No abstract

Manganese (Mn) exposure is related to industrial activities, where absorption by inhalation has high relevance. Manganism, a syndrome caused as a result of excessive accumulation of Mn in the central nervous system, has numerous symptoms similar to those seen in idiopathic Parkinson disease (IPD). Some of these symptoms, such as learning, memory, sensorial, and neurochemical changes, appear before the onset of motor deficits in both manganism and IPD. The aim of this study was to evaluate the possible neuroprotective effects of curcumin against behavioral deficits induced by Mn toxicity in young (2 months old) Swiss mice. We evaluated the effect of chronic inhalation of a Mn mixture [Mn(OAc)3 and MnCl2 (20:40 mM)], 1 h/session, three times a week, over a 14-week period on behavioral and neurochemical parameters. Curcumin was supplemented in the diet (500 or 1,500 ppm in food pellets). The Mn disrupted the motor performance evaluated in the single-pellet reach task, as well as the short- and long-term spatial memory evaluated in the step-down inhibitory avoidance task. Surprisingly, curcumin also produced similar deleterious effects in such behavioral tests. Moreover, the association of Mn plus curcumin significantly increased the levels of Mn and iron, and decreased the levels of dopamine and serotonin in the hippocampus. These alterations were not observed in the striatum. In conclusion, the current Mn treatment protocol resulted in mild deficits in motor and memory functions, resembling the early phases of IPD. Additionally, curcumin showed no beneficial effects against Mn-induced disruption of hippocampal metal and neurotransmitter homeostasis.

This study aimed to assess antioxidant effects of melatonin treatment compared to N-acetylcysteine (NAC) and to their combination in a sickle cell suspension. Sickle erythrocytes were suspended in phosphate-buffered saline, pH 7.4, composing external control group. They were also suspended and incubated at 37°C either in the absence (experimental control group) or in the presence of NAC, melatonin and their combination at concentrations of 100 pm, 100 nm and 100 μm for 1 hr (treatment groups). The melatonin influences were evaluated by spectrophotometric [hemolysis degree, catalase (CAT), glutathione S-transferase (GST), glutathione peroxidase (GPx), glutathione reductase (GR), glucose-6-phosphate dehydrogenase (G6PDH), and superoxide dismutase (SOD) activities] and chromatographic methods [glutathione (GSH) and malondialdehyde (MDA) levels]. Incubation period was able to cause a rise about 64% on hemolysis degree as well as practically doubled the lipid peroxidation levels (P < 0.01). However, almost all antioxidants tested treatments neutralized this incubation effect observed in MDA levels. Among the antioxidant biomarkers evaluated, we observed a modulating effect of combined treatment on GPx and SOD activities (P < 0.01), which showed ~25% decrease in their activities. In addition, we found an antioxidant dose-dependent effect for melatonin on lipid peroxidation (r = -0.29; P = 0.03) and for combined antioxidant treatments also on MDA levels (r = -0.37; P = 0.01) and on SOD activity (r = -0.54; P < 0.01). Hence, these findings contribute with important insight that melatonin individually or in combination with NAC may be useful for sickle cell anemia management.

Fossil fuels such as diesel are being gradually replaced by biodiesel, a renewable energy source, cheaper and less polluting. However, little is known about the toxic effects of this new energy source on aquatic organisms. Thus, we evaluated biochemical biomarkers related to oxidative stress in Nile tilapia (Oreochromis niloticus) after two and seven exposure days to diesel and pure biodiesel (B100) and blends B5 and B20 at concentrations of 0.01 and 0.1 mL L(-1). The hepatic ethoxyresorufin-O-deethylase activity was highly induced in all groups, except for those animals exposed to B100. There was an increase in lipid peroxidation in liver and gills in the group exposed to the higher concentration of B5. All treatments caused a significant increase in the levels of 1-hydroxypyrene excreted in the bile after 2 and 7d, except for those fish exposed to B100. The hepatic glutathione-S-transferase increased after 7d in animals exposed to the higher concentration of diesel and in the gill of fish exposed to the higher concentration of pure diesel and B5, but decreased for the two tested concentrations of B100. Superoxide dismutase, catalase and glutathione peroxidase also presented significant changes according to the treatments for all groups, including B100. Biodiesel B20 in the conditions tested had fewer adverse effects than diesel and B5 for the Nile tilapia, and can be suggested as a less harmful fuel in substitution to diesel. However, even B100 could activate biochemical responses in fish, at the experimental conditions tested, indicating that this fuel can also represent a risk to the aquatic biota.

To evaluate, in a longitudinal study, the profile of lipid peroxidation and antioxidant capacity markers in sickle cell anaemia patients receiving different treatments and medication over different time periods. The three groups were: patients undergoing transfusion therapy and receiving iron chelator deferasirox (DFX group, n = 20); patients receiving deferasirox and hydroxyurea (DFX + HU group, n = 10), and patients receiving only folic acid (FA group, n = 15). Thiobarbituric acid-reactive substance (TBARS) assays and trolox-equivalent antioxidant capacity (TEAC) assays were evaluated during two different periods of analysis, T0 and T1 (after ~388 days). Higher FA group TBARS values were observed compared with the DFX + HU group (p = 0.016) at T0; and at T1, higher FA group TBARS values were also observed compared with both the DFX group (p = 0.003) and the DFX + HU group (p = 0.0002). No variation in TEAC values was seen between groups, at either T0 or T1. The mean values of TBARS and TEAC for both the DFX and DFX + HU groups decreased at T1. The antioxidant effects of HU and DFX were observed by through an increase in TEAC levels in DFX and DFX + HU groups when compared with those of normal subjects. Increased TEAC values were not recorded in the FA group, and lipid peroxidation was seen to decrease after DFX and HU use.