1000 resultados para deforestation effects


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The main goal of the present research effort was to evaluate the physical-chemical properties of blends of lard and soybean oil following enzymatic interesterification catalyzed by an immobilized lipase from Thermomyces lanuginosa (Lipozyme (TM) TL IM). Lipase-catalyzed interesterification produced new tri-acylglycerols that changed the physical-chemical properties of the fat blends under study. Solid fat content (31.3 vs 31.5 g/100 g), consistency (104.7 vs 167.6 kPa), crystallized area (0.6 vs 11.8) and softening point (31.8 vs 32.2 degrees C) of lard increased after interesterification, and this was mostly due to the increase of SSS (saturated) + SSU (disaturated-monounsaturated) triacylglycerols. These contents (SSU + SSS) increased in lard after interesterification from 42.9 to 46.7 g/100 g. The interesterified blends exhibited lower values for the physical properties when compared with their counterparts before enzymatic interesterification. The interesterification of blends of lard with soybean oil increased the amounts of UUU (triunsaturated) and SSS triacylglycerols and reduced the amounts of UUS (diunsaturated-monosaturated) triacylglycerols. The interesterified blends of lard and soybean oil demonstrated physical properties and chemical composition similar to human milk fat and they could be used for the production of a human milk fat substitute. (C) 2009 Elsevier Ltd. All rights reserved.

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The behavior of S. platensis was investigated in this study through fed-batch pulse-feeding cultures performed at different carbon dioxide feeding rates (F = 0.44-1.03 g L-1 d(-1)) and photosynthetic photon flux density (PPFD = 80-250 mu mol photons m(-2) s(-1)) in a bench-scale helical photobioreactor. To achieve this purpose, an inorganic medium lacking the carbon source was enriched by gaseous carbon dioxide from a cylinder. The maximum cell concentration achieved was 12.8 g L-1 at PPFD = 166 mu mol photons m(-2) s(-1) and F= 0.44 g L-1 d(-1) of CO2. At PPFD = 80 and 125 mu mol photons m(-2) s(-1), the carbon utilization efficiency (CUE) reached maximum values of 50 and 69%, respectively, after about 20 days, and then it decreased, thus highlighting a photolimitation effect. At PPFD = 166 mu mol photons m(-2) s(-1), CUE was >= 90% between 20 and 50 days. The photosynthetic efficiency reached its maximum value (9.4%) at PPFD = 125 mu mol photons m(-2) s(-1). The photoinhibition threshold appeared to strongly depend on the feeding rate: at high PPFD, an increase in the amount of fed CO2 delayed the inhibitory effect on biomass growth, whereas at low PPFD, excess CO2 addition caused the microalga to stop growing. (c) 2007 Elsevier B.V. All rights reserved.

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Chemopreventive activities of the dietary isoprenoids beta-ionone (beta I) and geraniol (GOH) were evaluated during the promotion phase of hepatocarcinogenesis. Over 5 consecutive weeks, rats received daily 16 mg/100 g body weight (b.w.) of beta I (beta I group), 25 mg/100 g b.w. of GOH (GOH group), or only corn oil (CO group, controls). Compared to the CO group, the following was observed: only the beta I group showed a decrease in the mean number of visible hepatocyte nodules (P<.05); beta I and GOH groups had reduced mean number of persistent preneoplastic lesions (pPNLs) (P<.05), but no differences regarding number of remodeling PNL (rPNLs) were observed; only the beta I group exhibited smaller rPNL size and percentage of liver sections occupied by pPNLs (P<.05), whereas the GOH group displayed a smaller percentage of liver sections occupied by rPNLs (P<.05); a trend was observed in the beta I group, which showed reduced cell proliferation of pPNLs (P<.10), and the GOH group had increased apoptosis in pPNLs and rPNLs (P<.05); only the beta I group displayed reduced total plasma cholesterol concentrations (P<.05) and increased hepatic 3-hydroxy-3-methylglutaryl coenzyme A (HMGCoA) reductase mRNA levels (P<.05): only the GOH group had lower hepatic membrane RhoA protein levels (P<.05); both the beta I- and GOH-treated groups had higher hepatic concentrations of beta I and GOH, respectively (P<.05). Given these data, beta I and GOH show promising chemopreventive effects during promotion of hepatocarcinogenesis by acting through distinct mechanism of actions: beta I may inhibit cell proliferation and modulate HMGCoA reductase, and GOH can induce apoptosis and inhibit RhoA activation. (C) 2011 Elsevier Inc. All rights reserved.

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The vascular effects of nitrolinoleate (LNO(2)), an endogenous product of linoleic acid (LA) nitration by nitric oxide-derived species and a potential nitrosating agent, were investigated on rat endothelial-leukocyte interactions. Confocal microscopy analysis demonstrated that LNO(2) was capable to deliver free radical nitric oxide ((center dot)NO) into cells, 5 min after its administration to cultured cells, with a peak of liberation at 30 min. THP-1 monocytes incubated with LNO(2) for 5 min presented nitrosation of CD40, leading to its inactivation. Other anti-inflammatory actions of LNO(2) were observed in vivo by intravital microscopy assays. LNO(2) decreased the number of adhered leukocytes in postcapillary venules of the mesentery network. In addition to this, LNO(2) reduced mRNA and protein expression of 2-integrin in circulating leukocytes, as well as VCAM-1 in endothelial cells isolated from postcapillary venules, confirming its antiadhesive effects on both cell types. Moreover, 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, a nitric oxide scavenger, partially abolished the inhibitory action of LNO(2) on leukocyte-endothelium interaction, suggesting that the antiadhesion effects of LNO(2) involve a dual role in leukocyte adhesion, acting as a nitric oxide donor as well as through nitric oxide-independent mechanisms. In conclusion, LNO(2) inhibited adhesion molecules expression and promoted (center dot)NO inactivation of the CD40-CD40L system, both important processes of the inflammatory response. (C) 2010 Elsevier Inc. All rights reserved.

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Aim of the study: Species of Lychnophora are used in Brazilian folk medicine as analgesic and anti-inflammatory agents. Chlorogenic acid (CGA) and their analogues are important components of polar extracts of these species, as well in several European and Asian medicinal plants. Some of these phenolic compounds display anti-inflammatory effects. In this paper we report the isolation of CGA from Lychnophora salicifolia and its effects on functions involved in neutrophils locomotion. Materials and methods: LC-MS(n) data confirmed the presence of CGA in the plant. Actions of CGA were investigated on neutrophils obtained from peritoneal cavity of Wistar rats (4h after 1% oyster glycogen solution injection; 10 ml), and incubated with vehicle or with 50, 100 or 1000 mu M CGA in presence of lipopolysaccharide from Escherichia coil (LPS, 5 mu g/ml). Nitric oxide (NO; Griess reaction); prostaglandin E(2) (PGE(2)), interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha [TNF-alpha; enzyme-linked immunosorbent assay (EIA)]; protein (flow cytometry) and gene (RT-PCR) expression of L-selectin, beta(2)integrin and platelet-endothelial cell adhesion molecule-1 (PECAM-1) were quantified. In vitro neutrophil adhesion to primary culture of microvascular endothelial cell (PMEC) and neutrophil migration in response to formyl-methionil-leucil-phenilalanine (fMLP, 10(-8)M, Boyden chamber) was determined. Results: CGA treatment did not modify the secretion of inflammatory mediators, but inhibited L-selectin cleavage and reduced beta(2) integrin, independently from its mRNA synthesis, and reduced membrane PECAM-1 expression: inhibited neutrophil adhesion and neutrophil migration induced by fMLP. Conclusions: Based on these findings, we highlight the direct inhibitory actions of CGA on adhesive and locomotion properties of neutrophils, which may contribute to its anti-inflammatory effects and help to explain the use of Lychnophora salicifolia as an anti-inflammatory agent. (C) 2011 Elsevier Ireland Ltd. All rights reserved.

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Chemical investigation of the methanolic extract of the ascidian Didemnum psammatodes has led to the identification of fourteen known compounds: three methyl esters (methyl myristate, methyl palmitate and methyl stearate), four steroids (cholesterol, campesterol, stigmasterol and beta-sitosterol), two fatty acids (palmitic acid and stearic acid), three glyceryl ethers {(1,2-propanediol, 3-(heptadecyloxy), batyl alcohol and 1,2-propanediol, 3-[(methyloctadecyl)oxy]) and two nucleosides (thymidine and 2`-deoxyguanosine). Their structures were proposed by NMR and comparison with literature data and GC analysis in comparison with authentic sample. The cytotoxic activity of these compounds was evaluated against human leukemia cell line panel using the MTT assay. The mixture of the three methyl esters was the most active group of compounds, showing antiproliferative and cytotoxic effects. Further studies on their mode of action suggest that these activities are connected with inhibition of DNA synthesis and induction of both necrosis and apoptosis. (C) 2007 Elsevier Inc. All rights reserved.

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Aiming at contributing with the search for neuroactive substances from natural sources, we report for the first time antinociceptive and anticonvulsant effects of some Lychnophora species. We verify the protective effects of polar extracts (600 mg/kg, intraperitoneally), and methanolic fractions of L. staavioides and L. rupestris (100 mg/kg, intraperitoneally) in pentylenetetrazole-induced seizures on mice. Previously, a screening was accomplished, evaluating the antinociceptive central activity (hot plate test), with different extracts of L. rupestris, L. staavioides and L. diamantinana. It was possible to select the possible extracts of Lychnophora with central nervous system activity. Some of the active extracts were submitted to fractionation and purification process and the methanolic fractions of L. rupestris (stem) and L. staavioides (stem), with anticonvulsant properties (100 mg/kg, intraperitoneally), yielded 4,5-di-O-[E]-caffeoylquinic acid. This substance was injected intraperitoneally in mice and showed anticonvulsant effect against pentylenetetrazole-induced seizures at doses of 25 and 50 mg/kg. It has often been shown that seizures induced by pentylenetetrazole are involved in inhibition and/or attenuation of GABAergic neurotransmission. However, other systems of the central nervous system such as adenosinergic and glutamatergic could be involved in the caffeoylquinic acid effects. Further studies should be conducted to verify that the target receptor could be participating in this anticonvulsant property. Although other investigations have reported a series of biological activities from Lychnophora species, this is the first report of central analgesic and anticonvulsant activity in species of this genus.

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In vivo preventive effects of a Mangifera indica L extract (Vimang) or its major component mangiferin on iron overload injury have been studied in rats given respectively, 50, 100, 250 mg kg(-1) body weight of Vimang, or 40 mg kg(-1) body weight of mangiferin, for 7 days prior to, and for 7 days following the administration of toxic amounts of iron-dextran. Both Vimang or mangiferin treatment prevented iron overload in serum as well as liver oxidative stress, decreased serum and liver lipid peroxidation, serum GPx activity, and increased serum and liver GSH, serum SOD and the animals overall antioxidant condition. Serum iron concentration was decreased although at higher doses, Vimang tended to increase it; percent tranferrin saturation, liver weight/body mass ratios, liver iron content was decreased. Treatment increased serum iron-binding capacity and decreased serum levels of aspartate-amine transferase (ASAT) and alanine-amine transferase (ALAT), as well as the number of abnormal Kupffer cells in iron-loaded livers. It is suggested that besides acting as antioxidants, Vimang extract or its mangiferin component decrease liver iron by increasing its excretion. Complementing earlier in vitro results from our group, it appears possible to support the hypothesis that Vimang and mangiferin present therapeutically useful effects in iron overload related diseases. (C) 2007 Elsevier Ltd. All rights reserved.

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Lantana (Lantana camara Linn.) is a noxious weed to which certain medicinal properties have been attributed, but its ingestion has been reported to be highly toxic to animals and humans, especially in the liver. The main hepatotoxin in lantana leaves is believed to be the pentacyclic triterpenoid lantadene A (LA), but the precise mechanism by which it induces hepatotoxicity has not yet been established. This work addressed the action of LA and its reduced derivative (RLA) on mitochondrial bioenergetics. At the concentration range tested (5-25 mu M), RLA stimulated state-4 respiration, inhibited state-3 respiration, circumvented oligomycin-inhibited state-3 respiration, dissipated membrane potential and depleted ATP in a concentration-dependent manner. However. LA did not stimulate state-4 respiration, nor did it affect the other mitochondrial parameters to the extent of its reduced derivative. The lantadenes didn`t inhibit the CCCP-uncoupled respiration but increased the ATPase activity of intact coupled mitochondria. The ATPase activity of intact uncoupled or disrupted mitochondria was not affected by the compounds. We propose, therefore, that RLA acts as a mitochondrial uncoupler of oxidative phosphorylation, a property that arises from the biotransformation (reduction) of LA, and LA acts in other mitochondrial membrane components rather than the ATP synthase affecting the mitochondrial bioenergetics. Such effects may account for the well-documented hepatoxicity of lantana. (C) 2010 Elsevier Ltd. All rights reserved.

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Fluoxetine (FIX) is a drug commonly used as antidepressant. However, its effects on tumorigenesis remain controversial. Aiming to evaluate the effects of FIX treatment on early malignant changes, we analyzed serotonin (5-HT) metabolism and recognition, aberrant crypt foci (ACF), proliferative process, microvessels, vascular endothelial growth factor (VEGF), and cyclooxygenase-2 (COX-2) expression in colon tissue. Male Wistar rats received a daily FLX-gavage (30 mg kg(-1)) and, a single dose of 1.2 dimethylhydrazine (DMH; i.p., 125 mg kg(-1)). After 6 weeks of FIX-treatment, our results revealed that FIX and nor-fluoxetine (N-FIX) are present in colon tissue, which was related to significant increase in serotonin (5-HT) levels (P < 0.05) possibly through a blockade in SERT mRNA (serotonin reuptake transporter; P < 0.05) resulting in lower 5-hydroxyindoleacetic acid (5-HIAA) levels (P < 0.01) and, 5-HT2C receptor mRNA expressions. FIX-treatment decreased dysplastic ACF development (P < 0.01) and proliferative process (P < 0.001) in epithelia. We observed a significant decrease in the development of malignant microvessels (P < 0.05), VEGF (P < 0.001), and COX-2 expression (P < 0.01). These findings suggest that FIX may have oncostatic effects on carcinogenic colon tissue, probably due to its modulatory activity on 5-HT metabolism and/or its ability to reduce colonic malignant events. (C) 2011 Elsevier Ireland Ltd. All rights reserved.

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Under continuous photolysis at 675 nm, liposomal zinc phthalocyanine associated with nitrosyl ruthenium complex [Ru(NH.NHq)(tpy)NO](3+) showed the detection and quantification of nitric oxide (NO) and singlet oxygen ((1)O(2)) release. Photophysical and photochemical results demonstrated that the interaction between the nitrosyl ruthenium complex and the photosensitizer can enable an electron transfer process from the photosensitizer to the nitrosyl ruthenium complex which leads to NO release. Synergistic action of both photosensitizers and the nitrosyl ruthenium complex results in the production of reactive oxygen species and reactive nitrogen species, which is a potent oxidizing agent to many biological tissues, in particular neoplastic cells.

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The ruthenium nitrosyl complex trans-[Ru(NO)(NH(3))(4)(py)](PF(6))(3) (pyNO), a nitric oxide (NO) donor, was studied in regard to the release of NO and its impact both on isolated mitochondria and HepG2 cells. In isolated mitochondria, NO release from pyNO was concomitant with NAD(P)H oxidation and, in the 25-100 mu M range, it resulted in dissipation of mitochondrial membrane potential, inhibition of state 3 respiration, ATP depletion and reactive oxygen species (ROS) generation. In the presence of Ca(2+), mitochondrial permeability transition (MPT), an unspecific membrane permeabilization involved in cell necrosis and some types of apoptosis, was elicited. As demonstrated by externalization of phosphatidylserine and activation of caspase-9 and caspase-3, pyNO (50-100 mu M) induced HepG2 cell death, mainly by apoptosis. The combined action of the NO itself, the peroxynitrite yielded by NO in the presence of reactive oxygen species (ROS) and the oxidative stress generated by the NAD(P)H oxidation is proposed to be involved in cell death by pyNO, both via respiratory chain inhibition and ROS levels increase, or even via MPT, if Ca(2+) is present. (c) 2008 Elsevier Inc. All rights reserved.

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Vitamin A palmitate has been used in cosmetics; however, studies report that this substance shows photoreactivity that can lead to loss of safety and efficacy. On the other hand, photostabilizers have been used to increase sunscreen photostability and consequently their safety and effectiveness. Thus, this study aimed to evaluate the influence of photostabilizers on the photoprotective effects of a cosmetic formulation containing UV-filters and vitamin A palmitate. The formulation containing UV-filters was supplemented with vitamin A palmitate and the photostabilizers diethylhexyl 2,6-naphthalate (DEHN), bumetrizole and benzotriazolyl dodecyl p-cresol (BTDC). Hairless mice were treated daily by topical applications and irradiated (UVA/B). Erythema index, transepidermal water loss, histological/histometric analysis and number of sunburn cells (SBC) were evaluated. The results showed that all formulations protected from UV-induced enhancement of erythema and SBC but there was no difference among them. The formulation with no stabilizers reduced viable epidermis thickness due to atrophy induced by UV radiation. Thus, it can be concluded that the presence of photostabilizers influenced the effects of formulations containing UV-filters and vitamin A palmitate, which could be seen by histological and histometric analysis. Furthermore, the formulations containing the stabilizers DEHN and BTDC showed better protective effects on hairless mice skin.

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The effects of PLC and Pkc inhibitors on Aspergillus nidulans depend on the carbon source. PLC inhibitors Spm and C48/80 delayed the first nuclear division in cultures growing on glucose, but stimulated it in media supplemented with pectin. Less intense were these effects on the mutant transformed with PLC-A gene rupture (AP27). Neomycin also delayed the germination in cultures growing on glucose or pectin; however, on glucose, the nuclear division was inhibited whereas in pectin it was stimulated. These effects were minor in AP27. The effects of Ro-31-8425 and BIM (both Pkc inhibitors) were also opposite for cultures growing on glucose or pectin. On glucose cultures of both strains BIM delayed germination and the first nuclear division, whereas on pectin both parameters were stimulated. Opposite effects were also detected when the cultures were growing on glucose or pectin in the presence of Ro-31-8425.

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Ethnopharmacological relevance: Cordia ecalyculata Veil. and Echinodorus grandiflorus (Cham. & Schltdl) Micheli are extensively used in Brazil as therapeutic preparations for indigenous groups and the general population. These plants have been used in the folk medicine as: tonic, diuretic, anti-inflammatory, appetite suppressants, for the treatment of snake bites, and weight loss. Aim of the study: In this study, it was verified the possible cytotoxic and genotoxic effects of the crude extracts of. Cordia ecalyculata and Echinodorus grandiflorus, as well as their effectiveness in treating obesity. Materials and methods: The Micronucleus Test was used for the evaluation of possible clastogenic and aneugenic effects, and the Comet Assay was used for the evaluation of single-strand and double-strand DNA breaks. The cytotoxic effects of the crude extracts were verified by PCE/NCE ratio. Swiss mice (Mus musculus) were used as the experimental model. Results: It was observed a significant (P < 0.05) increase, dose-independent, in the average frequency of micronucleated erythrocytes in peripheral blood in mice treated with either the Cordia ecalyculata or Echinodorus grandiflorus extracts, in comparison with the negative control. There were no significant differences (P > 0.05) in the frequency of micronucleated polychromatic erythrocytes for both extract treatment. We observed that treatment with the Cordia ecalyculata extract at concentrations of 1000 and 2000 mg/kg bw resulted in a PCE/NCE ratio that was larger (P < 0.05) than the negative control. After 15 days of daily treatment. a dose of 2000 mg/kg bw of either phytotherapeutic did not reduce body mass gain or the amount of food consumed by Swiss mice when compared with the negative control (P > 0.05). Conclusion: The results of this study allowed us to infer that the crude extracts of Cordia ecalyculata and Echinodorus grandiflorus do not display cytotoxic or genotoxic activities. However, they do possess weak clastogenic activity (without significance) on peripheral blood cells. Contrary to commonly held beliefs it was also found in this study that the extracts are not effective for obesity treatments. (C) 2009 Elsevier Ireland Ltd. All rights reserved.