In vitro anthelmintic activity of an R-carvone nanoemulsions towards multiresistant Haemonchus contortus.

This work aimed to evaluate the in vitro anthelmintic effect of carvone nanoemulsions on Haemonchus contortus. Three R-carvone nanoemulsions were prepared: uncoated R-carvone nanoemulsions homogenized in a sonicator (UNAlg-son) and homogenized in an ultrahomogenizer (UNAlg-ultra) and sodium alginate-coated R-carvone (CNAlg-ultra). The physicochemical characterizations of the nanoemulsions were carried out. The anthelmintic activity was evaluated using egg hatch test (EHT), larval development test (LDT) and adult worm motility test (AWMT). Changes in cuticle induced in adult H. contortus were evaluated by scanning electron microscopy (SEM). The results were subjected to analysis of variance and compared using the Tukey test (P < 0.05). The effective concentration to inhibit 50% (EC50) of egg hatching and larval development was calculated. The particle sizes were 281.1 nm (UNAlg-son), 152.7 nm (UNAlg-ultra) and 557.8 nm (CNAlg-ultra), and the zeta potentials were −15 mV (UNAlg-son), −10.8 mV (UNAlg-ultra) and −24.2 mV (CNAlg-ultra). The encapsulation efficiency was 99.84 ± 0.01%. SEM of the nanoemulsions showed an increase in size. In EHT, the EC50 values of UNAlg-son, UNAlg-ultra and CNAlg-ultra were 0.19, 0.02 and 0.17 mg mL−1, respectively. In LDT, they were 0.29, 0.31 and 0.95 mg mL−1 for UNAlg-son, UNAlg-ultra and CNAlg-ultra, respectively. The adult motility inhibition was 100% after 12 h of exposure to UNAlg-ultra and CNAlg-ultra, while for UNAlg-son, it was 79.16%. SEM showed changes in the buccal capsule and cuticular damage. It was concluded that R-carvone nanoemulsions showed antiparasitic action demonstrating promise for the control of infections caused by gastrointestinal nematodes in small ruminants.

Occurrence of tick-borne pathogens in dogs in a coastal region of the state of Ceará, northeastern Brazil.

The aim of this study was to determine the occurrence of tick-borne pathogens (Ehrlichia canis, Babesia vogeli, Hepatozoon spp. and Rickettsia spp.) in dogs in Vila de Jericoacoara, coastal region of Ceará, Brazil. Blood samples were collected from 153 animals and analyzed using molecular and serological methods. Sixty animals were found to be infected or exposed to at least one of the pathogens studied. Babesia vogeli was the most prevalent pathogen (15%), followed by E. canis (13.7%) and Hepatozoon spp. (11.8%), which was identified as Hepatozoon canis through sequencing. Twenty dogs (13%) were seroreactive to Rickettsia spp. Rhipicephalus sanguineus sensu lato was observed on 11.8% of the animals. There were associations between age (< 3 years old) and positivity for B. vogeli, and between habitation (stray dogs) and positivity for H. canis. There were also associations between anemia and infection with H. canis, and between leukopenia and exposure to Rickettsia spp. No association was detected between clinical alterations and infection with or exposure to the pathogens studied. The results confirmed that pathogens of veterinary importance are circulating in northeastern Brazil and showed that dogs are exposed to Rickettsia species with zoonotic potential, thus indicating a need for vector control measures.

Phenotypic and genotypic approaches for detection of anthelmintic resistant sheep gastrointestinal nematodes from Brazilian northeast.

The aim of this study was to characterize the anthelmintic resistance (AR) of a sheep gastrointestinal nematode population, named Caucaia, from northeastern Brazil. Phenotypic tests performed were: egg hatch (EHT), larval development (LDT) and fecal egg count reduction (FECRT). Benzimidazoles (BZs) genotypic evaluation was by frequency of single nucleotide polymorphisms (SNPs) F200Y, F167Y and E198A, and for levamisole (LEV), by frequency of resistance alleles of Hco-acr-8 gene. The primers were designed specifically for Haemonchus contortus. Effective concentrations 50% (EC50) for BZs (EHT), and for macrocyclic lactones (MLs) and LEV (LDT) were 1.02 µg/mL, 1.81 ng/mL and 0.04 µg/mL, respectively. Resistance ratios for MLs and LEV were 0.91 and 3.07, respectively. FECRT efficacies of BZs, MLs, monepantel (MPTL) and LEV were 52.4; 87.0; 94.5 and 99.6%, respectively. qPCR for BZs demonstrated resistance allele frequencies of 0%, 26.24% and 69.08% for SNPs E198A, F200Y and F167Y, respectively. For LEV, 54.37% of resistance alleles were found. There was agreement between EHT, FECRT and qPCR for BZs, and agreement between LDT and qPCR for LEV. Thus, based on higher sensitivity of qPCR, and phenotypic evaluation, the Caucaia population was considered resistant to BZs, MLs, LEV and suspect for MPTL.

Anthelmintic activity of nanoencapsulated carvacryl acetate against gastrointestinal nematodes of sheep and its toxicity in rodents.

The objective of this study was to evaluate the efficacy of carvacryl acetate (CVA) and nanoencapsulated CVA (nCVA) on gastrointestinal nematodes of sheep. The CVA was nanoencapsulated with chitosan/gum arabic and the efficacy of nanoencapsulation (EE), yield, zeta potential, nanoparticle morphology and release kinetics at pH 3 and 8 were analyzed. Acute and subchronic toxicity were evaluated in rodents and reduction of egg counts in the faeces (FECRT) of sheep. The sheep were divided into four groups (n = 10): G1, 250 mg/kg CVA; G2, 250 mg/kg nCVA; G3, polymer matrix and G4: 2.5 mg/kg monepantel. EE and nCVA yield were 65% and 57%, respectively. The morphology of the nanoparticles was spherical, size (810.6±286.7 nm), zeta potential in pH 3.2 (+18.3 mV) and the 50% release of CVA at pHs 3 and 8 occurred at 200 and 10 h, respectively. nCVA showed LD50 of 2,609 mg/kg. CVA, nCVA and monepantel reduced the number of eggs per gram of faeces (epg) by 57.7%, 51.1% and 97.7%, respectively. The epg of sheep treated with CVA and nCVA did not differ from the negative control (P>0.05). Nanoencapsulation reduced the toxicity of CVA; however, nCVA and CVA presented similar results in the FECRT.

Anthelmintic effect of Cymbopogon citratus essential oil and its nanoemulsion on sheep gastrointestinal nematodes.

The anthelmintic resistance stimulated the search for strategies for controlling gastrointestinal nematodes, including the use of free essential oils or its nanoemulsion. This study evaluated the anthelmintic efficacy of Cymbopogon citratus essential oil (CcEO) and C. citratus essential oil nanoemulsion (CcEOn). Pysicochemical analyses were performed. The in vitro effect was determined using the egg hatch test (EHT) on Haemonchus contortus and in vivo effect was evaluated in sheep infected with gastrointestinal nematodes. The animals were treated with CcEO (500 mg/kg) or CcEOn (450 mg/kg) for the fecal egg count (FEC) and the determination of worm burden. The main component of CcEO was citral. The CcEO content in the nanoemulsion was 20% (v/v), and the mean particle size was 248 nm. In EHT, CcEO and CcEOn (1.25 mg/mL) inhibited larval hatching by 98.4 and 97.1%, respectively. Three animals treated with CcEO died whereas in the group treated with CcEOn one animal died. The FEC and total worm burden of the treated groups did not differ from the negative control (p>0.05). The CcEOn showed efficacy only on H. contortus (p<0.05). In conclusion, nanoencapsulation reduced toxicity and increased efficacy on H. contortus.

Anthelmintic activity of Eucalyptus citriodora essential oil and its major component, citronellal, on sheep gastrointestinal nematodes.

This study aimed to evaluate the anthelmintic activity of Eucalyptus citriodora essential oil and citronellal on sheep gastrointestinal nematodes. Essential oil composition was determined by gas chromatography mass spectrometry. The substances were evaluated in vitro using adult worm motility test (AWMT) and transmission electron microscopy (TEM). The acute toxicity test in mice and the fecal egg count reduction test (FECRT) in sheep were performed. Citronellal was confirmed as the essential oil major constituent (63.9%). According to the AWMT, 2 mg/mL of essential oil and citronellal completely inhibited Haemonchus contortus motility at 6 h post exposure. H. contortus exposed to essential oil and citronellal exhibited internal ultrastructural modifications. The lethal dose 50 values in mice were 5,000 and 2,609 mg/kg for essential oil and citronellal, respectively. E. citriodora essential oil reduced sheep epg at 14 days post treatment by 69.5% (P<0.05). No significant differences were observed in epg between the citronellal and negative control groups (P>0.05). The interaction between citronellal and other constituents in the essential oil may be relevant for its in vivo anthelmintic activity. Thus, E. citriodora essential oil and citronellal pharmacokinetic studies may help elucidate the anthelmintic activity of these compounds.

Profilaxia antirrábica humana: um diagnóstico de riscos e desperdícios em Fortaleza, Ceará, 2009 a 2019 / Human anti-rabies prophylaxis: a diagnosis of risks and wastes in Fortaleza, Ceará, 2009 to 2019 / Profilaxia humana antirrábica: um diagnóstico de riesgos y desperdicios en Fortaleza, Ceará, 2009 a 2019

Introdução: A raiva é uma antropozoonose que acomete apenas mamíferos. Todo atendimento por acidente por animal potencialmente transmissor da raiva deve ser notificado. A correta indicação de uso dos insumos para o tratamento profilático deve obedecer às normas do Ministério da Saúde, para que não sejam prescritos tratamentos incorretos ou desnecessários. Objetivo: Avaliar o desperdício de imunobiológicos e os riscos aos quais pacientes foram expostos devido a prescrições inadequadas da profilaxia antirrábica humana no município de Fortaleza, Ceará, de 2009 a 2019. Método: Estudo descritivo com dados secundários consolidados das Fichas de Investigação de Atendimento Antirrábico Humano do Sistema de Informação de Agravos de Notificação (SINAN). Resultados: Foram incluídas 53.251 notificações de atendimento antirrábico humano nesse trabalho. Deste total, 43,8% prescrições foram incorretas, sendo que 55,7% ofereceram risco à vida do paciente e 42,9% envolveram excesso de vacinas. Além disso, 43,3% continham lacunas em seu preenchimento. Conclusão: Foi possível constatar o alto percentual de fichas de atendimento antirrábico humano com prescrições inadequadas e preenchimento incompleto, evidenciando a necessidade de capacitação dos profissionais de saúde. Sugere-se a inclusão de médicos veterinários nos serviços de Atenção Primária e Vigilância Epidemiológica para reduzir erros e otimizar a utilização dos recursos públicos.

Introduction: Rabies is an anthropozoonosis that affects only mammals. All care for an accident by a potential rabies-transmitting animal must be notified. The correct designation of supplies for prophylactic treatment in Brazil must comply with the norms of the Brazilian Ministry of Health, so that incorrect or unnecessary treatments are not prescribed. Objective: To evaluate the immunobiological waste and the risks to which patients were exposed due to inadequate prescriptions for human anti-rabies prophylaxis in the city of Fortaleza, Ceará, from 2009 to 2019. Methods: Descriptive study using with consolidated secondary data from the Investigation Forms of Human Anti-rabies Care of the Brazilian Notifiable Diseases Information System. Results: 53,251 notifications of human anti-rabies care were included in this study. Of this total, 43.8% prescriptions were incorrect, with 55.7% offering risk to the patient's life and 42.9% involving excess vaccines. In addition, 43.3% contained gaps on notification form filling. Conclusion: It was possible to verify high percentage of records of human anti-rabies care with inadequate prescriptions and incomplete form filling, showing the need of training of health professionals. It is suggested that veterinarians be included in Primary Care and Epidemiological Monitoring services to reduce errors and optimize the use of public resources.

Introducción: La rabia es una antropozoonosis que afecta únicamente a los mamíferos. Toda atención a un accidente por un animal potencialmente transmisor de la rabia debe ser notificada. La indicación correcta para el uso de insumos para el tratamiento profiláctico debe cumplir con las normas del Ministerio de Salud brasileño, para que no se prescriban tratamientos incorrectos O innecesarios. Objetivo: Evaluar el desperdicio de inmunobiológicos y los riesgos que estuvieron expuestos los pacientes por prescripción inadecuada de profilaxis antirrábica humana en la ciudad de Fortaleza, Ceará, de 2009 a 2019. Métodos: Estudio descriptivo con datos secundarios consolidados de los Formularios de Investigación de Atención Antirrábica Humana del Sistema de Información de Enfermedades de Declaración Obligatoria brasileño. Resultados: En este estudio se incluyeron 53.251 notificaciones de atención antirrábica en humanos. De este total, el 43,8% de las prescripciones fueron incorrectas, el 55,7% de las cuales ofrecieron riesgo para la vida del paciente y el 42,9% involucró un exceso de vacunas. Además, el 43,3% contenía lagunas em su llenado. Conclusión: Se pudo constatar el alto porcentaje de registros de atención antirrábica humana con prescripción inadecuada y llenado incompleto, evidenciando la necesidad de capacitación de los profesionales de la salud. Se sugiere incluir a los veterinarios en los servicios de Atención Primaria y Vigilancia Epidemiológica para reducir errores y optimizar el uso de los recursos públicos.

Occurrence of tick-borne pathogens in dogs in a coastal region of the state of Ceará, northeastern Brazil / Ocorrência de patógenos transmitidos por carrapatos em cães em uma região litorânea do estado do Ceará, nordeste do Brasil

Abstract The aim of this study was to determine the occurrence of tick-borne pathogens (Ehrlichia canis, Babesia vogeli, Hepatozoon spp. and Rickettsia spp.) in dogs in Vila de Jericoacoara, coastal region of Ceará, Brazil. Blood samples were collected from 153 animals and analyzed using molecular and serological methods. Sixty animals were found to be infected or exposed to at least one of the pathogens studied. Babesia vogeli was the most prevalent pathogen (15%), followed by E. canis (13.7%) and Hepatozoon spp. (11.8%), which was identified as Hepatozoon canis through sequencing. Twenty dogs (13%) were seroreactive to Rickettsia spp. Rhipicephalus sanguineus sensu lato was observed on 11.8% of the animals. There were associations between age (< 3 years old) and positivity for B. vogeli, and between habitation (stray dogs) and positivity for H. canis. There were also associations between anemia and infection with H. canis, and between leukopenia and exposure to Rickettsia spp. No association was detected between clinical alterations and infection with or exposure to the pathogens studied. The results confirmed that pathogens of veterinary importance are circulating in northeastern Brazil and showed that dogs are exposed to Rickettsia species with zoonotic potential, thus indicating a need for vector control measures.

Resumo O objetivo deste estudo foi determinar a ocorrência de patógenos transmitidos por carrapatos (Ehrlichia canis, Babesia vogeli, Hepatozoon spp. e Rickettsia spp.) em cães na Vila de Jericoacoara, região costeira do Ceará, Brasil. Amostras de sangue foram coletadas de 153 animais e analisadas por métodos moleculares e sorológicos. Sessenta animais foram encontrados infectados ou expostos a pelo menos a um dos patógenos estudados. Babesia vogeli foi o patógeno mais prevalente (15%), seguido por E. canis (13,7%) e Hepatozoon spp. (11,8%), que foi identificado como Hepatozoon canis por sequenciamento. Vinte cães (13%) foram sororreativos à Rickettsia spp. Rhipicephalus sanguineus sensu lato foi observado em 11,8% dos animais. Houve associações entre idade (<3 anos) e positividade para B. vogeli, e entre habitação (cães de rua) e positividade para H. canis. Também houve associações entre anemia e infecção por H. canis, e entre leucopenia e exposição a Rickettsia spp. Não foi detectada associação entre alterações clínicas e infecção ou exposição aos patógenos estudados. Os resultados confirmaram que patógenos de importância veterinária estão circulando no nordeste do Brasil e mostraram que cães estão expostos a espécies de Rickettsia com potencial zoonótico, indicando a necessidade de medidas de controle do vetor.

Anthelmintic activity of Cymbopogon citratus against Haemonchus contortus.

Parasitic nematodes are of major economic importance in livestock. An alternative for the control of parasites is phytotherapy. This study evaluated the efficacy of Cymbopogon citratus decoction (CcD), C. citratus essential oil (CcEo) and citral against Haemonchus contortus using in vitro egg hatch test (EHT) and larval development test (LDT) and an in vivo test using a Meriones unguiculatus (gerbil) model. The effect of 800 mg/kg CcEo was evaluated in gerbils that had been artificially infected with 5,000 third-stage H. contortus larvae. The effective concentrations required to inhibit 50% (EC50) of egg hatching were 0.46, 0.14 and 0.13 mg/mL for CcD, CcEo and citral, respectively. The EC50 values in the LDT were 5.04, 1.92 and 1.37 mg/mL for CcD, CcEo and citral, respectively. H. contortus population in the group treated with C. citratus essential oil was reduced by 38.5% (P< 0.05) in comparison to the control group. These results suggest that it may be possible to use C. citratus essential oil to control of H. contortus parasite of small ruminant.

Chemical constituents of Calotropis procera latex and ultrastructural effects on Haemonchus contortus / Constituintes químicos do látex de Calotropis procera e efeitos ultraestruturais em Haemonchus contortus

This study aimed to evaluate the anthelmintic and ultrastructural effects of Calotropis procera latex on Haemonchus contortus. C. procera latex was twice centrifuged at 10,000×g and dialyzed to obtain a fraction rich in proteins, named LP (latex protein), and at 3,000 rpm to obtain a fraction rich in secondary metabolites, named LNP (latex non-protein). Specimens of H. contortus exposed to LNP, LP and PBS in the Adult Worm Motility Test (AWMT) were submitted to scanning (SEM) and transmission (TEM) electron microscopy to verify changes in their ultrastructure. Phytochemical tests in the LNP indicated the presence of phenols, steroids, alkaloids and cardenolides. High-Performance Liquid Chromatography (HPLC) characterized the presence of the compounds gallic acid and quercetin in the LNP. The protein content in the LP was 43.1 ± 1.1 mg/mL and 7.7 ± 0.3 mg/mL in LNP. In AWMT, LNP and LP inhibited the motility of 100% of the nematodes, with LNP being more effective than LP and ivermectin more effective than both (p <0.05). Cuticle changes were observed by SEM and TEM in nematodes treated with LP and LNP. Calotropis procera latex has anthelmintic effects against H. contortus, causing damage to its cuticle and other alterations in its ultrastructure.(AU)

Este estudo objetivou avaliar os efeitos anti-helmínticos e ultraestruturais do látex de Calotropis procera sobre Haemonchus contortus. Látex de C. procera foi centrifugado duas vezes à a 10.000xg e dialisado para obter uma fração rica em proteínas, denominada proteínas do látex (LP). E centrifugado e centrifugado a 3.000 rpm, para obter uma fração rica em metabólitos secundários, denominada LNP (látex não proteico). Espécimes de H. contortus expostos à LNP, LP e PBS no Teste de Motilidade dos Nematoides Adultos (TMNA) foram submetidos a microscopia eletrônica de varredura (MEV) e de transmissão (MET), para verificar alterações em sua ultraestrutura. Testes fitoquímicos em LNP indicaram a presença de fenóis, esteroides, alcaloides e cardenolídeos. A presença dos compostos ácido gálico e quercetina em LNP foi caracterizada por Cromatografia Líquida de Alta Eficiência (CLAE). O conteúdo de proteínas em LP foi de 43,1 ± 1,1 mg/mL e de 7,7 ± 0,3 mg/mL em LNP. No TMNA, LNP e LP inibiram a motilidade de 100% dos nematoides, sendo LNP mais eficaz que LP, e a ivermectina mais eficaz que ambos (p <0,05). Alterações na cutícula de nematoides tratados com LP e LNP foram observadas por MEV e MET. O látex de C. procera apresenta efeito anti-helmíntico sobre H. contortus, causando danos à sua cutícula e outras alterações em sua ultraestrutura.(AU)

Anthelmintic activity of nanoencapsulated carvacryl acetate against gastrointestinal nematodes of sheep and its toxicity in rodents / Atividade anti-helmíntica do acetato de carvacrila nanoencapsulado sobre nematoides gastrintestinais de ovinos e toxicidade em roedores

The objective of this study was to evaluate the efficacy of carvacryl acetate (CVA) and nanoencapsulated CVA (nCVA) on gastrointestinal nematodes of sheep. The CVA was nanoencapsulated with chitosan/gum arabic and the efficacy of nanoencapsulation (EE), yield, zeta potential, nanoparticle morphology and release kinetics at pH 3 and 8 were analyzed. Acute and subchronic toxicity were evaluated in rodents and reduction of egg counts in the faeces (FECRT) of sheep. The sheep were divided into four groups (n = 10): G1, 250 mg/kg CVA; G2, 250 mg/kg nCVA; G3, polymer matrix and G4: 2.5 mg/kg monepantel. EE and nCVA yield were 65% and 57%, respectively. The morphology of the nanoparticles was spherical, size (810.6±286.7 nm), zeta potential in pH 3.2 (+18.3 mV) and the 50% release of CVA at pHs 3 and 8 occurred at 200 and 10 h, respectively. nCVA showed LD50 of 2,609 mg/kg. CVA, nCVA and monepantel reduced the number of eggs per gram of faeces (epg) by 57.7%, 51.1% and 97.7%, respectively. The epg of sheep treated with CVA and nCVA did not differ from the negative control (P>0.05). Nanoencapsulation reduced the toxicity of CVA; however, nCVA and CVA presented similar results in the FECRT.(AU)

O objetivo deste trabalho foi avaliar a eficácia do acetato de carvacrila (ACV) e do ACV nanoencapsulado (nACV) sobre nematóides gastrintestinais de ovinos. O ACV foi nanoencapsulado com quitosana/goma arábica e foi analisada a eficácia de nanoencapsulamento (EE), o rendimento, potencial zeta, morfologia das nanopartículas e cinética de liberação em pH 3 e 8. Foram avaliadas as toxicidades aguda e subcrônica em roedores e a redução da contagem de ovos nas fezes (RCOF) de ovinos. Os ovinos foram divididos em quatro grupos (n = 10): G1, 250 mg/kg ACV; G2, 250 mg/kg de nACV; G3, matriz polimérica e G4: 2,5 mg/kg de monepantel. A EE e o rendimento de nACV foram de 65% e 57%, respectivamente. A morfologia das nanopartículas foi esférica, tamanho (810,6±286,7 nm), potencial zeta no pH 3,2 (+18,3 mV) e a liberação de 50% de CVA nos pHs 3 e 8 ocorreu às 200 e 10 h, respectivamente. nACV apresentou DL50 de 2.609 mg/kg. ACV, nACV e o monepantel reduziram a contagem de ovos por grama de fezes (opg) em 57,7%, 51,1% e 97,7%, respectivamente. A contagem de opg de ovelhas tratadas com ACV e nCVA não diferiu do controle negativo (P>0,05). O nanoencapsulamento reduziu a toxicidade do AVC; no entanto, nACV e ACV apresentaram resultados semelhantes na RCOF.(AU)

Anthelmintic activity of nanoencapsulated carvacryl acetate against gastrointestinal nematodes of sheep and its toxicity in rodents / Atividade anti-helmíntica do acetato de carvacrila nanoencapsulado sobre nematoides gastrintestinais de ovinos e toxicidade em roedores

Abstract The objective of this study was to evaluate the efficacy of carvacryl acetate (CVA) and nanoencapsulated CVA (nCVA) on gastrointestinal nematodes of sheep. The CVA was nanoencapsulated with chitosan/gum arabic and the efficacy of nanoencapsulation (EE), yield, zeta potential, nanoparticle morphology and release kinetics at pH 3 and 8 were analyzed. Acute and subchronic toxicity were evaluated in rodents and reduction of egg counts in the faeces (FECRT) of sheep. The sheep were divided into four groups (n = 10): G1, 250 mg/kg CVA; G2, 250 mg/kg nCVA; G3, polymer matrix and G4: 2.5 mg/kg monepantel. EE and nCVA yield were 65% and 57%, respectively. The morphology of the nanoparticles was spherical, size (810.6±286.7 nm), zeta potential in pH 3.2 (+18.3 mV) and the 50% release of CVA at pHs 3 and 8 occurred at 200 and 10 h, respectively. nCVA showed LD50 of 2,609 mg/kg. CVA, nCVA and monepantel reduced the number of eggs per gram of faeces (epg) by 57.7%, 51.1% and 97.7%, respectively. The epg of sheep treated with CVA and nCVA did not differ from the negative control (P>0.05). Nanoencapsulation reduced the toxicity of CVA; however, nCVA and CVA presented similar results in the FECRT.

Resumo O objetivo deste trabalho foi avaliar a eficácia do acetato de carvacrila (ACV) e do ACV nanoencapsulado (nACV) sobre nematóides gastrintestinais de ovinos. O ACV foi nanoencapsulado com quitosana/goma arábica e foi analisada a eficácia de nanoencapsulamento (EE), o rendimento, potencial zeta, morfologia das nanopartículas e cinética de liberação em pH 3 e 8. Foram avaliadas as toxicidades aguda e subcrônica em roedores e a redução da contagem de ovos nas fezes (RCOF) de ovinos. Os ovinos foram divididos em quatro grupos (n = 10): G1, 250 mg/kg ACV; G2, 250 mg/kg de nACV; G3, matriz polimérica e G4: 2,5 mg/kg de monepantel. A EE e o rendimento de nACV foram de 65% e 57%, respectivamente. A morfologia das nanopartículas foi esférica, tamanho (810,6±286,7 nm), potencial zeta no pH 3,2 (+18,3 mV) e a liberação de 50% de CVA nos pHs 3 e 8 ocorreu às 200 e 10 h, respectivamente. nACV apresentou DL50 de 2.609 mg/kg. ACV, nACV e o monepantel reduziram a contagem de ovos por grama de fezes (opg) em 57,7%, 51,1% e 97,7%, respectivamente. A contagem de opg de ovelhas tratadas com ACV e nCVA não diferiu do controle negativo (P>0,05). O nanoencapsulamento reduziu a toxicidade do AVC; no entanto, nACV e ACV apresentaram resultados semelhantes na RCOF.

Anthelmintic activity of Eucalyptus citriodora essential oil and its major component, citronellal, on sheep gastrointestinal nematodes / Atividade anti-helmíntica do óleo essencial de Eucalyptus citriodora e seu componente majoritário, citronelal, sobre nematoides gastrintestinais de ovinos

This study aimed to evaluate the anthelmintic activity of Eucalyptus citriodora essential oil and citronellal on sheep gastrointestinal nematodes. Essential oil composition was determined by gas chromatography mass spectrometry. The substances were evaluated in vitro using adult worm motility test (AWMT) and transmission electron microscopy (TEM). The acute toxicity test in mice and the fecal egg count reduction test (FECRT) in sheep were performed. Citronellal was confirmed as the essential oil major constituent (63.9%). According to the AWMT, 2 mg/mL of essential oil and citronellal completely inhibited Haemonchus contortus motility at 6 h post exposure. H. contortus exposed to essential oil and citronellal exhibited internal ultrastructural modifications. The lethal dose 50 values in mice were 5,000 and 2,609 mg/kg for essential oil and citronellal, respectively. E. citriodora essential oil reduced sheep epg at 14 days post treatment by 69.5% (P 0.05). No significant differences were observed in epg between the citronellal and negative control groups (P>0.05). The interaction between citronellal and other constituents in the essential oil may be relevant for its in vivo anthelmintic activity. Thus, E. citriodora essential oil and citronellal pharmacokinetic studies may help elucidate the anthelmintic activity of these compounds.(AU)

Este trabalho objetivou avaliar a atividade anti-helmíntica do óleo essencial de Eucalyptus citriodora e citronelal sobre nematoides gastrintestinais de ovinos. A composição do óleo essencial foi determinada por cromatografia gasosa acoplada à espectrometria de massas. As substâncias foram avaliadas in vitro utilizando-se teste de motilidade de vermes adultos (AWMT) e microscopia eletrônica de transmissão (TEM). Teste de toxicidade aguda em camundongos e teste de redução da contagem de ovos fecais (FECRT) em ovinos foram realizados. Citronelal foi confirmado como componente majoritário do óleo essencial (63,9%). No AWMT, 2 mg/mL de óleo essencial e citronelal inibiram completamente a motilidade de H. contortus 6 h pós-exposição. H. contortus expostos ao óleo essencial e citronelal exibiram modificações ultraestruturais internas. Os valores da dose letal 50 em camundongos foram 5.000 e 2.609 mg/kg para óleo essencial e citronelal, respectivamente. Óleo essencial de E. citriodora reduziu opg de ovinos 14 dias pós-tratamento em 69,5% (P 0,05). Não houve diferença significativa de opg entre grupo controle negativo e citronelal (P>0,05). A interação entre citronelal e outros constituintes do óleo essencial pode ser relevante na atividade anti-helmíntica in vivo. Portanto, avaliação farmacocinética do óleo essencial de E. citriodora e citronelal pode auxiliar a elucidar a atividade anti-helmíntica desses compostos.(AU)

Anthelmintic activity of Eucalyptus citriodora essential oil and its major component, citronellal, on sheep gastrointestinal nematodes / Atividade anti-helmíntica do óleo essencial de Eucalyptus citriodora e seu componente majoritário, citronelal, sobre nematoides gastrintestinais de ovinos

Abstract This study aimed to evaluate the anthelmintic activity of Eucalyptus citriodora essential oil and citronellal on sheep gastrointestinal nematodes. Essential oil composition was determined by gas chromatography mass spectrometry. The substances were evaluated in vitro using adult worm motility test (AWMT) and transmission electron microscopy (TEM). The acute toxicity test in mice and the fecal egg count reduction test (FECRT) in sheep were performed. Citronellal was confirmed as the essential oil major constituent (63.9%). According to the AWMT, 2 mg/mL of essential oil and citronellal completely inhibited Haemonchus contortus motility at 6 h post exposure. H. contortus exposed to essential oil and citronellal exhibited internal ultrastructural modifications. The lethal dose 50 values in mice were 5,000 and 2,609 mg/kg for essential oil and citronellal, respectively. E. citriodora essential oil reduced sheep epg at 14 days post treatment by 69.5% (P<0.05). No significant differences were observed in epg between the citronellal and negative control groups (P>0.05). The interaction between citronellal and other constituents in the essential oil may be relevant for its in vivo anthelmintic activity. Thus, E. citriodora essential oil and citronellal pharmacokinetic studies may help elucidate the anthelmintic activity of these compounds.

Resumo Este trabalho objetivou avaliar a atividade anti-helmíntica do óleo essencial de Eucalyptus citriodora e citronelal sobre nematoides gastrintestinais de ovinos. A composição do óleo essencial foi determinada por cromatografia gasosa acoplada à espectrometria de massas. As substâncias foram avaliadas in vitro utilizando-se teste de motilidade de vermes adultos (AWMT) e microscopia eletrônica de transmissão (TEM). Teste de toxicidade aguda em camundongos e teste de redução da contagem de ovos fecais (FECRT) em ovinos foram realizados. Citronelal foi confirmado como componente majoritário do óleo essencial (63,9%). No AWMT, 2 mg/mL de óleo essencial e citronelal inibiram completamente a motilidade de H. contortus 6 h pós-exposição. H. contortus expostos ao óleo essencial e citronelal exibiram modificações ultraestruturais internas. Os valores da dose letal 50 em camundongos foram 5.000 e 2.609 mg/kg para óleo essencial e citronelal, respectivamente. Óleo essencial de E. citriodora reduziu opg de ovinos 14 dias pós-tratamento em 69,5% (P<0,05). Não houve diferença significativa de opg entre grupo controle negativo e citronelal (P>0,05). A interação entre citronelal e outros constituintes do óleo essencial pode ser relevante na atividade anti-helmíntica in vivo. Portanto, avaliação farmacocinética do óleo essencial de E. citriodora e citronelal pode auxiliar a elucidar a atividade anti-helmíntica desses compostos.

Anthelmintic effect of Cymbopogon citratus essential oil and its nanoemulsion on sheep gastrointestinal nematodes / Efeito anti-helmíntico do óleo essencial de Cymbopogon citratus e sua nanoemulsão sobre nematoides gastrintestinais de ovinos

The anthelmintic resistance stimulated the search for strategies for controlling gastrointestinal nematodes, including the use of free essential oils or its nanoemulsion. This study evaluated the anthelmintic efficacy of Cymbopogon citratus essential oil (CcEO) and C. citratus essential oil nanoemulsion (CcEOn). Pysicochemical analyses were performed. The in vitro effect was determined using the egg hatch test (EHT) on Haemonchus contortus and in vivo effect was evaluated in sheep infected with gastrointestinal nematodes. The animals were treated with CcEO (500 mg/kg) or CcEOn (450 mg/kg) for the fecal egg count (FEC) and the determination of worm burden. The main component of CcEO was citral. The CcEO content in the nanoemulsion was 20% (v/v), and the mean particle size was 248 nm. In EHT, CcEO and CcEOn (1.25 mg/mL) inhibited larval hatching by 98.4 and 97.1%, respectively. Three animals treated with CcEO died whereas in the group treated with CcEOn one animal died. The FEC and total worm burden of the treated groups did not differ from the negative control (p>0.05). The CcEOn showed efficacy only on H. contortus (p 0.05). In conclusion, nanoencapsulation reduced toxicity and increased efficacy on H. contortus.(AU)

A resistência anti-helmíntica estimulou a busca por estratégias de controle de nematoides gastrintestinais, incluindo óleos essenciais livres ou em nanoemulsão. Este estudo avaliou a eficácia anti-helmíntica do óleo essencial de Cymbopogon citratus (OECc) e da nanoemulsão do óleo essencial de C. citratus (nOECc). Análises físico-químicas foram realizadas. O efeito in vitro foi determinado no teste de eclosão de ovos (TEO) sobre Haemonchus contortus e o efeito in vivo foi avaliado em ovinos infectados com nematoides gastrintestinais. Os animais foram tratados com OECc (500 mg/kg) ou nOECc (450 mg/kg) para determinação do número de ovos por grama de fezes (OPG) e carga parasitária. O principal constituinte do OECc foi citral. O conteúdo de OECc na nanoemulsão foi 20% e o tamanho médio de partícula foi 248 nm. No TEO, OECc e nOECc (1,25 mg/mL) inibiram 98,4 e 97,1% da eclosão larvar, respectivamente. Três animais tratados com o OECc morreram, enquanto um animal do grupo tratado com a nOECc morreu. O OPG e a carga parasitária total dos grupos tratados não diferiram do controle negativo (p>0.05). A nOECc apresentou eficácia somente sobre H. contortus (p 0.05). Como conclusão, o nanoencapsulamento reduziu a toxicidade e aumentou a eficácia sobre H. contortus.(AU)

Anthelmintic effect of Cymbopogon citratus essential oil and its nanoemulsion on sheep gastrointestinal nematodes / Efeito anti-helmíntico do óleo essencial de Cymbopogon citratus e sua nanoemulsão sobre nematoides gastrintestinais de ovinos

Abstract The anthelmintic resistance stimulated the search for strategies for controlling gastrointestinal nematodes, including the use of free essential oils or its nanoemulsion. This study evaluated the anthelmintic efficacy of Cymbopogon citratus essential oil (CcEO) and C. citratus essential oil nanoemulsion (CcEOn). Pysicochemical analyses were performed. The in vitro effect was determined using the egg hatch test (EHT) on Haemonchus contortus and in vivo effect was evaluated in sheep infected with gastrointestinal nematodes. The animals were treated with CcEO (500 mg/kg) or CcEOn (450 mg/kg) for the fecal egg count (FEC) and the determination of worm burden. The main component of CcEO was citral. The CcEO content in the nanoemulsion was 20% (v/v), and the mean particle size was 248 nm. In EHT, CcEO and CcEOn (1.25 mg/mL) inhibited larval hatching by 98.4 and 97.1%, respectively. Three animals treated with CcEO died whereas in the group treated with CcEOn one animal died. The FEC and total worm burden of the treated groups did not differ from the negative control (p>0.05). The CcEOn showed efficacy only on H. contortus (p<0.05). In conclusion, nanoencapsulation reduced toxicity and increased efficacy on H. contortus.

Resumo A resistência anti-helmíntica estimulou a busca por estratégias de controle de nematoides gastrintestinais, incluindo óleos essenciais livres ou em nanoemulsão. Este estudo avaliou a eficácia anti-helmíntica do óleo essencial de Cymbopogon citratus (OECc) e da nanoemulsão do óleo essencial de C. citratus (nOECc). Análises físico-químicas foram realizadas. O efeito in vitro foi determinado no teste de eclosão de ovos (TEO) sobre Haemonchus contortus e o efeito in vivo foi avaliado em ovinos infectados com nematoides gastrintestinais. Os animais foram tratados com OECc (500 mg/kg) ou nOECc (450 mg/kg) para determinação do número de ovos por grama de fezes (OPG) e carga parasitária. O principal constituinte do OECc foi citral. O conteúdo de OECc na nanoemulsão foi 20% e o tamanho médio de partícula foi 248 nm. No TEO, OECc e nOECc (1,25 mg/mL) inibiram 98,4 e 97,1% da eclosão larvar, respectivamente. Três animais tratados com o OECc morreram, enquanto um animal do grupo tratado com a nOECc morreu. O OPG e a carga parasitária total dos grupos tratados não diferiram do controle negativo (p>0.05). A nOECc apresentou eficácia somente sobre H. contortus (p<0.05). Como conclusão, o nanoencapsulamento reduziu a toxicidade e aumentou a eficácia sobre H. contortus.

Óleos essenciais e seus compostos bioativos no controle de nematoides gastrintestinais de pequenos ruminantes / Essential oils and their bioactive compounds in the control of gastrointestinal nematodes of small ruminants

Background: Gastrointestinal nematodes are one of the major health and economic problem of sheep and goats in the world. The control of these nematodes is carried out conventionally with synthetic anthelminths, which favored the selection of gastrointestinal nematode (GIN) populations multiresistant to anthelmintics. The emergence of anthelmintic resistance has stimulated the search for new alternatives to control small ruminant GIN, standing out the use of plants and their bioactives compounds, such as essential oils (EO). The objective of this review was to present the main characteristics and anthelmintic activity of EO, their isolated compounds and drug delivery systems in the control of GIN.Review: Essential oils are a complex blend of bioactive compounds with volatile, lipophilic, usually odoriferous and liquid substances. EO are composed of terpenes, terpenoids, aromatic and aliphatic constituents. EO has various pharmacological activities of interest in preventive veterinary medicine such as antibacterials, antifungals, anticoccicids, insecticides and anthelmintics. In vitro and in vivo tests are used to validate the anthelmintic activity of EO on GIN. In vitro tests are low cost screening tests that allow the evaluation of the anthelmintic activity of a large amount of bioactive compounds on eggs, first (L1) and third stage larvae (L3), and adult nematodes. The antiparasitic effect of EO is related to its main compound or to the interaction of the compounds. These bioactive compounds penetrate the cuticle of the nematodes by transcuticular diffusion, altering the mechanisms of locomotion, besides causing cuticular lesions. Following in vitro evaluation, the acute and sub-chronic toxicity test should be performed to assess the toxicity of the bioactive compounds and to define the dose to be used in in vivo tests.[...]

Óleos essenciais e seus compostos bioativos no controle de nematoides gastrintestinais de pequenos ruminantes / Essential oils and their bioactive compounds in the control of gastrointestinal nematodes of small ruminants

Background: Gastrointestinal nematodes are one of the major health and economic problem of sheep and goats in the world. The control of these nematodes is carried out conventionally with synthetic anthelminths, which favored the selection of gastrointestinal nematode (GIN) populations multiresistant to anthelmintics. The emergence of anthelmintic resistance has stimulated the search for new alternatives to control small ruminant GIN, standing out the use of plants and their bioactives compounds, such as essential oils (EO). The objective of this review was to present the main characteristics and anthelmintic activity of EO, their isolated compounds and drug delivery systems in the control of GIN.Review: Essential oils are a complex blend of bioactive compounds with volatile, lipophilic, usually odoriferous and liquid substances. EO are composed of terpenes, terpenoids, aromatic and aliphatic constituents. EO has various pharmacological activities of interest in preventive veterinary medicine such as antibacterials, antifungals, anticoccicids, insecticides and anthelmintics. In vitro and in vivo tests are used to validate the anthelmintic activity of EO on GIN. In vitro tests are low cost screening tests that allow the evaluation of the anthelmintic activity of a large amount of bioactive compounds on eggs, first (L1) and third stage larvae (L3), and adult nematodes. The antiparasitic effect of EO is related to its main compound or to the interaction of the compounds. These bioactive compounds penetrate the cuticle of the nematodes by transcuticular diffusion, altering the mechanisms of locomotion, besides causing cuticular lesions. Following in vitro evaluation, the acute and sub-chronic toxicity test should be performed to assess the toxicity of the bioactive compounds and to define the dose to be used in in vivo tests.[...](AU)

Effect of six tropical tanniferous plant extracts on larval exsheathment of Haemonchus contortus.

Tanniferous plants represent a promising alternative for controlling gastrointestinal nematodes of small ruminants. This experiment evaluated the effects of extracts from the leaf and stem of Anadenanthera colubrina, Leucaena leucocephala and Mimosa tenuiflora on larval exsheathment of Haemonchus contortus in vitro and verified the role of tannins in this process. Third-stage larvae of H. contortus were incubated with extracts for 3 hours and were exposed to sodium hypochlorite solution. The extracts were tested at 300 µg.mL(-1) and accompanied by controls: phosphate buffer solution (PBS) and polyvinyl polypyrrolidone (PVPP). The larval exsheathment was evaluated for 60 minutes, and the results were subjected to the Kruskal-Wallis test (p < 0.05). The six extracts blocked larval exsheathment. After PVPP addition, a tannin inhibitor, the exsheathment percentage was similar to the PBS (p > 0.05), except for L. leucocephala and M. tenuiflora leaf extracts. However, pre-incubation with PVPP of these two extracts significantly changed larval exsheathment when compared to the non-treated extracts (p < 0.05). These results suggest that A. colubrina, L. leucocephala and M. tenuiflora could be useful in gastrointestinal nematode control and that tannins are probably the main compounds involved in the observed effects. However, in vivo and toxicological studies should be conducted.

Anthelmintic activity of Cymbopogon citratus against Haemonchus contortus / Atividade anti-helmíntica de Cymbopogon citratus sobre Haemonchus contortus

Parasitic nematodes are of major economic importance in livestock. An alternative for the control of parasites is phytotherapy. This study evaluated the efficacy of Cymbopogon citratus decoction (CcD), C. citratus essential oil (CcEo) and citral against Haemonchus contortus using in vitro egg hatch test (EHT) and larval development test (LDT) and an in vivo test using a Meriones unguiculatus (gerbil) model. The effect of 800 mg/kg CcEo was evaluated in gerbils that had been artificially infected with 5,000 third-stage H. contortus larvae. The effective concentrations required to inhibit 50% (EC50) of egg hatching were 0.46, 0.14 and 0.13 mg/mL for CcD, CcEo and citral, respectively. The EC50 values in the LDT were 5.04, 1.92 and 1.37 mg/mL for CcD, CcEo and citral, respectively. H. contortus population in the group treated with C. citratus essential oil was reduced by 38.5% (P 0.05) in comparison to the control group. These results suggest that it may be possible to use C. citratusessential oil to control of H. contortus parasite of small ruminant.(AU)

O parasitismo por nematoides tem grande importância econômica no rebanho. Uma alternativa para o controle de parasitas é a fitoterapia. Este estudo avaliou a eficácia do decocto de Cymbopogon citratus (DCc), do óleo essencial de C. citratus (OECc) e do citral contra Haemonchus contortus utilizando o teste in vitro de eclosão dos ovos (TEO) e o teste de desenvolvimento larval (TDL) e um teste in vivo com modelo Meriones unguiculatus (gerbil). O efeito de 800 mg/kg de OECc foi avaliado em gerbils infectados artificialmente com 5000 larvas de terceira fase de H. contortus. As concentrações efetivas necessárias para inibir 50% (CE50) da eclosão dos ovos foram 0,46; 0,14 e 0,13 mg/mL para DCc, OECc e citral, respectivamente. Os valores da CE50 no TDL foram de 5,04; 1,92 e 1,37 mg/mL para DCc, OECc e citral, respectivamente. No grupo tratado com óleo de C. citratus a população H. contortus foi reduzida em 38,5% (P 0,05) em comparação com o grupo controle. Estes resultados sugerem que pode ser possível a utilização de óleo essencial de C. citratus para controle de H. contortus, parasita de pequenos ruminantes.(AU)