Propolis: Is there a potential for the development of new drugs?

Introduction: Propolis has plenty of biological and pharmacological properties and its mechanisms of action have been widely investigated in the last years, using different experimental models in vitro and in vivo. Researchers have been interested in the investigation of isolated compounds responsible for propolis action; however, there is lack of clinical research on the effects of propolis.Strategy and objectives: Since propolis-containing products have been marketed and humans have used propolis for different purposes, the goal of this review is to discuss the potential of propolis for the development of new drugs, by comparing data from the literature that suggest candidate areas for the establishment of drugs against tumors, infections, allergy, diabetes, ulcers and with immunomodulatory action.Conclusions: The efficacy of propolis in different protocols in vitro and in vivo suggests its therapeutic properties, but before establishing a strategy using this bee product, it is necessary to study: (a) the chemical nature of the propolis sample. (b) Propolis efficacy should be compared to well-established parameters, e.g. positive or negative controls in the experiments. Moreover, possible interactions between propolis and other medicines should be investigated in humans as well. (c) Clinical investigation is needed to evaluate propolis potential in patients or healthy individuals, to understand under which conditions propolis may promote health. Data point out the importance of this research field not only for the readers and researchers in the scientific community waiting for further clarification on the potential of propolis but also for the pharmaceutical industry that looks for new drugs. (C) 2010 Elsevier B.V. All rights reserved.

Structural and functional characterization of two novel peptide toxins isolated from the venom of the social wasp Polybia paulista

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Advantages of using nested collision induced dissociation/post-source decay with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry: sequencing of novel peptides from wasp venom

We have examined the applicability of the 'nested' collision induced dissociation/post-source decay (CID/PSD) method to the sequencing of novel peptides from solitary wasps which have neurotoxic venom for paralyzing other insects. The CID/PSD spectrum of a ladder peptide derived from an exopeptidase digest was compared with that of the intact peptide. The mass peaks observed only in the CID/PSD spectrum of a ladder peptide were extracted as C-terminal fragment ions. Assignment of C-terminal fragment ions enabled calculation of N-terminal fragment masses, leading to differentiation between N-terminal fragment ions and internal fragment ions. This methodology allowed rapid and sensitive identification by removing ambiguity in the assignment of the fragment ions, and proved useful for sequencing unknown peptides, in particular those available as natural products with a limited supply. Copyright (C) 2000 John Wiley & Sons, Ltd.

Antiplasmodial Natural Products

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

In vitro antibacterial efficacy of endodontic irrigants against Enterococcus faecalis

Objective. The objective of this study was to compare the in vitro antimicrobial activity of 2% chlorhexidine gel against Enterococcus faecalis with sodium hypochlorite in 2 different concentrations (1.5% and 5.25%).Study design. Eighty human lower premolars with single root canals were prepared, autoclaved, and infected for 7 days with E. faecalis monocultures. The roots were then separated into 5 experimental groups according to the irrigant solution used during the standardized preparation. To assess the antimicrobial action of the irrigant solutions, 3 microbial samples were taken: S1-initial (before the biomechanical preparation), S2-posttreatment (immediately after the biomechanical preparation), and S3-final (7 days after the biomechanical preparation). The microbiological samples were plated to count the colony-forming units (CFU).Results. The 2% chlorhexidine gel and 5.25% sodium hypochlorite significantly reduced the E. faecalis CFU in the posttreatment and final microbiological samples. The 1.5% sodium hypochlorite also reduced the E. faecalis CFU immediately after the root canal instrumentation, but the E. faecalis CFU increased in the final sample showing no statistical difference from the control group.Conclusion. The 2% chlorhexidine gluconate gel and 5.25% sodium hypochlorite were effective in eliminating E. faecalis even 7 days after the instrumentation; moreover, the higher the concentration of sodium hypochlorite the better its antimicrobial action.

Acao antioxidante de extratos de alecrim (Rosmarinus officinalis L.) em files de peixes da especie pacu (Piaractus mesopotamicus Holmberg)

The antioxidant effect of plant extract has been an interesting issue for many researchers in past few years. Spices have been identified as products with large amounts of antioxidants, and rosemary is one the most studied spice. Studies have shown evidences that population with high intake of these substances have less incidence of coronary heart disease. The objective of this work was verify the antioxidant action of the commercial rosemary oleoresin Herbalox® (used to feed the pacu (Piaractus mesopotamicus) fish. The juveniles pacu were fed with isocaloric and isoproteic diets, for two groups the lipid source was soybean oil and for the another it was corn oil. For each group of the different lipid sources, rosemary extract Herbalox® (were added in one lot and on the other which was used as control. The results showed that the addition of rosemary extracts to the ration protected them against peroxidation, when compared with the control, the lipid source also have influence on these protection.

Contribution to the study of the solid-state reaction of mercury with pure rhodium

Thermogravimetry (TG) and other analysis techniques (EDX, SEM, Mapping surface, X-ray diffraction, inductively coupled argon plasma emission spectroscopy and atomic spectrometry with cold vapor generation) were used to study the reaction of Hg with Rh. The results permitted the suggestion that, when subjected to heat, an electrodeposited Hg film reacts with Rh to form intermetallic products with different stabilities, as indicated by at least three mass loss steps. In the first step, between room temperature and 160°C, only the bulk Hg is removed. From this temperature up to about 175°C, the mass loss can be attributed to the desorption of a film of metallic Hg. The last step, from 175 to 240°C, can be ascribed to the removal of Hg from a thin dark film of RhHg2.

The acylpolyamines from spider venoms

Acylpolyamines are low molecular mass toxins occurring exclusively in the venoms from solitary wasps and some groups of spiders. Their chemical structures have been elucidated using hyphenated techniques of mass spectrometry, such as LC-MS and MS/MS, or through direct analysis with different types of NMR analyses. The chemical structures of the acylpolyamine toxins from the venoms of Nephilinae orb-web spiders appear to be organized into four parts based on the combinatorial way that the chemical building blocks are bound to each other. An aromatic moiety (part I) is connected through a linker amino acid (part II) to a polyamine chain (part III), which in turn may be connected to an optional tail (part IV). The polyamine chains were classified into seven subtypes according to the different combinations of chemical building blocks. These polyamine chains, in turn, are connected to one of three chromophore moieties: a 2,4-dihydroxyphenyl acetyl group, a 4-hydroxyindolyl acetyl group, or an indolyl acetyl group. They may be connected through an asparagine residue or sometimes through the dipeptide ornithyl asparagine. Also, nine different types of backbone tails may be attached to the polyamine chains. These toxins are noncompetitive blockers of ionotropic glutamate receptors with neuroprotective action against the neuronal death and antiepileptic effect. Thus, compounds of this class of spider venom toxin seem to represent interesting molecular models for the development of novel neuropharmaceutical drugs. © 2012 Elsevier B.V. All rights reserved.

Biomass and yield of peanut grown on tropical soil amended with sewage sludge contaminated with lead

Application of sewage sludge with high lead (Pb) contents may pollute soils and contaminate crops. The objective of this work was to evaluate peanut responses to application of sewage sludge with varying Pb contents in order to supply phosphorus (P) to the plant. A greenhouse experiment was carried out with peanut grown on soil sample from a medium-textured Haplustox. Treatments were arranged in 3 × 2 + 2 factorial scheme, replicated three times, distributed in randomized block design, and consisted of: three Pb rates applied to soil with sewage sludge (3, 21, and 42 mg kg-1) × two times of sewage sludge application (30 days before peanut sowing and at the day of the sowing) + mineral fertilization + control (without sewage sludge and mineral fertilization). Sewage sludge was efficient to supply P to peanut. Sewage sludge containing high rates of Pb, when applied, did not harm biomass and yield of the plant, but increased HCl-extractable Pb in soil and Pb content in shoot, roots, and pod husks. Increase of Pb content in pod husks may represent contamination risk of kernels and their products with fragments from husks detached during manipulation or industrial processing of peanuts. © 2012 Fábio Camilotti et al.

Avaliação de dois diferentes meios de cultura para o desenvolvimento de biopesticidas à base de Bacillus thuringiensis e sua aplicação em larvas de Aedes aegypti

The bacteria Bacillus thuringiensis var. israelensis (Bti) generates certain toxins with pesticide action, which can be used on the control of transmissible diseases by culicides, specially Aedes aegypti, the dengue vector. This biopesticide has been produced by submerged fermentation and, in Brazil, this production has been made by very little research centers and, more recently, by a unique small enterprise. For the implementation of a viable vectors control program through biopesticides, some studies about culture media are essential in order to join efficiency and low costs. In this way, agroindustrial wastes or by-products have been used as a nutrient source for the culture media production. In this study, corn steep liquor, a corn industrial processing by-product and tryptose, both with/without sugar addition, were compared as culture media. Cellular growth was evaluated by optical density at 620 nm, spore production by total viable cell count and LC50 by bioassays against 4th instar larvae. Among the four examined substrates, the medium composed by glucose plus corn steep liquor presented the best spore production and bioassay results.

Photodynamic and Antibiotic Therapy Impair the Pathogenesis of Enterococcus faecium in a Whole Animal Insect Model

Enterococcus faecium has emerged as one of the most important pathogens in healthcare-associated infections worldwide due to its intrinsic and acquired resistance to many antibiotics, including vancomycin. Antimicrobial photodynamic therapy (aPDT) is an alternative therapeutic platform that is currently under investigation for the control and treatment of infections. PDT is based on the use of photoactive dye molecules, widely known as photosensitizer (PS). PS, upon irradiation with visible light, produces reactive oxygen species that can destroy lipids and proteins causing cell death. We employed Galleria mellonella (the greater wax moth) caterpillar fatally infected with E. faecium to develop an invertebrate host model system that can be used to study the antimicrobial PDT (alone or combined with antibiotics). In the establishment of infection by E. faecium in G. mellonella, we found that the G. mellonella death rate was dependent on the number of bacterial cells injected into the insect hemocoel and all E. faecium strains tested were capable of infecting and killing G. mellonella. Antibiotic treatment with ampicillin, gentamicin or the combination of ampicillin and gentamicin prolonged caterpillar survival infected by E. faecium (P = 0.0003, P = 0.0001 and P = 0.0001, respectively). In the study of antimicrobial PDT, we verified that methylene blue (MB) injected into the insect followed by whole body illumination prolonged the caterpillar survival (P = 0.0192). Interestingly, combination therapy of larvae infected with vancomycin-resistant E. faecium, with antimicrobial PDT followed by vancomycin, significantly prolonged the survival of the caterpillars when compared to either antimicrobial PDT (P = 0.0095) or vancomycin treatment alone (P = 0.0025), suggesting that the aPDT made the vancomycin resistant E. faecium strain more susceptible to vancomycin action. In summary, G. mellonella provides an invertebrate model host to study the antimicrobial PDT and to explore combinatorial aPDT-based treatments.

Contribuição eletrostática e não eletrostática na interação de peptídeos líticos com membranas modelo

Pós-graduação em Biofísica Molecular - IBILCE

Investigação dos efeitos tóxicos, mutagênicos e genotóxicos do herbicida Trifluralina, utilizando Allium cepa e Oreochromis niloticus como sistemas-testes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito do uso de enzimas proteolíticas na maturação de queijo Prato com teor reduzido de gordura

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Síntese de sucroésteres derivados de ácidos piridínicos (ácido nicotínico, isonicotínico e pícolínico) e avaliação de suas atividades antimicrobianas

Pós-graduação em Engenharia e Ciência de Alimentos - IBILCE