In vitro ovicidal and larvicidal activity of condensed tannins on gastrointestinal nematode infestations in sheep (Ovis aries)

Abstract

Infestations of gastrointestinal parasitic nematodes in sheep result in significant costs to farmers. These infestations are controlled using synthetic anthelmintic treatments, which can result in the development of anthelmintic resistance in nematodes. The use of plants rich in condensed tannins (CTs) is a promising alternative for controlling infestations of harmful parasites in sheep, and could allow reduction of the chemical products used. This study investigated the in vitro effect of CTs from Acacia mearnsii extract (AE) on egg hatching and motility of third-stage larvae. Egg-hatching rate was measured after incubation with extracts for 48 h at 27 °C. The egg hatch test was performed with dilutions of 0. 09, 0.19, 0.39, 0.78, 1.56, 3.12, 6.25, 12.5, 25, 50, and 100 mg mL -1 . Distilled water was used as the negative control. The corresponding egg hatching inhibition percentages were 22.3, 32.3, 39.2, 49.1, 56.7, 59.0, 62.3, 77.3, 92.7, 98.3, and 100%. The concentration required to inhibit egg hatching in 50% of eggs (LC 50 ) was 2.85 mg mL -1 . The inhibition achieved with the negative control was 7.06%. A larval migration inhibition test was carried out after incubation with the extracts for 48 h at 27 o C, with AE and distilled water used in dilutions of 3.12, 6.25, 12.5, 25, 50, and 100 mg mL -1 . The corresponding percentages of migration inhibition were 16.5, 37.0, 56.3, 79.4, 91.8, and 97.1%. The concentration required to inhibit migration of 50% of larvae (LC 50 ) was 12.45 mg mL -1 . The inhibition achieved with the negative control was 8.53%. The in vitro ovicidal and larvicidal activity of CTs from AE indicate the anthelmintic effect of AE, suggesting the potential of CT extracts to be used as alternatives for controlling gastrointestinal nematode infestations in small ruminants. Key words: In vitro test, helminthes, tannins, phytotherapy, small ruminants ResumoO parasitismo gastrintestinal em ovinos acarreta inúmeros prejuízos aos produtores rurais. O controle é realizado basicamente através da administração de anti-helmínticos sintéticos o que estimula a seleção de parasitas resistentes. O uso de plantas ricas em taninos condensados (TC) apresenta-se como uma alternativa promissora no controle de helmintos em ovinos, reduzindo o uso de produtos químicos. Esse estudo avaliou o efeito in vitro dos TC provenientes da acácia (Acacia mearnsii) sobre a eclosão de ovos e a motilidade de larvas de terceiro estágio de nematódeos gastrintestinais de ovinos. A taxa de eclosão foi avaliada após incubação com o extrato por um período de 48 h a 27 o C. A eclodibilidade foi avaliada nas concentrações de 0,09; 0,19; 0,39; 0,78; 1,56; 3,12; 6,25; 12,5; 25; 50 e 100 mg mL -1 . No controle negativo utilizou-se água destilada. As inibições das eclosões foram 22,3; 32,3; 39,3; 49,1; 56,7; 59; 62,3; 77,3; 92,7; 98,3 . A ação ovicida e larvicida in vitro do tanino condensado do extrato de Acacia mearnsii encontrada no presente trabalho indica uma ação anti-helmíntica, apresentando potencial para sua apli...

Ovicidal and larvicidal potential of Rosmarinus officinalis to control gastrointestinal nematodes of sheep

“…Similar effect was observed with Melaleuca alternifolia, which at a concentration of 56mg/mL and 3.5mg/mL inhibited 88% larval migration and 100% hatchability of H. contortus, respectively (GRANDO et al, 2016). The concentration required to inhibit larval migration is higher than that needed to inhibit hatchability (GRANDO et al, 2016;YOSHIHARA et al, 2014;QI et al, 2015). This is probably due to the fact that infecting larvae can survive in the environment exposed for long periods to deleterious weathering.…”

“…In recent years, studies involving plants have stood out among the lines of research that seek alternative methods to control ruminant parasites. These studies have revealed promising anthelmintic activity on gastrointestinal parasites of sheep (CAMURCA-VASCONCELOS et al, 2007;YOSHIHARA et al, 2014;RIBEIRO et al, 2014;MARIE-MAGDELEINE et al, 2014;MACEDO et al, 2015).…”

Antihelminthic action of the Anethum graveolens essential oil on Haemonchus contortus eggs and larvae

“…In the larval migration inhibition test (LMI), the 9.4 mg/mL concentration obtained 63.7% efficacy; a similar study carried out by Yoshihara et al (2014), who tested condensed tannins extracted from Acacia mearnsii, found that the 12.5 mg/mL concentration showed 56.3% inhibition, and only reaching 97.1% at the highest concentration used -100 mg/mL, thus demonstrating that better results can be obtained with a concentration increase. When analyzing the results of A. graveolens essential oil action in the different H. contortus development phases, L3 was found to be the most resistant, which can be attributed to the presence of the double cuticle at this larval stage as well as to the lower metabolic activity that occurs at this stage, a fact which was also mentioned by Amarante et al (2014).…”

SYNTHESIS, CHARACTERIZATION AND in vitro CYTOTOXICITY OF Acacia mearnsii PROANTHOCYANIDIN LOADED PLGA MICROPARTICLES

“…1) (Botha et al, 1978;Botha et al, 1981;Drewes et al, 1967;Drewes and Roux, 1963;Hundt and Roux, 1978;Hundt and Roux, 1982;Roux and Maihs, 1960;Saayman and Roux, 1965;Viviers et al, 1983). In addition to technological applications, these compounds also exhibit interesting biological properties such as antioxidant (Olajuyigbe and Afolayan, 2011b;Shen et al, 2010), antitumor (Shen et al, 2010), antimicrobial (Olajuyigbe and Afolayan, 2011a;Olajuyigbe and Afolayan, 2012b), bacteriostatic (Olajuyigbe and Afolayan, 2012ab) and anti-inflammatory (Yoshihara et al, 2014). Yoshihara et al (2014) investigated the effect of PAC from Black Wattle on eclosion eggs and larvae mortality.…”

“…In addition to technological applications, these compounds also exhibit interesting biological properties such as antioxidant (Olajuyigbe and Afolayan, 2011b;Shen et al, 2010), antitumor (Shen et al, 2010), antimicrobial (Olajuyigbe and Afolayan, 2011a;Olajuyigbe and Afolayan, 2012b), bacteriostatic (Olajuyigbe and Afolayan, 2012ab) and anti-inflammatory (Yoshihara et al, 2014). Yoshihara et al (2014) investigated the effect of PAC from Black Wattle on eclosion eggs and larvae mortality. Gastrointestinal parasitism in sheep causes numerous losses to farmers.…”