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In vitro larval migration and kinetics of exsheathment of Haemonchus contortus larvae exposed to four tropical tanniniferous plant extracts.

Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Yucatán, Km 15.5 Carretera Mérida-Xmatkuil, Mérida, Yucatán, Mexico.
Veterinary Parasitology (Impact Factor: 2.55). 05/2008; 153(3-4):313-9. DOI: 10.1016/j.vetpar.2008.01.042
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ABSTRACT As for some temperate forage, some tropical tanniniferous plants (TTP) from browsing might represent an alternative to chemical anthelmintic. The anthelmintic effect of four TTP (Acacia pennatula, Lysiloma latisiliquum, Piscidia piscipula, Leucaena leucocephala) on Haemonchus contortus was measured using two in vitro assays. First, the effects of increasing concentrations of lyophilized extracts (150, 300, 600, 1200 microg/ml PBS) were tested on H. contortus larvae (L(3)) using the larval migration inhibition (LMI) test. An inhibitor of tannin, polyvinyl polypyrrolidone (PVPP), was used to verify whether tannins were responsible for the AH effect. Secondly, the effects of extracts on larval exsheathment were examined. Larvae (L(3)) were in contact with extracts (1200 microg/ml) for 3h, and then were exposed to an artificial exsheathment procedure with observations of the process at 10 min intervals. A general lineal model (GLM) test was used to determine the dose effect in the LMI test and the difference of the percentage of exsheathed larvae between the control and the treatment groups. A Kruskal Wallis test was used to determine the effect of PVPP on LMI results. The LMI test showed a dose-dependent anthelmintic effect for A. pennatula, L. latisiliquum and L. leucocephala (P<0.01), which disappeared after PVPP addition, confirming the role of tannins. No effect was found for P. piscipula on H. contortus in the LMI test. However, all four plant extracts interfered with the process of L(3) exsheathment which might be involved as a mechanism of action of tannins on H. contortus larvae. A. pennatula, L. latisiliquum and L. leucocephala could be used as an anthelmintic for the control of H. contortus after confirmation based on in vivo studies.

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    • "In previous studies, similar or higher concentrations of plant extracts have been used to control H. contortus (Costa et al., 2008; Alonso-Díaz et al., 2008; Manolaraki et al., 2010). Alonso-Díaz et al. (2008) using Lysiloma latisiliquum, Acacia pennatula and Leucaena lucocephala, showed that 1.2 mg/mL of plant extract inhibited 33.0%, 43.0% and 44.0% of larval migration of H. contortus, respectively. "
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    ABSTRACT: The in vivo anthelmintic (AH) activity of the ethanolic extract from leaves of Phytolacca icosandra was evaluated in goats artificially infected with Haemonchus contortus. Parasite naïve goats were artificially infected with 3000 H. contortus infective larvae per animal. Once the infection was patent (day 28 post-infection) all the animals were sampled to determine the faecal egg counts (FEC) for five consecutive days. Two groups of animals were formed balanced for their FEC and body-weight (BW) (n=6/group): the non-treated control group and the treated group in which goats were individually administered with the ethanolic extract of P. icosandra. The extract was administered orally using gelatin capsules (250mg/kg BW) which were dosed on two consecutive days using a pill-dispenser. Faecal samples were collected from each animal from the day of dosage (Day 0) on a daily basis to determine the number of eggs per gram of feces (EPG) for 15 days post-treatment (PT). The FEC of the two groups were compared using the repeated measures analyses of variance using the log transformed data Ln (FEC+1). The presence of saponins, coumarins, flavonoids, steroids and terpenoids were detected by standard methodologies in the extract. The P. icosandra ethanolic extract was further analyzed by gas chromatography (GC) coupled to a mass spectrometry (GC-MS). A significant reduction in FEC was observed in the treated group compared to the control from day 7 until day 15 PT (P<0.05). The highest percentage reduction (72%) was found on day 11 PT. No adverse reactions were observed in all treated animals for the entire trial. The GC-MS analysis of the organic extracts revealed the presence of three fatty acids as compounds with highest abundance. The three compounds that were identified by their mass fragmentation patterns were: 2-Pentadecanone, 6, 10, 14-trimethyl (RT 10.3min), Pentadecanoic acid, 14-methyl-, methyl ester (RT 10.8min) and Hexadecanoic acid, ethyl ester (RT 11.2min). It is concluded that the P. icosandra ethanolic extract obtained from leaves showed in vivo anthelmintic activity against H. contortus when administered orally to goats at a dose of 250mg/kg BW on two consecutive days. The dose used did not cause any negative effects on the health of goats.
    Veterinary Parasitology 04/2012; 189(2-4):284-90. DOI:10.1016/j.vetpar.2012.04.017 · 2.55 Impact Factor
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    • "In previous studies, similar or higher concentrations of plant extracts have been used to control H. contortus (Costa et al., 2008; Alonso-Díaz et al., 2008; Manolaraki et al., 2010). Alonso-Díaz et al. (2008) using Lysiloma latisiliquum, Acacia pennatula and Leucaena lucocephala, showed that 1.2 mg/mL of plant extract inhibited 33.0%, 43.0% and 44.0% of larval migration of H. contortus, respectively. "
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    ABSTRACT: The development of anthelmintic resistance has impacted on the success of conventional anthelmintics (AH) for the control of gastrointestinal nematodes in grazing/browsing sheep and goats. Medicinal plants from the traditional herbolary in Mexico may provide new candidates that can be explored as alternative sources of AHs for ruminants. This study evaluated the leaf extracts derived from Phytolacca icosandra against infective L(3) larvae and eggs from Haemonchus contortus collected from sheep. Three extracts of different polarities were obtained from the leaf plants using ethanol, n-hexane and dichloromethane as the solvents. The effectiveness of the in vitro AH activity of the plant extracts was evaluated using larval migration inhibition (LMI) and egg hatch (EHA) assays. For the LMI assays, the ethanolic extract of P. icosandra showed 55.4% inhibition of larval migration at 2mg/mL (p<0.05). The dichloromethane extract of P. icosandra showed 67.1% inhibition of migration at 3mg/mL (p<0.05) and a dose-dependent response with an LD(50) of 0.90 mg/mL. The n-hexane extract failed to show inhibition of larval migration at any concentration explored. In the EHA for the ethanol extract, the lowest concentration tested (0.15 mg/mL) resulted in inhibition of egg hatching greater than 72.6%. Therefore, the LD(50) could not be calculated for this extract. The LD(50) of the dichloromethane extract of P. icosandra was 0. 28 mg/mL. An egg hatch inhibition greater than 90% was observed with both the ethanolic and dichloromethane extracts when using a concentration of 0.90 mg/mL or higher. The n-hexane extract failed to show egg hatch inhibition at any concentration tested. The AH activity reported for P. icosandra could be attributable to the flavonoids, steroids, terpenoids, coumarins and/or saponins that were present in the ethanolic and dichloromethane extracts. A combination of more than one component may also explain the observed AH activity against the H. contortus life stages that were evaluated. In conclusion, the ethanolic and dichloromethane extracts of P. icosandra showed clear in vitro AH activity against the H. contortus eggs and the L(3) larvae. However, the hexanic extract of the plant leaves failed to show any in vitro AH activity.
    Veterinary Parasitology 03/2011; 179(1-3):100-6. DOI:10.1016/j.vetpar.2011.02.019 · 2.55 Impact Factor
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    • "species were chosen because of their high content of CT (Bobadilla-Hernández et al 2007, Monforte-Briceño et al 2005, Alonso-Díaz et al 2008 c ). Fresh leaves of each plant species (500 g) were chopped to obtain the extracts. "
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    ABSTRACT: El efecto antihelmíntico (AH) in vitro de los extractos ricos en taninos de Acacia pennatula, Lysiloma latisiliquum, Piscidia piscipula y Leucaena leucocephala sobre larvas L3 de tres cepas mexicanas de Haemonchus contortus fue evaluado. Extractos acetona/agua fueron obtenidos del follaje de A. pennatula, L. latisiliquum, P. piscipula y L. leucocephala proveniente de la vegetación de Yucatán, México. Concentraciones crecientes de extractos liofilizados (300, 600, 1.200, 1.800 and 2.400 mg/ml PBS) fueron empleados para evaluar el efecto AH utilizando la prueba de inhibición de la migración larvaria (LMI). Se utilizaron tres cepas mexicanas no relacionadas de H. contortus (CENID-INIFAP, UADY y UNAM). El papel de los taninos sobre el efecto AH fue confirmado mediante el uso de polivinil polipirrolidona (PVPP), un inhibidor de taninos. Las cepas de H. contortus mostraron diferente respuesta a los extractos. Unicamente un extracto de planta (L. latisiliquum) mostró efecto sobre la migración larvaria en la cepa de Yucatán (UADY). Dos extractos de plantas (A. pennatula y L. latisiliquum) inhibieron la migración larvaria en la cepa CENID-INIFAP. Mientras que tres extractos tuvieron efecto sobre la cepa UNAM (A. pennatula, L. latisiliquum y P. piscipula). Adicionalmente, la cepa UNAM fue afectada con dosis menores de los extractos en comparación con las cepas CENID-INIFAP y UADY. Los resultados indican que las larvas obtenidas de Yucatán, México, son menos sensibles a los extractos de PRT obtenidos de la misma región sugiriendo una posible adaptación a los taninos.
    Archivos de Medicina Veterinaria 12/2009; 42(3):165-171. · 0.41 Impact Factor
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