973 resultados para Bothrops jararacussu snake
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Rutin, one of the major flavonoids found in an assortment of plants, was reported to act as a sun protection factor booster with high anti-UVA defense, antioxidant, antiaging, and anticellulite, by improvement of the cutaneous microcirculation. This research work aimed at evaluating the rutin in vitro release from semisolid systems, in vertical diffusion cells, containing urea, isopropanol and propylene glycol, associated or not, according to the factorial design with two levels with center point. Urea (alone and in association with isopropanol and propylene glycol) and isopropanol (alone and in association with propylene glycol) influenced significant and negatively rutin liberation in diverse parameters: flux (g/cm2.h); apparent permeability coefficient (cm/h); rutin amount released (g/cm2); and liberation enhancement factor. In accordance with the results, the presence of propylene glycol 5.0% (wt/wt) presented statistically favorable to promote rutin release from this semisolid system with flux = 105.12 8.59 g/cm2.h; apparent permeability coefficient = 7.01 0.572 cm/h; rutin amount released = 648.80 53.01 g/cm2; and liberation enhancement factor = 1.21 0.07.
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Assortments of biophysical methods are used to the study the stratum corneum morphology and dynamic with the objective to elucidate the correlation between its structure and functions. Among these methods, there are: X-ray diffraction, electron paramagnetic resonance, differential scanning calorimetry, Raman spectroscopy with Fourrier transform, infrared spectroscopy and photoacustic spectroscopy. In this manuscript, methods are presented and discussed in relation to the use indication, interpretation of results and advantages and limitations to the stratum corneum analysis.
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Objectives In the present study we investigated the anti nociceptive, anti-inflammatory and antipyretic effects of 7-hydroxycoumarin (7-HC) in animal models. Methods The effects of oral 7-HC were tested against acetic acid-induced writhing, formalin test, tail flick test, complete Freund`s adjuvant (CFA)-induced hypemociception, carrageenan-induced paw oedema, lipopolysaccharide-induced fever and the rota rod test. Key findings 7-HC (3-60 mg/kg) produced a dose-related antinociception against acetic acid-induced writhing in mice and in the formalin test. In contrast, treatment with 7-HC did not prevent thermal nociception in the tail flick test. A single treatment with 7-HC, 60 mg/kg, produced a long-lasting antinociceptive effect against CFA-induced hypernociception, a chronic inflammatory pain stimulus. Notably, at 60 mg/kg per day over 4 days the administration of 7-HC produced a continuous antinociceptive effect against CFA-induced hypernociception. 7-HC (30-120 mg/kg) produced anti-inflammatory and antipyretic effects against carrageenan-induced inflammation and lipopolysaccharide-induced fever, respectively. Moreover, 7-HC was found to be safe with respect to ulcer induction. In the rota rod test, 7-HC-treated mice did not show any motor performance alterations. Conclusions The prolonged antinociceptive and anti-inflammatory effects of 7-HC, in association with its low ulcerogenic activity, indicate that this molecule might be a good candidate for development of new drugs for the control of chronic inflammatory pain and fever.
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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.
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This study investigated the effect of a pool of peptides, isolated from venom of Crotalus durissus terrificus (South American rattlesnake) on glucose concentration in C57BL/6 mice fed on a high-fat diet for 6 weeks. The pool of peptides (molecular mass around of 10 kDa) was obtained using a MidJet apparatus with a cartridge of 10 KDa. The peptide pool was injected intraperitoneally in mice in a single dose (0.5 mg/animal) or multiple doses (0.2 mg/dose). After predetermined times (30, 60, 90 and 120 min) post injections, venous blood samples were collected for enzymatic measurement of serum glucose using a commercial glucose kit (glucose oxidase method). High-fat fed mice showed an increase in blood glucose concentration, in comparison with mice fed on the chow diet. Thirty minutes after a single dose of the peptide pool, high-fat fed animals showed a significant decrease (similar to 47%) in glycemia. However, the glucose level increased again at 60 and 120 min. Conversely, after multiple injections of the pool of peptides administered every 30 min, the blood glucose concentration in the high-fat mice was significantly decreased (similar to 37%) and remained at low levels until 120 min. These results suggest that the tested pool of peptides from Crotalus durissus terrificus contained a peptide (or peptides) with a beneficial role on glucose-lowering action of high-fat fed mice.
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Crotalus durissus rattlesnakes are responsible for the most lethal cases of snakebites in Brazil. Crotalus durissus collilineatus subspecies is related to a great number of accidents in Southeast and Central West regions, but few studies on its venom composition have been carried out to date. In an attempt to describe the transcriptional profile of the C. durissus collilineatus venom gland, we generated a cDNA library and the sequences obtained could be identified by similarity searches on existing databases. Out of 673 expressed sequence tags (ESTs) 489 produced readable sequences comprising 201 singletons and 47 clusters of two or more ESTs. One hundred and fifty reads (60.5%) produced significant hits to known sequences. The results showed a predominance of toxin-coding ESTs instead of transcripts coding for proteins involved in all cellular functions. The most frequent toxin was crotoxin, comprising 88% of toxin-coding sequences. Crotoxin B, a basic phospholipase A(2) (PLA(2)) subunit of crotoxin, was represented in more variable forms comparing to the non-enzymatic subunit (crotoxin A), and most sequences coding this molecule were identified as CB1 isoform from Crotalus durissus terrificus venom. Four percent of toxin-related sequences in this study were identified as growth factors, comprising five sequences for vascular endothelial growth factor (VEGF) and one for nerve growth factor (NGF) that showed 100% of identity with C. durissus terrificus NGF. We also identified two clusters for metalloprotease from PII class comprising 3% of the toxins, and two for serine proteases, including gyroxin (2.5%). The remaining 2.5% of toxin-coding ESTs represent singletons identified as homologue sequences to cardiotoxin, convulxin, angiotensin-converting enzyme inhibitor and C-type natriuretic peptide, Ohanin, crotamin and PLA(2) inhibitor. These results allowed the identification of the most common classes of toxins in C. durissus collilineatus snake venom, also showing some unknown classes for this subspecies and even for C. durissus species, such as cardiotoxins and VEGF. (C) 2009 Published by Elsevier Masson SAS.
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Fear-relevant stimuli, such as snakes, spiders and heights, preferentially capture attention as compared to nonfear-relevant stimuli. This is said to reflect an encapsulated mechanism whereby attention is captured by the simple perceptual features of stimuli that have evolutionary significance. Research, using pictures of snakes and spiders, has found some support for this account; however, participants may have had prior fear of snakes and spiders that influenced results. The current research compared responses of snake and spider experts who had little fear of snakes and spiders, and control participants across a series of affective priming and visual search tasks. Experts discriminated between dangerous and nondangerous snakes and spiders, and expert responses to pictures of nondangerous snakes and spiders differed from those of control participants. The current results dispute that stimulus fear relevance is based purely on perceptual features, and provides support for the role of learning and experience.
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Pain is the most conspicuous symptom observed in patients wounded by stingrays, and skin necrosis is common in accidents by freshwater stingrays. The extract from the stinger integumentary tissue of Potamotrygon falkneri containing toxic components (venom) was tested for its ability to induce histopathological changes in the dorsal skin of mice at different times. 3-6 h after injection, foci of necrosis in isolated basal epidermal cells were observed. Full coagulative necrosis of the skin, subcutaneous tissue and skeletal muscle was evident as soon as 24 h after venom exposure, with a clear demarcation from the normal skin. After 48 h, round collections of necrotic cells start to coalesce originating extensive skin necrotic plaques that detach from viable tissue after 72-96 h. Inflammatory infiltrate was observed after 6 h, but was always mild. Acute vascular thrombosis was rare, and hemorrhage was not present at any time. Superficial bacterial infection was present in two of the examined cases. In conclusion, the venom of P. falkneri is responsible for the development of an early necrosis with mild inflammatory reaction, probably due to direct action of the venom. The severe local damage is probably worsened by the mechanical trauma caused by the stinger. (c) 2010 Elsevier Ltd. All rights reserved.
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Previous studies have shown that venoms of social wasps and bees exhibit strong anticoagulant activity. The present study describes the anticoagulant and fibrinogen-degrading pharmacological properties of the venom of Polybia occidentalis social wasp. The results demonstrated that this venom presented anticoagulant effect, inhibiting the coagulation at different steps of the clotting pathway (intrinsic, extrinsic and common pathway). The venom inhibited platelet aggregation and degraded plasma fibrinogen, possibly containing metal-dependent metalloproteases that specifically cleave the B beta-chain of fibrinogen. In conclusion, fibrinogenolytic and anticoagulant properties of this wasp venom find a potential application in drug development for the treatment of thrombotic disorders. For that, further studies should be carried out in order to identify and isolate the active compounds responsible for these effects. Blood Coagul Fibrinolysis 21: 653-659 (c) 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins.
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Plant-antivenom is a computational Websystem about medicinal plants with anti-venom properties. The system consists of a database of these plants, including scientific publications on this subject and amino acid sequences of active principles from venomous animals. The system relates these data allowing their integration through different search applications. For the development of the system, the first surveys were conducted in scientific literature, allowing the creation of a publication database in a library for reading and user interaction. Then, classes of categories were created, allowing the use of tags and the organization of content. This database on medicinal plants has information such as family, species, isolated compounds, activity, inhibited animal venoms, among others. Provision is made for submission of new information by registered users, by the use of wiki tools. Content submitted is released in accordance to permission rules defined by the system. The database on biological venom protein amino acid sequences was structured from the essential information from National Center for Biotechnology Information (NCBI). Plant-antivenom`s interface is simple, contributing to a fast and functional access to the system and the integration of different data registered on it. Plant-antivenom system is available on the Internet at http://gbi.fmrp.usp.br/plantantivenom.
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The present study aimed to determine whether Cryptosporidium oocysts were present in stools from captive snakes at Fundacao Parque Zoo logic (Zoological Park Foundation) in Sno Paulo, Brazil. Two collections were performed; the first in July 2008 and the second in February 2009. Fecal samples were collected from 74 enclosures that housed 101 individuals of 23 snake species. The stool specimens collected from 16 out of the 74 enclosures (21.6%) contained Cryptosporidium spp. oocysts; all of them were confirmed as Cryptosporidium serpent is, using molecular techniques. Only in three (18.7%) out of the 16 enclosures with positive samples were there animals with clinical signs compatible with infection by C. serpentis, such as regurgitation and significant progressive weight loss. From the results, it was concluded that diagnostic examinations need to be performed periodically, even on clinically healthy animals, as a preventive measure.
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The nerve terminals of intrinsic muscular fibers of the tongue of adult wistar rats was studied by using silver impregnation techniques, transmission electron microscopy (TEM), and high resolution scanning electron microscopy (HRSEM) to observe the nerve fibers and their terminals. Silver impregnation was done according to Winkelman and Schmit, 1957. For TEM, small blocks were fixed in modified Karnovsky solution, postfixed in 1% buffered osmium tetroxide solution, and embedded in Spurr resin. For HRSEM, the parts were fixed in 2% osmium tetroxide solution with 1/15 M sodium phosphate buffer (pH 7.4) at 4 degrees C for 2 h, according to the technique described by Tanaka, 1989. Thick myelinated nerve bundles were histologically observed among the muscular fibers. The intrafusal nerve fiber presented a tortuous pathway with punctiform terminal axons in clusters contacting the surface of sarcolemma. Several myelinated nerve fibers involved by collagen fibers of the endoneurium were observed in HRSEM in three-dimensional aspects. The concentric lamellae of the myelin sheath and the axoplasm containing neurofilaments interspersed among the mitochondria were also noted. In TEM, myofibrils, mitochondria, rough endoplasmic reticulum, Golgi`s apparatus, and glycogen granules were observed in sarcoplasm. It is also noted that the sarcomeres constituted by myofilaments with their A, I, and H bands and the electron dense Z lines. In areas adjacent to muscular fibers, there were myelinated and unmyelinated nerve fibers involved by endoneurium and perineurium. In the region of the neuromuscular junction, the contact with the sarcolemma of the muscular cell occurs forming several terminal buttons and showing numerous evaginations of the cell membrane. In the terminal button, mitochondria and numerous synaptic vesicles were observed. Microsc. Res. Tech. 72:464-470, 2009. (C) 2009 Wiley-Liss. Inc.
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A range of topical products are used in veterinary medicine. The efficacy of many of these products has been enhanced by the addition of penetration enhancers. Evolution has led to not only a highly specialized skin in animals and humans, but also one whose anatomical structure and skin permeability differ between the various species. The skin provides an excellent barrier against the ingress of environmental contaminants, toxins, and microorganisms while performing a homeostatic role to permit terrestrial life. Over the past few years, major advances have been made in the field of transdermal drug delivery. An increasing number of drugs are being added to the list of therapeutic agents that can be delivered via the skin to the systemic circulation where clinically effective concentrations are reached. The therapeutic benefits of topically applied veterinary products is achieved in spite of the inherent protective functions of the stratum corneum (SQ, one of which is to exclude foreign substances from entering the body. Much of the recent success in this field is attributable to the rapidly expanding knowledge of the SC barrier structure and function. The bilayer domains of the intercellular lipid matrices within the SC form an excellent penetration barrier, which must be breached if poorly penetrating drugs are to be administered at an appropriate rate. One generalized approach to overcoming the barrier properties of the skin for drugs and biomolecules is the incorporation of suitable vehicles or other chemical compounds into a transdermal delivery system. Indeed, the incorporation of such compounds has become more prevalent and is a growing trend in transdermal drug delivery. Substances that help promote drug diffusion through the SC and epidermis are referred to as penetration enhancers, accelerants, adjuvants, or sorption promoters. It is interesting to note that many pour-on and spot-on formulations used in veterinary medicine contain inert ingredients (e.g., alcohols, amides, ethers, glycols, and hydrocarbon oils) that will act as penetration enhancers. These substances have the potential to reduce the capacity for drug binding and interact with some components of the skin, thereby improving drug transport. However, their inclusion in veterinary products with a high-absorbed dose may result in adverse dermatological reactions (e.g., toxicological irritations) and concerns about tissue residues. These a-re important considerations when formulating a veterinary transdermal product when such compounds ate added, either intentionally or otherwise, for their penetration enhancement ability. (C) 2001 Elsevier Science B.V. All rights reserved.
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Trypanosome infections are often difficult to detect by conventional microscopy and their pleomorphy often confounds differential diagnosis. Molecular techniques are now being used to diagnose infections and to determine phylogenetic relationships between species. Complete small subunit rRNA gene sequences were determined for isolates of Trypanosoma chelodina from the Brisbane River tortoise (Emydura signata), the saw-shelled tortoise (Elseya latisternum), and the eastern snake-necked tortoise (Chelodina longicollis) from southeast Queensland, Australia. Partial sequence data were also obtained for T. binneyi from a platypus (Ornithorhynchus anatinus) from Tasmania. Phylogenetic relationships between T. chelodina, T. binneyi and other species were examined by maximum parsimony and likelihood methods. The Australian tortoise and platypus trypanosomes did not exhibit any close phylogenetic relationships with those of mammals, reptiles or amphibians, but were closely related to each other, and to fish trypanosomes. This contra-indicates their co-evolution with their vertebrate hosts but does not exclude co-evolution with different groups of invertebrate vectors, notably insects and leeches.
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Although viperlike in appearance and habit, death adders belong to the Elapidae family of snakes. Systemic envenomation represents a serious medical problem with antivenom, which is raised against Acanthophis antarcticus venom, representing the primary treatment. This study focused on the major Acanthophis variants from Australia and islands in the Indo-Pacific region. Venoms were profiled using liquid chromatography-mass spectrometry, and analyzed for in vitro neurotoxicity (0.3-10 mug/ml), as well as the effectiveness of antivenom. (1-5 units/ml; 10 min prior to the addition of 10 mug/ml venom). The following death adder venoms were examined: A. antarcticus (from separate populations in New South Wales, Queensland, South Australia, and Western Australia), A. hawkei, A. praelongus, A. pyrrhus, A. rugosus, A. wellsi, and venom from an unnamed species from the Indonesian island of Seram. All venoms abolished indirect twitches of the chick isolated biventer cervicis nerve-muscle preparation in a dose-dependent manner. In addition, all venoms blocked responses to exogenous acetylcholine (1 m-M) and carbachol (20 muM), but not KCl (40 mM), suggesting postsynaptic neurotoxicity. Death adder antivenom (1 unit/ml) prevented the neurotoxic effects of A. pyrrhus, A. praelongus, and A. hawkei venoms, although it was markedly less effective against venoms from A. antarcticus (NSW, SA, WA), A. rugosus, A. wellsi, and A. sp. Scram. However, at 5 units/ml, antivenom was effective against all venoms tested. Death adder venoms, including those from A. antarcticus geographic variants, differed not only in their venom composition but also in their neurotoxic activity and susceptibility to antivenom. For the first time toxicological aspects of A. hawkei, A. wellsi, A. rugosus, and A. sp. Seram venoms were studied. (C) 2001 Academic Press.