Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 11 de 11
Filter
Add filters








Year range
1.
Rev. cuba. med. trop ; 68(3): 217-232, sep.-dic. 2016. ilus, tab
Article in Spanish | LILACS, CUMED | ID: biblio-844993

ABSTRACT

Introducción: la infección por Trypanosoma cruzi, conocida como enfermedad de Chagas, es un problema importante de salud pública en países de América Central y Sudamérica.Objetivo: evaluar la actividad de extractos crudos de acetato de etilo de plantas in vitro de 6-8 meses y 10-12 meses de edad, de tallos leñosos y hojas de plantas silvestres maduras y el lignano tetrahidrofurano grandisina, aislados de Piper solmsianum, sobre las formas epimastigota y tripomastigota de T. cruzi in vitro.Métodos: en la evaluación del efecto de diversos extractos crudos de acetato de etilo y grandisina de P. solmsianum, sobre la viabilidad de las formas epimastigota y tripomastigota de T. cruzi, se utilizó el método MTT (3-(4,5-dimetiltiazol-2-il)-2,5-difeniltetrazolium bromuro).Resultados: en la forma epimastigota, el mejor resultado en la inhibición del crecimiento fue obtenido con 50 µg/mL de extracto de tallo y en la forma tripomastigota con 25 y 50 µg/mL de grandisina y plantas in vitro de 6-8 meses de edad, respectivamente. En todos los casos los valores de inhibición oscilaron entre 86 a 96 por ciento. Plantas in vitro de 6-8 meses de edad y grandisina fueron más activas sobre las formas epimastigota y tripomastigota de T. cruzi con valores de CI50 de 0,018 y 0,360 µg/mL, respectivamente.Conclusiones: se demuestra la actividad tripanocida de extractos de plantas silvestres y plantas in vitro de P. solmsianum(AU)


Introduction: the infection by Trypanosoma cruzi, known as Chagas' disease, poses a major public health problem in Central and South America countries.Objective: to evaluate the activity of crude ethyl acetate extracts from in vitro plants of 6-8 and 10-12 months of age, stem barks and mature wild plant leaves and tetrahydrofuran lignin grandisin isolated from Piper solmsianum against the epimastigote and trypomastigote forms of T. cruzi in vitro.Methods: in the evaluation of the effect of various crude ethyl acetate extracts and grandisin from P. solmsianum on the viability of epimastigote and trypomastigote forms of T. cruzi, the MTT method (3-(4,5-dimethylthiazol-2-il)-2,5-diphenyltetrazolium bromide) was used.Results: in the epimastigote form, the best results in growth inhibition was obtained with 50 µg/mL of stem extract, and in the trypomastigote form, with 25 and 50 µg/mL of grandisin and 6-8 months-old in vitro plants, respectively. The inhibition values in all cases ranged from 86 to 96 percent. 6-8 months old in vitro plants and grandisin were found to be active against the epimastigote and trypomastigote forms of T. cruzi with IC50 of 0.018 µg/mL and 0.360 µg/mL, respectively.Conclusions: the trypanocidal activity of extracts from wild plants and in vitro plants of P. solmsianum was proved(AU)


Subject(s)
Humans , Trypanocidal Agents/therapeutic use , Trypanosoma cruzi/pathogenicity , Chagas Disease/pathology , South America , Central America
2.
J. venom. anim. toxins incl. trop. dis ; 22: [1-14], 2016. tab, graf, ilus
Article in English | LILACS, VETINDEX | ID: biblio-1484659

ABSTRACT

Scleractinian corals (stony corals) are the most abundant reef-forming cnidarians found in coral reefs throughout the world. Despite their abundance and ecological importance, information about the diversity of their toxins and their biological activities is very scarce. In this study, the chemical composition and the biological activities of the aqueous extracts of Pseudodiploria strigosa, Porites astreoides and Siderastrea siderea, three scleractinian corals from the Mexican Caribbean, have been assessed for the first time. Methods: Toxicity of the extracts was assessed in crickets; the presence of cytolysins was detected by the hemolysis assay; the vasoconstrictor activity was determined by the isolated rat aortic ring assay; the nociceptive activity was evaluated by the formalin test. The presence of phospholipases A2 (PLA2), serine proteases, and hyaluronidases was determined by enzymatic methods. Low-molecular-weight fractions were obtained by gel filtration chromatography and ultrafiltration. Results: Extracts from the three species were toxic to crickets, induced hemolysis in human and rat erythrocytes, produced vasoconstriction on isolated rat aortic rings, and presented phospholipase A2 and serine-protease activity. Despite the fact that these corals are not considered to be harmless to humans, the extracts generated significant nociceptive responses. The matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry analysis of the low-molecular-weight fractions revealed the presence of peptides within a mass range of 3000 to 6000 Da. These fractions were toxic to crickets and two of them induced a transitory vasoconstrictor effect on isolated rat aortic rings. Conclusion: This study suggests that scleractinian corals produce low-molecular-weight peptides that are lethal to crickets and induce vasoconstriction.


Subject(s)
Anthozoa/classification , Anthozoa/microbiology , Anthozoa/chemistry , Biota
3.
J. venom. anim. toxins incl. trop. dis ; 22: 32, 2016. tab, graf, ilus
Article in English | LILACS, VETINDEX | ID: biblio-954792

ABSTRACT

Background: Scleractinian corals (stony corals) are the most abundant reef-forming cnidarians found in coral reefs throughout the world. Despite their abundance and ecological importance, information about the diversity of their toxins and their biological activities is very scarce. In this study, the chemical composition and the biological activities of the aqueous extracts of Pseudodiploria strigosa, Porites astreoides and Siderastrea siderea, three scleractinian corals from the Mexican Caribbean, have been assessed for the first time. Methods: Toxicity of the extracts was assessed in crickets; the presence of cytolysins was detected by the hemolysis assay; the vasoconstrictor activity was determined by the isolated rat aortic ring assay; the nociceptive activity was evaluated by the formalin test. The presence of phospholipases A2 (PLA2), serine proteases, and hyaluronidases was determined by enzymatic methods. Low-molecular-weight fractions were obtained by gel filtration chromatography and ultrafiltration. Results: Extracts from the three species were toxic to crickets, induced hemolysis in human and rat erythrocytes, produced vasoconstriction on isolated rat aortic rings, and presented phospholipase A2 and serine-protease activity. Despite the fact that these corals are not considered to be harmless to humans, the extracts generated significant nociceptive responses. The matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry analysis of the low-molecular-weight fractions revealed the presence of peptides within a mass range of 3000 to 6000 Da. These fractions were toxic to crickets and two of them induced a transitory vasoconstrictor effect on isolated rat aortic rings. Conclusion: This study suggests that scleractinian corals produce low-molecular-weight peptides that are lethal to crickets and induce vasoconstriction.(AU)


Subject(s)
Animals , Vasoconstriction , Cnidaria/growth & development , Biological Specimen Banks , Nociceptive Pain , Hemolysis , Ecological Equilibrium
4.
J. venom. anim. toxins incl. trop. dis ; 20: 1-9, 04/02/2014. ilus, tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1484600

ABSTRACT

Background Millepora complanata is a plate-like fire coral common throughout the Caribbean. Contact with this species usually provokes burning pain, erythema and urticariform lesions. Our previous study suggested that the aqueous extract of M. complanata contains non-protein hemolysins that are soluble in water and ethanol. In general, the local damage induced by cnidarian venoms has been associated with hemolysins. The characterization of the effects of these components is important for the understanding of the defense mechanisms of fire corals. In addition, this information could lead to better care for victims of envenomation accidents.Methods An ethanolic extract from the lyophilized aqueous extract was prepared and its hemolytic activity was compared with the hemolysis induced by the denatured aqueous extract. Based on the finding that ethanol failed to induce nematocyst discharge, ethanolic extracts were prepared from artificially bleached and normal M. complanata fragments and their hemolytic activity was tested in order to obtain information about the source of the heat-stable hemolysins.Results Rodent erythrocytes were more susceptible to the aqueous extract than chicken and human erythrocytes. Hemolytic activity started at ten minutes of incubation and was relatively stable within the range of 28-50°C. When the aqueous extract was preincubated at temperatures over 60°C, hemolytic activity was significantly reduced. The denatured extract induced a slow hemolytic activity (HU50= 1,050.00 ± 45.85 g/mL), detectable four hours after incubation, which was similar to that induced by the ethanolic extract prepared from the aqueous extract (HU50= 1,167.00 ± 54.95 g/mL). No significant differences were observed between hemolysis induced by ethanolic extracts from bleached and normal fragments, although both activities were more potent than hemolysis induced by the denatured extract...


Subject(s)
Animals , Cytotoxins/analysis , Hydrozoa , Hemolysin Proteins , Cnidarian Venoms
5.
J. venom. anim. toxins incl. trop. dis ; 20: 49, 04/02/2014. tab, ilus, graf
Article in English | LILACS, VETINDEX | ID: biblio-954713

ABSTRACT

Background Millepora complanata is a plate-like fire coral common throughout the Caribbean. Contact with this species usually provokes burning pain, erythema and urticariform lesions. Our previous study suggested that the aqueous extract of M. complanata contains non-protein hemolysins that are soluble in water and ethanol. In general, the local damage induced by cnidarian venoms has been associated with hemolysins. The characterization of the effects of these components is important for the understanding of the defense mechanisms of fire corals. In addition, this information could lead to better care for victims of envenomation accidents.Methods An ethanolic extract from the lyophilized aqueous extract was prepared and its hemolytic activity was compared with the hemolysis induced by the denatured aqueous extract. Based on the finding that ethanol failed to induce nematocyst discharge, ethanolic extracts were prepared from artificially bleached and normal M. complanata fragments and their hemolytic activity was tested in order to obtain information about the source of the heat-stable hemolysins.Results Rodent erythrocytes were more susceptible to the aqueous extract than chicken and human erythrocytes. Hemolytic activity started at ten minutes of incubation and was relatively stable within the range of 28-50°C. When the aqueous extract was preincubated at temperatures over 60°C, hemolytic activity was significantly reduced. The denatured extract induced a slow hemolytic activity (HU50= 1,050.00 ± 45.85 μg/mL), detectable four hours after incubation, which was similar to that induced by the ethanolic extract prepared from the aqueous extract (HU50= 1,167.00 ± 54.95 μg/mL). No significant differences were observed between hemolysis induced by ethanolic extracts from bleached and normal fragments, although both activities were more potent than hemolysis induced by the denatured extract.Conclusions The results showed that the aqueous extract of M. complanata possesses one or more powerful heat-labile hemolytic proteins that are slightly more resistant to temperature than jellyfish venoms. This extract also contains slow thermostable hemolysins highly soluble in ethanol that are probably derived from the body tissues of the hydrozoan.(AU)


Subject(s)
Cnidarian Venoms , Hydrozoa , Defense Mechanisms , Hemolysis
6.
Article in English | LILACS, VETINDEX | ID: biblio-1484523

ABSTRACT

Lung cancer causes 1.4 million deaths worldwide while non-small-cell lung cancer (NSCLC) represents 80-85% of the cases. Cisplatin is a standard chemotherapy against this type of cancer; however, tumor cell resistance to this drug limits its efficacy. Sea anemones produce compounds with pharmacological activities that may be useful for augmenting cisplatin efficacy. This study aimed to evaluate the pharmacological activities of crude venom (CV) from the sea anemone Bunodeopsis globulifera and four derived fractions (F1, F2, F3 and F4) to test their increase efficiency cisplatin cytotoxicity in human lung adenocarcinoma cells. Results Pre-exposure to CV, F1 and F2 fractions increases cisplatin cytotoxicity in human lung adenocarcinoma cells under specific conditions. Exposure to CV at 50 μgmL-1 induced a reduction of approximately 50% in cell viability, while a similar cytotoxic effect was observed when cell culture was exposed to F1 at 25 μgmL -1 or F2 at 50 μgmL-1. The cell culture exposure to F1 (10 μgmL-1) fraction combined with cisplatine (25 μM) provoked a decrease in MTT reduction until 65.57% while F2 (25 μgmL-1) fraction combined with cisplatin (10 μM) provoked a decrease in MTT reduction of 72.55%. Conclusions The F1 fraction had the greatest effect on the lung adenocarcinoma cell line compared with CV and F2. The combination of antineoplastic drugs and sea anemone toxins might allow a reduction of chemotherapeutic doses and thus mitigate side effects.


Subject(s)
Humans , Animals , Adenocarcinoma , Toxins, Biological/analysis , Pharmacology/instrumentation , Lung Neoplasms/pathology
7.
Article in English | LILACS | ID: lil-686622

ABSTRACT

Background: Lung cancer causes 1.4 million deaths worldwide while non-small-cell lung cancer (NSCLC) represents 80-85% of the cases. Cisplatin is a standard chemotherapy against this type of cancer; however, tumor cell resistance to this drug limits its efficacy. Sea anemones produce compounds with pharmacological activities that may be useful for augmenting cisplatin efficacy. This study aimed to evaluate the pharmacological activities of crude venom (CV) from the sea anemone Bunodeopsis globulifera and four derived fractions (F1, F2, F3 and F4) to test their increase efficiency cisplatin cytotoxicity in human lung adenocarcinoma cells. Results: Pre-exposure to CV, F1 and F2 fractions increases cisplatin cytotoxicity in human lung adenocarcinoma cells under specific conditions. Exposure to CV at 50 μgmL-1 induced a reduction of approximately 50% in cell viability, while a similar cytotoxic effect was observed when cell culture was exposed to F1 at 25 μgmL -1 or F2 at 50 μgmL-1. The cell culture exposure to F1 (10 μgmL-1) fraction combined with cisplatine (25 μM) provoked a decrease in MTT reduction until 65.57% while F2 (25 μgmL-1) fraction combined with cisplatin (10 μM) provoked a decrease in MTT reduction of 72.55%. Conclusions: The F1 fraction had the greatest effect on the lung adenocarcinoma cell line compared with CV and F2. The combination of antineoplastic drugs and sea anemone toxins might allow a reduction of chemotherapeutic doses and thus mitigate side effects.


Subject(s)
Humans , Lung Neoplasms , Cnidarian Venoms/pharmacology , Cnidarian Venoms/therapeutic use
8.
Mem. Inst. Oswaldo Cruz ; 97(2): 175-183, Mar. 2002. mapas, tab
Article in English | LILACS | ID: lil-326288

ABSTRACT

Information on the distribution and synanthropic behaviour of triatomines is essential for Chagas disease vector control. This work summarises such information from northern Peru, and presents new data on Rhodnius ecuadoriensis - an important local vector infesting 10-35 percent of dwellings in some zones. Three species are strongly synanthropic and may be suitable targets for chemical control of domestic/peridomestic bug populations. Panstrongylus herreri, the main domestic vector in the area, is probably present in sylvatic ecotopes in the Marañón river system. R. ecuadoriensis and Triatoma dimidiata seem exclusively domestic; biogeographical and ecological data suggest they might have spread in association with humans in northern Peru. Confirmation of this hypothesis would result in a local eradication strategy being recommended. Presence of trypanosome natural infection was assessed in 257 R. ecuadoriensis; Trypanosoma rangeli was detected in 4 percent of bugs. Six further triatomine species are potential disease vectors in the region (T. carrioni, P. chinai, P. rufotuberculatus, P. geniculatus, R. pictipes, and R. robustus), whilst Eratyrus mucronatus, E. cuspidatus, Cavernicola pilosa, Hermanlentia matsunoi, and Belminus peruvianus have little or no epidemiological significance. A strong community-based entomological surveillance system and collaboration with Ecuadorian public health authorities and researchers are recommended


Subject(s)
Animals , Ecosystem , Insect Vectors , Triatominae , Trypanosoma cruzi , Ecuador , Longitudinal Studies
9.
Arch. venez. pueric. pediatr ; 62(3): 124-127, jul.-sept. 1999. tab
Article in Spanish | LILACS | ID: lil-308950

ABSTRACT

La fracción III del veneno del escorpión es pancreotóxico por excelencia, ocasionando una pancreatitis edematosa que se autolimita en corto tiempo. Se realizó estudio prospectivo de 137 pacientes que ingresaron al Servicio de Pediatría del Hospital "Dr. Leopoldo Manrique Terrero" por escorpionismo con clínica colinérgica y/o adrenergica con edades comprendidas entre 8 meses y 11 años + 5 meses, con un promedio de 6 años + 7 meses. Al total de los pacientes se le realizaron exámenes de laboratorio (amilasemia-glicemia y ecosonograma abdominal durante su hospitalización y se controlaron los valores de amilasemia y glisemia a los 4 y 8 meses pos-emponzoñamiento, luego anual y ecosonograma anual durante 5 años. De los pacientes, 88 (64,23 por ciento) resultaron con páncreas normales a la ecosonografía, y 49 (35,76 por ciento) con ecogenicidad positiva para pancreatitis, a los 7 días aún persistía este cuadro en 12 (24,48 por ciento) pacientes desapareciendo a los 15 días. Al 100 por ciento de los pacientes se les realizó seguimiento con exámenes de laboratorio y ecosonograma anual, resultando normales, durante el lapso que duró el estudio. Se recomienda control cercano a los pacientes con glicemia mayor de 200 mg por ciento y amilasemia mayor de 520 u/l en el momento del accidente, ya que en este estudio se pudo comprobar que persistió la pancreatitis hasta por 2 días cuando se encontraron estos valores. En cuanto a complicaciones, sólo se encontró a corto plazo pancreatitis aguda edematosa


Subject(s)
Humans , Male , Female , Infant, Newborn , Infant , Child, Preschool , Pancreatitis , Venoms/poisoning , Scorpions , Child Care , Pediatrics , Venezuela
10.
Arch. venez. pueric. pediatr ; 62(3): 132-137, jul.-sept. 1999. tab
Article in Spanish | LILACS | ID: lil-308952

ABSTRACT

Las madres refieren antecedentes de síndrome disentérico de probable etiología amibiana cuyas características clínicas, epidemiológicas y microscópicas, hacen dudar de la certeza diagnóstica, por ello se realizó un estudio con la finalidad de conocer la frecuencia del síndrome disentérico y los agentes responsables del mismo, en el Hospital "Dr. Leopoldo Manrique Terreno", en pacientes con edades comprendidas entre tres meses y doce años. Se estudiaron 68 pacientes con un predominio de lactantes: 54(79,41 por ciento). La sintomatología más frecuente fue: fiebre 57(88,32 por ciento); evacuaciones con moco y sangre: 55(80,88 por ciento); deshidratación: 41(60,29 por ciento); convulsiones: 10(14,60 por ciento). En el examen de heces se trató de precisar la cantidad de leucocitos fecales, encontrándose predominio de polimorfonucleares en 26(49,05 por ciento). En el coprocultivo que se realizó a todos los pacientes el agente más aislado fue shigella flexneri en 40(55,97 por ciento). Se encontró asociación parásito-bacteriana en trece casos: tricocéfalo, un caso; ascaris lumbricoides dos casos; quistes de entamoeba histolíticas dos casos; quistes de giardia lamblia cuatro casos y trofozoitos de entamoeba histolítica cuatro casos. El tratamiento de elección fue trimetoprim-sulfametoxazol en 48(70,58 por ciento). Clínicamente el síndrome disentérico de probable etiología bacteriana se acompaña de fiebre alta y evacuaciones con moco y sangre. Debe solicitarse examen de heces en fresco con recuento diferencial leucocitario y el coprocultivo nos permite detectar el agente causal. Cuando se encuentra asociación parásito-bacteriana generalmente los primeros no son causantes del cuadro. El trimetoprin-sulfametoxazol puede ser utilizado como tratamiento de elección. En nuestro estudio la amibiasis resultó ser poco frecuente, en especial en niños menores de cinco años


Subject(s)
Humans , Male , Female , Bacteria , Blood , Dysentery , Strategic Evacuation , Fever , Mucus , Pediatrics , Venezuela
SELECTION OF CITATIONS
SEARCH DETAIL