Antitumor effects of snake venom chemically modified Lys49 phospholipase A(2)-like BthTX-I and a synthetic peptide derived from its C-terminal region

The present work evaluates both in vitro and in vivo antitumor activity of BPB-modified BthTX-I and its cationic synthetic peptide derived from the 115-129 C-terminal region. BPB-BthTX-1 presented cytotoxicity of 10-40% on different tumor cell lines, which were also susceptible to the lytic action of the synthetic peptide. Injection of the modified protein or the peptide in mice, 5 days after transplantation of S 180 tumor cells, reduced 30 and 36% of the tumor size on day 14th and 76 and 79% on day 60th, respectively, when compared to the untreated control group. Thus, these antitumor properties might be of interest in the development of therapeutic strategies against cancer. (C) 2009 The International Association for Biologicals. Published by Elsevier Ltd. All rights reserved.

Effect of chloride concentration on the electrochemical treatment of a synthetic tannery wastewater

The electrochemical treatment of a synthetic tannery wastewater prepared with 30 compounds used in animal skin processing was studied. Electrolyses were performed in a one-compartment flow cell at a current density of 20 mA cm(-2), using a dimensionally stable anode (DSA (R)) of composition Ti/Ir(0.10)Sn(0.90)O(2) as the working electrode. Effects of chloride concentration and presence of sulfate were evaluated. Variation in the concentration of phenolic compounds as a function of electrolysis time revealed a first-order exponential decay; faster phenol removals were obtained with increasing chloride concentration in the wastewater. Lower phenol removals were obtained in the presence of sulfate. Higher chloride concentrations led to a faster decrease in total organic carbon (TOC), chemical oxygen demand (COD), and absorbance values at 228 nm. Faster wastewater color removal, higher current efficiency and lower energy consumption were also obtained. This electrochemical treatment was also able to reduce the wastewater toxicity for Daphnia similis. (C) 2008 Elsevier Ltd. All rights reserved.

Electrochemical oxidation of synthetic tannery wastewater in chloride-free aqueous media

The electrochemical treatment of a synthetic tannery wastewater, prepared with several compounds used by finishing tanneries, was studied in chloride-free media. Boron-doped diamond (Si/BDD), antimony-doped tin dioxide (Ti/SnO(2)-Sb), and iridium-antimony-doped tin dioxide (Ti/SnO(2)-Sb-Ir)were evaluated as anode. The influence of pH and current density on the treatment was assessed by means of the parameters used to measure the level of organic contaminants in the wastewater; i.e., total phenols, chemical oxygen demand (COD), total organic carbon (TOC), and absorbance. Results showed that faster decrease in these parameters occurred when the Si/BDD anode was used. Good results were obtained with the Ti/SnO(2)-Sb anode, but its complete deactivation was reached after 4h of electrolysis at 25 mA cm(-2), indicating that the service life of this electrode is short. The Ti/SnO(2)-Sb-Ir anode is chemically and electrochemically more stable than the Ti/SnO(2)-Sb anode, but it is not suitable for the electrochemical treatment under the studied conditions. No significant changes were observed for electrolyses performed at different pH conditions with Si/BDD, and this electrode led to almost complete mineralization after 4 h of electrolysis at 100mAcm(-2). The increase in current density resulted in faster wastewater oxidation, with lower current efficiency and higher energy consumption. Si/BBD proved to be the best electrodic material for the direct electrooxidation of tannery wastewaters. (C) 2010 Elsevier B.V. All rights reserved.

Biomimetic Oxidation of Piperine and Piplartine Catalyzed by Iron(III) and Manganese(III) Porphyrins

Synthetic metalloporphyrins, in the presence of monooxygen donors, are known to mimetize various reactions of cytochrome P450 enzymes systems in the oxidation of drugs and natural products. The oxidation of piperine and piplartine by iodosylbenzene using iron(III) and manganese(III) porphyrins yielded mono- and dihydroxylated products, respectively. Piplartine showed to be a more reactive substrate towards the catalysts tested. The structures of the oxidation products were proposed based on electrospray ionization tandem mass spectrometry.

Monoamine oxidase inhibitory activities of indolylalkaloid toxins from the venom of the colonial spider Parawixia bistriata: Functional characterization of PwTX-I

Colonial spiders evolved a differential prey-capture behaviour in concert with their venom chemistry, which may be a source of novel drugs. Some highly active tetrahydro-beta-carboline (TH beta C) toxins were recently isolated from the venom of the colonial spider Parawixia bistriata; the spiders use these toxins as part of their chemical arsenal to kill and/or paralyze preys. The major TH beta C compound isolated from this venom was identified as 6-hydroxytrypargine, also known as PwTX-I. Most natural compounds of animal origin occur in low abundance, and the natural abundance of PwTX-I is insufficient for complete functional characterization. Thus, PwTx-I was synthesized using a Pictet-Spengler condensation strategy, and the stereoisomers of the synthetic toxin were separated by chiral chromatography. The fraction of venom containing a mixture of three natural TH beta C toxins and enantiomers of PwTx-I were analyzed for inhibition of monoamine oxidase (MAO)-A and -B and for toxicity to insects. We reveal that the mixture of the natural TH beta C toxins, as well as the enantiomers of PwTx-I, were non-competitive inhibitors of MAO-A and MAO-B and caused potent paralysis of honeybees. The (-)-PwTX-I enantiomer is 2-fold more potent than the (+)-PwTX-I enantiomer in the assays performed. (C) 2009 Elsevier Ltd. All rights reserved.

Development of a synthetic 7-ketocholesterol- rich emulsion resembling chylomicrons

Lipid emulsions that mimic natural lipoproteins help to understand the metabolism and the constitutional organization of circulating lipids. Chylomicrons synthesised by enterocyte cells usually contain oxysterols such as 7-ketocholesterol (7-KC). Here we describe the development of a 7-KC-containing emulsion as a model for oxisterol-rich chylomicron. Different amounts of 7-KC were used. Emulsion characteristics as effective diameter, lipid saturation with radiolabeled lipids was evaluated. In conclusion, the production of a synthetic 7-KC-rich emulsion resembling hylomicrons was feasible, being a model for in vivo metabolism studies.

Synthetic nanoemulsion resembling a protein-free model of 7-ketocholesterol containing low density lipoprotein: In vitro and in vivo studies

7-ketocholesterol (7-KC) differs from cholesterol by a functional ketone group at C7. It is an oxygenated cholesterol derivative (oxysterol), commonly present in oxidized low-density lipoprotein (LDL). Oxysterols are generated and participate in several physiologic and pathophysiologic processes. For instance, the cytotoxic effects of oxidized LDL have been widely attributed to bioactive compounds like oxysterols. The toxicity is in part due to 7-KC. Here we aimed to demonstrate the possibility of incorporating 7-KC into the synthetic nanoemulsion LDE, which resembles LDL in composition and behavior. This would provide a suitable artificial particle resembling LDL to study 7-KC metabolism. We were able to incorporate 7-KC in several amounts into LDE. The incorporation was evaluated and confirmed by several methods, including gel filtration chromatography, using radiolabeled lipids. The incorporation did not change the main lipid composition characteristics of the new nanoparticle. Particle sizes were also evaluated and did not differ from LDE. In vivo studies were performed by injecting the nanoemulsion into mice. The plasma kinetics and the targeted organs were the same as described for LDE. Therefore, 7-KC-LDE maintains composition, size and some functional characteristics of LDE and could be used in experiments dealing with 7-ketocholesterol metabolism in lipoproteins.

Patients Receiving Physical Rehabilitation: Records of Sexual Function Before the Introduction of Erectogenic Drugs

The objective of this study is to evaluate the entries associated to the sexual function of patients undergoing physical disability rehabilitation, as well as the course of changes and medical approach through a retrospective review of medical charts. Methods: Medical records referring to the period between July and September, 1998 were evaluated. The data was divided into two groups, records containing physician`s entries on sexual function and/or entries of other health care professionals. The following aspects were investigated: whether complaints were spontaneously voiced by the patient, and whether diagnosis had been reached, with corresponding management. Results: Out of 245 medical records investigated, 17 (6.9%) contained clinical observations on the sexual function; out of those, 14 reached diagnosis. Twelve records (4.9%) had information by non-medical healthcare professionals. Out of 17 entries by doctors, 16 referred to male patients, which was found to be significant (p = 0.0202). Conclusions: Records for the sexual function of patients undergoing physical rehabilitation are scarce. In this population, the sexual function of male patients had more extensive investigation on the part of physicians when compared to other health care professionals.

Frequency of thrombophilia determinant factors in patients with livedoid vasculopathy and treatment with anticoagulant drugs - a prospective study

Background Livedoid vasculopathy (LV) is a chronic idiopathic disease characterized by painful purpuric macules on lower extremities. Its exact aetiology remains uncertain, but thrombotic and microcirculatory phenomena have been implicated as possible pathogenic factors. Objectives To assess prospectively the frequency of thrombophilia and to verify the effectiveness of anticoagulant therapy among LV patients. Methods Thirty-four LV patients were tested for prothrombin time, activated partial thromboplastin time, antithrombin activity, protein C and S activity, anticardiolipin antibodies, lupus anticoagulant, prothrombin gene mutation, factor V Leiden mutation, methylenetetrahydrofolate reductase mutation, plasma homocysteine and fibrinogen. Thirteen of these patients were treated with anticoagulant drugs (either warfarin or heparin). Results Of 34 patients, 18 (52%) presented laboratory abnormalities of procoagulant conditions. Positive treatment response to anticoagulant therapy was observed in 11 patients. Improvement of pain was obtained in 1-3 weeks, an average of 1.8 week. Complete healing of the lesions was observed in about 2.3 months. Remission was sustained even after treatment interruption and lasted an average 7.8 months. No severe adverse effects were noticed. Conclusion The authors suggest all patients with diagnosis of LV to be investigated for thrombophilic status. Anticoagulant drugs were well tolerated and seemed to be effective in treating not only LV symptoms but also its ulcerations.

Rebound acid hypersecretion after withdrawal of gastric acid suppressing drugs: new evidence of similitude

Background: Homeopathy is based on the principle of similitude (similia similibus curentur) using medicines that cause effects similar to the symptoms of disease in order to stimulate the reaction of the organism. Such vital, homeostatic or paradoxical reaction of the organism is closely related to rebound effect of drugs. Method: Review of the literature concerning the rebound effects of drugs used to suppress gastric acidity, particularly proton pump inhibitors (PPIs). Results: The mechanism of action of these effects is discussed. Rebound in terms of clinical symptoms and physiological effects occur in about 40% of people taking PPIs, their timing depends on the half-life of the drug and the adaptation period of the physiological mechanisms involved. The wide use of PPIs may be linked to the rising incidence of carcinoid tumours. Conclusions: These findings support Hahnemann`s concept of secondary action of drugs. We are developing a homeopathic materia medica and repertory of modern drugs on the basis of reported rebound effects. Homeopathy (2011) 100, 148-156.

An evaluation of the genotoxic and cytotoxic effects of the anti-obesity drugs sibutramine and fenproporex

Anti-obesity medications deserve special considerations at the present time due to an increasing number of overweight and obese people who require these therapeutic alternatives. Obesity is positively associated with several chronic illnesses, including cancer. In this work, we evaluated the possible genotoxic and/or cytotoxic actions of two drugs, sibutramine and fenproporex, in the doses of 10, 20 and 40 mg/kg body weight (bw), administered intraperitoneally in male Swiss mice. The genotoxic effect was analyzed by comet assay and micronucleus test. We found that both drugs increased the frequency of genotoxic damage in Swiss mice, but did not present cytotoxic activities towards the polychromatic erythrocytes of the bone marrow of these animals.

Preimplantation development and expression of Hsp-70 and Bax genes in bovine blastocysts derived from oocytes matured in alpha-MEM supplemented with growth factors and synthetic macromolecules

In vitro culture conditions affect both the maternal and embryonic expression of genes and is likely to alter both oocyte and embryo developmental competence. The search for better and less variable culture conditions simulating those in vivo has led to the development of defined culture media, with lower impact on the molecular reprogramming of oocytes and embryos. We evaluated embryo development and relative abundance (RA) of Hsp-70 and Bax transcripts in bovine blastocysts produced from oocytes matured in a chemically defined IVM system with synthetic polymers. Immature cumulus oocyte complexes (COCs) were matured for 22-24 h in alpha-MEM supplemented with IGF-1, insulin, 0.1% polyvinyl alcohol (PVA), or 0.1% polyvinylpyrrolidone (PVP), but without FSH or LH. The control group consisted of COCs matured it, TCM plus FSH and 10% estrous cow serum. After fertilization. presumptive zygotes were co-cultured with cumulus cells until 224 h post-insemination. Total RNA was isolated from embryo pools, reverse transcribed into cDNA, and subjected to transcript analysis by real-time PCR. Cleavage rate was higher (P < 0.05) for the control group (68.3%) than for the PVA (54.4%) and PVP-40 (58.3%) groups. Nevertheless. there was no difference among the PVA, PVP-40 and control groups in blastocyst or hatching rates. similarly, no difference in relative abundance of Hsp-70 and Bax transcripts was detected in comparison to the control group. We inferred that bovine oocytes can be matured in serum- and gonadotrophin-free medium supplemented with PVA or PVP, enriched with IGF-I and insulin, without altering post-cleavage development and relative abundance of some genes associated with stress and apoptosis. (C) 2009 Elsevier Inc. All rights reserved.

Polymorphisms in genes encoding drugs and xenobiotic metabolizing enzymes in a Brazilian population

Polymorphic variations of several genes associated with drugs and xenobiotic metabolism have been linked to the factors that predispose to the carcinogenesis process. As considerable interindividual and interethnic variation in metabolizing enzyme activity has been associated with polymorphic alleles, we evaluated the frequency of the polymorphisms of CYP2D6, EPHX1 and NQO1 genes in 361 Brazilian individuals separated by ethnicity (European and African ancestry), using the polymerase chain reaction-restriction fragment length (PCR-RFLP) method. The allele frequencies of the variants *3 and *4 for the gene CYP2D6 were 0.04 and 0.14 for white subjects and 0.03 and 0.10 for black individuals, respectively. For the both variants of the gene EPHX1, we found higher allele frequencies among white individuals compared with mulatto subjects (0.62 vs 0.54 and 0.18 vs 0.14, respectively); however, these differences were not statistically significant (p = 0.39 and 0.56, respectively). For the NQO1 gene we observed a higher frequency of the homozygous genotype among black individuals (7.9%) compared with white subjects (6.3%) (p = 0.003). The genotype frequencies were within the Hardy-Weinberg equilibrium. We concluded that the allele frequencies of CYP2D6, EPHX1 and NQO1 gene polymorphisms in this Brazilian population showed ethnic variability when compared with those observed in other populations.

Evaluation of IGF-2/ApaI polymorphism in pregnant women infected with human immunodeficiency virus type 1 taking antiretroviral drugs

Objective: Studies carried Out to assess the effects of antiretroviral drugs (ARV) in HIV-1 infected pregnant women have demonstrated carbohydrate intolerance. Some reports also refer to the effect of disturbances in the expression of the insulin-like growth factor (IGF) system on pancreas beta-cell function in humans and IGF-2/ApaI polymorphisms have been associated with obesity and features of the metabolic syndromes. in the present study, we tested the association between IGF-2/ApaI genotype and hyperglycemia in HIV-1 infected pregnant women receiving ARV. Design: We studied IGF-2/ApaI polymorphism in 87 healthy pregnant women, 43 HIV-1 infected pregnant women taking ARV with hyperglycemia during pregnancy, and 43 HIV-1-negative pregnant women with gestational diabetes. Blood samples were obtained for DNA extraction, PCR and genotyping. Data were analyzed statistically by the Kolmogorov-Smirnov normality, ANOVA and chi-square tests. Results: There were no significant differences in genotype frequency among the three groups analyzed. Considering the HIV-1-infected pregnant women, there were no significant differences in genotype frequency between the zidovudine group and the triple antiretroviral treatment group. There were no significant differences in allele frequencies among the groups evaluated. Non-white pregnant women tended to present the GG genotypes compared to white pregnant women. Conclusion: These results contribute to a better understanding of metabolic glycemic disorders in HIV-1 infected pregnant women using ARV, showing that IGF-2/ApaI polymorphisms are not responsible as a single Causative factor of glycemic alterations. These data indicate that other variables should be studied in order to explain these glycemic abnormalities. (C) 2009 Elsevier Ltd. All rights reserved.

Compound 48/80 induces endothelium-dependent and histamine release-independent relaxation in rabbit aorta

Compound 48/80 (C48/80) is a synthetic condensation product of N-methyl-p-methoxyphenethyl am me with formaldehyde and is an experimental drug used since the 1950s to induce anaphylactic shock through histamine release. This study was carried out to further elucidate the mechanism by which this drug induces nitric oxide (NO) release. Our specific goals were: (a) to verify if C48/80`s relaxation occurs through the stimulation of histamine receptors; (b) to evaluate the endothelium-dependent relaxation induced by C48/80; (c) to identify NO as the endothelium-relaxing factor released by C48/80; (d) to identify the NO synthase (NOS) responsible for NO release; and (e) to verify if the relaxation induced by C48/80 is calcium and cyclic guanidine monophosphate (cGMP) dependent. Rabbit aorta segments, with and without endothelium, were suspended in organ chambers (25 ml) filled with Krebs solution maintained at 37 degrees C, bubbled with 95% O-2/5% CO2 (pH 7.4). Phenylephrine was used to contract the segments. Other protocol drugs included H-1- and H-2-receptor antagonists, cyclooxygenase, NOS, guanylyl cyclase and phospholipase C (PLC) inhibitors. Endothelium-dependent relaxation induced by C48/80 was also studied in calcium-free Krebs solution associated with a calcium chelator. In summary, our investigation demonstrated that the C48/80 vasodilating action: (a) does not depend on H-1 and H-2 histamine receptors; (b) is NO endothelium-dependent; (c) is dependent on the endothelial constitutive NOS (NOS-3) isoform activation; (d) is cGMP-dependent; and that NOS-3 activation by C48/80: (a) is independent of PLC up to 25 mu g/ml and (b) is partially dependent of this lipase in higher doses. (C) 2007 Elsevier Inc. All rights reserved.