Anthelmintic activity of Lippia sidoides essential oil on sheep gastrointestinal nematodes.

Medicinal plants have been investigated for their anthelmintic properties and shown to be effective against eggs and larvae of gastrointestinal nematodes. The aim of this study was to evaluate the efficacy of the Lippia sidoides essential oil (LsEO) on sheep gastrointestinal nematodes. Initially, 44 naturally infected sheep were divided and treated with 200 microg kg(-1) ivermectin and 230 and 283 mg kg(-1) LsEO, respectively, plus the control. Fecal samples were collected from each animal to determine epg at 7, 14 and 21 days after treatment. In another test, 21 sheep were distributed and treated with 200 microg kg(-1) ivermectin, 283 mg kg(-1) LsEO and the control, respectively. Seven days after treatment, they were euthanized and necropsied to count and identify the nematodes from the abomasum, small and large intestines. In the first test, the efficacy of 230 and 283 mg kg(-1) LsEO and ivermectin was 38%, 45.9% and 40.2%, respectively, 7 days after treatment, and 30%, 54% and 39.6%, respectively, 14 days after treatment. In the second experiment, the respective efficacy of 283 mg kg(-1) LsEO and ivermectin was 56.9% and 34.4% against Haemonchus spp., and 39.3% and 63.6% against Trichostrongylus spp.

Anthelmintic activity of Croton zehntneri and Lippia sidoides essential oils.

Because of the development of anthelmintic resistant populations, the search for new drugs is essential to maintain the productivity of small ruminants. The aim of this study was to evaluate the anthelmintic activity of Croton zehntneri and Lippia sidoides essential oils and their major constituents, anethole and thymol. The effects of these oils and their constituents were determined by in vitro assays with the eggs and larvae of the sheep gastrointestinal nematode Haemonchus contortus. The two essential oils were evaluated on intestinal nematodes of mice at 800 mg kg(-1) dose. In the last experiment, the mice were treated with larger doses of L. sidoides, 1200 and 1600 mg kg(-1). The essential oils and their constituents prevented more than 98% of the H. contortus eggs from hatching at a concentration of 1.25 mg ml(-1) and inhibited more than 90% of H. contortus larval development at a concentration of 10 mg ml(-1). At a concentration of 800 mg kg(-1), the two essential oils were 46.3% and 11.64% effective against Syphacia obvelata and Aspiculuris tetraptera. At 1200 and 1600 mg kg(-1), L. sidoides essential oil's efficacy on the mouse worm burden was 57.6% and 68.9%, respectively. The fact that L. sidoides essential oil was almost 70% effective against mouse intestinal nematodes indicates it should be evaluated against gastrointestinal nematodes of sheep and goats.

Ovicidal and larvicidal activity of Melia azedarach extracts on Haemonchus contortus.

Haemonchus contortus is responsible for severe economic losses in sheep and goat breeding in the Northeast of Brazil. However, the effectiveness of control is compromised due to anthelmintic resistance and misuse. In the search for natural anthelmintics, Melia azedarach L., a plant indigenous to India but now distributed throughout Brazil, was selected due to the reported anthelmintic properties of its seeds. The aim of this study was to evaluate the anthelmintic activity of the seed and leaf extracts of the Brazilian adapted plant and investigate the type of organic chemical compounds present in the most active extracts. The ovicidal and larvicidal activity of M. azedarach extracts on H. contortus was evaluated through egg hatching and larval development tests. Hexane and ethanol extracts of seeds and chloroform and ethanol extracts of leaves of M. azedarach were used in the tests. To perform the larval development test, feces of an animal free from parasites were mixed with third instar H. contortus larvae and extracts in several concentrations. The coprocultures were incubated for 7 days at 30 degrees C, then the larvae were recovered and counted. LC50 was calculated by probits using the SPSS 8.0 program. The seed ethanol extract was the most active on eggs (LC50=0.36mgmL(-1)) and the leaf ethanol extract showed the best inhibition of larval development (LC50=9.18mgmL(-1)). Phytochemical analysis of the most active extracts revealed the presence of condensed tannins, triterpenes and alkaloids.

Anthelmintic activity of Azadirachta indica A. Juss against sheep gastrointestinal nematodes.

Gastrointestinal nematode control has been performed through use of anthelmintics. However, the development of resistant populations has required research into new alternatives. There are popular reports about anti-parasitic activity of Azadirachta indica in animals and plants. The aim of this study was to evaluate the anthelmintic activity of A. indica after feeding sheep with the dried leaves. In this experiment, 40 sheep were allotted into four treatment groups. Group I received a treatment of A. indica dry leaves mixed in a concentrate at a rate of 0.1 g/kg dose for 3 months. Group II was treated with double the dose of Group I. Group III was treated with closantel (Diantel) at the manufacturer-recommended dose once at the beginning of the study and Group IV was not treated. To compare treatment effects, the following parameters were evaluated: egg count per gram of feces (EPG), worm burden, weight gain and haematocrit. EPG and worm burden results were statistically evaluated using the Kruskal-Wallis test. Haematocrit and live weight gain were submitted to analysis of variance (ANOVA) and the means evaluated by Tukey's test with 95% probability. None of the evaluated parameters of the treatment groups were statistically different when compared to the control group, demonstrating that, with the protocol used, A. indica has no anthelmintic effect.

Intake, digestibility, ingestive behavior and performance of goats fed spineless cactus genotypes resistant to carmine cochineal / Consumo, digestibilidade, comportamento ingestivo e desempenho de caprinos alimentados com genótipos de palma forrageira resistentes à cochonilha-do-carmim

The objective was to evaluate the intake and digestibility of nutrients, ingestive behavior, and performance of goats fed with spineless cactus genotypes resistant to carmine cochineal (Miúda or Orelha de Elefante Mexicana (OEM). Thirty castrated male goats, without defined breed, aged 12 to 14 months, with an average body weight of 19.0±2.8kg, were distributed in a completely randomized design among three treatments (Control - Tifton hay, Miúda, and OEM) and ten replicates; the initial weight was considered as the covariate. The intake of organic matter (OM), neutral detergent fiber (NDF) was highest in the control treatment, while the intake of NFC was higher in the OEM diet. Treatments containing forage cactus showed the highest digestibility of DM, OM, and NFC. The animals fed the control diet spent more time on rumination and total chewing, but the time spent feeding or feeding efficiency, and performance did not differ. The use of spineless cactus genotypes resistant to carmine cochineal (Miúda and Orelha de Elefante Mexicana) in a diet for goats, in the amount of 450g/kg of DM does not interfere with the performance of the animals and improves the digestibility of OM and NFC.(AU)

Objetivou-se com o presente estudo avaliar o consumo e a digestibilidade de nutrientes, o comportamento ingestivo e o desempenho de caprinos alimentados com genótipos de palma forrageira resistentes à cochonilha-carmim (miúda ou orelha-de-elefante-mexicana (OEM). Trinta cabritos machos, castrados, sem raça definida, com idades entre 12 e 14 meses e peso corporal médio de 19,0±2,8kg, foram distribuídos em delineamento inteiramente ao acaso, em três tratamentos (controle - feno de tifton; miúda e OEM) e 10 repetições; o peso inicial foi considerado a covariável. O consumo de matéria orgânica (MO) e de fibra em detergente neutro (FDN) foi maior no tratamento controle; enquanto a ingestão de CNF foi maior na dieta OEM. Tratamentos contendo palma forrageira apresentaram as maiores digestibilidades de MS, MO e CNF. Os animais alimentados com a dieta controle gastaram mais tempo em ruminação e em mastigação total, mas o tempo gasto com alimentação ou a eficiência alimentar e o desempenho não diferiram. A utilização de genótipos de palma forrageira resistentes à cochonilha-carmim (miúda e orelha-de-elefante-mexicana) na dieta de caprinos, na quantidade de 450g/kg de MS, não interfere no desempenho dos animais e melhora a digestibilidade de MO e CNF.(AU)

Determination of arsenic in chicken feed by hydride generation atomic absorption spectrometry after pre-concentration with polyurethane foam.

A pre-concentration procedure with solid-phase extraction was developed for the determination of arsenic (As) in chicken feed using hydride generation atomic absorption spectrometry (HG-AAS). The procedure was based on the sorption of As(III) ions as complexes with ammonium pyrrolidine dithiocarbamate onto a mini-column packed with polyurethane foam. After pre-concentration, the As was removed from the mini-column by acid solution, and the analyte content in the eluate was measured by HG-AAS. The following main experimental conditions were established: adjustment of the As solution pH with 0.05 mol l⁻¹ HCl, 2.88 × 10⁻³ mol l⁻¹ complexing agent concentration and 6.0 mol l⁻¹ eluting hydrochloric acid concentration. The proposed method produced an enrichment factor of 67, with 0.050 and 0.165 µg g⁻¹ limits of detection and quantification, respectively. The procedure was applied to the determination of As content in two types of chicken feed using the proposed procedure and atomic absorption spectrometry with electrothermal atomisation (ETAAS). The t-test indicated that the results were not significantly different at a confidence level of 95%.

Anthelmintic activity of Cocos nucifera L. on intestinal nematodes of mice.

In this study, we evaluated the anthelmintic activity of the liquid extracted from the bark of the green coconut (LBGC), as well as butanol extract obtained from LBGC, on mouse intestinal nematodes. Thirty-six naturally infected mice were distributed into six groups receiving the following treatments: Group I: 1000 mg/kg of LBGC; Group II: 2000 mg/kg of LBGC; Group III: 500 mg/kg of butanol extract; Group IV: 1000 mg/kg of butanol extract; Group V: 0.56 mg/kg febendazole; and Group VI: 3% dimethylsulfoxide. The chemical composition of the LBGC and its butanol extract was determined by phytochemical tests. A dose of 1000 mg/kg of butanol extract had 90.70% efficacy in reducing the mouse worm burden (p<0.05). Phytochemical tests revealed the presence of triterpens, saponnins and condensed tannins in the LBGC and butanol extracts. These results suggest that Cocos nucifera extracts may be useful in the control of intestinal nematodes.

Chemical composition of Eucalyptus spp. essential oils and their insecticidal effects on Lutzomyia longipalpis.

The chemical composition of essential oils from three species of plants belonging to the Eucalyptus genus was determined and, their insecticidal effects on egg, larva and adult phases of Lutzomyia longipalpis were assessed. The insects were collected in the municipality of Sobral in the State of Ceará, Brazil. Five treatments with different concentrations were performed along with two negative controls, distilled water and Tween 80 (3%), and a positive control, cypermethrin (0.196mg/ml). The tests were carried out in plastic pots internally coated with sterile plaster and filled with a substrate made of rabbit feces and crushed cassava leaves. The eggs, larvae and adults were sprayed with the oils. The hatched larvae were counted for 10 consecutive days and observed until pupation. Insect mortality was observed after 24, 48 and 72h. E. staigeriana oil was the most effective on all three phases of the insect, followed by E. citriodora and E. globulus oils, respectively. The major constituents of the oils were Z-citral and alpha-citral (E. staigeriana), citronellal (E. citriodora) and 1,8-cineole (E. globulus). The Eucalyptus essential oils constitute alternative natural products for the control of L. longipalpis since the median effective concentration (EC(50)) values revealed relevant action as compared with other natural products, some of their chemical constituents are already known for their insecticidal activity and these oils are produced in commercial scale in Brazil.

Extratos vegetais usados no controle de dípteros vetores de zoonoses / Plant extracts used in the control of dipteran vectors of zoonosis

Os insetos são importantes transmissores de doenças que cada vez mais ocorrem em áreas periurbanas ou urbanas, devido à introdução ou reaparecimento de seus respectivos vetores. As estratégias de controle das doenças transmissíveis por vetores biológicos são de difícil execução, principalmente quando associadas à existência de reservatórios domésticos e silvestres e aos aspectos ambientais. O uso de inseticidas direcionado ao combate de formas adultas de dípteros vetores tem sido freqüente. Entretanto, o amplo uso dos inseticidas sintéticos desde a descoberta do DDT para o controle de pragas domésticas e da agricultura, como também de vetores que transmitem doenças ao homem, levou a uma maior preocupação em relação à toxicidade e impacto ambiental destes agentes. Além disso, a resistência a inseticidas tornou-se uma preocupação crescente na agricultura, economia e na saúde pública. Um grande número de diferentes espécies de plantas representando diferentes áreas geográficas ao redor do mundo tem se mostrado capaz de causar efeitos letais e subletais sobre insetos. Esta revisão aborda a utilização de extratos de plantas com potencial no controle de dípteros vetores de zoonoses.

Insects are important transmitters of diseases increasingly occurring in peri-urban or urban areas due to the introduction or the reemergence of their respective vectors. Strategies to control diseases transmitted by biological vectors are difficult to implement, especially when associated with the existence of domestic and wild reservoirs and environmental aspects. The use of insecticides against adult forms of dipteran vectors has been frequent. However, the widespread use of synthetic insecticides since the discovery of DDT to control domestic and agricultural pests, as well as vectors that transmit diseases to humans, has led to greater concern for the toxicity and environmental impact of these agents. Moreover, resistance to insecticides has become an increasing concern in agriculture, economy and public health. A large number of different plant species representing different geographical areas around the world have been capable of causing lethal and sublethal effects on insects. This review addresses the use of potential plant extracts to control dipteran vectors of zoonosis.