Anticonvulsant Activity of Extracts of Plectranthus barbatus Leaves in Mice

Plectranthus barbatus is a medicinal plant used to treat a wide range of disorders including seizure. However, the anticonvulsant activity of this plant has not been studied in depth. We therefore sought to evaluate the anticonvulsant activity of a hydroalcoholic extract of P. barbatus leaves on seizures induced by strychnine sulphate (2.0 mg/kg) and pilocarpine (600 mg/kg) in mice. The extract was administered orally at 1, 10, 30, and 100 mg/kg. We report that the P. barbatus extract had marked anticonvulsant activity against strychnine-induced convulsions, but was quite ineffective against pilocarpine-induced convulsions. Further experiments will be required to identify the active molecules(s) and their mechanism(s) of action

Toxicidade in vitro de plantas tóxicas: avaliação do teste de ação hemolítica

As plantas tóxicas são importantes causas de patologias em animais de interesse pecuário no Brasil. Para que umaplanta apontada como responsável por intoxicações acidentais venha a ser classificada como espécie tóxica, sua toxicidade deve ser comprovada experimentalmente em animais. No entanto, a sociedade atual vem clamando por redução na utilização de animais em pesquisas científicas, fazendo com que testes de toxicidade  in vitro sejam cada vez mais empregados. Como falta validação para o uso destes testes para avaliação de plantas tóxicas, seu uso prático se torna inviável. Assim, o objetivo do presente trabalho foi avaliar a eficácia do teste de ação hemolítica in vitro para avaliação preliminar da toxicidade de plantas, usando espécies com toxicidade conhecida. As espécies de plantas usadas foram Crotalaria retusa, Ipomoea asarifolia, Ipomoea fistulosa, Datura stramonium, Nerium oleander, Ricinus communis, Lantana camara, Dieffenbachia picta e Alocacia sp. e Calotropis procera. Todas estas amostras foram submetidas à avaliação da ação hemolítica in vitro, utilizando-se uma suspensão de eritrócitos de eqüino. Nenhuma das plantas utilizadas apresentou este efeito hemolítica. Assim, é possível afirmar que a utilização do teste de hemólise in vitro é ineficaz para a avaliação preliminar, como triagem, de plantas tóxicas. Deste modo, o uso de animais de laboratório atualmente permanece sendo a forma mais eficaz de identificação de novas espécies de plantas tóxicas

Toxicity of Mimosa tenuiflora pollen to Africanized honey bees (Apis mellifera L.)

Background:  :  :  : Mimosa tenuiflora (Willd.) Poir. (Mimosaceae) is a xerophilous plant which is very common in degraded areas in the Brazilian semi-arid region, including areas of beekeeping. The ingestion of leaves from M. tenuiflora by ruminants is responsible for malformations. Chemical analyses of this plant revealed that it contains several secondary compounds including three triterpenoidal saponins, designated Mimonosides A–C, four flavones, five flavanones and four chalcones. Several plant species contain secondary compounds in nectar and pollen that could be toxic to pollinators, including bees. Experimental approaches are necessary to identify plant species that produce pollen that is toxic to bees. The present study aimed to determine the toxic potential of M. tenuiflora (Willd.) Poir. (Mimosaceae) pollen to Africanized honey bees (Apis mellifera L.). Materials, Methods & Results: The plant species utilized in this study was Mimosa tenuiflora (Willd.) Poir. (Mimosaceae) and a voucher specimen was deposited (no. 9591) at the Dárdano de Andrade-Lima (MOSS) Herbarium, Universidade Federal Rural do Semi-Árido (UFERSA), Mossoró, RN, Brazil. Pollen samples were collected near Mossoró city, RN, in northeastern Brazil (5°11‘15"S and 37°20‘39"W). Honeycombs that contained pupae of africanized honey bees (Apis mellifera) were collected from the apiary of UFERSA. Newly emerged forager bees, identified on basis of their body size and coloration, were used for the experiment. All the bees used were of the same age. Groups of twenty bees were put into wooden boxes (11 x 11 x 7 cm). The boxes were kept in an acclimatized chamber (BOD) at 32°C and 70% humidity. M. tenuiflora pollen was added to the food (5 parts of sugar mixed to one part of honey) at doses of 0 (control group; n=195), 2.5% (n=178), 5.0% (n=186) and 10.0% (n=186). The bees were observed daily until the last one died. Statistical analyses were performed using a statistical software (GraphPad Prism v.4 for Mac). Median survival times, with 95% confidence intervals, were estimated using Kaplan–Meier survival analysis. Differences in the time distributions between groups were tested for statistical significance using the logrank test. The median survival times of the bees were four days for all groups. Kaplan–Meier survival analysis revealed a significant difference (P=0.0041) between the survival curves, but the log-rank test did not show statistical difference (P=0.2825). The survival curve of controls differed (P=0.001) from the survival curve of the group fed 2.5% M. tenuiflora, but did not differ from the other groups. Discussion: Several plant species contain secondary compounds in nectar and pollen that could be toxic to animals that consume them. Bees collect large amounts of pollen grains very efficiently, making these grains generally unavailable for pollination. Thus, presence of secondary compounds in pollen grains could be a strategy designed to restrict the loss of pollen to bees. Even though it contains several secondary metabolites, the results of the present study indicate that the ingestion of the pollen of Mimosa tenuiflora by Africanized honey bees (Apis mellifera L.) at conditions of the present study did not promote toxic effect

Glicemia em cães obesos e senis

Diabetes mellitus, uma das endocrinopatias mais comuns nos cães, é caracterizada por alteração no metabolismo da glicose. Em animais, alguns dos fatores predisponentes à diabetes são a obesidade e a senilidade. Assim, o presente trabalho objetivou avaliar a influência da obesidade e da senilidade na glicemia de cães saudáveis na cidade de Mossoró, RN. Foram utilizados 60 cães, divididos em quatro grupos: 22 animais idosos (maiores de 8 anos); 15 cães obesos; 3 animais obesos e idosos; e 20 cães não obesos adultos (entre 1 e 6 anos). Após um período de jejum alimentar de 8 a 12 horas, foram coletadas amostras de sangue total sem anticoagulante que foram utilizadas imediatamente para determinação da glicemia em glicosímetro. As médias dos diferentes grupos foram avaliados estatisticamente utilizando a análise de variância ANOVA, seguido pelo teste de comparações múltiplas de Tukey-Kramer. Os resultados das glicemias (média±erro-padrão) foram: idosos 63,6±3,11 mg/dL; obesos 59,9±3,90 mg/dL; idosos obesos 62,7±7,45 mg/dL; e adultos não obesos 58,6±1,83 mg/dL. No entanto, a avaliação estatística relevou não haver diferença significante entre os grupos. Assim, os grupos de animais obesos, idosos e idosos obesos não apresentaram glicemia significantemente diferente daquela dos animais adultos não obesos. Deste modo, não é necessário o estabelecimento de diferentes valores de referência para glicose sangüínea para cães obesos e senis

Association of Trypanosoma vivax in extracellular sites with central nervous system lesions and changes in cerebrospinal fluid in experimentally infected goats

Changes in cerebrospinal fluid (CSF) and anatomical and histopathological central nervous system (CNS) lesions were evaluated, and the presence of Trypanosoma vivax in CNS tissues was investigated through PCR. Twelve adult male goats were divided into three groups (G): G1, infected with T. vivax and evaluated during the acute phase; G2, infected goats evaluated during the chronic phase; and G3, consisting of non-infected goats. Each goat from G1 and G2 was infected with 1.25 × 105 trypomastigotes. Cerebrospinal fluid (CSF) analysis and investigation of T. vivax was performed at the 15th day post-infection (dpi) in G1 goats and on the fifth day after the manifestation of nervous system infection signs in G2 goats. All goats were necropsied, and CNS fragments from G1 and G2 goats were evaluated by PCR for the determination of T. vivax. Hyperthermia, anemia and parasitemia were observed from the fifth dpi for G1 and G2, with the highest parasitemia peak between the seventh and 21st dpi. Nervous system infection signs were observed in three G2 goats between the 30th and 35th dpi. CSF analysis revealed the presence of T. vivax for G2. Meningitis and meningoencephalitis were diagnosed in G2. PCR were positive for T. vivax in all the samples tested. In conclusion, T. vivax may reach the nervous tissue resulting in immune response from the host, which is the cause of progressive clinical and pathological manifestations of the CNS in experimentally infected goats

Bovine enzootic haematuria from consumption of Pteris deflexa and Pteris plumula in northwestern Argentina

Bovine enzootic haematuria (BEH) is caused by prolonged ingestion of toxic principles of bracken fern, essentiallybyPteridium spp. In northwestern Argentina, this disease has a greateconomic impact ant it is attributed a chronic consumption to Pteridium arachnoideum. This paper describes two endemic areas for enzootic hematuria due to the consumption of Pteris deflexa and Pteris plumula. Two areas where P. deflexa and P. plumula are endemic, but free of Pteridium species, were devised and seven farms were visited. The disease was confirmed basedon the presence of clinicallyaffected animals. Infournecropsies bleeding neoplastic lesions were observed in the mucosa of the urinary bladder. At phytochemical analysis, both ptaquiloside and pterosin B were found in P. deflexa and P. plumula. Thus, the consumption of P. deflexa and P. plumula can also cause BEH.EEA SaltaFil: Micheloud, Juan Francisco. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación Animal del Chaco Semiárido. Área de investigación en Salud Animal -EEA Salta; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Colque Caro, Luis Adrian. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Martinez, Olga Gladys. Universidad Nacional de Salta. Faculta de Ciencias Naturales. Museo de Ciencias Naturales. Herbario; ArgentinaFil: Gimeno, Eduardo Juan. Universidad Nacional de La Plata, Facultad de Ciencias Veterinarias; ArgentinaFil: Ribeiro, Debora De Silva Freitas. Universidad Federal de Minas Gerais. Escola de Veterinaria. Departamento de Clínica e Cirugia Veterinarias; BrasilFil: Soto Blanco, Benito. Universidad Federal de Minas Gerais. Escola de Veterinaria. Departamento de Clínica e Cirugia Veterinarias; Brasi

Spontaneous Poisoning by Blutaparon portulacoides in a Horse

Background: In the Rio Grande do Norte state, Northeastern Brazil, several outbreaks of poisoning affecting horses, cattle and sheep have been attributed by a number farmers to the consumption of the leaves of Blutaparon portulacoides, a plant from family Amaranthaceae, known as “pirrixiu”, “bredo-de-praia” and “capotiraguá”. However, the spontaneous poisoning was reported in the literature exclusively in sheep. Thus, the present study aims to report the clinical signs found in a spontaneous poisoning by B. portulacoides in a horse.Case: A 8-year-old mixed-breed mare, weighing 268 kg, was referred to veterinary care showing loss of appetite and diarrhea. The clinical evolution was reported by the owner as for six days. During the physical examination, the animal presented slight apathy, pale mucous membranes, tachypnea, dehydration, intestinal hypermobility, and watery diarrhea. The predominant plant in the paddock where the mare was maintained was B. portulacoides. According to the owner, the poisoning by this plant is common in the neighborhood of the farm and has already occurred in other species (cattle and sheep). After the origin of poisoning was identified, the access to the plant was restricted and it was established fluid therapy to treat the dehydration. After three days, the animal returned to eat normally and the diarrhea ceased.Discussion: The exclusive feeding of sheep with B. portulacoides is responsible for disorders in the digestive tract, characterized by softening of feces and intestinal epithelial lesions (intestinal villi epithelium detachment, goblet cell hyperplasia, submucosal inflammatory cells infiltrate and infiltration of the lamina propria by mononuclear cells). Given the similarity of the frame displayed by the horse, described in the present report, it is believed that the sensitivity to poisoning by B. portulacoides is not exclusive to sheep, but also occurs in horses. Taking into account that B. portulacoides is found widespread through the Atlantic coast of Brazil, it is feasible to speculate that several other cases of poisoning might occur without accurate diagnosis. A plant that promotes similar poisoning is Portulaca elatior Mart. (family Portulacaceae), described in the literature affecting goats, sheep, and cattle. However, the poisoning by P. elatior is typically acute, showing clinical evolution within 48 hours after ingestion of the plant, whereas B. portulacoides poisoning occurs after a few days of consumption. Phytochemical analysis of B. portulacoides leaves revealed the occurrence of a number compounds, including three steroids, one flavone, one isoflavone and two flavonoids. However, the toxic principle of the plant is still unknown. The possible mechanism of poisoning is the osmotic imbalance in the digestive tract promoted by scarcity of sodium and excess of magnesium, potassium and calcium in the plant. Future studies are desirable to determine the toxic principle present in B. portulacoides and the exact mechanism of poisoning. In conclusion, the clinical presentation of the referred mare is similar to that described in sheep that ingested Blutaparon portulacoides, thus this plant can be considered as responsible for toxic effects in the digestive system of horses

Congenital Cutaneous Hemangioma in a Newborn Lamb

Background: Hemangioma is a benign dermal or subcutaneous endothelial cell tumor composed of vascular spaces of varying sizes filled with erythrocytes and lined with a single layer of uniform endothelial cells. Although the pathogenesis is not well defined, these tumors are considered to result from an imbalance in angiogenesis, leading to uncontrolled proliferation of vascular elements. To the best of our knowledge, there are no reports of congenital cutaneous hemangioma in sheep. This report describes the clinical, laboratory, and pathological findings of a case of congenital hemangioma affecting a newborn lamb. Case: A 5-day-old crossbred (Dorper x Santa Inês) lamb presenting with an ear nodule that expanded in the right ear was necropsied. An expansive subcutaneous nodule was observed macroscopically; it occupied approximately 90% of the right ear and had a crusty, irregular surface. The cut surface had multiple cavitations delimited by firm fibrous tissue and a light yellow-to-translucent content. Microscopically, it showed focally extensive subcutaneous neoplastic proliferation and moderate cellularity; it was formed of vascular beds of varied sizes and supported by moderate fibrocollagenous stroma. Suppurative inflammation was observed in the neoplastic vascular beds with large amounts of free basophilic coccoid bacteria inside macrophages. Immunohistochemistry analysis was performed to confirm the diagnosis. Strong cytoplasmic labeling was observed in neoplastic endothelial cells for CD31 and factor VIII. The Ki67 proliferation marker was positive in approximately 5% of neoplastic cells. The cells did not express smooth muscle actin (1A4) or pan-cytokeratin (AE1AE3). Histological characteristics and immunohistochemistry findings were consistent with those of congenital cutaneous hemangioma, a rare neoplasm in sheep. Discussion: The association of clinical, anatomopathological, and immunohistochemical data enabled the diagnosis of congenital cutaneous hemangioma in the 5-day-old lamb. Reports of vascular tumors in sheep are not frequent in literature and usually involve adult animals with no anatomical site predilection. In sheep, the occurrence of nasotracheal hemangioma in a 2-year-old ewe and gingival hemangioma in a 5-year-old sheep have already been described. A cutaneous extra-neural hemangioblastoma was diagnosed in the ear of a 1-month-old lamb. IHC was also used to confirm the diagnosis of hemangioblastoma. Macroscopically, hemangiomas can present as well-delimited and encapsulated masses that when cut, show a reticulated pattern similar to honeycombs that separate the blood-filled cavities. The present case showed a similar conformation but without enough erythrocytes to result in a bloody appearance. Tumor drainage and the predominance of blood serum in the content possibly made it macroscopically translucent. Microscopically, the hemangioma was classified as cavernous. This morphological variation forms large channels separated by fibrous connective tissue stroma, which may contain inflammatory cells. IHC confirmed the endothelial lining of the cystic cavities and was crucial in excluding differential diagnoses. Thus, factor VIII-related antigen was used as a marker for normal and neoplastic cells, as well as for tumoral and reactive neovascularization, in which neoplastic cells were immuno-expressed for CD31 and Factor VIII. In domestic animals, the association between CD31 and Factor VIII is considered more specific for vascular endothelial cells, differentiating them from cells of lymphatic origin. Congenital cutaneous hemangioma occurs in sheep, and its diagnosis and differentiation can be based on histopathology associated with conventional immunohistochemical panels for vascular neoformation. Keywords: sheep, mesenchymal neoplasm, vascular tumour, small ruminant, histopathology, immunohistochemistry