Despite the overall progress of sheep farming in Brazil, infections with the gastrointestinal parasite Haemonchus contortus represent one the most important problems in sheep production, aggravated by the increasing resistance of nematodes to traditional anthelmintic drugs caused by inadequate sheep flock management by breeders. Ethnopharmacological data indicate Annona muricata as a promising alternative for the control of gastrointestinal nematodes because of its general anthelmintic properties. The aim of this work was to evaluate the in vitro anthelmintic effects of A. muricata aqueous leaf extract against eggs, infective larvae and adult forms of parasitic nematode H. contortus. At higher doses, A. muricata extract showed 84.91% and 89.08% of efficacy in egg hatch test (EHT) and larval motility test (LMT), respectively. In the adult worm motility test, worms were completely immobilized within the first 6-8h of nematode exposition to different dilutions of extract. Phytochemical analysis indicated the presence of phenolic compounds in A. muricata aqueous leaf extract that may be responsible for the anthelmintic effects observed. Moreover those results validate the traditional use of A. muricata as a natural anthelmintic and then the pharmacological potential of its compounds for future in vivo investigations.

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BackgroundInfections of sheep with gastrointestinal parasites, especially Haemonchus contortus, have caused serious losses in livestock production, particularly after the emergence of resistance to conventional anthelmintics. The search for new anthelmintic agents, especially those of botanical origin, has grown substantially due to the perspective of less contamination of meat and milk, as well as other advantages related to their cost and accessibility in less developed countries. The aim of this study was to evaluate the in vitro anthelmintic activity of essential oils of the plant species Citrus aurantifolia, Anthemis nobile and Lavandula officinalis against the main developmental stages of the parasite H. contortus.ResultsPlant species were selected based on substantial ethnopharmacological information. Analysis of the composition of each oil by gas chromatography coupled to mass spectrometry (GC-MS) demonstrated the presence of limonene (56.37%), isobutyl angelate (29.26%) and linalool acetate (35.97%) as the major constituents in C. aurantifolia, A. nobile and L. officinalis, respectively. Different concentrations of each oil were tested in vitro for their capacity to inhibit egg hatching (EHT), larval development (LDT) and adult worm motility (AWMT) using a multidrug-resistant strain of H. contortus (Embrapa 2010). The IC50 values obtained for the oils of C. aurantifolia, A. nobile and L. officinalis were 0.694, 0.842 and 0.316 mg/ml in the EHT and 0.044, 0.117 and 0.280 mg/ml in the LDT, respectively. The three oils were able to inhibit adult worm motility completely within the first 8–12 h of observation in the AWMT.ConclusionsThe present results demonstrate significant anthelmintic activity of the three oils against the different developmental stages of H. contortus. Furthermore, this study is of ethnopharmacological importance by validating the anthelmintic activity of the oils studied. Although new experiments are necessary, these data contribute to the development of pharmaceutical-veterinary products for sheep farming by opening up new therapeutic possibilities against gastrointestinal infections caused by H. contortus.

Cancer has become a major public health problem worldwide and the number of deaths due to this disease is increasing almost exponentially. In the constant search for new treatments, natural products of plant origin have provided a variety of new compounds to be explored as antitumor agents. Tabernaemontana catharinensis is a medicinal plant that produces alkaloids with expressive antitumor activity, such as heyneanine, coronaridine and voacangine. The aim of present study was firstly to screen the cytotoxic activity of the indole alkaloids heyneanine, coronaridine and voacangine against HeLa (human cervix tumor), 3T3 (normal mouse embryo fibroblasts), Hep-2 (human laryngeal epithelial carcinoma) and B-16 (murine skin) cell lines by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide); and secondly to analyze the apoptotic activity, cell membrane damage and genotoxicity of the compound that showed the best cytotoxic activity against the tumor cell lines tested. Coronaridine was the one that exhibited greater cytotoxic activity in the laryngeal carcinoma cell line Hep-2 (IC50 = 54.47 μg/mL) than the other alkaloids tested (voacangine IC50 = 159.33 g/mL, and heyneanine IC50 = 689.45 μg/mL). Coronaridine induced apoptosis in cell lines 3T3 and Hep-2, even at high concentrations. The evaluation of genotoxicity by comet assay showed further that coronaridine caused minimal DNA damage in the Hep-2 tumor cell line, and the LDH test showed that it did not affect the plasma membrane. These results suggest that further investigation of coronaridine as an antitumor agent has merit.

The increasing demand of meat requires the adoption of sustainable intensification livestock systems, applying nutritional strategies to reduce any negative contribution from beef cattle to global warming and, at the same time, to increase animal performance and productive efficiency. The pasture management practices and feed supplementation, mainly using non-edible feed with less costs, could minimize environmental and social impacts, resulting in higher productivity with less inputs utilization. Tropical grass submitted to grazing management according to plant height present high soluble protein and low levels of indigestible neutral detergent fiber contents. Energy or rumen undegradable protein supplementation, associated to alternative additives to antibiotics effects, such as probiotics, tannin, essential oils and saponin, can help to fully exploit the animal genetic potential and nutrient utilization efficiency, which decreases greenhouse gases emissions and improves animal performance. Hence, more information about these tools can make the livestock systems in tropical pasture more efficient and eco-friendlier.