Cell migration inhibition activity of a non-RGD disintegrin from Crotalus durissus collilineatus venom

In recent decades, snake venom disintegrins have received special attention due to their potential use in anticancer therapy. Disintegrins are small and cysteine-rich proteins present in snake venoms and can interact with specific integrins to inhibit their activities in cell-cell and cell-ECM interactions. These molecules, known to inhibit platelet aggregation, are also capable of interacting with certain cancer-related integrins, and may interfere in important processes involved in carcinogenesis. Therefore, disintegrin from Crotalus durissus collilineatus venom was isolated, structurally characterized and evaluated for its toxicity and ability to interfere with cell proliferation and migration in MDA-MB-231, a human breast cancer cell line. Methods: Based on previous studies, disintegrin was isolated by FPLC, through two chromatographic steps, both on reversed phase C-18 columns. The isolated disintegrin was structurally characterized by Tris-TricineSDS-PAGE, mass spectrometry and N-terminal sequencing. For the functional assays, MTT and wound-healing assays were performed in order to investigate cytotoxicity and effect on cell migration in vitro, respectively. Results: Disintegrin presented a molecular mass of 7287.4 Da and its amino acid sequence shared similarity with the disintegrin domain of P-II metalloproteases. Using functional assays, the disintegrin showed low cytotoxicity (15% and 17%, at 3 and 6 µg/mL, respectively) after 24 h of incubation and in the wound-healing assay, the disintegrin (3 µg/mL) was able to significantly inhibit cell migration (24%, p < 0.05), compared to negative control. Conclusion: Thus, our results demonstrate that non-RGD disintegrin from C. d. collilineatus induces low cytotoxicity and inhibits migration of human breast cancer cells. Therefore, it may be a very useful molecular tool for understanding ECM-cell interaction cancer-related mechanisms involved in an important integrin family that highlights molecular aspects of tumorigenesis. Also, non-RGD disintegrin has potential to serve as an agent in anticancer therapy or adjuvant component combined with other anticancer drugs.(AU)

Cell migration inhibition activity of a non-RGD disintegrin from Crotalus durissus collilineatus venom

Background:In recent decades, snake venom disintegrins have received special attention due to their potential use in anticancer therapy. Disintegrins are small and cysteine-rich proteins present in snake venoms and can interact with specific integrins to inhibit their activities in cell-cell and cell-ECM interactions. These molecules, known to inhibit platelet aggregation, are also capable of interacting with certain cancer-related integrins, and may interfere in important processes involved in carcinogenesis. Therefore, disintegrin from Crotalus durissus collilineatus venom was isolated, structurally characterized and evaluated for its toxicity and ability to interfere with cell proliferation and migration in MDA-MB-231, a human breast cancer cell line.Methods:Based on previous studies, disintegrin was isolated by FPLC, through two chromatographic steps, both on reversed phase C-18 columns. The isolated disintegrin was structurally characterized by Tris-Tricine-SDS-PAGE, mass spectrometry and N-terminal sequencing. For the functional assays, MTT and wound-healing assays were performed in order to investigate cytotoxicity and effect on cell migration in vitro, respectively.Results:Disintegrin presented a molecular mass of 7287.4 Da and its amino acid sequence shared similarity with the disintegrin domain of P-II metalloproteases. Using functional assays, the disintegrin showed low cytotoxicity (15% and 17%, at 3 and 6 μg/mL, respectively) after 24 h of incubation and in the wound-healing assay, the disintegrin (3 μg/mL) was able to significantly inhibit cell migration (24%, p < 0.05), compared to negative control.Conclusion:Thus, our results demonstrate that non-RGD disintegrin from C. d. collilineatus induces low cytotoxicity and inhibits migration of human breast cancer cells. Therefore, it may be a very useful molecular tool for understanding ECM-cell interaction cancer-related mechanisms involved in...(AU)

Snake venom L-amino acid oxidases: an overview on their antitumor effects

The L-amino acid oxidases (LAAOs) constitute a major component of snake venoms and have been widely studied due to their widespread presence and various effects, such as apoptosis induction, cytotoxicity, induction and/or inhibition of platelet aggregation, hemorrhage, hemolysis, edema, as well as antimicrobial, antiparasitic and anti-HIV activities. The isolated and characterized snake venom LAAOs have become important research targets due to their potential biotechnological applications in pursuit for new drugs of interest in the scientific and medical fields. The current study discusses the antitumor effects of snake venom LAAOs described in the literature to date, highlighting the mechanisms of apoptosis induction proposed for this class of proteins.(AU)

Snake venom L-amino acid oxidases: an overview on their antitumor effects

The L-amino acid oxidases (LAAOs) constitute a major component of snake venoms and have been widely studied due to their widespread presence and various effects, such as apoptosis induction, cytotoxicity, induction and/or inhibition of platelet aggregation, hemorrhage, hemolysis, edema, as well as antimicrobial, antiparasitic and anti-HIV activities. The isolated and characterized snake venom LAAOs have become important research targets due to their potential biotechnological applications in pursuit for new drugs of interest in the scientific and medical fields. The current study discusses the antitumor effects of snake venom LAAOs described in the literature to date, highlighting the mechanisms of apoptosis induction proposed for this class of proteins.

Snake venom L-amino acid oxidases: an overview on their antitumor effects

The L-amino acid oxidases (LAAOs) constitute a major component of snake venoms and have been widely studied due to their widespread presence and various effects, such as apoptosis induction, cytotoxicity, induction and/or inhibition of platelet aggregation, hemorrhage, hemolysis, edema, as well as antimicrobial, antiparasitic and anti-HIV activities. The isolated and characterized snake venom LAAOs have become important research targets due to their potential biotechnological applications in pursuit for new drugs of interest in the scientific and medical fields. The current study discusses the antitumor effects of snake venom LAAOs described in the literature to date, highlighting the mechanisms of apoptosis induction proposed for this class of proteins.(AU)

Cholinesterase activity in serum, whole blood and lymphocytes of dogs experimentally infected with Rangelia vitalii

Background: The cholinergic system is involved in many biological functions in mammals and is associated with pathogenesis of infectious diseases, as has participation in transmission of nerve impulses in cholinergic synapses, haematopoiesis, regulation of inflammatory markers, production and coordination of movement, and memory. Rangelia vitalii is a parasite endemic to south of Brazil. This parasite multiplies in the blood and can be visualized in plasma in its free form and/or within leukocytes and erythrocytes, causing various pathologies. Therefore, the purpose of this study was to investigate the activity of cholinergic system enzymes in dogs experimentally infected with R. vitalii. Materials, Methods & Results: Twelve dogs were used, divided into two groups: control group (n = 5), consisting of healthy animals, and infected group with R. vitalii (n = 7). Fresh blood samples of these infected animals were inoculated in seven dogs (2 mL/dog through the jugular vein). Blood samples were collected on days 0, 10 and 20 post-infection (PI). Butyrylcholinesterase (BChE) activity was measured in serum and acetylcholinesterase (AChE) in lymphocytes and whole blood. Boold samples were diluted 1:50 (v/v) in lysis solution (0.1 mmol/L potassium/sodium phosphate buffer containing 0.03% Triton X-100) and frozen (-20 ºC by 7 days) to determine AChE activity in whole blood. Lymphocytes were also obtained from whole blood with EDTA by gradient separation using Ficoll-Histopaque™ plus to AChE activity this cell. After analysis of the samples, was observed that the dogs infected with R. vitalii presented a signifi cant (P < 0.01) increase in AChE activity in whole blood on days 10 and 20 PI. However, the infected group showed a reduced activity in AChE in lymphocytes (P < 0.01) and BChE in serum (P < 0.05) on day 20 PI. Discussion: According to the literature, infected dogs R. vitalii develop regenerative anemia evidenced by an increase in the erytroid precursors in bone marrow associated with alterations of leucogram as leukopenia, neutropenia, eosinopenia, lymphocytosis and monocytosis. Furthermore, it was observed severe thrombocytopenia, with alteration in platelet aggregation and activity of enzymes involved in the control of ATP, ADP and adenosine levels on platelets, thereby influencing hemostasis and contributing to the typical bleeding disease. AChE activity in whole blood was increased in dogs parasitized by R. vitalii observed in this study. This increase may be a compensatory effect to severe anemia caused by the parasite infection, because this enzyme is involved in the maturation of erythrocytes and in the regulation of hematopoiesis. In the present study, we found that the reduction in AChE activity in lymphocytes is associated to lymphocytosis; and it is known that ACh is produced within lymphocytes and has the ability to negatively modulate the immune response, acting directly on the inhibition of inflammatory mediators. Therefore, the decrease of AChE activity may have an anti-inflammatory action in order to have more free ACh to bind lymphocytes and inhibit inflammation. The enzyme BChE can also act as an inflammatory marker in various diseases, similar to AChE, because the enzyme can hydrolyze acetylcholine when AChE is inhibited. In conclusion, our results indicate that canine rangeliosis alters the activity of cholinesterase's, which may be involved in the pathogenesis of the disease, as well as various pathological conditions.

Correlação entre uso de anti-inflamatório não esteroidais e efeitos adversos em equinos: revisão de literatura / Correlation between the use of nonsteroidal antiinflammatory use causing side effects in equine: review article / Correlacion entre el uso de anti-inflamatorios no esteroideos y los efectos adversos en equinos: revision bibliográfica

O controle da dor nos animais vem sendo foco de vários estudos em virtude de significativasalterações no bem-estar animal e pela influência da mesma em diversos parâmetros fisiológicos. Uma das causas prováveis de efeitos adversos promovidos pelos agentes anti-inflamatórios não esteroidais (AINES) é a inibição da cicloxigenase 1, enzima responsável pela produção não só de mediadores inflamatórios, mas também da camada protetora estomacal, agregação plaquetária e irrigação renal. Os AINES são amplamente utilizados em equinos, sendo os agentes mais empregados para o tratamento da dor nesta espécie. Porém, devido particularidades da espécie, os efeitos adversos em trato gastrointestinal (TGI) são os mais recorrentes em equinos, principalmente nos animais já hospitalizados sendo que vários fármacos utilizados para o controle da dor podem piorar este quadro. Para redução do risco de lesão em TGI com o emprego de AINES, deve-se considerar o uso concomitante de protetores gástricos, principalmente os bloqueadores da bomba de prótons. Outros efeitos adversos também podem aparecer, como lesão renal, hipoproteinemia e alterações na agregação plaquetária. Sendo assim, esta revisão tem o objetivo de explicitar os efeitos adversos mais recorrentes ao uso de AINES em equinos, assim como suas consequências e possíveis tratamentos.

Pain control has been the focus of several studies in animais because of significant changes inanimal welfare and the influence of various physiological parameters. One of the probable causes of the side effetcs regarding the use of nonsteroidal antiinflammatory agents (NSAIDS) is the inhibition of cyclooxygenase 1, enzyme responsible for the production not only of inflammatory mediators, but also the stomach protective layer, platelet agregation and renal irrigation. NSAIDS are widely used in horses, being the most used agent for the treatment of pain in this species. However, due to species peculiarities, the gastrointestinal tract (GIT) side effects are the most frequent in horses, especially in animais already hospitalized, and several drugs used to control pain may worsen this condition. To reduce the risk of injury to GITwith the use of NSAIDs, the concomitant use of gastric protectors, especially proton pump blockers, should be considered. Other side effects may also appear, such as renal damage, hypoproteinemia and changes in platelet aggregation. Therefore, this review aims to explain the most frequent side effects ofthe use of NSAIDs in horses, as well as their consequences and possible treatments.

El control del dolor en los animales viene siendo un foco de varios estudios en virtud de significativas alteración es en el bienestar animal y por la influencia de la misma en diversos parámetros fisiológicos. Una de las causas más probables de los efectos adversos promovida por los agentes anti-inflamatorios no esteroideos (AINES) es la inhibición de la cicloxigenasa 1, enzima responsable por la producción no solo de mediadores inflamatorios , sino también de uma camada protectora estomacal, agregación plaquetaria y irrigación renal. Los AINES son ampliamente utilizados en los Equinos, siendo los agentes más utilizados para el tratamiento del dolor en esta especie. Entonces, debido a la particularidad de esta especie, los efectos adversos a nivel del tracto gastrointestinal (TGI) son los más frecuentes en los equinos, principalmente en los animales que ya están hospitalizados siendo que varios fármacos utilizados para el control del dolor pueden empeorar este cuadro. Para la reducción dei riego de lesión a nivel gastrointestinal con el uso de los AINES, debemos considerar el uso concomitante de protectores gástricos, principalmente el empleo de los bloqueadores de la bomba de protones. Otros efectos también pueden aparecer, como lesión renal, hipoproteinemia e alteraciones en la agregación plaquetario. Siendo así, esta revisión tiene un objetivo de ser explícito en los efectos adversos más frecuentes con el uso de AINES en equinos, así como sus consecuencias y posibles tratamientos.

Correlação entre uso de anti-inflamatório não esteroidais e efeitos adversos em equinos: revisão de literatura / Correlation between the use of nonsteroidal antiinflammatory use causing side effects in equine: review article / Correlacion entre el uso de anti-inflamatorios no esteroideos y los efectos adversos en equinos: revision bibliográfica

O controle da dor nos animais vem sendo foco de vários estudos em virtude de significativasalterações no bem-estar animal e pela influência da mesma em diversos parâmetros fisiológicos. Uma das causas prováveis de efeitos adversos promovidos pelos agentes anti-inflamatórios não esteroidais (AINES) é a inibição da cicloxigenase 1, enzima responsável pela produção não só de mediadores inflamatórios, mas também da camada protetora estomacal, agregação plaquetária e irrigação renal. Os AINES são amplamente utilizados em equinos, sendo os agentes mais empregados para o tratamento da dor nesta espécie. Porém, devido particularidades da espécie, os efeitos adversos em trato gastrointestinal (TGI) são os mais recorrentes em equinos, principalmente nos animais já hospitalizados sendo que vários fármacos utilizados para o controle da dor podem piorar este quadro. Para redução do risco de lesão em TGI com o emprego de AINES, deve-se considerar o uso concomitante de protetores gástricos, principalmente os bloqueadores da bomba de prótons. Outros efeitos adversos também podem aparecer, como lesão renal, hipoproteinemia e alterações na agregação plaquetária. Sendo assim, esta revisão tem o objetivo de explicitar os efeitos adversos mais recorrentes ao uso de AINES em equinos, assim como suas consequências e possíveis tratamentos.

Pain control has been the focus of several studies in animais because of significant changes inanimal welfare and the influence of various physiological parameters. One of the probable causes of the side effetcs regarding the use of nonsteroidal antiinflammatory agents (NSAIDS) is the inhibition of cyclooxygenase 1, enzyme responsible for the production not only of inflammatory mediators, but also the stomach protective layer, platelet agregation and renal irrigation. NSAIDS are widely used in horses, being the most used agent for the treatment of pain in this species. However, due to species peculiarities, the gastrointestinal tract (GIT) side effects are the most frequent in horses, especially in animais already hospitalized, and several drugs used to control pain may worsen this condition. To reduce the risk of injury to GITwith the use of NSAIDs, the concomitant use of gastric protectors, especially proton pump blockers, should be considered. Other side effects may also appear, such as renal damage, hypoproteinemia and changes in platelet aggregation. Therefore, this review aims to explain the most frequent side effects ofthe use of NSAIDs in horses, as well as their consequences and possible treatments.(AU)

El control del dolor en los animales viene siendo un foco de varios estudios en virtud de significativas alteración es en el bienestar animal y por la influencia de la misma en diversos parámetros fisiológicos. Una de las causas más probables de los efectos adversos promovida por los agentes anti-inflamatorios no esteroideos (AINES) es la inhibición de la cicloxigenasa 1, enzima responsable por la producción no solo de mediadores inflamatorios , sino también de uma camada protectora estomacal, agregación plaquetaria y irrigación renal. Los AINES son ampliamente utilizados en los Equinos, siendo los agentes más utilizados para el tratamiento del dolor en esta especie. Entonces, debido a la particularidad de esta especie, los efectos adversos a nivel del tracto gastrointestinal (TGI) son los más frecuentes en los equinos, principalmente en los animales que ya están hospitalizados siendo que varios fármacos utilizados para el control del dolor pueden empeorar este cuadro. Para la reducción dei riego de lesión a nivel gastrointestinal con el uso de los AINES, debemos considerar el uso concomitante de protectores gástricos, principalmente el empleo de los bloqueadores de la bomba de protones. Otros efectos también pueden aparecer, como lesión renal, hipoproteinemia e alteraciones en la agregación plaquetario. Siendo así, esta revisión tiene un objetivo de ser explícito en los efectos adversos más frecuentes con el uso de AINES en equinos, así como sus consecuencias y posibles tratamientos.(AU)

Functional and structural characterization of phospholipases A2 isolated from Bothrops asper snake venom in Panamá

Envenoming by Bothrops snakes is the most serious type of envenoming from the medical and economic point of view in Central America. Bothrops asper is responsible for 90% of the snakebites registered in Panamá every year. Despite its medical and economic relevance, only the venom of Costa Rican and Guatemalan populations of this species has been studied to some detail, and there is very little information on intraspecies variability in venom composition and toxicity. In this study the crude venom of B. asper from Panamá was characterized and its pharmacological and biochemistry activities were investigated with standard laboratory assays. Furthermore, we described the isolation, functional and structural characterization of four basic phospholipases A2, namely MTX-I, MTX-II, MTX-III, MTX-IV, and a new acid phospholipase A2 called Basp-I-PLA2. The proteins were isolated from the crude venom by a combination of two chromatographic steps, using ion-exchange chromatography on CM-Sepharose (0.05 M NH4HCO3 pH 8.1 buffer), and hydrophobic chromatography on Phenyl-Sepharose (0.05 M Tris-HCl pH 7.4), followed by concentration gradient from 4 to 0 M NaCl at 25°C in the same buffer. Analyses of phospholipids hydrolyzed by these enzymes have shown that all phospholipases belong to type A2. The acidic isoform demonstrated more catalytic activity than basic PLA2s. This enzyme was more active on substrates such as phosphotidylcholine and phosphatidylglycerol. The isoelectric focusing evidenced pIs between 8.1 to 8.3 for MTXs and 4.6 for the isoform Basp-I-PLA2. The molecular weight was estimated by mass spectrometry to be: MTX-1 = 14,156.5; MTX-2 = 14,249.5 and MTX-3 = 14,253.0 and Basp-I-PLA2 = 14,246.0.8 Da.(AU)

Functional and structural characterization of phospholipases A² isolated from Bothrops asper snake venom in Panamá

Envenoming by Bothrops snakes is the most serious type of envenoming from the medical and economic point of view in Central America. Bothrops asper is responsible for 90% of the snakebites registered in Panamá every year. Despite its medical and economic relevance, only the venom of Costa Rican and Guatemalan populations of this species has been studied to some detail, and there is very little information on intraspecies variability in venom composition and toxicity. In this study the crude venom of B. asper from Panamá was characterized and its pharmacological and biochemistry activities were investigated with standard laboratory assays. Furthermore, we described the isolation, functional and structural characterization of four basic phospholipases A2, namely MTX-I, MTX-II, MTX-III, MTX-IV, and a new acid phospholipase A2 called Basp-I-PLA2. The proteins were isolated from the crude venom by a combination of two chromatographic steps, using ion-exchange chromatography on CM-Sepharose (0.05 M NH4HCO3 pH 8.1 buffer), and hydrophobic chromatography on Phenyl-Sepharose (0.05 M Tris-HCl pH 7.4), followed by concentration gradient from 4 to 0 M NaCl at 25°C in the same buffer. Analyses of phospholipids hydrolyzed by these enzymes have shown that all phospholipases belong to type A2. The acidic isoform demonstrated more catalytic activity than basic PLA2s. This enzyme was more active on substrates such as phosphotidylcholine and phosphatidylglycerol.(AU)

In vitro screening of Amazonian plants for hemolytic activity and inhibition of platelet aggregation in human blood

In the present study, different aerial parts from twelve Amazonian plant species found in the National Institute for Amazon Research's (INPA's) Adolpho Ducke Forest Reserve (in Manaus, Amazonas, Brazil) were collected. Separate portions of dried, ground plant materials were extracted with water (by infusion), methanol and chloroform (by continuous liquid-solid extraction) and solvents were removed first by rotary evaporation, and finally by freeze-drying which yielded a total of seventy-one freeze-dried extracts for evaluation. These extracts were evaluated initially at concentrations of 500 and 100 µg/mL for in vitro hemolytic activity and in vitro inhibition of platelet aggregation in human blood, respectively. Sixteen extracts (23 % of all extracts tested, 42 % of all plant species), representing the following plants: Chaunochiton kappleri (Olacaceae), Diclinanona calycina (Annonaceae), Paypayrola grandiflora (Violaceae), Pleurisanthes parviflora (Icacinaceae), Sarcaulus brasiliensis (Sapotaceae), exhibited significant inhibitory activity towards human platelet aggregation. A group of extracts with antiplatelet aggregation activity having no in vitro hemolytic activity has therefore been identified. Three extracts (4 %), all derived from Elaeoluma nuda (Sapotaceae), exhibited hemolytic activity. None of the plant species in this study has known use in traditional medicine. So, these data serve as a baseline or minimum of antiplatelet and hemolytic activities (and potential usefulness) of non-medicinal plants from the Amazon forest. Finally, in general, these are the first data on hemolytic and inhibitory activity on platelet aggregation for the genera which these plant species represent.

No presente estudo, partes aéreas obtidas de doze (12) espécies vegetais da Amazônia encontradas na Reserva Florestal Adolpho Ducke (localizada na cidade de Manaus, Estado do Amazonas, Brasil) do Instituto Nacional de Pesquisas da Amazônia foram coletadas, secadas e moídas. Porções dos materiais vegetais em pó foram extraídas com água (por infusão), metanol e clorofórmio (por extração líquido-sólido contínua) e os solventes foram removidos por evaporação rotatória e finalmente liofilização, forneceram um total de setenta e one (71) extratos liofilizados. Esses extratos foram avaliados inicialmente para atividade hemolítica in vitro e atividade inibitória da agregação plaquetária em sangue humano in vitro em concentrações de 500 e 100 µg/mL, respectivamente. Dezesseis (16) extratos (23 % dos extratos testados, 42 % das espécies vegetais) representando as seguintes plantas, apresentaram inibição significativa frente a agregação de plaquetas humanas in vitro: Chaunochiton kappleri (Olacaceae), Diclinanona calycina (Annonaceae), Paypayrola grandiflora (Violaceae), Pleurisanthes parviflora (Icacinaceae), Sarcaulus brasiliensis (Sapotaceae). Como principal resultado, um grupo de extratos apresentando atividade inibitória da agregação plaquetária e em que não há atividade hemolítica in vitro foi identificado. Três (3) extratos (4 % do total de extratos testados), todos obtidos a partir de Elaeoluma nuda (Sapotaceae), apresentaram atividade hemolítica. Nenhuma das espécies vegetais nesse estudo tem uso medicinal conhecido. Assim, esses dados servem de linha base ou mínimas das atividades antiplaquetária e hemolítica (e utilidade potencial) de plantas da floresta Amazônica. Finalmente, em geral, esses dados são os primeiros disponíveis sobre ação hemolítica e inibição da agregação plaquetária dos gêneros representados por essas espécies de plantas.

In vitro screening of Amazonian plants for hemolytic activity and inhibition of platelet aggregation in human blood

In the present study, different aerial parts from twelve Amazonian plant species found in the National Institute for Amazon Research's (INPA's) Adolpho Ducke Forest Reserve (in Manaus, Amazonas, Brazil) were collected. Separate portions of dried, ground plant materials were extracted with water (by infusion), methanol and chloroform (by continuous liquid-solid extraction) and solvents were removed first by rotary evaporation, and finally by freeze-drying which yielded a total of seventy-one freeze-dried extracts for evaluation. These extracts were evaluated initially at concentrations of 500 and 100 µg/mL for in vitro hemolytic activity and in vitro inhibition of platelet aggregation in human blood, respectively. Sixteen extracts (23 % of all extracts tested, 42 % of all plant species), representing the following plants: Chaunochiton kappleri (Olacaceae), Diclinanona calycina (Annonaceae), Paypayrola grandiflora (Violaceae), Pleurisanthes parviflora (Icacinaceae), Sarcaulus brasiliensis (Sapotaceae), exhibited significant inhibitory activity towards human platelet aggregation. A group of extracts with antiplatelet aggregation activity having no in vitro hemolytic activity has therefore been identified. Three extracts (4 %), all derived from Elaeoluma nuda (Sapotaceae), exhibited hemolytic activity. None of the plant species in this study has known use in traditional medicine. So, these data serve as a baseline or minimum of antiplatelet and hemolytic activities (and potential usefulness) of non-medicinal plants from the Amazon forest. Finally, in general, these are the first data on hemolytic and inhibitory activity on platelet aggregation for the genera which these plant species represent.

No presente estudo, partes aéreas obtidas de doze (12) espécies vegetais da Amazônia encontradas na Reserva Florestal Adolpho Ducke (localizada na cidade de Manaus, Estado do Amazonas, Brasil) do Instituto Nacional de Pesquisas da Amazônia foram coletadas, secadas e moídas. Porções dos materiais vegetais em pó foram extraídas com água (por infusão), metanol e clorofórmio (por extração líquido-sólido contínua) e os solventes foram removidos por evaporação rotatória e finalmente liofilização, forneceram um total de setenta e one (71) extratos liofilizados. Esses extratos foram avaliados inicialmente para atividade hemolítica in vitro e atividade inibitória da agregação plaquetária em sangue humano in vitro em concentrações de 500 e 100 µg/mL, respectivamente. Dezesseis (16) extratos (23 % dos extratos testados, 42 % das espécies vegetais) representando as seguintes plantas, apresentaram inibição significativa frente a agregação de plaquetas humanas in vitro: Chaunochiton kappleri (Olacaceae), Diclinanona calycina (Annonaceae), Paypayrola grandiflora (Violaceae), Pleurisanthes parviflora (Icacinaceae), Sarcaulus brasiliensis (Sapotaceae). Como principal resultado, um grupo de extratos apresentando atividade inibitória da agregação plaquetária e em que não há atividade hemolítica in vitro foi identificado. Três (3) extratos (4 % do total de extratos testados), todos obtidos a partir de Elaeoluma nuda (Sapotaceae), apresentaram atividade hemolítica. Nenhuma das espécies vegetais nesse estudo tem uso medicinal conhecido. Assim, esses dados servem de linha base ou mínimas das atividades antiplaquetária e hemolítica (e utilidade potencial) de plantas da floresta Amazônica. Finalmente, em geral, esses dados são os primeiros disponíveis sobre ação hemolítica e inibição da agregação plaquetária dos gêneros representados por essas espécies de plantas.

Novel role of antiplatelet agents (aspirin plus clopidogrel) in an incoagulable blood of a victim of russell's viper snakebite

Snake antivenom is a specific antidote to the venom action, neutralizing the circulating venom. However, it fails to neutralize the venom fixed to target organs such as platelets, renal tubules, etc. Russell's viper venom initiates rapid coagulation in a victim by activating blood platelets, factors V, X, and anticoagulant cofactors. Activation of thrombin, resulting in formation of micro-thrombi, fibrinolysis, and a vicious cascade, sets in. Inhibition of activated platelets by aspirin (cyclooxygenase inhibitor) and clopidogrel (ADP receptor inhibitor) helps to break this vicious circle induced by Russell's venom and may initiate the natural physiological clotting mechanism. They can be utilized as an adjuvant treatment.(AU)

Alterações fetais induzidas pelo uso de antiinflamatórios durante a gestação

In general, all effects of the antiinflammatory drugs are related to the inhibition of the arachidonic acid and inhibition of prostaglandins and tromboxans production. Two types of ciclo-oxygenasis (COX) exist, which are COX-1 and COX-2. COX-1 is a constitutional enzyme expressed in many sites, including platelets, and is involved in tecidual homeostasis. On the other hand, COX-2 is induced in inflammatory cells when they are activated, and it is considered as being the enzyme that produces the mediators of the inflammation. The action of antiinflammatory drugs is related to the inhibition of COX-2 and is probable that their undesirable effects are due mainly to the inhibition of COX-1. Maternal treatments with NSAIDs have been frequently associated, with the vasoconstriction of the fetal ductus arteriosus, lung arterial hypertension and inhibition of platelet aggregation. Alterations in hemostasis are some of the collateral effects produced by the indiscriminate use of NSAIDs, which induce to an unbalance in the prostaglandins and tromboxans liberation, that are reflected in the adhesiveness and platelet aggregation. The haemostatic alterations observed in neonates, caused by salicilatess ingestion by the mother, are due to inhibition of the platelet aggregation and the decrease of the activity of the factor XII related to the clotting. Studies in mice revealed that corticoidss use during the gestation can lead to abnormalities in fetal development, because of the alterations in the cellular differentiation.

Em geral, todos os efeitos dos antiinflamatórios estão relacionados com a inibição da ciclo-oxigenase (COX) do ácido araquidônico e, portanto, inibição da produção de prostaglandinas e tromboxanos. Existem dois tipos de COX, quais sejam COX-1 e COX-2. A COX-1 é uma enzima constitucional expressa em muitos tecidos, incluindo plaquetas sangüíneas, e está envolvida na homeostase tecidual. Por outro lado, a COX-2 é induzida em células inflamatórias quando elas são ativadas, sendo considerada a enzima que produz os mediadores da inflamação da classe dos prostanóides. A ação dos antiinflamatórios está relacionada à inibição da COX-2 e é provável que seus efeitos indesejados se devam principalmente à inibição da COX-1. Tratamentos maternos com antiinflamatórios não esteroidais (AINEs) têm sido associados, com freqüência, à vasoconstrição do ducto arterioso fetal, hipertensão arterial pulmonar e inibição da agregação plaquetária. Alterações na hemostasia são alguns dos efeitos colaterais produzidos pelo uso incontrolado dos AINEs, os quais induzem a um desequilíbrio na liberação de prostaglandinas e tromboxanos, que se reflete na adesividade e agregação plaquetária. As alterações hemostáticas observadas em neonatos, decorrentes do uso de salicilatos pela mãe, ocorrem devido à inibição da agregação plaquetária e à diminuição da atividade do fator XII relacionado à coagulação sangüínea. Estudos em camundongos revelaram que o uso de corticóides durante a gestação pode levar a anormalidades no desenvolvimento fetal, por alterações na diferenciação celular.

Alterações fetais induzidas pelo uso de antiinflamatórios durante a gestação

In general, all effects of the antiinflammatory drugs are related to the inhibition of the arachidonic acid and inhibition of prostaglandins and tromboxans production. Two types of ciclo-oxygenasis (COX) exist, which are COX-1 and COX-2. COX-1 is a constitutional enzyme expressed in many sites, including platelets, and is involved in tecidual homeostasis. On the other hand, COX-2 is induced in inflammatory cells when they are activated, and it is considered as being the enzyme that produces the mediators of the inflammation. The action of antiinflammatory drugs is related to the inhibition of COX-2 and is probable that their undesirable effects are due mainly to the inhibition of COX-1. Maternal treatments with NSAIDs have been frequently associated, with the vasoconstriction of the fetal ductus arteriosus, lung arterial hypertension and inhibition of platelet aggregation. Alterations in hemostasis are some of the collateral effects produced by the indiscriminate use of NSAIDs, which induce to an unbalance in the prostaglandins and tromboxans liberation, that are reflected in the adhesiveness and platelet aggregation. The haemostatic alterations observed in neonates, caused by salicilates’s ingestion by the mother, are due to inhibition of the platelet aggregation and the decrease of the activity of the factor XII related to the clotting. Studies in mice revealed that corticoids’s use during the gestation can lead to abnormalities in fetal development, because of the alterations in the cellular differentiation.

Em geral, todos os efeitos dos antiinflamatórios estão relacionados com a inibição da ciclo-oxigenase (COX) do ácido araquidônico e, portanto, inibição da produção de prostaglandinas e tromboxanos. Existem dois tipos de COX, quais sejam COX-1 e COX-2. A COX-1 é uma enzima constitucional expressa em muitos tecidos, incluindo plaquetas sangüíneas, e está envolvida na homeostase tecidual. Por outro lado, a COX-2 é induzida em células inflamatórias quando elas são ativadas, sendo considerada a enzima que produz os mediadores da inflamação da classe dos prostanóides. A ação dos antiinflamatórios está relacionada à inibição da COX-2 e é provável que seus efeitos indesejados se devam principalmente à inibição da COX-1. Tratamentos maternos com antiinflamatórios não esteroidais (AINEs) têm sido associados, com freqüência, à vasoconstrição do ducto arterioso fetal, hipertensão arterial pulmonar e inibição da agregação plaquetária. Alterações na hemostasia são alguns dos efeitos colaterais produzidos pelo uso incontrolado dos AINEs, os quais induzem a um desequilíbrio na liberação de prostaglandinas e tromboxanos, que se reflete na adesividade e agregação plaquetária. As alterações hemostáticas observadas em neonatos, decorrentes do uso de salicilatos pela mãe, ocorrem devido à inibição da agregação plaquetária e à diminuição da atividade do fator XII relacionado à coagulação sangüínea. Estudos em camundongos revelaram que o uso de corticóides durante a gestação pode levar a anormalidades no desenvolvimento fetal, por alterações na diferenciação celular.