of assessment of individuals in ultra high risk to develop psychosis and first-episode population.

Phytochemical screening, antinociceptive and anti-inflammatory activities of Chrysopogon zizanioides essential oil

Chrysopogon zizanioides (L.) Roberty, Poaceae, is a plant widely used in northeast Brazil in folk medicine for the treatment of various pathological conditions, including inflammatory pain. The present study evaluated the antinociceptive and anti-inflammatory effects of C. zizanioides essential oil (EO) in rodents. EO was further characterized by GC/MS. The major components of EO were identified as khusimol (19.57%), E-isovalencenol (13.24%), α-vetivone (5.25%), β-vetivone (4.87%) and hydroxy-valencene (4.64%). Following intraperitoneal injection (i.p.), EO at 50 and 100 mg/kg significantly reduced the number of writhes (51.9 and 64.9%, respectively) and the number of paw licks during phase 2 (56.7 and 86.2%, respectively) of a formalin model when compared to control group animals. However, EO-treated mice were ineffective at all doses in hot-plate and rota-rod tests. The EO inhibited the carrageenan-induced leukocyte migration to the peritoneal cavity in a dose-dependent manner (34.7, 35.4, and 62.5% at doses of 25, 50 and 100 mg/kg, respectively). In the paw edema test, the EO (100 mg/kg) inhibited all three phases of the edema equally well, suggesting that the EO has a non-selective inhibitory effect on the release or actions of these mediators. Our results suggest possible antinociceptive and anti-inflammatory effects of the EO.

Peripheral biomarkers and illness activity in bipolar disorder.

Recent evidence suggests that peripheral markers related to oxidative stress, inflammation and neurotrophins may be altered during mood episodes in bipolar disorder. These can be seen as proxies of peripheral toxicity or markers of illness activity. Here we report an en bloc assessment of a set of previously described biomarkers in different mood states (n = 60) as well as in healthy subjects (n = 80). To make the point that these are ominous changes, we obtained the same measures from a group of septic patients (n = 15) as a "positive" control group. In this sample, we measured serum levels of brain derived neurotrophic factor, neurotrophin 3, tumor necrosis factor α, interleukin 6, interleukin 10, total reactive antioxidant potential, thiobarbituric acid reactive substances and protein carbonyl content. Several of the markers discriminated between the bipolar and control groups, especially when patients were in acute episodes. In some cases, toxicity was as high in bipolar disorder as that seen in patients with sepsis. We believe these findings highlight the potential of using biomarkers to assess illness activity in bipolar disorder.

Antioxidant potential of peels and fleshes of peaches from different cultivars.

Increasing recent interest in nutraceuticals and functional foods has led researchers to investigate the antioxidant potential of several fruits. This article evaluates the antioxidant potential and reactivity based on luminol-enhanced chemiluminescence capacity of peach extracts (peels and fleshes) and the contribution of a major compound present in these extracts to antioxidant potential and reactivity. The results obtained showed that the extracts of peels and fleshes of Maciel, Leonense, and Eldorado peach cultivars present free radical scavenging activity in all concentrations tested, with a concentration-dependent action. The immediate inhibition of chemiluminescence and the duration of this inhibition were significantly higher with the extracts than with the major compound (chlorogenic acid) alone, and it can be due to a synergistic or additive effect of other antioxidants present in the extracts. The 50% inhibitory concentration (IC(50)) values for peach extract and chlorogenic acid were 1.19 microg/mL and 8.43 microg/mL, respectively, when total radical-trapping antioxidant potential was evaluated, whereas IC(50) values of 0.41 microg/mL and 1.89 microg/mL was found when total antioxidant reactivity was evaluated in peach extract and chlorogenic acid, respectively. Chlorogenic acid presented a good contribution to antioxidant reactivity and potential, but the fruit extracts provide better antioxidant action. Peach could be of great interest as an important antioxidant source including chlorogenic acid, and it may provide health-promoting advantages to consumers by intake of this fruit or by utilization of its peels as antioxidant sources in industry.

Differential effects of retinol and retinoic acid on cell proliferation: a role for reactive species and redox-dependent mechanisms in retinol supplementation.

While some authors suggest that retinoids are potential anti-proliferative and antioxidant agents, evidence has suggested those present pro-oxidant properties, which might lead to malignant proliferation. These discordances stimulated one to investigate the proliferative/anti-proliferative properties of two major retinoids, retinol (ROH) and retinoic acid (RA). In Sertoli cells, ROH increased proliferation while RA was anti-proliferative. ROH increased DNA synthesis, decreased p21 levels and induced cell cycle progression. ROH increased reactive species (RS) production and stimulated p38, JNK1/2 and ERK1/2 MAPKs activation. Antioxidant treatment with Trolox blocked ROH-induced RS production, MAPKs activation and proliferation; MAPKs inhibition blocked proliferation. The potential sites of RS indicate that ROH-induced RS is promoted via mitochondria and xanthine oxidase. In contrast, RA induced neither RS production nor MAPKs activation. RA decreased DNA synthesis and increased p21 leading to cell arrest. Overall, data show that ROH, but not RA, is able to induce proliferation through non-classical and redox-dependent mechanisms.

Xanthine oxidase-dependent ROS production mediates vitamin A pro-oxidant effects in cultured Sertoli cells.

Several studies have suggested that vitamin A (retinol, ROH) presents pro-oxidant properties in biological systems. Recent studies point out that xantine oxidase, a ROS-generating enzyme, catalyses ROH oxidation to RA in vitro. These works stimulated the authors to investigate whether xanthine oxidase could be involved on the ROH pro-oxidative effects reported in cultured Sertoli cells. In vitro, it was demonstrate that xanthine oxidase generates superoxide in the presence of ROH as assessed by superoxide mediated-NBT reduction. Superoxide production is potentiated in the presence of NADH and inhibited by allopurinol. In Sertoli cells, ROH treatment increased xanthine oxidase activity and inhibition of the enzyme with allopurinol attenuated ROH-induced ROS production, protein damage and cytotoxicity. Moreover, inhibition of ROH oxidation to RA by retinaldehyde dehydrogenase inhibitor potentiated both xanthine oxidase-dependent ROS production and cell damage in ROH-treated cells. The data show that xanthine oxidase may play a role on vitamin A pro-oxidant effects.

Retinoic acid induces apoptosis by a non-classical mechanism of ERK1/2 activation.

Even though RA is involved in differentiation and apoptosis of normal and cancer cells, being sometimes used as adjuvant in chemotherapy, its mechanisms of action involve multiple overlapping pathways that still remain unclear. Recent studies point out that RA exerts rapid and non-genomic effects, which are independent of RAR/RXR-mediated gene transcription. In this work, we reported that RA treatment for 24 h decreases cell viability, induces apoptosis dependent on caspase-3 activation, and activates the transcription factor AP-1 in cultured Sertoli cells. Moreover, RA induced a rapid and non-classical stimulation of ERK1/2. ERK1/2 activation was mediated by MEK1/2, and the protein synthesis inhibitor cycloheximide did not alter the pattern of RA-induced ERK1/2 phosphorylation. Pharmacological inhibition of MEK1/2-ERK1/2 pathway with UO126 blocked caspase-3 activation, decreased AP-1 binding to DNA and inhibited apoptosis. Overall, our data suggest that a rapid and non-genomic effect of RA upon MEK1/2-ERK1/2 pathway leads to caspase-3 activation and caspase-3-dependent apoptosis in cultured Sertoli cells. The non-canonical RA signaling presented in this work evokes new perspectives of RA action, which may play an important role in mediating early biological effects of RA modulating cell death in normal and tumor cells.

Mitochondrial superoxide production is related to the control of cytokine release from peritoneal macrophage after antioxidant treatment in septic rats.

BACKGROUND: Reactive oxygen species are involved in several intracellular pathways that ultimately lead to the activation of the innate immune system. In addition, oxidized proteins and lipids could stimulate cytokine release from macrophages through the activation of membrane receptors. Thus we here describe the effects of antioxidant administration to septic rats on peritoneal macrophage parameters of oxidative stress and cytokine release. MATERIALS AND METHODS: Peritoneal macrophages from Wistar rats subjected to cecal ligation and puncture (CLP). The animals were divided into four groups: sham operated, CLP, basic support (saline plus antibiotics), basic support plus N-acetylcysteine, and deferoxamine. Several times after CLP macrophages were cultured to the determination of thiobarbituric acid reactive species (TBARS), protein carbonyls, mitochondrial superoxide production, catalase, superoxide dismutase activities, and released cytokines. RESULTS: Sepsis increased TBARS, protein carbonyls, and mitochondrial superoxide production in macrophages and this was associated with an increase release of pro-inflammatory cytokines. Basic support reversed TBARS and protein carbonyls content, but not mitochondrial superoxide production. The addition of antioxidants prevented all oxidative parameters in macrophages, and this was associated with lower cytokine release. Catalase and superoxide dismutase were modulated in the basic support group, but not in the antioxidant treated animals. CONCLUSIONS: Mitochondrial superoxide production seemed to be the differential oxidative parameter associated with antioxidant-induced modulation of cytokine release.