Antioxidant capacity and biological activity of essential oil and methanol extract of Conobea scoparioides (Cham. & Schltdl.) Benth

Os óleos essenciais da planta sub-aquática Conobea scoparioides (fresca e previamente seca) apresentaram rendimentos de 3,4 e 3,3%, respectivamente. Os principais constituintes identificados foram o éter metílico do timol (39,6 e 47,7%), timol (40,0 e 26,4%), α-felandreno (12,1 e 14,3%) e p-cimeno (1,5 e 1,7%), totalizando mais de 90% nos referidos óleos. A concentração de seqüestro do radical DPPH (CE50) dos óleos e extrato foi de 46,7 ± 3,6 µg mL^-1 para a planta fresca (CsO-f), de 56,1 ± 2,4 µg mL^-1 para a planta seca (CsO-d), e de 23,0 ± 2,2 µg mL^-1 para o extrato metanólico (CsE-d). O valor do extrato é comparável ao BHT (19,8 ± 0,5 µg mL^-1), usado como padrão antioxidante. O valor médio dos óleos é duas vezes menor, mas igualmente importante como agente antioxidante. O teor de Fenólicos Totais (TP, 124,6 ± 8,7 mg GAE per g) e o Trolox Equivalente (TEAC, 144,1 ± 4,9 mg TE per g) do extrato metanólico confirmaram a significativa atividade antioxidante de C. scoparioides. Da mesma forma, nos bioensaios com larva de camarão (Artemia salina) o valor médio da concentração letal dos óleos (CL₅₀, 7,7 ± 0,3 µg mL^-1) foi dez vezes maior que no extrato metanólico (CL₅₀, 77,6 ± 7,1 µg mL^-1) mostrando importante atividade biológica.

Potential utility of melatonin as an antioxidant therapy in the management of sickle cell anemia

This study aimed to assess antioxidant effects of melatonintreatment compared to N-acetylcysteine (NAC) and to their combination in asickle cell suspension. Sickle erythrocytes were suspended in phosphate-buffered saline, pH 7.4, composing external control group. They were alsosuspended and incubated at 37°C either in the absence (experimental controlgroup) or in the presence of NAC, melatonin and their combination atconcentrations of 100 pM, 100 nM and 100 lM for 1 hr (treatment groups).The melatonin influences were evaluated by spectrophotometric [hemolysisdegree, catalase (CAT), glutathione S-transferase (GST), glutathioneperoxidase (GPx), glutathione reductase (GR), glucose-6-phosphatedehydrogenase (G6PDH), and superoxide dismutase (SOD) activities] andchromatographic methods [glutathione (GSH) and malondialdehyde (MDA)levels]. Incubation period was able to cause a rise about 64% on hemolysisdegree as well as practically doubled the lipid peroxidation levels (P < 0.01).However, almost all antioxidants tested treatments neutralized this incubationeffect observed in MDA levels. Among the antioxidant biomarkers evaluated,we observed a modulating effect of combined treatment on GPx and SODactivities (P < 0.01), which showed ~25% decrease in their activities. Inaddition, we found an antioxidant dose-dependent effect for melatonin onlipid peroxidation (r = 0.29; P = 0.03) and for combined antioxidanttreatments 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 insightthat melatonin individually or in combination with NAC may be useful forsickle cell anemia management.

Reductions in systemic and skeletal muscle blood flow and oxygen delivery limit maximal aerobic capacity in humans

[EN] BACKGROUND: A classic, unresolved physiological question is whether central cardiorespiratory and/or local skeletal muscle circulatory factors limit maximal aerobic capacity (VO2max) in humans. Severe heat stress drastically reduces VO2max, but the mechanisms have never been studied. METHODS AND RESULTS: To determine the main contributing factor that limits VO2max with and without heat stress, we measured hemodynamics in 8 healthy males performing intense upright cycling exercise until exhaustion starting with either high or normal skin and core temperatures (+10 degrees C and +1 degrees C). Heat stress reduced VO2max, 2-legged VO2, and time to fatigue by 0.4+/-0.1 L/min (8%), 0.5+/-0.2 L/min (11%), and 2.2+/-0.4 minutes (28%), respectively (all P<0.05), despite heart rate and core temperature reaching similar peak values. However, before exhaustion in both heat stress and normal conditions, cardiac output, leg blood flow, mean arterial pressure, and systemic and leg O2 delivery declined significantly (all 5% to 11%, P<0.05), yet arterial O2 content and leg vascular conductance remained unchanged. Despite increasing leg O2 extraction, leg VO2 declined 5% to 6% before exhaustion in both heat stress and normal conditions, accompanied by enhanced muscle lactate accumulation and ATP and creatine phosphate hydrolysis. CONCLUSIONS: These results demonstrate that in trained humans, severe heat stress reduces VO2max by accelerating the declines in cardiac output and mean arterial pressure that lead to decrements in exercising muscle blood flow, O2 delivery, and O2 uptake. Furthermore, the impaired systemic and skeletal muscle aerobic capacity that precedes fatigue with or without heat stress is largely related to the failure of the heart to maintain cardiac output and O2 delivery to locomotive muscle.

(Table 1) Antioxidant concentrations in liver of wild sea bird chicks from the Norwegian arctic region

The efficiency of antioxidant defenses and relationship with body burden of metal and organic contaminants has not been previously investigated in arctic seabirds, neither in chicks nor in adults. The objective of this study was to compare such defenses in chicks from three species, Black-legged kittiwake (Rissa tridactyla), Northern fulmar (Fulmarus glacialis), and Herring gull (Larus argentatus), and the relationship with tissue concentrations of essential metals such as selenium and iron and halogenated organic compounds, represented by polychlorinated biphenyl (PCB). The results showed significant species-specific differences in the antioxidant responses which also corresponded with metal and PCB levels in different ways. The capability to neutralize hydroxyl radicals (TOSC-HO°) and the activities of catalase and Se-dependent glutathione peroxidases (GPX) clearly increased in species with the higher levels of metals and PCBs, while the opposite trend was observed for Se-independent GPX, TOSC against peroxyl radicals (ROO°) and peroxynitrite (ONOOH). Less clear relationships were obtained for glutathione levels, GSH/GSSG ratio, glutathione reductase and superoxide dismutase. The results showed differences in antioxidant efficiency between the species, and some of these defenses exhibited dose-response-like relationships with measured levels of selenium, iron and XPCBs. PCBs, selenium and iron levels were positively related to the responses of antioxidants with potential to reduce HO°/H2O2 (Se-dependent GPX, CAT and TOSC against HO°). However, direct causal relationships between antioxidant responses and contaminant concentrations could not be shown on individual level. Varying levels of metals and contaminants due to different diet and age were probably the main explanations for the species differences in antioxidant defense.

Kidney volume, blood pressure, and albuminuria: Findings in an Australian Aboriginal community

Background. Australian Aborigines are experiencing epidemic proportions of renal disease, marked by albuminuria and, variably, hematuria. They also have high rates of low birth weight, which have been associated with lower kidney volumes and higher blood pressures. The authors evaluated relationships between kidney volume, blood pressure, albuminuria, and hematuria in 1 homogeneous group. Methods Forty-three percent (672 of 1,560) of the population in a remote coastal Australian Aboriginal community aged 4.4 to 72.1 years participated in the study. Results: Kidney size correlated closely with body size. Systolic blood pressure (SBP) was correlated inversely with kidney length and kidney volume, after adjusting for age, sex, and body surface area (BSA); a 1-cm increase in mean kidney length was associated with a 2.2-mm Hg decrease in SBP, and a 10-mL increase in mean kidney volume was associated with a 0.6-mm Hg decrease in SBP (P = 0.001). Mean kidney volume explained 10% of the variance in SBP in a multivariate model containing age, sex, and BSA. In addition to higher SBP, adults who had the lowest quartiles of kidney volume also had the highest levels of overt albuminuria (P = 0.044). Conclusion: Smaller kidneys predispose to higher blood pressures and albuminuria in this population. The lower volumes possibly represent kidneys with reduced nephron numbers, which might be related to an adverse intrauterine environment. Susceptibility to renal disease could be a direct consequence of reduced nephron numbers; the higher blood pressures with which they are associated could also contribute to, as well as derive from, this association.

Antioxidant status in rats after long-term intake of anthocyanins and ellagitannins from blackberries

BACKGROUND: This study reported the effects of the daily intake of anthocyanins and ellagitannins (ET) extracted from blackberries on the markers for oxidative status in healthy rats. RESULTS: The phenolic compounds were administered from three different extracts: an aqueous extract of blackberry (BJ) and its two derived fractions: anthocyanin-enriched (AF) and ET-enriched (EF) fractions. After 35 days` administration, the AF and EF extracts significantly reduced thiobarbituric acid reactive substance levels and increased glutathione levels in the liver, kidney and brain. Plasma antioxidant capacity increased only in the group that received AF. Antioxidant enzyme activity and expression did not follow a pattern of response varying according to the tissues and extracts. A significant increase in the catalase activity was observed only in the plasma of the groups administered anthocyanin-containing extracts, which were the BJ and AF groups. Glutathione peroxidase activity was significantly increased in the liver and brain after EF treatment, and the highest increase in its expression was observed in the livers and brains of rats that received AF and EF, respectively. CONCLUSION: The results demonstrate that long-term intake of anthocyanin and ET through diet affects antioxidant enzyme activity and expression, and enhances oxidative markers in healthy rats. (C) 2010 Society of Chemical Industry

Isoflavones and Antioxidant Capacity of Commercial Soy-Based Beverages: Effect of Storage

Samples of 11 different brands of commercially available soy-based beverages (n = 65), including products made from soy protein isolate (SPI) and soy milk, mixed with fruit juice and/or flavoring, were analyzed for their isoflavone content and in vitro antioxidant activity. There was a large variation in isoflavone and total phenolics contents ranging from 0.7 to 13 mg of isoflavones/200 mL and from 6 to 155 mg equivalents of catechin/200 mL, respectively. The antioxidant activity also varied significantly among products. Storage of the beverages at room temperature caused a significant decrease of antioxidant capacity, soluble phenolics, and isoflavone contents after 9 months. When soybeans used for beverage production were stored for up to 6 months in silos, the resulting products were not affected. However, a decrease of malonyl and a proportional increase of free glucosidic forms of isoflavones were observed after storage of both the raw material and the beverages.

Antioxidant capacity of Brazilian fruit, vegetables and commercially-frozen fruit pulps

Several epidemiological and research studies suggest that a high intake of foods rich in natural antioxidants increases the antioxidant capacity of the plasma and reduces the risk of some kinds of cancers, heart diseases, and stroke. These health benefits are attributed to a variety of constituents, including vitamins, minerals, fiber, and numerous phytochemicals, such as flavonoids. Thus, in addition to measuring the composition of the usual macronutrients and micronutrients, it seems important to also measure the antioxidant capacity of foods. For this purpose, 28 foods including fruits, vegetables and commercially-frozen fruit pulps were analyzed for antioxidant capacity. The antioxidant capacity of the foods varied from 0.73 to 19.8 mu mol BHT equiv/g. The highest values were observed for wild mulberries (19.8 mu mol BHT equiv/g), acai fruit pulp (18.2 mu mol BHT equiv/g) and watercress (9.6 mu mol BHT equiv/g). The antioxidant capacities are only indicative of the potential of the bioactive compounds; however, these data are important to explore and understand the role of fruit, vegetables and other foods in health promotion. (C) 2009 Elsevier Inc. All rights reserved.

Isoflavones and antioxidant capacity of Peruvian and Brazilian lupin cultivars

Seed coats, cotyledons and hypocotyls from six Peruvian (Lupinus mutabilis Sweet) and two Brazilian (Lupinus albus and Lupinus angustifolius) lupin cultivars were assessed regarding their content of isoflavones and antioxidant capacity. Genistein and a genistein derivative were detected in seed coats and cotyledons from Peruvian cultivars. Total isoflavones ranged from 9.8 to 87, 16.1 to 30.8 and 1.3 to 6.1 mg/100 g of sample in fresh weight (expressed as genistein) in seed coat, cotyledon and hypocotyl fractions, respectively, from mutabilis species, whereas no isoflavones were detected in L. angustifolius and L. albus. A significant correlation (r = 0.99) was found between the total isoflavone levels and the antioxidant capacity measured by the 2,2-diphenyl-1-picrylhydrazyl radical-scavenging method in all fractions of Peruvian samples. No condensed tannins were detected in any of the lupin cultivars. The H-6 Andean cultivar is promising for its high isoflavone content and antioxidant capacity. Insights from this study indicate that lupin cultivars of the mutabilis species have similar isoflavone profiles and that isoflavones are more concentrated in the cotyledon seed fraction than in the seed coat or hypocotyl fractions. (C) 2008 Elsevier Inc. All rights reserved.

Antioxidant Status in Humans after Consumption of Blackberry (Rubus fruticosus L.) Juices With and Without Defatted Milk

The present study was designed to evaluate the possible effect of the consumption of blackberry juices (BJ) prepared with water (BJW) and defatted milk (BJM) on the plasma antioxidant capacity and the. enzymatic and nonenzymatic antioxidants. A significant (p < 0.05) increase in the ascorbic acid content in the plasma was observed after intake of both BJs. However, no changes were observed in the plasma urate and a-tocopherol levels. An increase on the plasma antioxidant capacity, by ORAC assay, was observed only after consumption of BJW but not statistically significant. Plasma antioxidant capacity had a good positive correlation with ascorbic acid (r = 0.93) and a negative correlation with urate level (r = -0.79). No correlation was observed between antioxidant capacity and total cyanidin or total ellagic acid contents. Further, it was observed that plasma catalase increased following intake of BJ`s. No change was observed on the plasma and erythrocyte CAT and glutathione peroxidase activities. A significant decrease (p < 0.05) in the urinary antioxidant capacity between 1 and 4 h after intake of both BJs was observed. A good correlation was observed between total antioxidant capacity and urate and total cyanidin levels. These results suggested association between anthocyanin levels and CAT and a good correlation between antioxidant capacity and ascorbic acid in the human plasma after intake of BJs. Follow-up studies investigating the antioxidant properties and health benefits are necessary to demonstrate the health benefits of polyphenols.

Antioxidant properties in cashew apple byproduct (Anacardium occidentale L.): effect on lipoperoxidation and on the polyunsaturated fatty acids profile in rats

The cashew apple (Anacardium occidentale L.) contains phenolic compounds usually related with antioxidant properties. Then, the aim of this study was to investigate its antioxidant capacity. The antioxidant capacity of the hydroalcoholic extract of the cashew apple pulp (EHAlc.) was assessed for the scavenging of the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) by in vitro method and by an in vivo essay. For this essay a 30-day oral (gavage, EHAlc. 200 and 400 mg/kg) study was conducted in Wistar male rats, evaluating hepatic, plasma and brain tissues. In DPPH model, the extract demonstrated antioxidant activity of 95% (largest concentration, 1000 mu g/mL). There were found no relevant peroxidation comparing the treated animals with the control group. However, the treated group presented a lower level of brain lipoperoxidation. Also in the treated animals brain tissue was found the largest amount of polyunsaturated fatty acids (PUFA), mainly docosahexaenoic (DHA). Therqfore, the analyzed extract from cashew apple pulp clone CCP-76 contains effective natural antioxidants, responsible for free radical scavenging in vitro and also for decreasing the brain lipoperoxidation and keeping the PUFAS levels in Wistar rats.