Brazilian Propolis: Seasonal Variation of the Prenylated p-Coumaric Acids and Antimicrobial Activity

Brazilian green propolis, which is used in food and beverages to improve health and to prevent diseases, demostrates antioxidant, antimutagenic, and antimicrobial activities. Most biological activities are thought to be related to the high levels of drupanin, artepillin C, and baccharin, which are compounds also present in Baccharis dracunculifolia D.C. (Asteraceae). Since propolis chemical composition depends on the region and the period of collection, as well as its plant origin, the effect of seasonal variation on the both content of prenylated p-coumaric acids and in vitro antimicrobial activity of Brazilian propolis from four different sites, was performed. The results showed that MIC values ranged from 100 to 300 mu g/mL against both Staphylococcus aureus and Kocuria rhizophila, while none of the propolis samples was active against Pseudomonas aeruginosa, Escherichia coli, and Candida albicans. HPLC analysis showed that the content of drupanin, artepillin C, and baccharin varied throughout the year, as well as among the different study sites. Also, it is suggested that Baccharis dracunculifolia is the main botanical source of Brazilian propolis in sites I and 2, while in sites 3 and 4, other plant species are also used by bees to produce propolis. All the evaluated propolis samples exhibited similar antibacterial activity, but different contents of prenylated p-coumaric acids throughout the year.

In vitro antioxidant activity and in vivo efficacy of topical formulations containing vitamin C and its derivatives studied by non-invasive methods

Background/purpose: Vitamins C and its derivatives, mainly due to their antioxidant properties, are being used in cosmetic products to protect and to reduce the signs of ageing. However, there are no studies comparing the effects of vitamin C [ascorbic acid (AA)] and its derivatives, magnesium ascorbyl phosphate (MAP) and ascorbyl tetra-isopalmitate (ATIP), when vehiculated in topical formulations, mainly using objective measurements, which are an important tool in clinical efficacy studies. Thus, the objective of this study was to determine the in vitro antioxidant activity of AA and its derivatives, MAP and ATIP, as well as their in vivo efficacy on human skin, when vehiculated in topical formulations. Methods: The study of antioxidant activity in vitro was performed with an aqueous and a lipid system. The in vivo methodology consisted of the application of these formulations on human volunteers` forearm skin and the analysis of the skin conditions after 4-week period daily applications in terms of transepidermal water loss (TEWL), stratum corneum moisture content and viscoelasticity using a Tewameter (R), Corneometer (R) and Cutometer (R), respectively. Results: In vitro experiments demonstrated that in an aqueous system, AA had the best antioxidant potential, and MAP was more effective than ATIP, whereas in the lipid system ATIP was more effective than MAP. In in vivo studies, all formulations enhanced stratum corneum moisture content after a 4-week period daily applications when compared with baseline values; however, only the formulation containing AA caused alterations in TEWL values. The formulations containing MAP caused alterations in the viscoelastic-to-elastic ratio, which suggested its action in the deeper layers of the skin. Conclusion: AA and its derivates presented an in vitro antioxidant activity but AA had the best antioxidant effect. In in vivo efficacy studies, only the formulation containing AA caused alterations in TEWL values and the formulation containing MAP caused alterations in the viscoelastic-to-elastic ratio. This way, vitamin C derivatives did not present the same effects of AA on human skin; however, MAP showed other significant effect-improving skin hydration, which is very important for the normal cutaneous metabolism and also to prevent skin alterations and early ageing.

Effect of the Maillard reaction on properties of casein and casein films

The use of biodegradable natural polymers has increased due to the over-solid packaging waste. In this study, a chemical modification of the casein molecule was performed by Maillard reaction, and the modified polymer was evaluated by polyacrylamide gel electrophoresis (PAGE), thermogravimetry/derivative thermogravimetry (TG/DTG), FT-IR, and (1)H-NMR spectroscopy. Subsequently, films based on the modified casein were obtained and characterized by mechanical analysis, water vapor transmission, and erosion behavior. The PAGE results suggested an increase of molecular mass of the modified polymer, and FT-IR spectroscopy data indicated inclusion of C-OH groups into this molecule. The TG/DTG curves of modified casein presented a different thermal decomposition profile compared to the individual compounds. Mechanical tests showed that the chemical modification of the casein molecules provided higher elongation rates (45.5%) to the films, suggesting higher plasticity, than the original molecules (13.4%). The modified casein films presented higher permeability (0.505 +/- A 0.006 mu g/h mm(3)) than the original polymer (0.387 +/- A 0.006 mu g/h mm(3)) films at 90% relative humidity (RH). In pH 1.2, modified casein films presented higher erosion rates (32.690 +/- A 0.692%) than casein films (19.910 +/- A 2.083%) after 8 h, suggesting an increased sensibility for erosion of the modified casein films in acid environment. In water (pH 7.0), the films erosion profiles were similar. Those findings indicate that the modification of molecule by Maillard reaction provided films more plastic, hydrophilic, and sensitive to erosion in acid environment, suggesting that a new polymer with changed properties was founded.

Renal toxicity caused by oral use of medicinal plants: The yacon example

Aim of the study: Yacon [Smallanthus sonchifolius (Poepp. 82 Endl.) H. Robinson, Asteraceae] is an Andean species that has traditionally been used as an anti-diabetic herb in several countries around the world, including Brazil. Its hypoglycaemic action has recently been demonstrated in normal and diabetic rats. However, studies about the safety of prolonged oral consumption of yacon leaf extracts are lacking. Thus, this work was undertaken to evaluate the repeated-dose toxicity of three extracts from yacon leaves: the aqueous extract (AE) prepared as a tea infusion; the leaf-rinse extract (LRE), which is rich in sesquiterpene lactones (STLs); and a polar extract from leaves without trichomes, or polar extract (PE), which lacks STLs but is rich in chlorogenic acids (CGAs). Materials and methods: The major classes of the compounds were confirmed in each extract by IR spectra and HPLC-UV-DAD profiling as well as comparison to standard compounds. The toxicity of each extract was evaluated in a repeated-dose toxicity study in Wistar rats for 90 days. Results: The PE was rich in CGAs, but we did not detect any STLs. The AE and LEE showed the presence of STLs. The polar extract caused alterations in some biochemical parameters, but the animals did not show signs of behavioural toxicity or serious lesions in organs. Alterations of specific biochemical parameters in the blood (creatinine 7.0 mg/dL, glucose 212.0 mg/dL, albumin 2.8 g/dL) of rats treated with AE (10,50 and 100 mg/kg) and LRE (10 and 100 mg/kg) pointed to renal damage, which was confirmed by histological analysis of the kidneys. Conclusions: The renal damage was associated with increased blood glucose levels after prolonged oral administration of the AE. This observation suggested that the hypoglycaemic effect observed after treatment for 30 days in an earlier study is reversible and was likely the result of renal injury caused by the toxicity of yacon. Because STLs were detected in both AE and LRE, there is strong evidence that these terpenoids are the main toxic compounds in the leaves of the yacon. Based on our results, we do not recommend the oral use of yacon leaves to treat diabetes. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

Fragmentation studies and electrospray ionization mass spectrometry of lapachol: protonated, deprotonated and cationized species

Electrospray ionization mass spectrometric analysis of lapachol (2-hydroxy-3-(3-methy1-2-butenyl)-1,4-naphthoquinone) was accomplished in order to elucidate the gas-phase dissociation reactions of this important biologically active natural product. The occurrence of protonated and cationized species in the positive mode and of deprotonated species in the negative mode was explored by means of collision-induced dissociation (CID) experiments. For the protonated molecule, the H(2)O and C(4)H(8) losses occur by two competitive channels. For the deprotonated molecule, the even-electron rule is not conserved, and the radicalar species are eliminated by formation of distonic anions. The fragmentation mechanism for each ion was suggested on the basis of computational thermochemistry. Atomic charges, relative energies, and frontier orbitals were employed aiming at a better understanding of the gas-phase reactivity of lapachol. Potential energy surfaces for fragmentation reactions were obtained by the B3LYP/6-31+G(d,p) model. Copyright (C) 2010 John Wiley & Sons, Ltd.

O/W Nanoemulsion After 15 Years of Preparation: A Suitable Vehicle for Pharmaceutical and Cosmetic Applications

The application of nanoemulsions is due to have good stability, uniform spreading and enhance active penetration upon skin. Nanometer emulsions can be obtained by low-energy emulsification method. The required hydrophilic and lipophilic balance indicates the better balance of emulsifier for optimum system emulsification. Emulsion stability is evidently controlled for the properties of the adsorbed layer formed in the surface of its globules, know as potential zeta. The aim of this work was to evaluate the oil/water nanoemulsion of formulation obtained after 15 years of preparation. The results suggested that the nanoemulsion have performed stability for many years.

Antiulcerogenic Activity of the Essential Oil of Baccharis dracunculifolia on Different Experimental Models in Rats

Baccharis dracunculifolia DC (Asteraceae), a native plant from Brazil, commonly known as `Alecrim-do-campo` is widely used in folk medicine to treat inflammation, hepatic disorders and stomach ulcers, and it is the most important botanical source of Southeastern Brazilian propolis, known as green propolis. Its essential oil is composed of non-oxygenated and oxygenated terpenes. In this work, the effects of the essential oil obtained from the aerial parts of R dracunculifolia on gastric ulcers were evaluated. The antiulcer assays were undertaken using the following protocols in rats: nonsteroidal antiinflammatory drug (NSAID)-induced ulcer, ethanol-induced ulcer, stress-induced ulcer, and determination of gastric secretion using ligated pylorus. The treatment in the doses of 50, 250 and 500 mg/kg of R dracunculifolia essential oil significantly diminished the lesion index, the total lesion area and the percentage of lesions in comparison with both positive and negative control groups. With regard to the model of gastric secretion a reduction of gastric juice volume and total acidity was observed, as well as an increase in the gastric pH. No sign of toxicity was observed in the acute toxicity study. Considering the results, it is suggested that the essential oil of B. dracunculifolia could probably be a good therapeutic agent for the development of new phytotherapeutic medicine for the treatment of gastric ulcer. Copyright (C) 2009 John Wiley & Sons, Ltd.

Transcription regulation of the PbGP43 gene by nitrogen in the human pathogen Paracoccidioides brasiliensis

We show indirect evidences for the possible involvement of NIT-2-like binding motifs in transcription modulation of the PbGP43 gene, which codes for an important antigen from the human fungal pathogen Paracoccidioides brasiliensis. This investigation was motivated by the finding of 23 NIT2-like sites within the proximal -2047 nucleotides of the PbGP43 5` intergenic region from the Pb339 isolate. They compose four clusters, two of them identical. We found four NIT2-containing probes that were positive in electrophoretic mobility shift assays and further analyzed them. PbGP43 could be modulated by nitrogen primary sources in Pb339, Pb3 and Pb18 isolates, as observed by reverse transcription (RT) real time-PCR. Gene reporter assays conducted in Aspergillus nidulans suggested that the minimal fragment responsible for nitrogen modulation lies within -480 bp of the PbGP43 gene. This is the first report on PbGP43 transcription modulation in response to nitrogen primary sources, which might help understand its regulation during infection. (C) 2008 Elsevier Inc. All rights reserved.

Environmental Exposure to Methylmercury is Associated with a Decrease in Nitric Oxide Production

Some studies have recently suggested that mercury (Hg)-exposed populations face increased risks of cardiovascular diseases, and experimental data indicate that such risks might be due to reductions in nitric oxide bioavailability. However, no previous study has examined whether Hg exposure affects plasma nitrite concentrations in humans as an indication of nitric oxide production. Here, we investigated whether there is an association between circulating nitrite and Hg concentrations in whole blood, plasma and hair from an exposed methylmercury (MeHg) population. Hair and blood samples were collected from 238 persons exposed to MeHg from fish consumption. Hg concentrations in plasma (PHg), whole blood (BHg) and hair Hg (HHg) were determined by inductively coupled plasma-mass spectrometry. Mean BHg content was 49.8 +/- 35.2 mu g/l, mean PHg was 7.8 +/- 6.9 mu g/l and HHg 14.6 +/- 10.6 mu g/g. Mean plasma nitrite concentration was 253.2 +/- 105.5 nM. No association was found between plasma nitrite concentration and BHg or HHg concentrations in a univariate model. However, multiple regression models adjusted for gender, age and fish consumption showed a significant association between plasma nitrite and plasma Hg concentration (beta = -0.1, p < 0.001). Our findings constitute preliminary clinical evidence that exposure to MeHg may cause inhibitory effects on the production of endothelial nitric oxide.

Low level and sub-chronic exposure to methylmercury induces hypertension in rats: nitric oxide depletion and oxidative damage as possible mechanisms

Increased risk of hypertension after methylmercury (MeHg) exposure has been suggested. However, the underlying mechanisms are not well explored. In this paper, we have analyzed whether sub-chronic exposure to MeHg increases systolic blood pressure even at very low levels. In addition, we analyzed if the methylmercury-induced hypertension is associated with a decreased plasmatic nitric oxide levels and with a dysregulation of the activities of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), as well as the levels of MDA and glutathione. For this study, Wistar rats were treated with methylmercury chloride (100 mu g/kg per day) or vehicle. Total treatment time was 100 days. Malondialdehyde (MDA) and circulating NOx levels and superoxide dismutase (SOD) and catalase (CAT) activities were determined in plasma, whereas glutathione levels were determined in erythrocytes. Our results show that long-term treatment at a low level of MeHg affected systolic blood pressure, increasing and reducing the levels of plasmatic MDA and NOx, respectively. However, the activity of SOD did not decrease in the MeHg exposed group when compared to the control. We found a negative correlation between plasmatic nitrite/nitrate (NOx) levels and systolic blood pressure (r = -0.67; P = 0.001), and a positive correlation between MDA and systolic blood pressure (r = 0.61; P = 0.03), thus suggesting increased inhibition of NO formation with the increase of hypertension. In conclusion, long-term exposure to a low dose of MeHg increases the systolic pressure and is associated, at least in part, with increased production of ROS as judged by increased production of malondialdehyde and depressed NO availability.

Differential roles of galectin-1 and galectin-3 in regulating leukocyte viability and cytokine secretion

Galectin-1 (Gal-1) and galectin-3 (Gal-3) exhibit profound but unique immunomodulatory activities in animals but their molecular mechanisms are incompletely understood. Early studies suggested that Gal-1 inhibits leukocyte function by inducing apoptotic cell death and removal, but recent studies show that some galectins induce exposure of the common death signal phosphatidylserine (PS) independently of apoptosis. In tfhis study, we report that Gal-3, but not Gal-1, induces both PS exposure and apoptosis in primary activated human T cells, whereas both Gal-1 and Gal-3 induce PS exposure in neutrophils in the absence of cell death. Gal-1 and Gal-3 bind differently to the surfaces of T cells and only Gal-3 mobilizes intracellular Ca(2+) in these cells, although Gal-1 and Gal-3 bind their respective T cell ligands with similar affinities. Although Gal-1 does not alter T cell viability, it induces IL-10 production and attenuates IFN-gamma production in activated T cells, suggesting a mechanism for Gal-1-mediated immunosuppression in vivo. These studies demonstrate that Gal-1 and Gal-3 induce differential responses in T cells and neutrophils, and identify the first factor, Gal-3, capable of inducing PS exposure with or without accompanying apoptosis in different leukocytes, thus providing a possible mechanism for galectin-mediated immunomodulation in vivo.

Circulating Interleukin-6 and High-Sensitivity C-Reactive Protein Decrease After Periodontal Therapy in Otherwise Healthy Subjects

Background: Periodontal disease has been associated with many chronic inflammatory systemic diseases, and a common chronic inflammation pathway has been suggested for these conditions. However, few studies have evaluated whether periodontal disease, in the absence of other known inflammatory conditions and smoking, affects circulating markers of chronic inflammation. This study compared chronic inflammation markers in control individuals and patients with periodontal disease and observed whether non-surgical periodontal therapy affected inflammatory disease markers after 3 months. Methods: Plasma and serum of 20 controls and 25 patients with periodontal disease were obtained prior to and 3 months after non-surgical periodontal therapy. All patients were non-smokers, they did not use any medication, and they had no history or detectable signs and symptoms of systemic diseases. Periodontal and systemic parameters included probing depth, bleeding on probing, clinical attachment level, hematologic parameters, as well as the following inflammatory markers: interleukin (IL)-6, high-sensitivity C-reactive protein (hs-CRP), CD40 ligand, monocyte chemoattractant protein (MCP)-1, soluble P-selectin (sP-selectin), soluble vascular adhesion molecule (sVCAM)-1, and soluble intercellular adhesion molecule (sICAM)-1. Results: There were no differences in the hematologic parameters of the patients in the control and periodontal disease groups. Among the tested inflammatory markers, IL-6 concentrations were higher in the periodontal disease group at baseline compared to the controls (P=0.006). Therapy was highly effective (P<0.001 for all the analyzed clinical parameters), and a decrease in circulating IL-6 and hs-CRP concentrations was observed 3 months after therapy (P=0.001 and P=0.006, respectively). Our results also suggest that the CD40 ligand marker may have been different in the control and periodontal disease groups prior to the therapy (P=0.009). Conclusions: In apparently otherwise healthy patients, periodontal disease is associated with increased circulating concentrations of IL-6 and hs-CRP, which decreased 3 months after non-surgical periodontal therapy. With regard to the CD40 ligand, MCP-1, sP-selectin, sVCAM-1, and sICAM-1, no changes were seen in the periodontal disease group between baseline and 3 months after therapy. J Periodontol 2009;80:594-602.

Evaluation of the genotoxic and antigenotoxic effects after acute and subacute treatments with acai pulp (Euterpe oleracea Mart.) on mice using the erythrocytes micronucleus test and the comet assay

Acai, the fruit of a palm native to the Amazonian basin, is widely distributed in northern South America, where it has considerable economic importance. Whereas individual polyphenolics compounds in Acai have been extensively evaluated, studies of the intact fruit and its biological properties are lacking. Therefore, the present study was undertaken to investigate the in vivo genotoxicity of Acai and its possible antigenotoxicity on doxorubicin (DXR)-induced DNA damage. The Acai pulp doses selected were 3.33, 10.0 and 16.67 g/kg b.w. administered by gavage alone or prior to DXR (16 mg/kg b.w.) administered by intraperitoneal injection. Swiss albino mice were distributed in eight groups for acute treatment with acai pulp (24 h) and eight groups for subacute treatment (daily for 14 consecutive days) before euthanasia. The negative control groups were treated in a similar way. The results of chemical analysis suggested the presence of carotenoids, anthocyanins, phenolic. and flavonoids in Acai pulp. The endpoints analyzed were micronucleus induction in bone marrow and peripheral blood cells polychromatic erythrocytes, and DNA damage in peripheral blood, liver and kidney cells assessed using the alkaline (pH > 13) comet assay. There were no statistically significant differences (p > 0.05) between the negative control and the groups treated with the three doses of Acai pulp alone in all endpoints analyzed, demonstrating the absence of genotoxic effects. The protective effects of Acai pulp were observed in both acute and subacute treatments, when administered prior to DXR. In general, subacute treatment provided greater efficiency in protecting against DXR-induced DNA damage in liver and kidney cells. These protective effects can be explained as the result of the phytochemicals present in Acai pulp. These results will be applied to the developmental of food with functional characteristics, as well as to explore the characteristics of Acai as a health promoter. (C) 2009 Elsevier B.V. All rights reserved.

Association Among Microalbuminuria and Oxidative Stress Biomarkers in Patients With Type 2 Diabetes

Aim: Hyperglycemia in diabetes mellitus (DM) may be one of the most important factors responsible for the development of oxidative stress, which promotes the main complications in DM patients. Therefore, this study evaluated if the hyperglycemia could be related to oxidative stress biomarkers, lipid profile, and renal function in type 2 diabetes patients without clinic complications. Methods: Plasmatic malondialdehyde (MDA), serum protein carbonyl (PCO), serum creatinine levels, microalbuminuria, glycated hemoglobin, and lipid profile were analyzed in 37 type 2 diabetic patients and 25 subjects with no diabetes. Results: Serum creatinine levels were within the reference values, but microalbuminuria presented increased levels in all the patients compared with controls (P G 0.05) and above of the reference values. The MDA, PCO, low- density lipoprotein, and triglyceride levels showed positive correlation with microalbuminuria levels. Moreover, glycated hemoglobin presented positive correlation with MDA, PCO, and microalbuminuria levels. Conclusions: The hyperglycemia could be responsible for the increase of the microalbuminuria levels and for the oxidation process in lipids and proteins in DM patients. Therefore, we suggested that the microvascular lesion is a direct consequence from hyperglycemia and an indirect one from the increased oxidative stress. Malondialdehyde and protein carbonyl levels could be suggested as additional biochemical evaluation to verify tissue damage in type 2 DM patients.

IB Theory and the Entry of MNCs in Brazil from 1850 to 2007

This paper analyses the applicability of the main enterprise internationalization theories to the entry of the multinational corporations into Brazil, throughout five phases of Brazilian economy, from 1850 to nowadays. It seeks to verify the explanation power of each theory over the FDI flows in Brazil. It concludes that there is a contingency relation between the theories and the phases of the economy, and. it shows such relationship in a table. In addition, it concludes that the most powerful theory along the researched period was Dunning`s eclectic paradigm, mainly due to the Localization considerations. Theoretical propositions are put forward as a contribution to future research.