RESUMO
Citrus fruits are consumed all over the world and their by-products are used for animal feed and essential oils production. This study aimed to evaluate the in vitro and in vivo activity of Citrus aurantium var. Dulcis essential oil (CaEO) combined with ABZ against benzimidazole resistant Haemonchus contortus. In vitro egg hatching assays (EHA) were performed using CaEO and ABZ to estimate the effective concentration to achieve 50% egg death (EC50) values and calculate the test essential oil and drug combinations using a simplex-centroid mixture design. These concentrations were used for a second round of EHAs. Sixteen sheep were randomly allocated into two groups and treated with ABZ and the combination of CaEO and ABZ, and faecal egg count reduction tests were performed. In the first round of EHA, CaEO and ABZ showed EC50 values of 0.57 and 0.0048 mg mL-1, respectively. The H. contortus strain used in the study was shown to be highly benzimidazole resistant, with only 1.5% of parasites having susceptible ß-tubulin SNP genotypes. The ABZ reduced the shedding of nematode eggs by 78%, however, its combination with CaEO reduced faecal egg counts by only 9%. The present study is important to highlight the interferences of natural products in anthelmintic metabolism and consequently in drug efficacy.
Assuntos
Anti-Helmínticos , Citrus , Hemoncose , Haemonchus , Nematoides , Óleos Voláteis , Doenças dos Ovinos , Animais , Ovinos , Albendazol/farmacologia , Albendazol/uso terapêutico , Óleos Voláteis/farmacologia , Óleos Voláteis/uso terapêutico , Anti-Helmínticos/farmacologia , Anti-Helmínticos/uso terapêutico , Benzimidazóis/farmacologia , Fezes/parasitologia , Doenças dos Ovinos/tratamento farmacológico , Doenças dos Ovinos/parasitologia , Contagem de Ovos de Parasitas/veterinária , Resistência a Medicamentos , Hemoncose/tratamento farmacológico , Hemoncose/veterinária , Hemoncose/parasitologiaRESUMO
Hyptis dilatata and Mesosphaerum suaveolens belong to Lamiaceae, are aromatic and medicinal subshrubs with antiparasitic potential and occurrence in the Amazon Region. The essential oils of both species were extracted, analyzed, and identified by GC and GC-MS and then evaluated their anthelmintic activities against the nematode Caenorhabditis elegans. Primary constituents of the samples of H. dilatata oils were limonene (72.6%), myrcene (11.5%), and p-cymene (10.3%) to PAMA19 sample, and camphor (25.5%), α-pinene (25.4%), 1,8-cineole (18.8%), ß-pinene (12.0%), and limonene (5.9%) to PAMA108 sample, while in the oil of M. suaveolens, PAMA131 sample, predominated bicyclogermacrene (23.5%, 1,8-cineole (23.0%), germacrene D (17.2%), and (E)-caryophyllene (10.4%). The sample oil of H. dilatata (PAMA108) exhibited the lower anthelmintic inhibitory concentration, with an IC50 value of 2.09 mg/mL for C. elegans Bristol N2 strain, while the oils of H. dilatata (PAMA19) and M. suaveolens (PAMA131) showed an IC50 up of 4 mg/mL for C. elegans IVR15 and Bristol N2 strains. These results suggest that the H. dilatata and M. suaveolens oils constituents' combination can be helpful as a nematicidal agent due to their synergistic action.
Assuntos
Anti-Helmínticos , Hyptis , Óleos Voláteis , Animais , Anti-Helmínticos/farmacologia , Caenorhabditis elegans , Cromatografia Gasosa-Espectrometria de Massas , Óleos Voláteis/farmacologia , Óleos de Plantas/farmacologiaRESUMO
The resistance of Haemonchus contortus to synthetic anthelmintics is of increasing concern; and different strategies are being evaluated to improve parasite control. The present study investigated the in vitro effects of combinations of synthetic compounds and monoterpenes. Additionally, the chemical association of the best combinations and their impact on the ultrastructural and biophysical properties of H. contortus eggs was evaluated. We assessed the efficacy of the monoterpenes, carvacrol, thymol, r-carvone, s-carvone, citral, and p-cymene and the anthelmintics, albendazole and levamisole using the egg hatch test (EHT) and the larval migration inhibition test (LMIT), respectively. The minimum effective concentrations of the monoterpenes, according to the EHT (efficacy ranging from 4.4%-11.8%) and LMIT (efficacy ranging from 5.6%-7.4%), were used in combination with different concentrations of synthetic compounds, and the IC50 and synergism rate (SR) were calculated. Fourier-transform infrared spectroscopy (FTIR) was used to analyze the chemical association between the best combinations as revealed by the in vitro tests (albendazole and levamisole with r-carvone or s-carvone). Atomic force microscopy (AFM) was used to assess the ultrastructural and biophysical properties of H. contortus eggs treated with the albendazole and r-carvone combination. Among the monoterpenes, the highest efficacies were exhibited by carvacrol (IC50 = 185.9 µg/mL) and thymol (IC50 = 187.0 µg/mL), according to the EHT, and s-carvone and carvacrol (IC50 = 1526.0 and 1785.3 µg/mL, respectively), according to the LMIT. According to the EHT, albendazole showed a slight statistically significant synergism in combination with r-carvone (SR = 3.8) and s-carvone (SR = 3.0). According to the LMIT, among the monoterpenes, r-carvone (SR = 1.7) and s-carvone (SR = 1.7) showed an increase in efficacy with levamisole; however, this was not statistically significant. The FTIR spectra of albendazole and levamisole, in association with r-carvone and s-carvone, indicated the presence of chemical interactions between the synthetic and natural molecules, contributing to the possible synergistic effects of these associations. Eggs treated with albendazole and r-carvone showed an increase in roughness and a decrease in height, suggesting that the treatment induced damage to the egg surface and an overflow of its internal contents. Overall, the combination of albendazole with r-carvone and s-carvone was efficacious against H. contortus, demonstrating a chemical association between the compounds; the significant changes in the egg ultrastructure justify this efficacy.
Assuntos
Anti-Helmínticos/síntese química , Anti-Helmínticos/farmacologia , Haemonchus/efeitos dos fármacos , Monoterpenos/química , Monoterpenos/farmacologia , Animais , Haemonchus/ultraestrutura , Larva/efeitos dos fármacos , Larva/fisiologia , Microscopia de Força Atômica , Estrutura Molecular , Atividade Motora/efeitos dos fármacos , Óvulo/efeitos dos fármacos , Espectroscopia de Infravermelho com Transformada de Fourier , Relação Estrutura-AtividadeRESUMO
Our current understanding of differences in the epidemiology of gastrointestinal nematode (GIN) species in co-grazed sheep and goats is inadequate with reference to the development of sustainable control strategies. The next-generation metabarcoding sequencing method referred to as the 'nemabiome' allows some of these differences to be explored to describe the intensity of co-infecting GIN species. We applied this platform to study sheep and goats that were co-grazed on Guinea grass pasture in northeastern Brazil. Co-grazed goats and sheep were treated with a monepantel anthelmintic, then exposed to the same gastrointestinal nematode species. Overall, there were differences in the prevalence of GIN species identified in the sheep and goats; Trichostrongylus colubriformis and Teladorsagia circumcincta predominated in goat kids, while Haemonchus contortus predominated in adult does, ewes and lambs once burdens became re-established after anthelmintic treatment. Description of the pattern of re-infection following anthelmintic treatment was prevented by the unpredicted poor efficacy of 2.5 mg/kg and 5 mg/kg, respectively, of monepantel against O. columbianum and T. circumcincta in lambs, and T. circumcincta adult does. Differences in drug efficacy between host age and species groups may be important when considering sustainable GIN control strategies for co-grazed animals. The aggregated FECs of the adult does and goat kids representing re-established GIN burdens, were higher than those of the co-grazed adult ewes and lambs. This implies that there are inherent differences in GIN species adaptation to the two naïve small ruminant host species, and shows the need for better understanding of the factors giving rise to this situation associated with exposure to infective larvae and host responses. At the start of the study, the adult does were co-infected with several GIN species, with the highest intensity of T. circumcincta, contrasting with the situation in the adult ewes, in which H. contortus predominated. However, once burdens became re-established after treatment, H. contortus predominated in both adult does and ewes. This demonstrates the potential for host burdens of H. contortus to establish and predominate after anthelmintic treatment when burdens of co-infecting GIN species are low.
Assuntos
Código de Barras de DNA Taxonômico , Doenças das Cabras/parasitologia , Nematoides/genética , Infecções por Nematoides/veterinária , Doenças dos Ovinos/parasitologia , Aminoacetonitrila/análogos & derivados , Aminoacetonitrila/uso terapêutico , Animais , Anti-Helmínticos/uso terapêutico , Fezes/parasitologia , Feminino , Genômica , Cabras , Masculino , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/parasitologia , Contagem de Ovos de Parasitas , Reação em Cadeia da Polimerase , OvinosRESUMO
Azathioprine (Aza) is a purine antimetabolite immunosuppressant that is widely employed for immunosuppressive therapy in post-transplant recipients or patients with autoimmune diseases. Chronic use of immunosuppressants might produce several side effects, including a high rate of neoplasms in these patients. Considering that genotoxic effects are associated with an increased risk of developing cancer, the aim of this study was to examine the recombinogenic, genotoxic, and cytotoxic effects of Aza using Somatic Mutation and Recombination Test (SMART) in Drosophila melanogaster, as well as comet and micronucleus assays in mouse bone marrow cells. Further, the adverse effects of Aza were determined in mouse hepatic and renal tissues using histopathological analysis. Data demonstrated that Aza induced significant increased genotoxicity in D. melanogaster and mouse bone marrow cells at all concentrations tested. Homologous recombination was the predominant genotoxic event noted for the first time to be initiated by Aza in SMART. In histopathological analysis, Aza did not show any marked toxic activity in mouse hepatic and renal tissues. Therefore, the high rate of neoplasms reported in patients with long-term use of Aza may be attributed, at least partially, to the genotoxic action of this drug.
Assuntos
Azatioprina/toxicidade , Drosophila melanogaster/efeitos dos fármacos , Imunossupressores/toxicidade , Animais , Células da Medula Óssea/efeitos dos fármacos , Ensaio Cometa , Camundongos , Testes para Micronúcleos , Testes de MutagenicidadeRESUMO
Anticarsia gemmatalis Hübner, 1818 (Lepidoptera) is a major pest of soybean in the Brazil. It is known that the reduction of proteolytic activity by the ingestion of protease inhibitors reduces digestion and larval development of the insects. Control via inhibition of the digestive enzymes necessitates deeper knowledge of the enzyme kinetics and the characterization of the inhibition kinetics of these proteases, for better understanding of the active centers and action mechanisms of this enzyme. Trypsin-like proteases found in the gut of Anticarsia gemmatalis were purified in a p-aminobenzamidine agarose column. Kinetic characterization showed KM 0.503 mM for the L-BApNA substrate; Vmax= 46.650 nM s-1; Vmax/[E]= 9.256 nM s-1 mg L-1 and Vmax/[E]/KM= 18.402 nM s-1 mg L-1 mM. The Ki values for the inhibitors benzamidine, berenil, SKTI and SBBI were 11.2 µM, 32.4 µM, 0.25 nM and 1.4 nM, respectively, and all revealed linear competitive inhibition. The SKTI showed the greatest inhibition, which makes it a promising subject for future research to manufacture peptide mimetic inhibitors.
Assuntos
Trato Gastrointestinal/enzimologia , Lepidópteros/enzimologia , Inibidores de Proteases/farmacologia , Animais , Controle de Insetos/métodos , Cinética , Lepidópteros/crescimento & desenvolvimentoRESUMO
Anticarsia gemmatalis represents a relevant factor for lowering soybean and other legume crop productivities. Protease inhibitors affect protein degradation and reduce the availability of amino acids, impairing the development and survival of insect pests. To evaluate the possible use of proteinaceous protease inhibitors in the management of this pest, the activities of midgut proteases and the growth and development of A. gemmatalis larvae exposed to soybean Bowman-Birk trypsin-chymotrypsin inhibitor (SBBI) and soybean Kunitz trypsin inhibitor (SKTI) were determined. The survival curves obtained using Kaplan-Meier estimators indicated that SKTI and SBBI stimulated larval survival. However, the development of A. gemmatalis was delayed, and prepupal weight decreased in the presence of both inhibitors. The results showed that SKTI and SBBI inhibited the trypsin-like and total proteolytic activities of larvae on the 12th day after eclosion. On the 15th day after eclosion, larvae exposed to SKTI increased the activities of trypsin and total proteases. Although SKTI and SBBI did not affect the survival of the insect, they had effects on midgut proteases in a stage wherein A. gemmatalis fed voraciously, increased the larval cycle, and decreased prepupal weight. These findings provide baseline information about the potential of proteinaceous protease inhibitors to manage the velvetbean caterpillar, avoiding chemical pesticides.
Assuntos
Mariposas/efeitos dos fármacos , Inibidor da Tripsina de Soja de Bowman-Birk/farmacologia , Inibidor da Tripsina de Soja de Kunitz/farmacologia , Animais , Trato Gastrointestinal/enzimologia , Larva/efeitos dos fármacos , Larva/enzimologia , Larva/crescimento & desenvolvimento , Mariposas/enzimologia , Mariposas/crescimento & desenvolvimento , Peptídeo Hidrolases/metabolismo , Inibidores de Proteases/farmacologia , Glycine max/enzimologia , Tripsina/metabolismoRESUMO
Twig girdlers have a short adult life and a long larval stage (up to one year in some species). This fact, together with lack of morphological traits to identify the species from the larval stage, poses obstacles for the taxonomic identification and characterization of the many twig girdlers found in the wild. To solve this matter, Random Amplified Polymorphic DNA (RAPD) molecular markers have been applied to identify some insect species and to determine species boundaries. The aim of this study was to identify three species of Oncideres using the RAPD technique. Adults and larvae of O. saga, O. ocularis and O. ulcerosa were collected in Minas Gerais, Brazil. Two RAPD primers were used (OPA-05 and OPB-13), which produced different electrophoretic profiles that were used to construct a UPGMA phenogram. Three groups identified in the analyses accurately separated the three species, based on individuals in two different stages of development (adults and larvae): I: O. saga, II: O. ulcerosa, and III: O. ocularis. Molecular markers, such as RAPD, are valuable tools that help taxonomists in species identification.
Assuntos
Besouros/genética , Marcadores Genéticos/genética , Animais , Besouros/classificação , Técnica de Amplificação ao Acaso de DNA Polimórfico , Especificidade da EspécieRESUMO
Lectins have been studied in the past few years as an alternative to inhibit the development of pathogenic bacteria and gastrointestinal nematodes of small ruminants. The development of new antibacterial and anthelmintic compounds is necessary owing to the increase in drug resistance among important pathogens. Therefore, this study aimed to evaluate the capacity of a glucose/mannose-binding lectin from Parkia platycephala seeds (PPL) to inhibit the development of Haemonchus contortus and to modulate antibiotic activity against multi-resistant bacterial strains, thereby confirming its efficacy when used in combination with gentamicin. PPL at the concentration of 1.2â¯mg/mL did not show inhibitory activity on H. contortus in the egg hatch test or the exsheathment assay. However, it did show significant inhibition of H. contortus larval development with an IC50 of 0.31â¯mg/mL. The minimum inhibitory concentration (MIC) obtained for PPL against all tested bacterial strains was not clinically relevant (MICâ¯≥â¯1024⯵g/mL). However, when PPL was combined with gentamicin, a significant increase in antibiotic activity was observed against S. aureus and E.coli multi-resistant strains. The inhibition of hemagglutinating activity by gentamicin (MICâ¯=â¯50â¯mM) revealed that it may be interacting with the carbohydrate-binding site of PPL. It is this interaction between the antibiotic and lectin carbohydrate-binding site that may be responsible for the enhanced activity of gentamicin against multi-resistant strains. It can be concluded that PPL showed selective anthelmintic effect, inhibiting the development of H. contortus larvae and that it increased the effect of the antibiotic gentamicin against multi-resistant bacterial strains, thus constituting a potential therapeutic resource against resistant bacterial strains and H. contortus.
Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Fabaceae/química , Haemonchus/efeitos dos fármacos , Haemonchus/crescimento & desenvolvimento , Lectinas/farmacologia , Extratos Vegetais/farmacologia , Animais , Anti-Helmínticos/farmacologia , Gentamicinas/farmacologia , Haemonchus/microbiologia , Larva/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Sementes/química , Staphylococcus aureus/efeitos dos fármacosRESUMO
Ipomoea imperati is widely used in tropical areas to treat several pathological conditions. The effect of this plant against parasitic species has not been investigated even being used for this purpose in the Brazilian northeastern. This study aimed to evaluate the anthelmintic and acaricide potential of a hydroethanolic extract of I. imperati leaves and stolons. I. imperati leaves and stolons were crushed and subjected to maceration in ethanol 70% (v/v), after which the solvent was removed using a rotary evaporator. The chromatographic profile of the extract was obtained by UV Spectrum high-performance liquid chromatography and compounds were identified by liquid chromatography/electrospray ionization tandem mass spectrometry. Identification of the compounds present in the extract was achieved by comparing their retention times and UV spectra with data in the literature. Anthelmintic activity was evaluated by larval exsheathment inhibition assays using Haemonchus contortus larvae and five concentrations of each extract ranging from 0.07 to 1.2 mg/mL. Acaricide activity was evaluated via larval immersion of Rhipicephalus microplus in eight concentrations of each extract ranging from 5.0 to 25.0 mg/mL. Live and dead larvae were counted after 24 hours. The median inhibitory concentration (IC50) for H. contortus larvae and the median lethal concentration (LC50) for R. microplus larvae were calculated. Twelve compounds were observed in the hydroethanolic extract of leaves, with a predominance of the aglycone form of flavonoids and tannins. This extract was effective against H. contortus larvae, presenting an average inhibitory concentration of 0.22 mg/mL, but showed no activity toward R. microplus larvae. The stolon hydroethanolic extract presented 11 compounds, with phenolic acids and glycosylated flavonoids prevailing. This extract showed low activity on R. microplus and no effect on inhibiting H. contortus larval exsheathment at the concentrations tested. This study is the first to assess the anthelmintic and acaricidal activities of I. imperati. Data reported confirm promising potential of I. imperati leaves hydroethanolic extract against H. contortus. This effect could be due to its secondary compounds presents in this extract, such as procyanidin, kaempferol, isoquercitrin and rutin.
Assuntos
Anti-Helmínticos/química , Ipomoea/química , Extratos Vegetais/química , Animais , Anti-Helmínticos/farmacologia , Cromatografia Líquida de Alta Pressão , Flavonoides/química , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Haemonchus/efeitos dos fármacos , Haemonchus/crescimento & desenvolvimento , Ipomoea/metabolismo , Larva/efeitos dos fármacos , Extratos Vegetais/análise , Folhas de Planta/química , Folhas de Planta/metabolismo , Caules de Planta/química , Caules de Planta/metabolismo , Rhipicephalus/efeitos dos fármacos , Rhipicephalus/crescimento & desenvolvimento , Espectrometria de Massas por Ionização por Electrospray , Taninos/química , Taninos/isolamento & purificação , Taninos/farmacologiaRESUMO
The response of plants to grazing includes the production of chemical defense compounds such as proteases inhibitors and secondary metabolites as flavonoids, which makes them less palatable to feeding and negatively affecting the physiology of insects. The aim of this study was to evaluate the phytochemical response of soybean cultivars (Glycine max (L.) Merrill) resistant (IAC-17, IAC-24) and susceptible (IAC-P1) to insects after mechanical damage. These cultivars were mechanically injured, and after 24 hours samples of these plants were analyzed by HPLC to identify and quantify flavonoids. The flavonoids daidzein, quercetin, and rutin were quantified, with the highest concentration of daidzin in soybean cultivars after mechanical damage. Rutin was biosynthesized by IAC-24. The cultivars IAC-PL1, IAC-17, and IAC-24 did not show a flavonoid response to mechanical damage. The soybean cultivars are not dependent on mechanical damage to produce flavonoids.
Assuntos
Glycine max/química , Isoflavonas/análise , Folhas de Planta/química , Quercetina/análise , Rutina/análise , Cromatografia Líquida de Alta Pressão , Fenômenos Mecânicos , Fenômenos Fisiológicos VegetaisRESUMO
The recognition of protease inhibitors with insecticidal activity is important as a basis for the development of mimetic peptides with potential use as biorational insecticides. We sprayed benzamidine on soybean plants and assessed whether this potent synthetic trypsin-inhibitor has protease inhibitory, insecticidal and deterrent effects on the velvetbean caterpillar Anticarsia gemmatalis Hübner (Lepidoptera: Erebidae). Activity of trypsin inhibition in soybean leaves was increased and total proteolytic activity in the midgut extract from larvae fed on these leaves was reduced by benzamidine. Different concentrations of benzamidine sprayed on the plant caused approximately 50 % of larval mortality, and larval choice and moth preference and oviposition were all negatively affected. Low concentrations of benzamidine increased mortality and hindered insect choice and oviposition as well as higher doses. Since many synthetic protease inhibitors are usually expensive, small doses of benzamidine may be effective to protect soybean against A. gemmatalis attack. Our results highlight the potential of synthetic protease inhibitors for insecticidal and deterrent purposes in insect pest management.
Assuntos
Benzamidinas/farmacologia , Glycine max/parasitologia , Inseticidas/farmacologia , Larva/efeitos dos fármacos , Mariposas/efeitos dos fármacos , Inibidores da Tripsina/farmacologia , Animais , Controle de Insetos/métodos , Inseticidas/química , Larva/enzimologia , Larva/crescimento & desenvolvimento , Mariposas/enzimologia , Inibidores de Proteases/farmacologiaRESUMO
Haemonchus contortus is one of the most economically important parasites infecting small ruminants worldwide. This nematode has shown a great ability to develop resistance to anthelmintic drugs, calling for the development of alternative control approaches. Because lectins recognize and bind to specific carbohydrates and glycan structures present in parasites, they can be considered as an alternative to develop new antiparasitic drugs. Accordingly, this work aimed to investigate the anthelmintic effect of Canavalia brasiliensis (ConBr) lectin against H. contortus and to evaluate a possible interaction of ConBr with glycans of this parasite by molecular docking. ConBr showed significant inhibition of H. contortus larval development with an IC50 of 0.26 mg mL-1. Molecular docking assays revealed that glycans containing the core trimannoside [Man(α1-3)Man(α1-6)Man] of H. contortus interact in the carbohydrate recognition domain of ConBr with an interaction value of MDS = -248.77. Our findings suggest that the inhibition of H. contortus larval development is directly related to the recognition of the core trimannoside present in the glycans of these parasites. This work is the first to report on the structure-function relationships of the anthelmintic activity of plant lectins.
Assuntos
Anti-Helmínticos/química , Anti-Helmínticos/metabolismo , Haemonchus/efeitos dos fármacos , Manosídeos/metabolismo , Lectinas de Plantas/química , Lectinas de Plantas/metabolismo , Animais , Anti-Helmínticos/isolamento & purificação , Sítios de Ligação , Canavalia/química , Haemonchus/crescimento & desenvolvimento , Concentração Inibidora 50 , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Simulação de Acoplamento Molecular , Lectinas de Plantas/isolamento & purificação , Ligação ProteicaRESUMO
Seed exudates are plant-derived natural bioactive compounds consisting of a complex mixture of organic and inorganic molecules. Plant seed exudates have been poorly studied against parasite nematodes. This study was undertaken to identify proteins in the Myracrodruon urundeuva seed exudates and to assess the anthelmintic activity against Haemonchus contortus, an important parasite of small ruminants. M. urundeuva seed exudates (SEX) was obtained after immersion of seeds in sodium acetate buffer. SEX was fractionated with ammonium sulfate at 0-90% concentration to generate the ressuspended pellet (SEXF1) and the supernatant (SEXF2). SEX, SEXF1, and SEXF2 were exhaustively dialyzed against distilled water (cut-off: 12 kDa) and the protein contents determined. Mass spectrometry analyses of SEX, SEXF1, and SEXF2 were done to identify proteins and secondary metabolites. The seed exudates contained protease, protease inhibitor, peptidase, chitinase, and lipases as well as the low molecular weight secondary compounds ellagic acid and quercetin rhamnoside. SEX inhibited H. contortus larval development (LDA) (IC50 = 0.29 mg mL-1), but did not affect larval exsheathment (LEIA). On the other hand, although SEXF1 and SEXF2 inhibited H. contortus LEIA (IC50 = 1.04 and 0.93 mg mL-1, respectively), they showed even greater inhibition efficiency of H. contortus larval development (IC50 = 0.29 and 0.42 mg mL-1, respectively). To the best of our knowledge, this study is the first to show the anthelmintic activity of plant exudates against a gastrointestinal nematode. Moreover, it suggests the potential of exuded proteins as candidates to negatively interfere with H. contortus life cycle.
Assuntos
Anacardiaceae/química , Haemonchus/efeitos dos fármacos , Extratos Vegetais/química , Sementes/química , Animais , Anti-Helmínticos/química , Anti-Helmínticos/farmacologia , Extratos Vegetais/farmacologiaRESUMO
Haemonchus contortus is the most prevalent nematode in tropical and subtropical regions and is responsible for significant losses in small ruminant production systems. Control of this parasite is based on the use of synthetic anthelmintics; although effective, prolonged and indiscriminate use can select for populations of resistant nematodes. Hydrolyzed yeast can help prevent populations of nematodes and is low in cost. The present study aimed to evaluate the preventive effect of hydrolyzed yeast on H. contortus through in vitro and in vivo assays. In in vitro experiments, the yeast preparation was tested at different stages of the H. contortus life cycle via tests of egg hatchability, larval development, larval exsheathment and larval migration. Both eggs and L3 larvae were obtained from sheep artificially infected with a monospecific strain of H. contortus. In in vivo experiments, animals were treated with hydrolyzed yeast (53.4â¯mg/kg/BW), and fecal egg counts (FECs), feces culture and Famacha were performed. The yeast preparation inhibited larval exsheathment in a dose-dependent manner (IC95 of 0.46â¯mg/mL), though no activity at the other stages of the H. contortus life cycle was observed. The hydrolyzed yeast preparation was able to reduce FECs in treated animals from D40 to D54 (pâ¯<â¯0.05), showing an average efficiency of 60%. The yeast exhibited preventive properties, and the IC95 value suggests that H. contortus is highly susceptible. Our results indicate that administration of hydrolyzed yeast, which is already used commercially in ruminant nutrition, is an alternative method for the control of nematodes, mainly H. contortus.
Assuntos
Antinematódeos/farmacologia , Doenças das Cabras/tratamento farmacológico , Hemoncose/veterinária , Haemonchus/efeitos dos fármacos , Fermento Seco/farmacologia , Animais , Antinematódeos/administração & dosagem , Fezes/parasitologia , Doenças das Cabras/parasitologia , Cabras , Hemoncose/tratamento farmacológico , Hemoncose/parasitologia , Haemonchus/crescimento & desenvolvimento , Técnicas In Vitro , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Contagem de Ovos de Parasitas/veterinária , Fermento Seco/administração & dosagemRESUMO
Helminth infections represent a serious problem for the production of small ruminants that is currently aggravated by resistance to anthelmintic products and has induced a search for control alternatives, such as natural products. In this study, extracts of Turnera ulmifolia L. (leaves and roots), Parkia platycephala Benth. (leaves and seeds) and Dimorphandra gardneriana Tul. (leaves and bark), which have been cited in ethnoveterinary studies and selected naturally by goats in the cerrado (Brazilian savanna), were tested in vitro against Haemonchus contortus. Hydroacetonic (ACT) and hydroalcoholic (ETH) extracts were evaluated using an Egg Hatching Assay (EHA), a Larval Exsheathment Inhibition Assay (LEIA) and a Larval Development Assay (LDA). A second set of incubations was performed using polyvinylpolypyrrolidone (PVPP) to determine the influence of polyphenols on the anthelmintic effects of EHA and LEIA. Data from each extract were used to calculate inhibition concentrations (IC50). All tested extracts showed activity against at least one life stage of H. contortus. The use of PVPP revealed that the tannins are not the only extracts of secondary metabolites responsible for the anthelmintic effects. The results showed clear in vitro anthelmintic activities against H. contortus at different stages and indicated the potential use of these species as a promising alternative approach to control helminthic infections of small ruminants.
Assuntos
Anti-Helmínticos/farmacologia , Fabaceae/química , Haemonchus/efeitos dos fármacos , Extratos Vegetais/farmacologia , Turnera/química , Animais , Brasil , Pradaria , Casca de Planta/química , Folhas de Planta/química , Raízes de Plantas/química , Sementes/químicaRESUMO
Eugenia dysenterica DC. (Myrtaceae), popularly known in Brazil as cagaiteira, is a widespread plant species in the Brazilian Cerrado. In folk medicine, the leaves of this plant are used to treat diarrhea and dysentery. The fruits are used for fresh consumption and industrial purposes. Because of the use of this plant as a therapeutic resource and food, the present study evaluated the genotoxic, cytotoxic, antigenotoxic, and anticytotoxic effects of the lyophilized ethanolic leaf extract of E. dysenterica using the mouse bone marrow micronucleus test. The genotoxicity and antigenotoxicity of this extract were evaluated using the frequency of micronucleated polychromatic erythrocytes, and the cytotoxicity and anticytotoxicity were assessed by the polychromatic and normochromatic erythrocyte ratio. According to our results, the lyophilized ethanolic leaf extract of E. dysenterica exhibited genotoxic and cytotoxic effects at the higher doses and protection against cyclophosphamide-induced genotoxic and cytotoxic actions at all doses tested.
Assuntos
Antimutagênicos/farmacologia , Ciclofosfamida/toxicidade , Eritrócitos/efeitos dos fármacos , Extratos Vegetais/farmacologia , Syzygium , Animais , Citotoxinas/farmacologia , Relação Dose-Resposta a Droga , Masculino , Camundongos , Testes para Micronúcleos , Mutagênicos/farmacologia , Extratos Vegetais/efeitos adversos , Folhas de PlantaRESUMO
Duguetia furfuracea (St. Hil.) Benth & Hook f. (1862), popularly known as "sofre-do-rim-quem-quer" and "araticum-seco", is a shrub of the Annonaceae family that occurs in several regions of Brazil. In folk medicine the infusion of its leaves and twigs is used to treat rheumatism and renal colic, whereas the seed powder is mixed with water to treat pediculosis. Previous studies have described biological activities of this plant with cytotoxic, antitumoral, trypanocidal, leishmanicidal, antiplasmodial and antiprotozoal effects. In the present work, genotoxicity and cytotoxicity of Duguetia furfuracea lyophilized leaf extract were evaluated using the prophage λ induction test (SOS-Inductest) and mouse bone marrow micronucleus test. Our results showed that Duguetia furfuracea lyophilized leaf extract did not present an increase either in the induction of prophage λ (P>0.05) using the SOS-inductest or in the micronucleated polychromatic erythrocytes (P>0.05) using the micronucleus test, suggesting absence of genotoxicity in both tests. On the other hand, a significant decrease in the number of bacteria, (P<0.05), as well as a significant decrease in the polychromatic erythrocytes and normochromatic erythrocytes ratio, (P<0.05), were observed, showing the cytotoxic action of Duguetia furfuracea lyophilized leaf extract. Thus, Duguetia furfuracea did not present the genotoxic action, but showed a cytotoxic effect in both assays utilized in the present work.
Assuntos
Annonaceae/química , Medula Óssea/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Extratos Vegetais/toxicidade , Animais , Masculino , Camundongos , Testes para Micronúcleos , Resposta SOS em GenéticaRESUMO
In 2004, an outbreak of HCPS in Brazil made hantaviruses a national threat to the rural and urban population. During this outbreak, 164 cases were reported, and 18.3% of them occurred in the Federal District. In this study, hantavirus genomic sequences were amplified from seven patients who resided in Central Brazil and then sequenced and compared to other hantavirus sequences. The complete S segment sequence, which is 1847 bases long and potentially encodes the 428 amino acid nucleocapsid protein, was determined for one patient. Moreover, a 700 base-pair sequence of the S segment was obtained from two other patients, and we analyzed M segment sequences from all samples. It can be inferred by both identity and phylogenetic analysis that the sequences obtained are highly related to Araraquara variant and Maciel virus. Phylogenetic results show that hantaviruses isolated in Central Brazil can be divided into two monophyletic groups: one group that clusters with Araraquara variant and the other group that includes the complete S segment sequence obtained in this study. Therefore, we propose the name Paranoa for this variant that co-exists with the Araraquara-like hantavirus in Central Brazil.
Assuntos
Infecções por Hantavirus/virologia , Orthohantavírus/classificação , Orthohantavírus/genética , Brasil/epidemiologia , DNA Viral/química , DNA Viral/genética , Orthohantavírus/isolamento & purificação , Infecções por Hantavirus/epidemiologia , Humanos , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNA , Homologia de Sequência do Ácido Nucleico , Proteínas Virais/genéticaRESUMO
Tricorynus herbarius (Gorham) é uma potencial praga de livros, especialmente em obras raras devido à composição do papel destas. Há carência de trabalhos referentes à sua biologia, principalmente por se tratar de um inseto que apresenta vários hábitos alimentares, sendo esse estudo uma etapa fundamental para o controle do inseto. Assim, a biologia de T. herbarius foi estudada em insetos mantidos em duas dietas diferentes: papel mata-borrão e farelo de trigo mais levedura de cerveja. Quatro ínstares foram obtidos em ambas dietas. A duração do período larval e a longevidade dos adultos foram mais curtas e a duração do período pupal foi maior quando os insetos foram mantidos em papel mata-borrão. Em ambas dietas a mortalidade foi alta, sempre acima de 50 por cento. A fecundidade observada para as fêmeas foi de 3,3 ± 3,93 ovos/fêmea em papel mata-borrão e 12,1 ± 12,61 em farelo de trigo. A razão sexual foi 0,5 para ambas dietas. A dieta de farelo de trigo mais levedura de cerveja mostrou-se a mais adequada para criação de T. herbarius.
Tricorynus herbarius (Gorham) is a potential bibliophagous insect, especially for rare books due to paper constituents of them. There are few studies with regards to the biology of this insect, perhaps because T. herbarius feeds on different resources, being this study an important feature to control the pest. The biological parameters of T. herbarius were studied in two different diets: blotting paper and wheat meal plus yeast extract. Four instars were obtained on both diets. The length of the larval period and adult longevity were shorter while the pupal period was longer when the insects fed on blotting paper. In both diets mortality was high, over 50 percent. Female fecundity was 3.3 ± 3.93 eggs per female for blotting paper and 12.1 ± 12.61 for wheat meal plus yeast extract. The sex rate was 0.5 for both diets. Wheat meal plus yeast extract is the best diet for rearing the book borer T. herbarius.