Turning weeds into feed: Ensiling Calotropis gigantea (Giant milkweed) reduces its toxicity and enhances its palatability for dairy cows.

Calotropis gigantea (Giant milkweed, GM) has the potential to be utilized as a new feed additive for ruminants, however, the presence of unpalatable or toxic compounds decreases animal feed intake. This study aimed to valorize GM as a potential new feed resource through the chemical and microbial biotransformation of toxic compounds that will henceforth, make the plant palatable for cows. After GM's ensiling using fermentative bacteria, the plant was sampled for UHPLC-MS/MS to analyse the metabolomic changes. Illumina Miseq of the 16 S rRNA fragment genes and ITS1 were used to describe the microbial composition and structure colonizing GM silage and contributing to the biodegradation of toxic compounds. Microbial functions were predicted from metataxonomic data and KEGG pathways analysis. Eight Holstein dairy cows assigned in a cross-over design were supplemented with GM and GM silage to evaluate palatability and effects on milk yield and milk protein. Cows were fed their typical diet prior to the experiment (positive control). After ensiling, 23 flavonoids, 47 amino acids and derivatives increased, while the other 14 flavonoids, 9 amino acids and derivatives decreased, indicating active metabolism during the GM ensiling process. Lactobacillus buchneri, Bacteroides ovatus, and Megasphaera elsdenii were specific to ensiled GM and correlated to functional plant metabolites, while Sphingomonas paucimobilis and Staphylococcus saprophyticus were specific to non-ensiled GM and correlated to the toxic metabolite 5-hydroxymethylfurfural."Xenobiotics biodegradation and metabolism", "cancer overview" and "neurodegenerative disease" were the highly expressed microbial KEGG pathways in non-ensiled GM. Non-ensiled GM is unpalatable for cows and drastically reduces the animal's feed intake, whereas ensiled GM does not reduce feed intake, milk yield and milk protein. This study provides essential information for sustainable animal production by valorizing GM as a new feed additive.

[Development of a Genus Identification Method for Poisonous Plants Using Real-Time PCR].

We have developed a rapid genus identification method for poisonous plants. The real-time PCR using the TaqMan® probe method was employed for detection, with the amplified targets being the "trnL (UAA)-intron" or "trnL-trnF intergenic spacer" regions of chloroplast DNA. The targeted plants were selected six genera (Aconitum, Colchicum, Veratrum, Brugmansia, Scopolia and Narcissus), which have been implicated in many instances of food poisoning in Japan. A tissue lysis solution was used for DNA extraction, which can be completed within approximate 30 min. A master mix corresponding to the tissue lysis solution was used for real-time PCR reagents. As a result, we were able to complete the entire process from DNA extraction to genus identification in 4 to 5 hr. The detection sensitivity was estimated at approximately 1 pg of DNA for all six plant genera. Remarkably, an amplification plot was discerned even with the crude cell lysates of all samples. It was also possible to obtain amplification curves for three plant samples that had been subjected to simulated cooking (boiling). This study suggests that the developed method can rapidly identify six genera of poisonous plants.

Toxic Causes of Intestinal Disease in Horses.

Because most poisonings occur by toxin ingestion, the gastrointestinal system is the first exposed and, in most cases, it is exposed to the highest toxin concentrations. Consequently, enterocyte damage is common. However, because many toxins produce organ-specific damage, and enterocyte necrosis is easily confused with autolysis, many gastrointestinal lesions are overlooked or overshadowed by other clinical and pathologic changes. The objective of this work is to review several common toxins and poisonous plants that produce primarily gastrointestinal disease.

Alkaloids from Oxytropis ochrocephala and antiproliferative activity of sophoridine derivatives against cancer cell lines.

Ten alkaloids (1-10), with sophoridine (1) as the most abundant component, were obtained from the whole plants of Oxytropis ochrocephala Bunge. Furthermore, eight new sophoridine derivatives (11-16, 20, 21), with modification on the C-14 position of 1 were synthesized. All compounds (1-16, 20, 21) were evaluated for antiproliferative activity against five human tumor cell lines. Among them, the newly synthesized derivative 20 exhibited the best inhibitory activity against the tested cell lines. Its activity was increased by more than fourfold as compared with parent compound 1.

Ochrocephalamine A, a new quinolizidine alkaloid from Oxytropis ochrocephala Bunge.

One dimeric matrine-type alkaloid, ochrocephalamine A (1), was isolated from the poisonous plant Oxytropis ochrocephala Bunge. Its structure was elucidated by spectroscopic data and single-crystal X-ray diffraction. The insecticidal and cytotoxic activities of 1 were evaluated.

Ethnobotanical uses and phytochemical, biological, and toxicological profiles of Datura metel L.: A review.

Datura metel L., a recognized poisonous plant in the Solanaceae family, is widely distributed in the world. Traditionally, D. metel is used in many diseases, including neurological and heart diseases; fever; catarrh; pain; diarrhea; skin diseases; chronic bronchitis; asthma; digestive disorders; and so on. It possesses many important phytochemicals that can be used to treat various types of diseases. This review aims at summarizing the traditional uses, phytochemical, biological, and toxicological profiles of D. metel based on the database reports. For this, an up-to-date (till March 20, 2023) search was made in the databases: PubMed, Google Scholar, Science Direct, Scopus, and MedLine, with relevant keywords for the published evidence. Findings suggest that the plant has many traditional uses, such as a cure for madness, epilepsy, psoriasis, heart diseases, diarrhea, mad dog bites, indigestion, etc. It possesses various important phytochemicals, including withanolides, daturaolone, datumetine, daturglycosides, ophiobolin A, baimantuoluoline A, and many others. D. metel has many important biological activities, including antioxidant, anti-inflammatory, anti-microbial, insecticidal, anti-cancer, anti-diabetic, analgesic, anti-pyretic, neurological, contraceptive, and wound healing capacity. In conclusion, the toxic plant, D. metel, can be considered a potential source of phyto-therapeutic lead compounds.

Different Ecological Niches of Poisonous Aristolochia clematitis in Central and Marginal Distribution Ranges-Another Contribution to a Better Understanding of Balkan Endemic Nephropathy.

Aristolochia clematitis L. is a perennial herbaceous plant distributed throughout Europe, Asia Minor and Caucasus. It has been used as a medicinal plant since antiquity but not in recent times because it contains poisonous aristolochic acid, causing progressive kidney failure. The aim of this work was to study Aristolochia clematitis ecology on the basis of vegetation plots from the European Vegetation Archive, and to investigate the differentiation of its ecological niche using a co-occurrence-based measure of ecological specialization (ESI). The ecological niche was studied on three spatial scales: on the entire distribution area, its differentiation across 200 × 200 km grid cells and the differences between three central and three marginal regions. Our results suggest that Aristolochia clematitis has a very broad ecological niche occurring in a range of different habitats and climatic conditions, with a trend of a niche width decrease with the distance from the geographical center. The plant prefers more stable communities with less anthropogenic influence moving towards the margin of the distribution area. Specialization towards the marginal area is a result of evolutionary history, which refers to the recent anthropogenically induced spread from its original home range. A high incidence of Aristolochia clematitis in the vegetation of arable lands and market gardens as well as anthropogenic herbaceous vegetation in the distribution center corresponds to the geographical incidence of Balkan Endemic Nephropathy.

Soil and vegetation characteristics during the formation of typical Ligularia virgaurea degraded grassland.

To understand the formation process of typical poisonous plant degraded grassland, we studied the cha-racteristics of vegetation and soil during the gradual expansion of Ligularia virgaurea into the native grassland of Qinghai-Tibet Plateau. The results showed that population density, plant height, coverage, and biomass of L. virgaurea increased during the formation of L. virgaurea degraded grassland. In comparison with native grassland, the degraded grassland had higher total aboveground biomass (113.9%), soil total nitrogen concentration (61.0%), NH4+-N (77.9%), organic carbon concentration (45.3%), available phosphorus concentration (78.8%) as well as soil microbial biomass carbon (42.1%) and nitrogen (47.4%), but lower NO3--N (40.1%) and species richness (28.5%) and aboveground biomass (45.7%) of other species beyond L. virgaurea. The extremely strong abilities of interspecific inhibition and morphological plasticity of L. virgaurea, as well as efficient nutrient accumulation and utilization were the keys to its successful expansion, which facilitated the formation of typical L. virgaurea degraded grassland.

Dermatopathy caused by Tephrosia noctiflora intoxication in cattle.

An outbreak of a disease characterized by emaciation, dermatitis with erythema, alopecia, foul-smelling exudation, crusting, hyperpigmentation, lichenification, and edema of fore- and hindlimbs, chest and dewlap is described affecting cattle in the State of Alagoas, Northeastern Brazil. Microscopically, the main lesions were characterized by diffuse dermatitis with infiltration of lymphocytes, histiocytes, parakeratotic hyperkeratosis and acanthosis. The plant Tephrosia noctiflora, which exhibited signs of consumption, infested the grazing areas of cattle. To test its toxicity, T. noctiflora was harvested, dried in the shade, crushed and sourced at a concentration of 50% mixed with commercial food for three guinea pigs. The main clinical signs in guinea pigs included weight loss and multifocal, moderate to severe areas of alopecia, diffuse erythema of the skin, vaginal edema and hematuria. Microscopically, lymphocytic and histiocytic dermatitis, parakeratotic hyperkeratosis and acanthosis were noted in guinea pigs. This experiment confirms that T. noctiflora is the cause of outbreaks of dermatitis observed in cattle grazing in areas infested by this plant.

Mineral-salt supplementation to ameliorate larkspur poisoning in cattle.

Larkspurs (Delphinium spp.) are native forbs that are poisonous to cattle and cost livestock producers millions of dollars in losses each year. Macro and micro minerals are required for normal functioning of essentially all metabolic processes in ruminants. The role that mineral status may play in larkspur poisoning in cattle is not clear. In this study, we seek to determine the effects a mineral-salt supplement, commonly used by cattle producers, to potentially reduce cattle losses to larkspur. The ability of mineral-salt supplementation to alter susceptibility to larkspur toxicosis was evaluated in a pen study. Animals supplemented with mineral-salt were found to be less susceptible to larkspur poisoning than the non-supplemented animals. A separate group of animals were then grazed on larkspur infested rangelands. One group was supplemented with a mineral-salt mix and the other group did not receive any mineral-salt. Supplementing cattle with the mineral-salt mix did not alter larkspur consumption (P > 0.05). However, overall larkspur consumption was low and averaged 3 ± 1.0% and 2 ± 1.1% for cattle supplemented with mineral and non-supplemented, respectively. Serum was collected from animals once a week during the grazing study. Average and maximum serum concentrations of toxic larkspur alkaloids were numerically higher in mineral-salt supplemented cattle compared with the non-supplemented animals. Results from the pen study suggest that a good mineral supplementation program will provide a protective effect for animals grazing in larkspur-infested ranges. The mineral-salt supplemented steers, in the grazing study, were not observed to consume less larkspur than the non-supplemented animals; however, the mineral-salt supplemented animals had higher concentrations of larkspur alkaloids in their serum indicating they may be able to tolerate higher larkspur consumption. The data also indicate that mineral-salt supplementation must be continuous throughout the time the animals are grazing these rangelands as the positive effects can be lost within 30 d post supplementation.

Larkspurs (Delphinium spp.) are native forbs poisonous to cattle and cost livestock producers millions of dollars in losses each year. The role mineral status may play in larkspur poisoning in cattle is unclear. The ability of mineral-salt supplementation to alter susceptibility to larkspur toxicosis was evaluated in a pen and grazing study. In the pen study, animals supplemented with mineral-salt were found to be less susceptible to larkspur poisoning than non-supplemented animals. A separate group of animals grazed on larkspur infested rangelands. One group was supplemented with a mineral-salt mix and the other group did not receive any mineral-salt. Supplementing cattle with the mineral-salt mix did not alter larkspur consumption of grazing cattle. However, overall larkspur consumption was low. Results from the pen study suggest that a good mineral supplementation program will provide a protective effect for animals grazing in larkspur-infested ranges. The mineral-salt supplemented steers, in the grazing study, had higher concentrations of larkspur alkaloids in their blood serum indicating they may be able to tolerate higher larkspur consumption. The data also indicate that mineral-salt supplementation must be continuous throughout the time the animals are grazing as the positive effects can be lost within 30 days after supplementation.

The cp genome characterization of Adenium obesum: Gene content, repeat organization and phylogeny.

Adenium obesum (Forssk.) Roem. & Schult. belonging to the family Apocynaceae, is remarkable for its horticultural and ornamental values, poisonous nature, and medicinal uses. In order to have understanding of cp genome characterization of highly valued medicinal plant, and the evolutionary and systematic relationships, the complete plastome / chloroplast (cp) genome of A. obesum was sequenced. The assembled cp genome of A. obesum was found to be 154,437 bp, with an overall GC content of 38.1%. A total of 127 unique coding genes were annotated including 96 protein-coding genes, 28 tRNA genes, and 3 rRNA genes. The repeat structures were found to comprise of only mononucleotide repeats. The SSR loci are compososed of only A/T bases. The phylogenetic analysis of cp genomes revealed its proximity with Nerium oleander.

Alternative method for oral administration of insoluble toxins to rats. A prenatal study of L-mimosine.

L-mimosine is a compound found in Leucaena leucocephala, that is used as animal feed due to its high protein content, but it can also cause intoxication. Due to its low solubility in organic and aqueous solvents, its administration in laboratory animals is difficult, especially in delicate periods such as pregnancy. Thus, to circumvent such problems, this study proposes a stress-free form of oral administration with gelatin tablets with flavoring (meat broth) for 14 consecutive days of the gestational period (GD06 to GD20). For that, 17 pregnant Wistar rats divided into 3 groups were used: control (CO; n = 5) not treated; gelatin (GEL; n = 6), which received a gelatin tablet with flavoring; and gelatin with flavoring added 140 mg/kg of L-mimosine (GM; n = 6). All animals received feed and water ad libitum. The parameters analyzed were body weight gain, water and feed consumption, serum biochemistry, blood count and reproductive indices. Among these, only the real and total weight gains of dams showed statistically significant differences, with a decrease in the group GM. Thus, we could observe that flavored gelatin was an efficient and effective administration method to insoluble compounds and long-term administration to pregnant rats, with quick adaptation and without refusal by the animals. In addition, we could observe a direct effect of L-mimosine on the animals' weight gain; however, the dose administered was not sufficient to confer maternal and fetal toxicity.

Neuroprotective and Anti-Neuroinflammatory Effects of a Poisonous Plant Croton Tiglium Linn. Extract.

Neuroinflammation is involved in various neurological diseases. Activated microglia secrete many pro-inflammatory factors and induce neuronal cell death. Thus, the inhibition of excessive proinflammatory activity of microglia leads to a therapeutic effect that alleviates the progression of neuronal degeneration. In this study, we investigated the effect of Croton tiglium(C. tiglium) Linn. extract (CTE) on the production of pro- and anti-inflammatory mediators in microglia and astrocytes via RT-PCR, Western blot, and nitric oxide assay. Neurotoxicity was measured by cell viability assay and GFP image analysis. Phagocytosis of microglia was measured using fluorescent zymosan particles. CTE significantly inhibited the production of neurotoxic inflammatory factors, including nitric oxide and tumor necrosis factor-α. In addition, CTE increased the production of the neurotrophic factor, brain-derived neurotrophic factor, and the M2 phenotype of microglia. The culture medium retained after CTE treatment increased the survival of neurons, thereby indicating the neuroprotective effect of CTE. Our findings indicated that CTE inhibited pro-inflammatory response and increased the neuroprotective ability of microglia. In conclusion, although CTE is known to be a poisonous plant and listed on the FDA poisonous plant database, it can be used as a medicine if the amount is properly controlled. Our results suggested the potential benefits of CTE as a therapeutic agent for different neurodegenerative disorders involving neuroinflammation.

A Probable Fatal Case of Oleander (Nerium oleander) Poisoning on a Cattle Farm: A New Method of Detection and Quantification of the Oleandrin Toxin in Rumen.

Oleander (Nerium oleander) is an ornamental plant common in tropical and sub-tropical regions that is becoming increasingly widespread, even in temperate regions. Oleander poisoning may occur in animals and humans. The main active components contained in the plant are cardiac glycosides belonging to the class of cardenolides that are toxic to many species, from human to insects. This work describes a case of oleander poisoning that occurred on a small cattle farm and resulted in the fatality of all six resident animals. Furthermore, the investigation of the poisonous agent is described, with particular focus on the characterization of the oleandrin toxin that was recovered from the forage and rumen contents. The innovation of this study is the first description of the detection and quantification of the oleandrin toxin by liquid chromatography-high resolution mass spectrometry (LC-HRMS) in rumen.

Successful use of digoxin-specific immune Fab in the treatment of severe Nerium oleander toxicosis in a dog.

OBJECTIVE: To describe a case in which digoxin-specific immune Fab was used successfully in a dog with severe oleander toxicosis secondary to ingesting plant material. CASE SUMMARY: A 6-year-old intact female Rhodesian Ridgeback mixed breed dog was presented for severe oleander toxicosis and was refractory to all antiarrhythmic therapies and supportive care. Digoxin-specific immune Fab was successful in treating this dog. The dog recovered but suffered ischemic injuries, the long-term effects of which are unknown. NEW OR UNIQUE INFORMATION PROVIDED: This report describes the successful use of digoxin-specific immune Fab in the treatment of oleander toxicosis in a dog, which has not previously been published in veterinary literature. Oleander poisoning can be associated with permanent cardiac arrhythmias due to the ischemic damage.

Detection of swainsonine and calystegines in Convolvulaceae species from the semiarid region of Pernambuco / Detecção de swainsonina e calisteginas em espécies de Convolvulaceae da região semiárida de Pernambuco

Numerous plant species worldwide including some Ipomoea (Convolvulaceae) and Sida (Malvaceae) species in Brazil cause lysosomal storage disease in herbivores and are known to contain swainsonine and calystegines as the main toxic compounds. The aim of this work was to determine swainsonine and calystegines concentrations in species of Convolvulaceae from the semiarid region of Pernambuco. Seven municipalities in the Moxotó region were visited and nine species were collected and screened for the presence of swainsonine and calystegines using an HPLC-APCI-MS method. The presence and concentration of these alkaloids within the same and in different species were very variable. Seven species are newly reported here containing swainsonine and/or calystegines. Ipomoea subincana contained just swainsonine. Ipomoea megapotamica, I. rosea and Jacquemontia corymbulosa contained swainsonine and calystegines. Ipomoea sericosepala, I. brasiliana, I. nil, I. bahiensis and I. incarnata contained just calystegines. The discovery of six Ipomoea species and one Jacquemontia species containing toxic polyhydroxy alkaloids reinforces the importance of this group of poisonous plants to ruminants and horses in the semiarid region of Pernambuco. Epidemiological surveys should be conducted to investigate the occurrence of lysosomal storage disease associated to these new species.(AU)

Numerosas espécies de plantas em todo o mundo, incluindo algumas espécies de Ipomoea (Convolvulaceae) e Sida (Malvaceae) no Brasil, causam doença de armazenamento lisossomal em herbívoros e são conhecidas por conterem swainsonina e calisteginas como princípios tóxicos. O objetivo deste trabalho foi determinar a concentração de swainsonina e calisteginas em espécies de Convolvulaceae da região semiárida de Pernambuco. Sete municípios na região do Sertão do Moxotó foram visitados, onde foram coletadas amostras das folhas de nove espécies de Convolvulaceae para avaliação da presença de swainsonina e calisteginas utilizando-se cromatografia líquida com espectrometria de massa. A presença e concentração destes alcaloides nas folhas de plantas da mesma espécie e dentre as espécies foram muito variáveis. Seis novas espécies de Ipomoea e uma espécie de Jacquemontia contendo swainsonina e/ou calisteginas são relatadas neste estudo. Ipomoea subincana continha apenas swainsonina. Ipomoea megapotamica, I. rosea e Jacquemontia corymbulosa continham swainsonina e calisteginas. Ipomoea sericosepala, I. brasiliana, I. nil, I. bahiensis e I. incarnata continham apenas calisteginas. A descoberta de novas espécies de Ipomoea e Jacquemontia contendo alcaloides polihidroxílicos tóxicos reforçam a importância deste grupo de plantas tóxicas para ruminantes e equinos na região semiárida de Pernambuco. Pesquisas epidemiológicas devem ser realizadas para investigar a ocorrência de doença de depósito lisossomal associada a essas novas espécies.(AU)

Alterações no SNC e morfometria cerebelar de bovinos intoxicados experimentalmente por Solanum paniculatum / Alterations in the CNS and cerebellar morphometry of cattle experimentally poisoned by Solanum paniculatum

Algumas espécies de Solanum causam intoxicações em ruminantes caracterizadas clinicamente por desordens cerebelares e microscopicamente como doença do depósito lisossomal. Não há lesões de necropsia específicas e microscopicamente ocorrem vacuolização e perda de neurônios de Purkinje. Por ser Solanum paniculatum a espécie de ocorrência na região Nordeste, sendo responsável pelos surtos de intoxicação espontânea descrito no Estado de Pernambuco foi realizado um delineamento experimental para caracterizar o quadro clínico-patológico da intoxicação. Foram usados cinco bovinos, sendo quatro no grupo experimental (GE) e um animal no controle (GC), de seis meses de idade, sem raça definida, com peso de 120 Kg, mantidos em baias durante cinco meses na Clínica de Bovinos de Garanhuns/UFRPE. Os animais receberam a planta, colhida nas propriedades em que ocorreram os surtos naturais, na dosagem de 5g/kg/PV/dia da planta dessecada misturada na ração por ingestão natural. Semanalmente realizou-se o Head Raising Test para determinar os sinais cerebelares e quando positivo os animais foram submetidos à colheita de sangue e do líquido céfalo-raquidiano e em seguida foi feito à eutanásia.

O SNC e a rete mirabile foram fixados em formol a 10% tamponado, processados rotineiramente e corados pela hematoxilina e eosina para avaliação histopatológica. Foi realizada análise morfométrica das lesões cerebelares. Para avaliação dos resultados laboratoriais utilizou-se análise descritiva e em relação à morfometria, empregou-se o teste T de Student (p<0.05) na contagem de células de Purkinje e para a espessura da camada molecular do cerebelo o teste de Mann Whitney, com nível de 5% de significância. Três animais apresentaram sinais de intoxicação com tempo em média de 90 dias e um com 155 dias. Os sinais clínicos observados foram ataques convulsivos transitórios, e distúrbios do equilíbrio. Na necropsia não foram encontradas lesões específicas da intoxicação. Não houve alterações no hemograma e no líquido céfalo-raquidiano causado pela planta. No histopatológico havia principalmente vacuolização fina do pericário e perda de células de Purkinje, com degeneração Walleriana e esferóides axonais na camada granular e na substância branca medular, com proliferação dos astrócitos de Bergman. Vacuolização e necrose neuronal também foram observadas no óbex, pedúnculos cerebelares e colículos rostral e caudal e raramente no tálamo, núcleos da base, hipocampo e medula oblonga. Na análise morfométrica não houve diferença significativa (p<0,05) entre o número de células de Purkinje e a espessura da camada molecular entre o GE e GC, demonstrando que apesar dos bovinos desenvolverem quadro clínico da intoxicação e alterações histopatológicas acentuadas, mas nestas condições experimentais não ocorreram alteração morfométricas significativas em relação ao GC.

Sugerindo que há necessidade de um tempo de administração maior da planta para o aparecimento de lesões mais acentuadas como as que ocorrem em casos naturais. Os resultados laboratoriais de sangue e do líquido céfalo-raquidiano não refletem alterações relacionadas à intoxicação pela planta.

Some species of Solanum cause poisoning in ruminants clinically characterized by cerebellar disorders and microscopically lysosomal storage disease. There are no specific necropsy injuries and microscopically occurs vacuolation and Purkinje cells loss. Since Solanum paniculatum is the species of greater occurrence in the Northeast region of Brazil and is responsible for spontaneous intoxication outbreaks in Pernambuco State, an experimental delineation was carried out to characterize the clinical and pathological condition of the intoxication. Five cattle were randomly allotted in two groups, with four animals in the experimental group (EG) and one animal as control (CG), with six months of age, no defined breed and weighting 120 kg. All animals were kept in stalls along 5 months in the Clínica de Bovinos de Garanhuns/UFRPE. All animals from the experimental group were fed 5g/kg/body weight/day of the dried leaves of S. paniculatum which was mixed in the ration. The plant was collected in farms where outbreaks of intoxication were described. A Head Raising Test was weekly performed to determine the occurrence of any cerebellum clinical signs and when the result was positive the animal was submitted to a blood and cerebrospinal fluid sampling and subsequently euthanized.

Relação entre a linfopenia e a persistência da papilomatose alimentar em bovinos intoxicados crônica e espontaneamente por samambaia (Pteridium aquilinum) / Relationship between lymphopenia and the persistence of alimentary papillomatosis in cattle chronically and spontaneously poisoned by bracken fern (Pteridium aquilinum)

Papilomavírus bovino tipo 4 (BPV-4) é responsável pelo desenvolvimento de papilomas no trato alimentar superior (TAS) de bovinos. Os passos necessários para o crescimento, o desenvolvimento e a regressão dos papilomas estão intimamente relacionados com o estado imunológico do animal. A ingestão de samambaia (Pteridium aquilinum) tem sido relacionada como o principal fator envolvido na persistência da infecção pelo BPV-4 no TAS. A teoria que estabelece a relação entre papilomatose alimentar e a formação de CCEs sugere a produção de um estado imunossupressivo crônico pela planta, permitindo a persistência dos papilomas no TAS. Os papilomas serviriam então como sítios de desenvolvimento dos CCEs através da interação entre as proteínas do BPV-4 e os carcinógenos da samambaia. O objetivo deste estudo foi avaliar a relação entre a quantidade de linfócitos circulantes e a papilomatose alimentar em casos de intoxicação espontânea crônica por P. aquilinum em bovinos com CCE no TAS. Quarenta bovinos com CCEs no TAS foram avaliados quanto à idade, à intensidade da papilomatose alimentar no TAS e ao leucograma. Três bovinos tinham leucopenia e um apresentava neutrofilia. A média de linfócitos foi de 5.395 (±1.696) na papilomatose leve, 4.560 (±1.561) na moderada e 5.007 (±1.786) na acentuada. Não houve diferença estatisticamente significativa entre o grau de papilomatose, a idade e a quantidade de linfócitos circulantes. Imunossupressão por linfopenia foi um achado esporádico (três casos) neste estudo. Os resultados indicam que a persistência da papilomatose alimentar em casos espontâneos de intoxicação crônica por samambaia em bovinos não tem relação com a quantidade de linfócitos circulantes e que talvez esteja relacionada a outros fatores imunológicos.

Bovine papillomavirus type-4 (BPV-4) is responsible for the development of papillomas in the upper digestive tract (UDT) of cattle. The necessary steps for the development, growth and regression of papillomas are intimately related with the immunological status of the animal. The consumption of bracken fern (Pteridium aquilinum) has been pointed out as the major factor involved in the persistence of BPV-4 infection of the UDT. The theory involving the relationship between alimentary papillomas and the formation of squamous cell carcinomas (SCCs) suggests the persistence of alimentary papillomatosis through a chronic immunosupressive lymphopenic state induced by bracken fern. The papillomas would serve then as a development site of SCCs through the interaction of BPV-4 oncoproteins and bracken carcinogens. The objective of this study was to evaluate the relationship between lymphopenia and alimentary papillomatosis in spontaneous cases of chronic bracken fern poisoning of cattle. The age, intensity of papillomatosis and the leukon were evaluated of 40 cattle with SCCs of the UDT. Three animals had leukopenia and one had neutrophilia. The mean lymphocyte count (and standart deviation) of mild, moderate and severe papillomatosis was 5,395(±1,696)/mm³, 4,560(±1,561)/mm³ and 5,007(±1,786)/mm³, respectively. There were no statistically significant differences between the intensity of alimentary papillomasis, age and the lymphocyte count. Immunosupression by lymphopenia was a sporadic finding (three cases) in the present study. The results demonstrate that the persistence of alimentary papilomatosis in spontaneous cases of bracken fern-related SCCs of the UDT is not related to lymphopenia and it may be related to other immunological factors.