Glucose control can be similarly improved after aquatic or dry-land aerobic training in patients with type 2 diabetes: A randomized clinical trial.

OBJECTIVES: To compare the effects of two aerobic training methods in water and on dry-land on glycemic, lipid, inflammatory, hormonal, cardiorespiratory, and functional outcomes in patients with type 2 diabetes. DESIGN: Randomized clinical trial. METHODS: Thirty-five patients with type 2 diabetes were randomly assigned to aquatic aerobic training group (n=17) or dry-land aerobic training group (n=18). Exercise training interventions had duration of 12 weeks, performed in three weekly sessions (45min/session), with intensity progressing from 85% to 100% of heart rate of anaerobic threshold during interventions. All outcomes were evaluated at baseline and 12 weeks later. RESULTS: Patients were 56.7±7.9 years old. Decreases in glycated hemoglobin were observed in both groups (AT: -0.42±0.28%, DLT: -0.35±1.8%). Total cholesterol, high density lipoprotein, low density lipoprotein levels, plasma renin activity, angiotensin II concentrations, C-reactive protein, systolic blood pressure, resting heart rate, and timed up and go test performed at the usual speed also decreased in both groups in response to both interventions (p<0.05), without between-group differences. Both groups increased the ratio between oxygen uptake at the anaerobic threshold and oxygen uptake of peak (p=0.01). CONCLUSIONS: Aerobic training in an aquatic environment provides effects similar to aerobic training in a dry-land environment in patients with type 2 diabetes.

Acaricidal properties of the essential oil and precocene II obtained from Calea serrata (Asteraceae) on the cattle tick Rhipicephalus (Boophilus) microplus (Acari: Ixodidae).

Calea serrata Less. (Asteraceae), an endemic species of south Brazil known as "quebra-tudo", is used in Afro-Brazilian religious rituals and in folk medicine for treating liver disorders. Phytochemical studies of the n-hexane extract of this plant demonstrated the presence of precocene II, a benzopyran derivative known for its insecticidal activity. The aim of this work was to isolate this benzopyran and determine the chemical composition of the essential oil of C. serrata and further to evaluate the acaricidal activity of the essential oil and precocene II against the larvae of Rhipicephalus (Boophilus) microplus. The LC(99.9) and LC(50) values obtained with the oil, which presents precocene II and sesquiterpenes, were 3.94 µL/mL and 0.28 µL/mL, respectively. For precocene II this values were 4.25mg/mL and 1.78 mg/mL, respectively. The results indicate a synergistic interaction between the components of the oil and precocene II.

Incorporation in polymeric nanocapsules improves the antioxidant effect of melatonin against lipid peroxidation in mice brain and liver.

It has been recently shown that the association of melatonin with polymeric nanoparticles causes a significant increase of the in vitro effect against lipid peroxidation. Hence, the aim of the present study was to compare the in vivo acute antioxidant effect of intraperitoneal administration of melatonin-loaded polysorbate 80-coated nanocapsules with that of melatonin aqueous solution in mice brain (frontal cortex and hippocampus) and liver. The lipid peroxidation through thiobarbituric acid reactive substance levels, the total antioxidant reactivity (luminol-enhanced chemiluminescence) and the free radical levels (formed dichlorofluorescein) has been carried out. Our results show that a single melatonin aqueous solution injection exerted no antioxidant activity in the evaluated range, while the administration of the melatonin-loaded polysorbate 80-coated nanocapsules caused a marked reduction on lipid peroxidation levels in all studied tissues. No differences on free radical content were found in the tissues. The melatonin-loaded nanocapsules also increased the total antioxidant reactivity in the hippocampus. These in vivo results are in accordance with our previous in vitro findings and confirm the hypothesis that polymeric nanocapsules improve the antioxidant effect of melatonin against lipid peroxidation.

Effects of protein malnutrition on oxidative status in rat brain.

OBJECTIVES: This study evaluated the effects of protein malnutrition on oxidative status in rat brain areas. METHODS: We investigated various parameters of oxidative status, free radical content (dichlorofluorescein formation), indexes of damage to lipid (thiobarbituric acid-reactive substances assay), and protein damage (tryptophan and tyrosine content) in addition to total antioxidant reactivity levels and antioxidant enzyme activities of superoxide dismutase, glutathione peroxidase, and catalase in different cerebral regions (cortex, hippocampus, and cerebellum) from rats subjected to prenatal and postnatal protein malnutrition (control 25% casein and protein malnutrition 7% casein). RESULTS: Protein malnutrition altered various parameters of oxidative stress, especially damage to macromolecules. Free radical content was unchanged by protein malnutrition. There was an increase in levels of thiobarbituric acid-reactive substances, the index of lipid peroxidation, in the cerebellum and cerebral cortex (P < 0.05) from protein-malnourished rats. Moreover, significant decreases in tryptophan and tyrosine in all tested brain structures (P < 0.05) were observed. Catalase activity was significantly decreased in the cerebellum (P < 0.05). In addition, a significant decrease in total antioxidant reactivity levels (P < 0.05) was observed in the cerebral cortex from protein-malnourished rats. CONCLUSIONS: The present data indicated that protein malnutrition increased oxidative damage to lipids and proteins from the studied brain areas. These results may be an indication of an important mechanism for changes in brain development that are caused by protein malnutrition.

Neuroprotection and protein damage prevention by estradiol replacement in rat hippocampal slices exposed to oxygen-glucose deprivation.

Here we investigated the effects of estradiol replacement in ovariectomized female rats using hippocampal slices exposed to oxygen-glucose deprivation (OGD). OGD induced lactate dehydrogenase (LDH) release to the incubation medium, what was assumed as a parameter of cellular death. In the estradiol-treated group the LDH release was markedly decreased by 23% as compared to the vehicle-treated group. In attempt to study a possible mechanism by which estradiol acts, we investigated some parameters of oxidative stress. In both vehicle-treated and estradiol-treated groups, OGD significantly increased the free radical production by 34% and 16%, respectively, although no significant differences on total antioxidant capacity were observed. Interestingly, estradiol replacement prevented the significant reduction in tryptophan and tyrosine contents caused by OGD observed in vehicle-treated animals. Our results show that estradiol replacement in ovariectomized female rats decreases cellular susceptibility to an ischemic-like injury and suggest a role for the hormone on protein damage prevention.

Repeated restraint stress induces oxidative damage in rat hippocampus.

It has been shown that emotional stress may induce oxidative damage, and considerably change the balance between pro-oxidant and antioxidant factors in the brain. The aim of this study was to verify the effect of repeated restraint stress (RRS; 1 h/day during 40 days) on several parameters of oxidative stress in the hippocampus of adult Wistar rats. We evaluated the lipid peroxide levels (assessed by TBARS levels), the production of free radicals (evaluated by the DCF test), the total radical-trapping potential (TRAP) and the total antioxidant reactivity (TAR) levels, and antioxidant enzyme activities (SOD, GPx and CAT) in hippocampus of rats. The results showed that RRS induced an increase in TBARS levels and in GPx activity, while TAR was reduced. We concluded that RRS induces oxidative stress in the rat hippocampus, and that these alterations may contribute to the deleterious effects observed after prolonged stress.

Neuroprotective effects of Ptychopetalum olacoides Bentham (Olacaceae) on oxygen and glucose deprivation induced damage in rat hippocampal slices.

Alcoholic infusions of Ptychopetalum olacoides Bentham (PO, Olacaceae) are used in traditional medicine by patients presenting age associated symptoms and those recovering from stroke. The aim of this study is to evaluate the neuroprotective properties of PO ethanol extract (POEE) using hippocampal slices from Wistar rats exposed to oxygen and glucose deprivation (OGD, followed by reoxygenation). Mitochondrial activity, an index of cell viability, was assessed by the MTT assay; in addition, the free radicals content was estimated by the use of dichlorofluorescein diacetate as probe. The OGD ischemic condition significantly impaired cellular viability, and increased free radicals generation. In non-OGD slices, incubation with POEE (0.6 microg/ml) increased (approximately 40%) mitochondrial activity, without affecting free radicals levels. In comparison to OGD controls, slices incubated with POEE (0.6 microg/ml) during and after OGD exposure had significantly increased cellular viability. In addition, at this same concentration, POEE prevented the increase of free radicals content induced by OGD. In view of the fact that respiratory chain inhibition and increased generation of free radicals are major consequences of the ischemic injury, this study suggests that Ptychopetalum olacoides contains useful neuroprotective compounds and, therefore, deserves further scrutiny.

Protective effect of pregnanolone against lipoperoxidation and free radicals generation induced in hypothalamus of ovariectomized rats submitted to CO2 exposure.

Several studies support an association between gonadal hormones and oxidative state. This study aimed to determine the consequence of the absence of ovarian hormones on the oxidative status of animals submitted to acute stress induced by CO(2) inhalation. We also evaluated the effect of pregnanolone administration upon the oxidative status in distinct brain structures of ovariectomized (OVX) rats exposed to CO(2). Female rats were divided into intact and OVX and exposed or unexposed to CO(2). Oxidative status was evaluated by 2',7'-dichlorofluorescein (DCF) assay, assessment of malondialdehyde (MDA), as an indicator of lipoperoxidation (through the thiobarbituric acid-reactive substances assay, TBARS), and the total antioxidant reactivity (TAR). Both DCF and TBARS were increased in the hypothalamus of animals submitted to OVX and stress. Nevertheless, free radical production and MDA levels were not affected in either condition alone. In the cerebral cortex, lower MDA levels were observed in OVX animals. Pregnanolone administered to rats submitted to CO(2)+OVX resulted in reduced MDA levels and free radicals production in hypothalamus. We suggest that ovarian hormones may protect the hypothalamus against oxidative stress, particularly when the animals are submitted to challenges. Pregnanolone may protect, at least in part, the hypothalamus of OVX rats from oxidative stress.

S100B content and SOD activity in amniotic fluid of pregnancies with Down syndrome.

OBJECTIVES: We measured S100B levels and superoxide dismutase (SOD) activity retrospectively in amniotic fluid samples from pregnancies with normal and Down syndrome (DS) fetuses. DESIGN AND METHODS: Samples from 26 normal and 71 Down syndrome fetuses were studied. S100B protein levels were determined using LIA-mat Sangtec kit, and SOD activity was measured with the RANSOD kit. RESULTS: We observed significantly higher levels of S100B in the Down group (median of 1.24 microg/l) than in the control group (median 0.69 microg/l). S100B concentration in DS samples increased from the 13th to the 18th week of gestation and was positively correlated with gestational age. The amniotic fluid SOD activity in the DS group (16.60 U/mg/prot) was significantly higher than in the normal one (10.78 U/mg/prot). CONCLUSIONS: This study indicates that S100B and SOD in amniotic fluid could be used as additional parameters for prenatal screening of trissomy 21 and that S100B values are associated with the gestational age.

Ketogenic diet increases glutathione peroxidase activity in rat hippocampus.

Ketogenic diets have been used in the treatment of refractory childhood epilepsy for almost 80 years; however, we know little about the underlying biochemical basis of their action. In this study, we evaluate oxidative stress in different brain regions from Wistar rats fed a ketogenic diet. Cerebral cortex appears to have not been affected by this diet, and cerebellum presented a decrease in antioxidant capacity measured by a luminol oxidation assay without changes in antioxidant enzyme activities--glutathione peroxidase, catalase, and superoxide dismutase. In the hippocampus, however, we observed an increase in antioxidant activity accompanied by an increase of glutathione peroxidase (about 4 times) and no changes in lipoperoxidation levels. We suggest that the higher activity of this enzyme induced by ketogenic diet in hippocampus might contribute to protect this structure from neurodegenerative sequelae of convulsive disorders.

Perturbations in the thiol homeostasis following neonatal cerebral hypoxia-ischemia in rats.

Changes in the thiol/disulphide status in the neonatal rat brain were evaluated after an episode of neonatal hypoxia-ischemia (HI) in 7-day-old rats. The glutathione level decreased in the post-HI period. The lowest values (43-68%) were obtained 24 h post-HI. A statistically significant difference first appeared in hippocampus, immediately after the HI event, and only 12 h later in striatum and cortex. On the 7th day post-HI the glutathione content was completely recovered in the hippocampus and the striatum, and partially in the cortex. The glutathione loss could not be explained through its conversion to glutathione disulphide or to protein mixed disulphide (S-thiolation), whose values remained constant. Furthermore, we found a consistent decrease (20-30%) in protein thiols, which were not recovered after 7 days post-HI. Perturbations in protein thiols, along with the glutathione loss, may represent a valuable marker of immature rat brain damage.

Protective properties of butanolic extract of the Calendula officinalis L. (marigold) against lipid peroxidation of rat liver microsomes and action as free radical scavenger.

Calendula officinalis (marigold) has many pharmacological properties. It is used for the treatment of skin disorders, pain and also as a bactericide, antiseptic and anti-inflammatory. Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are known to participate in the pathogenesis of various human diseases and may be involved in the conditions which C. officinalis is used to treat. The aim of this study was to investigate the relationship between the beneficial properties of this plant and its antioxidant action. The butanolic fraction (BF) was studied because it is non-cytotoxic and is rich in a variety of bioactive metabolites including flavonoids and terpenoids. Superoxide radicals (O(2)(*-)) and hydroxyl radicals (HO(*)) are observed in decreasing concentrations in the presence of increasing concentrations of BF with IC(50) values of 1.0 +/- 0.09 mg/ml and 0.5 +/- 0.02 mg/ml, respectively, suggesting a possible free radical scavenging effect. Lipid peroxidation in liver microsomes induced by Fe(2+)/ascorbate was 100% inhibited by 0.5 mg/ml of BF (IC(50) = 0.15 mg/ml). Its total reactive antioxidant potential (TRAP) (in microM Trolox equivalents) was 368.14 +/- 23.03 and its total antioxidant reactivity (TAR) was calculated to be 249.19 +/- 14.5 microM. The results obtained suggest that the butanolic fraction of C. officinalis possesses a significant free radical scavenging and antioxidant activity and that the proposed therapeutic efficacy of this plant could be due, in part, to these properties.