Alterations in circadian rhythms are associated with increased lipid peroxidation in females with bipolar disorder.

Disturbances in both circadian rhythms and oxidative stress systems have been implicated in the pathophysiology of bipolar disorder (BD), yet no studies have investigated the relationship between these systems in BD. We studied the impact of circadian rhythm disruption on lipid damage in 52 depressed or euthymic BD females, while controlling for age, severity of depressive symptoms and number of psychotropic medications, compared to 30 healthy controls. Circadian rhythm disruption was determined by a self-report measure (Biological Rhythm Interview of Assessment in Neuropsychiatry; BRIAN), which measures behaviours such as sleep, eating patterns, social rhythms and general activity. Malondialdehyde (MDA) levels were measured as a proxy of lipid peroxidation. We also measured the activity of total and extracellular superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST). Multiple linear regressions showed that circadian rhythm disturbance was independently associated with increased lipid peroxidation in females with BD (p < 0.05). We found decreased extracellular SOD (p < 0.05), but no differences in total SOD, CAT or GST activity between bipolar females and controls. Circadian rhythms were not associated with lipid peroxidation in healthy controls, where aging was the only significant predictor. These results suggest an interaction between the circadian system and redox metabolism, in that greater disruption in daily rhythms was associated with increased lipid peroxidation in BD only. Antioxidant enzymes have been shown to follow a circadian pattern of expression, and it is possible that disturbance of sleep and daily rhythms experienced in BD may result in decreased antioxidant defence and therefore increased lipid peroxidation. This study provides a basis for further investigation of the links between oxidative stress and circadian rhythms in the neurobiology of BD.

Vitamin A supplementation induces oxidative stress and decreases the immunocontent of catalase and superoxide dismutase in rat lungs.

Lungs require an adequate supply of vitamin A for normal embryonic development, postnatal maturation, and maintenance and repair during adult life. However, recent intervention studies revealed that supplementation with retinoids resulted in a higher incidence of lung cancer, although the mechanisms underlying this effect are still unknown. Here, the authors studied the effect of vitamin A supplementation on oxidative stress parameters in lungs of Wistar rats. Vitamin A supplementation either at therapeutic (1000 and 2500 IU/kg) or excessive (4500 and 9000 IU/kg) doses for 28 days induced lipid peroxidation, protein carbonylation, and oxidation of protein thiol groups, as well as change in catalase (EC 1.11.1.6; CAT) and superoxide dismutase (EC 1.15.1.1, SOD) activities and immunocontents. These results altogether suggest that vitamin A supplementation causes significant changes in redox balance the free radical status in lungs, which are frequently associated to severe lung dysfunction.

A statistical method to calculate blood contamination in the measurement of salivary hormones in healthy women.

OBJECTIVES: Previous studies have reported that salivary concentrations of certain hormones correlate with their respective serum levels. However, most of these studies did not control for potential blood contamination in saliva. In the present study we developed a statistical method to test the amount of blood contamination that needs to be avoided in saliva samples for the following hormones: cortisol, estradiol, progesterone, testosterone and oxytocin. DESIGN & METHODS: Saliva and serum samples were collected from 38 healthy, medication-free women (mean age=33.8±7.3yr.; range=19-45). Serum and salivary hormonal levels and the amount of transferrin in saliva samples were determined using enzyme immunoassays. RESULTS: Salivary transferrin levels did not correlate with salivary cortisol or estradiol (up to 3mg/dl), but they were positively correlated with salivary testosterone, progesterone and oxytocin (p<0.05). After controlling for blood contamination, only cortisol (r=0.65, P<0.001) and progesterone levels (r=0.57, P=0.002) displayed a positive correlation between saliva and serum. Our analyses suggest that transferrin levels higher than 0.80, 0.92 and 0.64mg/dl should be avoided for testosterone, progesterone and oxytocin salivary analyses, respectively. CONCLUSIONS: We recommend that salivary transferrin is measured in research involving salivary hormones in order to determine the level of blood contamination that might affect specific hormonal salivary concentrations.

Imbalance in redox status is associated with tumor aggressiveness and poor outcome in lung adenocarcinoma patients.

PURPOSE: The expression levels of human antioxidant genes (HAGs) and oxidative markers were investigated in light of lung adenocarcinoma aggressiveness and patient outcome. METHODS: We assayed in vitro the tumoral invasiveness and multidrug resistance in human lung adenocarcinoma (AdC) cell lines (EKVX and A549). Data were associated with several redox parameters and differential expression levels of HAG network. The clinicopathological significance of these findings was investigated using microarray analysis of tumor tissue and by immunohistochemistry in archival collection of biopsies. RESULTS: An overall increased activity (expression) of selected HAG components in the most aggressive cell line (EKVX cells) was observed by bootstrap and gene set enrichment analysis (GSEA). In vitro validation of oxidative markers revealed that EKVX cells had high levels of oxidative stress markers. In AdC cohorts, GSEA of microarray datasets showed significantly high levels of HAG components in lung AdC samples in comparison with normal tissue, in advanced stage compared with early stage and in patients with poor outcome. Cox multivariate regression analysis in a cohort of early pathologic (p)-stage of AdC cases showed that patients with moderate levels of 4-hydroxynonenal, a specific and stable end product of lipid peroxidation, had a significantly less survival rate (hazard ratio of 8.87) (P < 0.05). CONCLUSIONS: High levels of oxidative markers are related to tumor aggressiveness and can predict poor outcome of early-stage lung adenocarcinoma patients.

Preclinical and clinical evidence of antioxidant effects of antidepressant agents: implications for the pathophysiology of major depressive disorder.

Major depressive disorder (MDD) is a common mental disorder associated with a significant negative impact on quality of life, morbidity/mortality, and cognitive function. Individuals who suffer with MDD display lower serum/plasmatic total antioxidant potentials and reduced brain GSH levels. Also, F2-isoprostanes circulatory levels are increased in MDD subjects and are correlated with the severity of depressive symptoms. Urinary excretion of 8-OHdG seems to be higher in patients with MDD compared to healthy controls. Despite the fact that antidepressant drugs have been used for more than 50 years, their mechanism of action is still not fully understood. This paper examines preclinical (in vitro and animal model) and clinical literature on oxidative/antioxidant effects associated with antidepressant agents and discusses their potential antioxidant-related effects in the treatment of MDD. Substantial data support that MDD seems to be accompanied by elevated levels of oxidative stress and that antidepressant treatments may reduce oxidative stress. These studies suggest that augmentation of antioxidant defences may be one of the mechanisms underlying the neuroprotective effects of antidepressants in the treatment of MDD.

The curry spice curcumin selectively inhibits cancer cells growth in vitro and in preclinical model of glioblastoma.

Previous studies suggested that curcumin is a potential agent against glioblastomas (GBMs). However, the in vivo efficacy of curcumin in gliomas remains not established. In this work, we examined the mechanisms underlying apoptosis, selectivity, efficacy and safety of curcumin from in vitro (U138MG, U87, U373 and C6 cell lines) and in vivo (C6 implants) models of GBM. In vitro, curcumin markedly inhibited proliferation and migration and induced cell death in liquid and soft agar models of GBM growth. Curcumin effects occurred irrespective of the p53 and PTEN mutational status of the cells. Interestingly, curcumin did not affect viability of primary astrocytes, suggesting that curcumin selectivity targeted transformed cells. In U138MG and C6 cells, curcumin decreased the constitutive activation of PI3K/Akt and NFkappaB survival pathways, down-regulated the antiapoptotic NFkappaB-regulated protein bcl-xl and induced mitochondrial dysfunction as a prelude to apoptosis. Cells developed an early G2/M cell cycle arrest followed by sub-G1 apoptosis and apoptotic bodies formation. Caspase-3 activation occurred in the p53-normal cell type C6, but not in the p53-mutant U138MG. Besides its apoptotic effect, curcumin also synergized with the chemotherapeutics cisplatin and doxorubicin to enhance GBM cells death. In C6-implanted rats, intraperitoneal curcumin (50 mg kg(-1) d(-1)) decreased brain tumors in 9/11 (81.8%) animals against 0/11 (0%) in the vehicle-treated group. Importantly, no evidence of tissue (transaminases, creatinine and alkaline phosphatase), metabolic (cholesterol and glucose), oxidative or hematological toxicity was observed. In summary, data presented here suggest curcumin as a potential agent for therapy of GBMs.

Scavenging and antioxidant potential of physiological taurine concentrations against different reactive oxygen/nitrogen species.

While several studies have been conducted on the antioxidant properties of the beta-amino acid taurine, these studies all used concentrations lower than what is found physiologically. This study investigates the scavenging and antioxidant properties of physiological taurine concentrations against different reactive species. No reactivity between taurine and hydrogen peroxide was found; however, taurine exhibited significant scavenging potential against peroxyl radical, nitric oxide, and superoxide donors. This study also evaluated if taurine was able to minimize the in vitro CuZn-superoxide dismutase damage (SOD) induced by peroxynitrite. Taurine prevented both the formation of nitrotyrosine adducts and the decrease in SOD activity caused by peroxynitrite. In addition, taurine prevented the ex vivo damage caused by tert-butyl hydroperoxide in rat liver slices. These experimental data show that taurine, at different physiological concentrations efficiently scavenges many reactive oxygen and nitrogen species. This finding supports the hypothesis that the antioxidant properties of taurine may be critical for the maintenance of cellular functions, and it suggests a more important function of taurine that requires further investigation.

Acute treatment with diphenyl diselenide inhibits glutamate uptake into rat hippocampal slices and modifies glutamate transporters, SNAP-25, and GFAP immunocontent.

Diphenyl diselenide (PhSe)(2) is a selenium organic compound that has been described to inhibit glutamate binding at synaptic membranes and uptake into cortical slices, but there are no studies about its effects on glutamate transporters and related synaptic proteins. Hippocampal slices from rats treated acutely with (PhSe)(2) (1, 10, and 100 mg/kg, oral route) were evaluated on glutamate uptake, redox state, the immunocontent of glial (glutamate/aspartate transporter [GLAST] and glutamate transporter type I [GLT1]), neuronal (excitatory amino acid carrier 1 [EAAC1]), and vesicular (vesicular glutamate transporter 1 [VGLUT1]) glutamate transporters. Besides, cell viability was evaluated by glial fibrillar acid protein (GFAP) and synaptosomal-associated protein 25 (SNAP-25) immunocontent and 4', 6-diamidino-2-phenylindole (DAPI) and Fluoro Jade C staining. Hippocampal slices from rats treated with (PhSe)(2) exhibited a nondose-dependent inhibition of glutamate uptake (53, 38, and 45%, respectively). All doses increased EAAC1, decreased SNAP-25, did not modify GLT1 immunocontent, and there was no evidence of oxidative stress. (PhSe)(2) (100 mg/kg) increased 32% GLAST, decreased 34% VGLUT1, and 21% GFAP immunocontent. Besides, (PhSe)(2) (100 mg/kg) decreased by 25% GFAP-stained astrocytes and 27% DAPI-stained cells in the CA1 subfield. Our results suggest that the increase of EAAC1 and GLAST immunocontent by (PhSe)(2) might be a compensatory mechanism by surviving cells in order to reduce extracellular glutamate levels, avoiding possible neurotoxic effects. The impairment of glutamate uptake by the highest dose of (PhSe)(2) seems to be related to a decrease on VGLUT1, SNAP-25, and damage to astrocytes. Since there were no signs of oxidative stress, our findings revealed that depending on the dose, acute administration of (PhSe)(2) causes modifications in important synaptic-related proteins and damage to the astrocytes, and these events must be taken into account in its pharmacological properties.

Evaluation of redox and bioenergetics states in the liver of vitamin A-treated rats.

Vitamin A is normally stored in the mammalian liver and is physiologically released depending on the need of the organism for the vitamin. However, there is a compelling evidence showing that even the liver is affected by conditions of high vitamin A intake. Based on these previously reported findings showing negative effects of vitamin A on mammalian tissues, we have investigated the effects of a supplementation with vitamin A at clinical doses (1000-9000 IU/kg day(-1)) on some rat liver parameters. We have analyzed hepatic redox environment, as well as the activity of the mitochondrial electron transfer chain in vitamin A-treated rats. Additionally, activity of the detoxifying enzyme glutathione S-transferase was checked. Also, caspase-3 and caspase-8 and tumor necrosis factor-alpha levels were quantified to assess either cell death or inflammation effects of vitamin A on rat liver. We found increased free radical production and, consequently, increased oxidative damage in biomolecules in the liver of vitamin A-treated rats. Interestingly, we found increased mitochondrial electron transfer chain activity, as well as glutathione-S-transferase enzyme activity. Neither caspases activity, nor tumor necrosis factor-alpha levels change in this experimental model. Our results suggest a pro-oxidant, but not pro-inflammatory effect of vitamin A on rat liver.