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. In vivo tests are more reliable because the anthelmintic effectiveness of bioactive compounds is evaluated after the metabolization process. The metabolization process of the bioactive compounds can generate metabolites that exhibit or not anthelmintic effectiveness. The in vivo tests assessing the anthelmintic effectiveness of bioactive compounds in sheep and goats are the fecal egg count reduction test and the controlled test.  OE promoted reduction of egg elimination in faeces which may be related to cuticular and reproductive alterations in GIN, and reduction of parasite burden in in vivo tests. Due to the promising results obtained with OE in the in vivo tests, interest has been aroused in using nanotechnology as an alternative to increase the bioavailability of OE and consequently, potentializing its anthelmintic effect, reducing the dose and  toxicity of the biocompounds. In addition to nanotechnology, the isolation and chemical modification of compounds isolated from OE have been employed to obtain new molecules with anthelmintic action and understand the mechanism of action of EO on the small ruminant GIN.Conclusion: The use of EO and their compound bioactive in the control of resistant populations of GIN is a promising alternative. The adoption of strategies in which natural products can replace synthetic anthelmintics, such as in dry periods and use synthetic anthelmintics in the rainy season when the population in refugia in the pasture is high, thus reducing the dissemination of GIN resistant populations. As perspective, the evaluation of pharmacokinetics and pharmacodynamics of these natural products should be performed so that one defines treatment protocols that optimize the anthelmintic effect

Powdered coconut water (ACP®) at different temperatures as extender of guinea fowl (“Numida meleagris”) spermatozoa Uso da água de coco em pó (ACP®) em diferentes temperaturas como diluente de espermatozóides de capote ("Numida meleagris")

The in vitro efficiency of powdered coconut water (ACP®) as storage medium for fresh, cooled guinea fowl (Numida meleagris) sperm at 4 or 15ºC compared to a commercially available medium (DC) of poultry semen was evaluated. Sperm concentration, percentage of motile spermatozoa, vigor, and morphology at baseline (T0), 2h (T2) and 24h (T24) were recorded. Average pool concentration was of 4.88±0.17 x 109 sptz/mL in the sperm and 600 x 106 sptz/mL in the final aliquots. The number of spermatozoa in the pool averaged 11.4±0.95 x109sptz/ejaculate. No treatment effect (P>0.05) on any parameter (motility, vigor and viable spermatozoa percentage) at baseline was detected between four groups (4 and 15ºC in ACP® and DC). After two hours (T2), only the spermatozoa in ACP® at 4ºC was always higher than the acceptable values: motility 88%, vigor 8.9 and viable spermatozoa concentration of 10.01x109 sptz/mL (P<0.05). This fact was also observed at 24h. These results suggest that ACP® at 4ºC can be used in the artificial insemination in guinea fowl, because it was the best among in vitro treatments, in all storage times.Avaliou-se a eficiência in vitro do diluidor água de coco em pó (ACP®) em sêmen recém-colhido e resfriado de capotes (Numida meleagris), a 4 ou 15ºC, em comparação ao diluidor comercial (DC) de sêmen de aves. Registraram-se a concentração espermática, a motilidade, o vigor e as alterações morfológicas nos tempos 0 hora (T0), 2 horas (T2) e 24 horas (T24). A média dos pools foi de 4,88±0,17 x109 sptz/mL e a concentração final das alíquotas colhidas, de 600x106sptz/mL. A média/ejaculado do pool foi de 11,4 ± 0,95 x 109 sptz/ejaculado. Os quatro tratamentos (4 e 15°C em ACP® ou DC) não ocasionaram diferenças estatísticas (P>0,05) em nenhum dos parâmetros avaliados (motilidade, vigor e sptz viáveis) no tempo zero (T0). Após 2 horas, apenas os espermatozóides diluídos com ACP® a 4ºC mantiveram-se acima dos valores aceitáveis: motilidade 88%, vigor 8,9 e concentração de espermatozóides viáveis de 10,01 x109 sptz/mL (P<0,05), fato observado também após 24 horas. Os resultados sugerem o uso do ACP® a 4ºC na inseminação artificial em capotes (galinha-d’angola), pois este foi superior aos demais tratamentos in vitro em todos os tempos de conservação

In vitro efficacy of Coriandrum sativum, Lippia sidoides and Copaifera reticulata against Leishmania chagasi

Abstract The increased incidence of visceral leishmaniasis (VL) in Brazil is due to a lack of effective disease control measures. In addition to that, no effective treatment exists for canine VL in response to synthetic drugs. Thus, the objective of this study was to evaluate the effect of the essential oils of Coriandrum sativum and Lippia sidoides, and oleoresin from Copaifera reticulata, on Leishmania chagasi promastigotes and amastigotes. We also examined the toxicity of these treatments on the murine monocyte cell line RAW 264.7. To determine the IC50 a MTT test (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) was performed on promastigotes, and an in situ ELISA assay was conducted on amastigotes. Here, we demonstrate that oleoresin from C. reticulata was effective against both promastigotes (IC50 of 7.88 µg.mL -1 ) and amastigotes (IC50 of 0.52 µg.mL -1 ), and neither of the two treatments differed significantly (p > 0.05) from pentamidine (IC50 of 2.149 µg.mL -1 ) and amphotericin B (IC50 of 9.754 µg.mL -1 ). Of the three plant oils tested, only oleoresin showed no toxicity toward monocyte, with 78.45% viability after treatment. Inhibition of promastigote and amastigote growth and the lack of cytotoxicity by C. reticulata demonstrate that oleoresin may be a viable option for analyzing the in vivo therapeutic effects of leishmanicidal plants Keywords: Leishmanicidal plants, oils, cytotoxicity, amastigotes, promastigotes, Leishmania chagasi. Resumo O aumento na incidência da Leishmaníase Visceral (LV) no Brasil deve-se à ineficácia das medidas de controle da doença. Além disso, não há tratamento efetivo para LV canina com drogas sintéticas. Assim, o objetivo deste trabalho foi avaliar o efeito dos óleos essenciais de Coriandrum sativum e de Lippia sidoides e do óleo-resina de Copaifera reticulata sobre promastigotas e amastigotas de Leishmania chagasi e analisar o grau de toxicidade sobre células monocíticas murinas RAW 264.7. Para determinar a CI50 sobre promastigotas foi usado teste MTT (brometo de 3-[4,5-dimetiltiazol-2-il]-2,5-difeniltetrazólio) e sobre amastigotas foi realizado imunoensaio in situ pela técnica de ELISA. Os resultados obtidos comprovaram que o óleo-resina de C. reticulata foi o mais eficaz contra as formas promastigotas (CI50 de 7,88 µg.mL -1 ) e amastigotas (CI50 de 0,52 µg.mL -1 ) e em nenhum dos dois testes diferiu do controle pentamidina que obteve CI50 de 2,149 µg.mL -1 , no teste sobre promastigotas, e anfotericina B que obteve CI50 de 9,754 µg.mL -1 , nos testes com amastigotas (p > 0.05). Quanto à citotoxicidade apenas o óleo-resina não apresentou toxicidade com 78,45% de monócitos viáveis. Os resultados obtidos sobre promastigotas e amastigotas e a ausência de citotoxicidade do óleo-resina de C. reticulata evidenciam que este óleo-resina pode ser viável para a análise de seus efeitos terapêuticos em testes in vivo