Phenolic compounds in the fruits of Enterolobium cyclocarpum and the inhibition of Haemonchus contortus eggs

The fabacean Enterolobium cyclocarpum is a tree with multiple uses in production systems and its fruits serve as food for livestock, in addition, they contain phenolic compounds. The ovicidal effect of the secondary compounds of the Enterolobium cyclocarpum fruits extracted with hydroalcoholic solvent (HA-E) and the aqueous (Aq-F) and organic (AcOEt-F) fractions was evaluated. Additionally, a phytochemical analysis of the extract and fractions was performed by high performance liquid chromatography (HPLC). The HA-E showed an ovicidal effect close to 100% with the concentration evaluated of the 100 mg/mL. The fractionation of the extract allowed to potentiate the activity in the Aq (94.05% at 12 mg/mL) and AcOEt (99.45% at 3 mg/mL) fractions. The secondary compounds extracted from the fruits of E. cyclocarpum in the HA-E and fractions were flavonols, coumaric and ferulic acids and other derivatives of hydroxycinnamic acid and were responsible for the ovicidal activity observed against H. contortus.

First Record of Flavocillium subprimulinum (Cordycipitaceae, Hypocreales) in Mexico: Morphological and Molecular Characterisation, Nematocidal Activity of Its Liquid Culture Filtrates against Haemonchus contortus and Protease Activity

This is the first record of the fungus Flavocillium subprimulinum in Mexico. The isolate was taxonomically characterised and cultured in potato dextrose broth (PDB), Czapek-Dox broth (CzDoxB), and sweet potato dextrose broth (SPDB) to obtain its filtrates (FLCF). The nematocidal activity (NA) of three FLCF concentrations was assessed against Haemonchus contortus L3. Protease activity (PA) was assessed with SDS-PAGE, followed by a zymogram. The NA of the FLCF reached 94.43% in PDB and 95.82% in CzDoxB, respectively, at 100 mg/mL. Lower mortality (64%) was found in SPDB at 100 mg/mL. SDS-PAGE showed bands (in PBS) of ~25, ~40, and ~55 kDa. The zymogram showed protein bands (PBs) with PA in the media, including PBs of ~14, ~40, and ~55 kDa. This study establishes the basis for exploring the potential use of this fungus against H. contortus, which is considered the most pathogenic parasite affecting lambs.

Curcumin-PVP improves the in vitro efficacy of ivermectin against resistant and susceptible Haemonchus contortus

Ivermectin (IVM) resistance in parasitic nematodes such as Haemonchus contortus has spurred a search for substances that help to recover its efficacy. One potential agent is the natural product curcumin (CUR). In this study, CUR was combined with polyvinylpyrrolidone (PVP) (CUR/PVP) to improve its solubility and biological applicability. This study determined the effect of CUR preincubation on the effective concentration 50% (EC50) of IVM in three H. contortus isolates with different susceptibilities to IVM. The IVM EC50 was determined for three H. contortus isolates with different IVM susceptibilities using the larval migration inhibition (LMI) test. The three isolates were (i) PARAISO (IVM resistant), (ii) FMVZ-UADY (IVM susceptible), and (iii) CENID-SAI INIFAP (reference IVM susceptible). The L3 of each isolate were preincubated for 3 h with one of three concentrations of CUR (μg curcumin/mL): CONC-1 (3.67), CONC-2 (5.67), or CONC-3 (8.48). Corresponding controls were performed without CUR. The EC50 of IVM was determined for each isolate after they were exposed to the different CUR concentrations. The EC50 of IVM differed between the isolates PARAISO > FMVZ-UADY > CENID-SAI INIFAP (P < 0.05). The CUR preincubation at CONC-1 did not decrease the EC50 of IVM for any of the three isolates, suggesting a hormetic effect. By contrast, CUR preincubation at CONC-2 or CONC-3 decreased the IVM EC50 for the PARAISO isolate (P < 0.05) compared with the reference isolate and reduced the EC50 of IVM for the FMVZ-UADY and CENID-SAI INIFAP isolates below the EC50 for the CENID-SAI INIFAP isolate without CUR preincubation. In conclusion, preincubation of H. contortus L3 with CUR reduced the EC50 of IVM for field isolates classified as resistant and susceptible to IVM. The CUR preincubation reduced the IVM resistance factor in the different isolates tested.

Bioactive compounds from the parasitic plant Arceuthobium vaginatum inhibit Haemonchus contortus egg hatching

The aim of this study was to assess the in vitro ovicidal activity of an ethyl acetate extract from Arceuthobium vaginatum (EtOAc-E) and their subfractions (AvR5-AvR14) against Haemonchus contortus using the egg hatching inhibition (EHI) test. The EtOAc-E and subfractions were tested at 0.12-2.00 and at 0.015-2.0 mg/mL, respectively. Distilled water and methanol (2%) were used as negative controls and Thiabendazole (0.10 mg/mL) as a positive control. Treatments with a dependent effect on concentration were subjected to regression analysis to determine the effective concentrations (EC50 and EC90). The major secondary compounds present in the extract and subfractions were identified by high performance liquid chromatography (HPLC). The EtOAc-E and AvR9 exhibited the best ovicidal effect recording 97.5 and 100% of EHI at 0.25 mg/mL, respectively. The EtOAc-E and AvR9 displayed an EC50= 0.12 and 0.08 mg/mL, respectively. The HPLC analysis in the EtOAc-E and bioactive fractions indicated the presence of a polyphenol, glycosylated flavanones, quercetin glucoside, cinnamates, coumarin, cinnamic acid derivative, ferulic acid, coumarate, naringenin, protocatechuic acid and naringin. Results demonstrated that A. vaginatum extract and fraction is able to inhibit the egg hatch process of H. contortus and could be a viable option for the control of small ruminant haemonchosis.

Study of a Mexican isolate of Arthrobotrys musiformis (Orbiliales): Predatory behavior and nematocidal activity of liquid culture filtrates against Haemonchus contortus (Trichostrongylidae), protein profile and myco-constituent groups

A Mexican isolate of the nematophagous fungus Arthrobotrys musiformis was obtained from a soil sample from the Chapultepec ecological reserve zone, in Cuernavaca, Morelos, Mexico. This isolate demonstrated an important predatory activity (74.9%) against the parasitic nematode Haemonchus contortus (L3) and its fungal liquid culture filtrates (LCF) grown in two media showed the following highest nematocidal activities (NA): In Czapek-DoxBroth (CzDoxB) 80.66% and potato-dextrose broth (PDB) 49.84%. Additionally, two major compounds derived from carboxylic acids and two derivates from alkane group were identified by GC-MS. These compounds have been associated to many biological activities. On the other hand, the protein profile analysis by SDS-electrophoresis followed by a zymogram revealed a 10 kDa protein with protease activity. This study provides important information for future experiments focused to explore the potential use of this protein as well as the identified bioactive compounds presents in the LCF as potential candidates against sheep haemonchosis.

Recent Advances in the Control of Endoparasites in Ruminants from a Sustainable Perspective

Consumer awareness of animal welfare and environmental health has led to a plateau level of global consumption putting serious pressure on the livestock industry [...].

In vitro ovicidal effect of p-coumaric acid from Acacia bilimekii aerial parts against Haemonchus contortus

Acacia bilimekii is a plant with a high content of protein, fibre, and condensed tannins, making it an excellent feed for small ruminants with anthelmintic potential. This study aimed to evaluate the ovicidal activity of a hydroalcoholic extract (Ab-HA) and fractions from A. bilimekii aerial parts on Haemonchus contortus. The ovicidal activity of the Ab-HA extract and its fractions obtained by chromatographic fractionation were evaluated through the egg hatching inhibition (EHI) test. The results showed that the Ab-HA extract had 91% EHI at 20,000 µg/mL with a mean effective concentration (EC₅₀) of 9260 µg/mL. After liquid-liquid fractionation of Ab-HA extract, the aqueous fraction (Ab-Aq) did not show ovicidal activity, whereas the organic fraction (Ab-EtOAc) showed a better EHI than the Ab-HA extract (98.9% at 2500 µg/mL). Then, the chemical fractionation of Ab-EtOAc allowed obtaining six bioactive fractions (AbR12-17) with an EHI greater than 90% at 1500 µg/mL. The best treatment was AbR15 (98.7% EHI at 750 µg/mL). Chemical analysis by HPLC-PDA of AbR15 indicated the presence of p-coumaric acid and the flavone luteolin as major compounds. Additionally, the commercial p-coumaric acid standard was evaluated in the EHI assay and showed an EHI of 97% at 62.5 µg/mL. Meanwhile, the confocal laser scanning microscopy analysis demonstrated a colocalization effect between p-coumaric acid and the H. contortus embryonated eggs. These results indicate that due to their major chemical compounds (including p-coumaric acid), the aerial parts of the plant A. bilimekii, could be considered as natural potential tool for controlling haemonchosis in small ruminants.

Assembly and Analysis of Haemonchus contortus Transcriptome as a Tool for the Knowledge of Ivermectin Resistance Mechanisms

Haemonchus contortus (Hc) is an important parasitic nematode of small ruminants. In this study we assembled the transcriptome of Hc as a model to contribute to the knowledge about the profile of the differential gene expression between two Mexican Hc strains under different anthelmintic resistance statuses, one susceptible and the other resistant to ivermectin (IVMs and IVMr, respectively), in order to improve and/or to have new strategies of control and diagnosis. The transcript sequence reads were assembled and annotated. Overall, ~127 Mbp were assembled and distributed into 77,422 transcript sequences, and 4394 transcripts of the de novo transcriptome were matched base on at least one of the following criteria: (1) Phylum Nemathelminthes and Platyhelminthes, important for animal health care, and (2) ≥55% of sequence identity with other organisms. The gene ontology (GO) enrichment analysis (GOEA) was performed to study the level of gene regulation to IVMr and IVMs strains using Log Fold Change (LFC) filtering values ≥ 1 and ≥ 2. The upregulated-displayed genes obtained via GOEA were: 1993 (for LFC ≥ 1) and 1241 (for LFC ≥ 2) in IVMr and 1929 (for LFC ≥ 1) and 835 (for LFC ≥ 2) in IVMs. The enriched GO terms upregulated per category identified the intracellular structure, intracellular membrane-bounded organelle and integral component of the cell membrane as some principal cellular components. Meanwhile, efflux transmembrane transporter activity, ABC-type xenobiotic transporter activity and ATPase-coupled transmembrane transporter activity were associated with molecular function. Responses to nematicide activity, pharyngeal pumping and positive regulation of synaptic assembly were classified as biological processes that might be involved in events related to the anthelmintic resistance (AR) and nematode biology. The filtering analysis of both LFC values showed similar genes related to AR. This study deepens our knowledge about the mechanisms behind the processes of H. contortus in order to help in tool production and to facilitate the reduction of AR and promote the development of other control strategies, such as anthelmintic drug targets and vaccines.

Phytochemical profile and nematicidal activity of a hydroalcoholic extract from Cazahuate flowers (Ipomoea pauciflora M. Martens & Galeotti) against Haemonchus contortus infective larvae

Haemonchus contortus (Hc) is a hematophagous parasite affecting the health and productivity of flocks. The administration of chemical anthelmintic drugs (AH) is the common method of deworming; however, generates resistance in the parasites to AH and it is a public health risk due to drug residues in milk, meat and sub-products. Natural compounds from plants are explored to diminish this parasitosis, improving their health and productivity, without the negative effects of AH. Ipomoea genus is a group of climbing plants belonging to the Convulvulaceae family possessing perennial leaves and tuberous roots. Medicinal properties has been attributed to this plant including nutritional agents, emetics, diuretics, diaphoretics, purgatives and pesticides. The objective of this study was assessing the in vitro nematocidal activity of a hydroalcoholic extract (HA-E) obtained from Ipomoea pauciflora (Cazahuate) flowers against Hc infective larvae (L3) and to identify its phytochemical profile (PhC-P). The assay was carried out using microtiter plates (MTP). Four HA-E concentrations were assessed and Ivermectin and distilled water were used as positive and negative control groups, respectively. Approximately 100 Hc L3 were deposited in each well (n=12) and incubated at 25-35°C for 7 days. Data were analyzed using ANOVA and a General Linear Model (GLM) followed by Tukey test (P<0.05). The treatments showing a concentration-dependent effect (CDE) were analyzed to identify their 50% and 90% lethal concentrations (CL50, 90) via a Probit Analysis. The highest mortality was observed at 50 mg/mL (82.64 ± 0.71%) and the lowest at 6.25 mg/mL (56.46 ± 2.49%), showing a CDE with increasing mortality from 6.25 to 50 mg/mL. The PhC-P revealed the presence of alkaloids, coumarins, flavonoids, tannins and triterpenes/ sterols. A HA-E from flowers of I. pauciflora will be considered to assess its potential use in the control of haemonchosis in small ruminants.

3'-Demethoxy-6-O-Demethylisoguaiacin and Norisoguaiacin Nematocidal Lignans from Artemisia cina against Haemonchus contortus Infective Larvae

Artemisia cina is a plant used in traditional Chinese medicine as a remedy for parasitic diseases. This study describes the isolation and chemical characterization of anthelmintic compounds of A. cina against Haemonchus contortus infective larvae (L₃) through lethal testing. Previously, three extracts-n-hexane (HexAc), ethyl acetate (EtOAc) and methanol (MeOAc)-were evaluated at concentrations of 4 to 0.5 mg/mL, resulting in the HexAc extract with the greatest effect of 76.6% mortality of the larvae at 4 mg/mL. Then, this was chemically fractioned by polarity, obtaining seven fractions (C1F1-C1F7), and, when evaluated at concentrations from 2 to 0.25 mg/mL, the 2 mg/mL C1F5 fraction produced an effect against the nematode H. contortus of 100% mortality of the larvae. Thus, this fraction was fractionated again by column chromatography, obtaining twelve subfractions (C2F1-C2F12) which were evaluated from 1 to 0.125 mg/mL, with the C2F5 subfraction causing a nematicidal effect of 100% mortality. NMR analysis of one (¹H, ¹³C and DEPT) and two dimensions (COSY, HSQC and HMBC) and mass spectrometry of this fraction allowed us to identify the mixture of 3'-demethoxy-6-O-demethylisoguaiacin and norisoguaiacin. Therefore, it can be assumed that the mixture of these compounds is responsible for the anthelmintic effect. These results indicate that A. cina containing anthelmintic compounds and might be used as an antiparasitic drug against H. contortus.

Coffee Pulp: A Natural Alternative for Control of Resistant Nematodes in Small Ruminants

Goat production in Mexico is an important economic activity that is affected by different gastrointestinal nematode (GIN) species. GINs resistant to commercial anthelmintics have been reported. Plant extracts or agro-industrial by-products, such as coffee pulp, have been proposed as control alternatives, given their secondary metabolite content. The aim of the present study was to determine the anthelmintic activity of the hydroalcoholic extract of coffee pulp against benzimidazole-resistant GINs. Stool samples were collected from goats, from which GIN eggs were identified and quantified. Molecular techniques confirmed the genus of GINs and their benzimidazole resistance profile. The percentage of egg hatching inhibition (% EHI) and larval mortality (% LM) with the hydroalcoholic extract of coffee pulp was determined at concentrations from 200 to 0.39 mg/mL. The genera Haemonchus spp. and Trichostrongylus spp. were identified, and the presence of the β-tubulin gene mutation, associated with benzimidazole (BZ) resistance, was determined. Hydroalcoholic extract of coffee pulp inhibited 100% of egg hatching at 200 and 100 mg/mL, with no larvicidal effect at the evaluated concentrations.

Phenolic Acids and Flavonoids from Pithecellobium dulce (Robx.) Benth Leaves Exhibit Ovicidal Activity against Haemonchus contortus

Pithecellobium dulce (Robx.) Benth is an arboreal legume used in traditional medicine for the treatment of several ailments, including a number of intestinal disorders, and as a natural deworming. The objective of this study was to evaluate the ovicidal activity of a hydroalcoholic extract (HA-E) and its fractions (aqueous, Aq-F and organic, EtOAc-F) from P. dulce leaves, as well as subfractions (C1F1–C17) obtained from EtOAc-F against Haemonchus contortus eggs. The HA-E, Aq-F, and EtOAc-F were assessed at 0.03–5.00 mg/mL and subfractions (C1F1–C17) were assessed at 0.06–1.00 mg/mL. The HA-E and Aq-F showed an ovicidal activity close to 100% at 2.5 mg/mL, and EtOAc-F displayed the highest anthelmintic effect (100% at 0.25 mg/mL). Meanwhile, the sub-fractions with the highest ovicidal effect were C1F6, C1F9, C1F10, C1F11, and CIF13. The main compounds identified in the most active fractions (C1F9, C1F11, and C1F13) were kaempferol (1), quercetin (2), coumaric acid (3), ferulic acid (4), luteolin 7-O-rhamnoside (5), quercetin 3-O-rhamnoside (6), and a caffeoyl derivate (NI). The results indicate that P. dulce leaves exhibit a potent anthelmintic activity and contain bioactive compounds able to inhibit egg hatching in H. contortus. Therefore, this plant could be used for the control of gastrointestinal nematodes in small ruminants.

Arthrobotrys musiformis (Orbiliales) Kills Haemonchus contortus Infective Larvae (Trichostronylidae) through Its Predatory Activity and Its Fungal Culture Filtrates

Haemonchus contortus (Hc) is a parasite affecting small ruminants worldwide. Arthrobotrys musiformis (Am) is a nematode-trapping fungi that captures, destroys and feeds on nematodes. This study assessed the predatory activity (PA) and nematocidal activity (NA) of liquid culture filtrates (LCF) of Am against Hc infective larvae (L3), and additionally, the mycochemical profile (MP) was performed. Fungal identification was achieved by traditional and molecular procedures. The PA of Am against HcL3 was performed in water agar plates. Means of non-predated larvae were recorded and compared with a control group without fungi. LCF/HcL3 interaction was performed using micro-tittering plates. Two media, Czapek−Dox broth (CDB) and sweet potato dextrose broth (SPDB) and three concentrations, were assessed. Lectures were performed after 48 h interaction. The means of alive and dead larvae were recorded and compared with proper negative controls. The PA assessment revealed 71.54% larval reduction (p < 0.01). The highest NA of LCF was found in CDB: 93.42, 73.02 and 51.61%, at 100, 50 and 25 mg/mL, respectively (p < 0.05). Alkaloids and saponins were identified in both media; meanwhile, coumarins were only identified in CDB. The NA was only found in CDB, but not in SPDB. Coumarins could be responsible for the NA.

Oxalis tetraphylla (Class: Magnoliopsidae) Possess Flavonoid Phytoconstituents with Nematocidal Activity against Haemonchus contortus

The nematocidal activity of an Oxalis tetraphylla hydroalcoholic extract against the nematode Haemonchus contortus (Hc) was assessed in vitro and the major compounds associated with nematocidal activity were identified. One hydroalcoholic extract was obtained from O. tetraphylla stems and leaves (Ot HE-SLE). The in vitro lethal concentrations (LC50 and LC90) against both eggs and exsheathed Hc infective larvae (L3) were assessed. Ot HE-SLE showed a potent ovicidal activity (LC50 = 0.213 mg/mL; LC90 = 0.71 mg/mL) and larvicidal effect (LC50 = 28.01 mg/mL; LC90 = 69.3 mg/mL). Later on, the extract was bipartitioned to obtain an ethyl acetate phase (EtOAc-Ph) and an aqueous phase (Aq-Ph). Both phases were assessed against Hc eggs at 0.25 and 1.0 mg/mL concentrations. The results with EtOAc-Ph showed 93.6% ovicidal activity, while 96.6% was recorded with Aq-Ph at 48 h post-confrontation (PC). In the case of larvicidal activity, both phases were assessed at 28 mg/mL; Aq-Ph showed >80% larvicidal activity 24 and 72 h PC, while EtOAc-Ph did not show important activity. HPLC analysis showed the presence of coumaric acid and flavonols. Flavonol compounds were the major compounds and were associated with the nematocidal activity. Additionally, the Aq-Ph that showed the highest activity was purified, and the fraction F3 showed the highest nematocidal activity.

A Nematode Crude Extract Acts as an Elicitor of the Nematocidal Activity of Nematophagous Fungi Liquid Culture Filtrates Against Haemonchus contortus (Nematoda: Trichostrongylidae)

AIM

This study was designed to investigate if culturing nematophagous fungi (NF) in the presence of a Haemonchus contortus larva crude extract (HcCE) enhances the nematocidal activity of nematophagous fungi liquid culture filtrates (NFCF).

MATERIALS AND METHODS

Four NF Arthrobotrys oligospora, A. musiformis, Duddingtonia flagrans and Clonostachys rosea were cultured in flasks (n = 5) containing Czapek-Dox broth medium (CDB) in the presence or absence of HcCE. NFCF recovered by filtration of each fungus (200 mg/mL) were assessed on H. contortus infective larvae (L3) using 96-well micro-titer plates (n = 4). Additionally, CDB and water were considered negative controls, while Ivermectin acted as a positive control. After 48 h confrontation, ten 10-μL aliquots of each well were deposited on slides and observed under the microscope (40 ×). Dead and alive larvae in the aliquots were quantified, and a mortality rate (MR) was estimated.

RESULTS

The MR of the different NFCF was greatly enhanced by the presence of HcCE. The four NF incubated in the absence of HcCE showed low mortality percentages from 8.2 to 25.8%; in contrast, when the assessed NF growth in the presence of HcCE showed a lethal activity ranging from 66.8 to 80.5%. Only C. rosea showed a moderate increase in the presence of the elicitor (42.7%).

CONCLUSION

This study shows evidence about the HcCE enhances the production of nematocidal activity in NFCF. Future studies should be performed to elucidate the compounds responsible of the nematocidal activity that could have important implications in the control of sheep haemonchosis.

Antibacterial Potential of Caesalpinia coriaria (Jacq) Willd Fruit against Aeromonas spp. of Aquaculture Importance

Simple Summary

Aquaculture remains an important source of food, however, aquaculture systems are affected by different factors including the appearance of resistant or multiresistant bacteria to antimicrobials. An alternative in the search for new treatments for these bacteria is plant extracts. The aim of the present study was to determine the antibacterial activity of Caesalpinia coriaria fruit hydroalcoholic extract and gallic acid over Aeromonas hydrophila, Aeromonas veronii, and Aeromonas dhakensis to identify new molecules for the treatment of diseases caused by Aeromona spp. The hydroalcoholic extract of Caesalpinia coriaria and its fractions have antibacterial activity against Aeromonas hydrophila, Aeromonas veronii, and Aeromonas dhakensis and could be alternatives for the treatment of diseases caused by the genus Aeromonas.

Abstract

Aquaculture is an important source of food and livelihood for hundreds of millions of people around the world, however, aquaculture systems are affected by different factors, among them the appearance of resistant or multiresistant bacteria to antimicrobials. The secondary metabolites of plants have been proposed as alternatives for the treatment of these bacteria. The aim of the present study was to determine the antibacterial activity of Caesalpinia coriaria fruit hydroalcoholic extract and gallic acid over Aeromonas hydrophila, Aeromonas veronii,  and Aeromonas dhakensis to identify new molecules for the treatment of diseases caused by Aeromonas spp. The C. coriaria fruit hydroalcoholic extract (HECc) was obtained by hydroalcoholic maceration and subjected to bipartition with ethyl acetate and water to obtain an aqueous fraction (Ac-FrCc) and an organic fraction (Ac-FrEtCc); gallic acid was purchased commercially. The Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC), MBC/MIC ratio, and cytotoxicity of HECc, its fractions, and gallic acid were determined. The results indicate that HECc fractions (Ac-FrCc and Ac-FrEtCc) and gallic acid have bactericidal activity against A. hydrophila and A. dhakensis, but only gallic acid showed bactericidal activity against A. veronii. The HECc and Ac-FrCc showed no toxicity, Ac-FrEtCc showed low toxicity, and gallic acid showed medium toxicity. The HECc, Ac-FrCc, and Ac-FrEtCc may be alternatives for the treatment of diseases caused by the genus Aeromonas, however, in vivo assays are necessary to corroborate these results.

In Vitro Nematocidal Properties from Two Extracts: Lippia graveolens Leaves and Delonix regia Flowers Against Eggs and Infective Larvae of Haemonchus contortus

The objective of this study was to assay the ovicidal and larvicidal effects of two hydroalcoholic extracts (HA-E) and their aqueous fractions (Aq-F) and organic fractions (EtOAc-F) from Lippia graveolens (leaves) and Delonix regia (flowers) against the parasitic nematode Haemonchus contortus. The egg hatching inhibition test (% EHI) and mortality of infective larvae (% mortality) were used as biological models. The treatments of each plant (mg/mL, % EHI, and % mortality) were assigned as follows: HA-E (12.5-50, EHI; 25-200, mortality), Aq-F (6.25-25.00, EHI; 12.5-50, mortality), EtOAc-F (0.37-25, EHI; 3.12-50, mortality), negative controls (distilled water and methanol at 2% and 4%), and positive control (ivermectin at 5 mg/mL). Data were analyzed using a completely randomized design through an analysis of variance, considering the EHI and mortality percentages as the response variables. To identify the secondary metabolites, both plants were subjected to qualitative chemical analysis and HPLC. The results showed that both plants exhibited highly ovicidal and larvicidal effects. The bipartition in each HA extract allowed the increase of the anthelmintic effect in EtOAc-F, achieving a total ovicidal activity at 1.56 mg/mL and a larvicidal effect higher than 90% at 25 mg/mL. The qualitative chemical profile of both vegetal species identified alkaloids, flavonoids, condensed tannins, terpenes, and saponins. These results suggest that either L. graveolens leaves or D. regia flowers could be potential candidates for the control of parasitic gastrointestinal nematodes in small ruminants. However, in vivo studies with experimental animals to evaluate their possible toxicity and anthelmintic effect are necessary.

Control y prevención de nematodosis en pequeños rumiantes: antecedentes, retos y perspectivas en México

En esta revisión se presenta un panorama general de las nematodosis en pequeños rumiantes en México; así como los principales problemas que enfrentan los productores para mantener su actividad productiva. Del mismo modo, se muestra información general sobre las nematodosis gastrointestinales y sus efectos en la salud animal y en la productividad. Por otra parte, se analizan los principales retos o desafíos que se enfrenta el sector pecuario para contrarrestar estas importantes enfermedades, haciendo énfasis en las distintas estrategias de control y prevención incluyendo la quimioterapia, resistencia antihelmíntica, manejo del pastoreo, desparasitación selectiva, estrategia nutricional proteica, vacunación, selección de animales genéticamente resistentes a los nematodos, el uso de plantas y compuestos con actividad nematicida; así como los resultados más recientes en cuanto al uso de hongos nematófagos como agentes de control biológico, entre otras herramientas de control. En este trabajo se hace mención a importantes resultados obtenidos en la investigación generada en el Área de Helmintología del CENID-SAI del INIFAP y se plantea como perspectiva el establecimiento de un método integral de control de estas enfermedades a las distintas fases de desarrollo de los parásitos como “blancos” de ataque hacia dónde dirigir las estrategias de control, a los diferentes estadios evolutivos de estos parásitos, con lo que se esperan los mejores resultados contra este grupo de parásitos que tanto afectan a la salud de los rebaños y a la economía de los productores.

Analysis of the immunomodulatory activity of excreted and secreted products from Haemonchus placei transition infective larvae (xL3)

The excretory/secretory (E/S) products released by infective transitory larvae (xL₃) of Haemonchus placei have an important biological function in stimulating immune mechanisms during the invasive process. Our objective was to analyse the modulatory activity of 15 and 70 kDa E/S products from H. placei xL₃. Both E/S products were collected from xL₃in vitro cultures at 24 and 72 h. Proteins were confirmed by SDS-PAGE, and the corresponding spots were elicited by gel isoelectrofocusing (IEF) and characterised by mass spectrometry. Additionally, flow cytometry of CD4⁺/γδ⁺ T cells and immune gene expression were performed by proliferation assays using each E/S product to stimulate lymphocyte and peripheral blood mononuclear cells (PBMCs) from non-infected calves. The IEF results displayed two spots of 7.0 and 5.7 pI for the 15 and 70 kDa products, respectively. Additionally, 29 and 17 peptides from the 15 and 70 kDa E/S products, respectively, were identified with the hypothetical neurotransmitter and enzymatic functions necessary for larval development. The relative expression displayed upregulation of IL4, 5, 6, 8, 10, 13, IFNγ, and FCεR1A genes (from 2.0- to 17.6-fold, p < 0.05) stimulated by the 15 and 70 kDa proteins, indicating specific genes against haemonchosis. Although the percentage of median florescence intensity (MFI%) of CD4⁺/γδ⁺ T cells did not change for both E/S products compared to the negative control and concanavalin-A stimulated cells as the positive control (p > 0.05), the 15-kDa protein reduced the levels of both T cells, and the 70-kDa proteins increased the γδ⁺ cells slightly. Additionally, there was increased PBMCs proliferation by the 70 kDa proteins (p < 0.05), denoting the biological role of other immune cells. The 15 and 70 kDa protein E/S products from H. placei xL₃ showed modulation of the immune response, and although more studies are required, they indicate important functions in the host/parasite interaction.

Actividad antihelmíntica in vivo de hojas de Acacia cochliacantha sobre Haemonchus contortus en cabritos Boer

El objetivo del presente trabajo fue evaluar el efecto de la inclusión de hojas de Acacia cochliacantha en una dieta de mantenimiento para cabritos de la raza Boer en el conteo fecal de huevos (CFH) de Haemonchus contortus, consumo de agua y materia seca. Diez cabritos recién destetados (16.850 ± 1.630 kg de peso vivo inicial y 3 meses de edad), fueron experimentalmente infestados con larvas (L3) de H. contortus (350 larvas por kilogramo de peso vivo), para probar dos tratamientos: T1: testigo (animales infectados con larvas L3 de H. contortus, sin inclusión de hojas de A. cochliacantha) y T2: animales infectados con larvas L3 de H. contortus, con inclusión de 5% hojas de A. cochliacantha en la dieta. Antes de asignar los tratamientos a los animales, se realizó un CFH por gramos de heces en cada uno de ellos y de esta manera agruparlos de mayor a menor en relación a la cantidad de huevos presentes en las heces, en los dos animales con valores más altos se asignaron aleatoriamente T1 o T2 y así sucesivamente hasta completar cinco repeticiones verdaderas para cada tratamiento. Las variables medidas fueron: CFH (por gramo de heces), consumo de agua y consumo de materia seca (CMS). Los resultados encontrados demostraron reducción (P<0.05) en el CFH de H. contortus en los cabritos donde se incluyó el 5% de hojas de A. cochliacantha en su dieta. Para el consumo de agua y CMS (g día-1) no existieron diferencias entre tratamientos (P> 0.05). Se concluye que la adición de hojas de A. cochliacantha en dietas para cabritos tienen actividad antihelmíntica, por lo que esta leguminosa arbórea podría representar una opción en el manejo integral de la nematodiasis de cabritos Boer en crecimiento.

Vaccination with cathepsin L phage-exposed mimotopes, single or in combination, reduce size, fluke burden, egg production and viability in sheep experimentally infected with Fasciola hepatica

Fascioliasis is a worldwide emergent zoonotic disease that significantly constrains the productivity of livestock. In this study, fluke burdens, liver fluke size and biomass, faecal eggs counts, serum levels of hepatic enzymes and immune response were assessed in sheep vaccinated with peptide mimotopes of cathepsin L and infected with metacercariae. A total of 25 sheep were allocated randomly into five groups of five animals each, and experimental groups were immunised with 1 × 10¹³ filamentous phage particles of cathepsin L1 (CL1) (TPWKDKQ), CL2 (YGSCFLR) and mixtures of CL1 + CL2 mimotopes, in combination with Quil A adjuvant, and wild-type M13KE phage in a two-vaccination scheme on weeks 0 and 4. The control group received phosphate-buffered saline. All groups were challenged with 300 metacercariae two weeks after the last immunisation and euthanised 16 weeks later. The CL1 vaccine was estimated to provide 57.58% protection compared with the control group; no effect was observed in animals immunised with CL2 and CL1 + CL2 (33.14% and 11.63%, respectively). However, animals receiving CL2 had a significant reduction in parasite egg output. Vaccinated animals showed a significant reduction in fluke length and width and wet weights. In the CL1 group, there was a significant reduction in the total biomass of parasites recovered. Egg development was divided into seven stages: dead, empty, unembryonated, cell division, eyespot, hatched and hatching. The highest percentage of developmental stages was detected for vaccinated sheep administered CL1 + CL2 with cell division, and the lowest percentage was observed in the hatching stage. Furthermore, a significant difference in all developmental stages was observed between vaccinated animals and the control group (P < 0.01). The levels of anti-phage total IgG in immune sera increased significantly at four weeks after immunisation and were always significantly higher for cathepsin L vaccine group than in the challenged control group. Total IgG was inversely and significantly correlated with worm burden in the CL1 group.

Vaccination with cathepsin L mimotopes of Fasciola hepatica in goats reduces worm burden, morphometric measurements, and reproductive structures

Fasciolosis is a worldwide emergent zoonotic disease that significantly constrains the productivity of livestock. We conducted an experimental trial with four groups of five goats each, vaccinated with 1 × 10¹³ phage particles of cathepsin L1 (CLI: DPWWLKQ), CL1 (SGTFLFS), and CL2 (PPIRNGK) mimotopes combined with Quil A adjuvant. Animals received a booster four weeks later. The control group received phosphate-buffered saline. All animals were infected with 200 Fasciola hepatica metacercariae at week six and euthanised 16 weeks later. The percentage of significant worm reduction in CL1 (DPWWLKQ), CL1 (SGTFLFS), and CL2 (PPIRNGK) compared to the control group were 55.40%, 70.42% (P < 0.05), and 32.39%, respectively. Vaccinated animals showed a significant reduction in faecal egg production and egg viability. A significant reduction in the total biomass of parasites recovered was observed in the CL1 (DPWWLKQ) and CL1 (SGTFLFS) groups. In goats vaccinated with CL2 (PPIRNGK), fluke length and width were smaller than those in the control group. Furthermore, animals receiving CL mimotopes showed a significant reduction in the total area of reproductive structures. Goats immunised with phage-displayed mimotopes produced significantly high titres of specific IgG1 and IgG2 isotypes, indicating a mixed Th1/Th2 response. The liver fluke burdens in goats vaccinated with CL1 (DPWWLKQ) and CL1 (SGTFLFS) were significantly correlated with IgG and IgG1 levels.

Phage display-based vaccine with cathepsin L and excretory-secretory products mimotopes of Fasciola hepatica induces protective cellular and humoral immune responses in sheep

Fasciolosis is a foodborne zoonotic disease that affects grazing animals and causes substantial economic losses worldwide. Excretory/secretory (E/S) products and cathepsin L mimotopes from Fasciola hepatica were used to immunise experimentally infected sheep against liver flukes. The level of protection was measured in terms of fluke burden, morphometric measurements and faecal egg counts, as well as the humoral and cellular immune responses elicited. Five groups of 5 sheep each were immunised with 1 × 10¹³ phage particles of cathepsin L1 (group 1: SGTFLFS), cathepsin L1 (group 2: WHVPRTWWVLPP) and immunodominant E/S product (group 3) mimotopes with Quil A adjuvant, and wild-type M13KE phage (group 4) at the beginning and as a booster two weeks later. The control group received phosphate-buff ;ered saline. All groups were challenged with 300 metacercariae at week four and slaughtered 18 weeks later. The mean fluke burdens after challenge were reduced by 52.39 % and 67.17 % in sheep vaccinated with E/S products (group 3) and cathepsin L1 (group 1: SGTFLFS), respectively; no eff ;ect was observed in animals inoculated with cathepsin L1 (group 2: WHVPRTWWVLPP). Animals vaccinated showed a significant reduction in fluke length and width, wet weights and egg output Sheep immunised with phage-displayed mimotopes induced the development of specific IgG1 and IgG2, indicating a mixed Th1/Th2 immune response. Measurement of cytokine levels revealed higher levels of IFN-γ as well as lower production of IL-4 in sheep vaccinated with the mimotope peptide of F. hepatica. Fluke-specific production of IFN-γ in immunised animals was significantly correlated with fluke burden (P < 0.01). As helminth infection progressed, increased levels of IL-4 were evident in the wild-type M13KE phage (group 4) and the control groups (group 5), accompanied by a downregulation of IFN-γ production. Vaccinated animals with cathepsin L1 (group 1: SGTFLFS) showed that amino acids located in the middle (⁶⁴SG⁶⁵) of the linear sequence and C-terminal end (³¹⁴TFLFS³¹⁸) were associated with significant protection.

Acacia farnesiana pods (plant: Fabaceae) possesses anti-parasitic compounds against Haemonchus contortus in female lambs

Acacia farnesiana pods are rich in secondary metabolites and their biological activities have been recorded as antibacterial, antioxidant and anthelmintic. Previously, an in vitro bioguided study showed the important ovicidal and larvicidal effects of an organic fraction (EtOAc-F) from a hydroalcoholic extract of A. farnesiana pods against Haemonchus contortus. The present study aimed to assess the in vivo anthelmintic effect of EtOAc-F from A. farnesiana pods on the H. contortus faecal egg elimination in female lambs and on the infective larvae (L₃) population reduction in coprocultures. The EtOAc-F was obtained from a hydroalcoholic extract from A. farnesiana pods through chromatographic procedures; additionally, some secondary compounds were identified using high-performance liquid chromatography (HPLC). Twenty-one 'Katahdin' crossbred female lambs ranging from three to four months of age, with body weights 21.9 ± 0.39 kg were used. Animals were orally infected with H. contortus (L₃) by a single dose of 350 L₃/kg BW. Three experimental groups (n = 7) were assigned as follows: 1) Control (untreated), 2) Albendazole, as a positive control (at 7.5 mg/kg BW, unique dose) and 3) EtOAc-F (at 100 mg/kg BW, once every third day, with three applications in total). Individual faecal samples were collected once a week for 5 weeks (at days 38, 45, 52, 59 and 66) post-treatment, to measure the faecal egg counts (FEC) and to obtain the H. contortus (L₃) population from faecal cultures. The highest FEC reduction caused by EtOAc-F was 67.7%; meanwhile, albendazole showed a total FEC reduction after the second week post-treatment (day 45). On the other hand, the fraction caused an important reduction in the larval population in coprocultures (54.3-68.5%). The phytochemical analysis revealed the presence of galloyl derivatives and flavonoids as major compounds. The A. farnesiana pods could serve as a natural anthelmintic for the control of H. contortus, and perhaps for controlling other parasites of veterinary importance.

Immune response related to Pelibuey sheep naturally infected with gastrointestinal nematodes in a tropical region of Mexico

We analysed the immune response involved in sheep naturally infected with gastrointestinal (GI) nematodes. Fifteen Pelibuey lambs were grazed in paddocks contaminated with GI nematodes for 13 weeks. To assess the infection, the number of eggs per gram (epg) and the percentage of packed cell volume (pcv) were evaluated. Blood and abomasal tissue samples were collected at week 8 post-infection to analyse the expression levels of IL-4, IL-5, IL-6, IL-8, IL-13, TGF-β and FCεR1A genes. The nematode Haemonchus contortus was the main species identified. In addition, two groups of lambs were classified based on the x ± SE of epg and pcv values: G-1, with 151 ± 28 and 29 ± 0.33%, respectively, and G-2, with 475 ± 59.5 and 26 ± 0.38%, respectively. For G-1, upregulation of IL-4, IL-8, IL-13, TGF-β and FCεR1A genes from 2.42- to 14.99-fold was observed in blood and abomasal tissue samples (p > .05), and IL-5, IL-8 and TGF-β genes had significant gene expression levels in blood (p < .05). For G-2, moderate gene expression levels, ranging from 1.22- to 3.45-fold, were observed in abomasal tissue (p > .05), and the IL-5 gene presented significant gene expression in blood (p < .05). Strong positively correlated values (r) between pcv and IL-4, IL-8 and TGF-β genes were observed in G-1. In contrast, significant negative correlations between epg and IL-4, IL-5 and FCεR1A genes indicate acute infection for G-2. Our results suggest that IL-4, IL-5, IL-13, TGF-β and FCεR1A genes are important modulators of GI nematode infections of Pelibuey lambs.

Galloyl flavonoids from Acacia farnesiana pods possess potent anthelmintic activity against Haemonchus contortus eggs and infective larvae

ETHNOPHARMACOLOGY RELEVANCE

Acacia farnesiana (L.) Willd is a shrub legume used as condiment, medicinal plant and bioactive herbage. This species is used in traditional medicine of several countries to relieve the symptoms of gastrointestinal diseases, diarrhoea, stomach pain and typhoid as well as astringent, antidysenteric and anthelmintic. Some studies have shown that this plant displayed anthelmintic activity against several gastrointestinal nematode parasites of livestock, and also against parasites of human beings, such as malaria.

AIM OF THE STUDY

This work describes the isolation and chemical identification of the anthelmintic compounds of Acacia farnesiana pods against eggs and infective larvae of the sheep parasitic nematode Haemonchus contortus. The bio-guided chemical fractioning of A. farnesiana pods using ethyl acetate against H. contortus eggs and infective larvae allowed for the identification of naringenin 7-O-(6″-galloylglucoside) (flavonol group) as the compound responsible for the anthelmintic activity against this important parasitic nematode.

MATERIALS AND METHODS

Anthelmintic activity was assessed using the egg hatching inhibition assay (EHI) and mortality tests. A complete hydroalcoholic extract (HA-E) at 12.5-50 mg/mL, an aqueous fraction (Aq-F) at 3.12-25 mg/mL and an ethyl acetate fraction (EtOAc-F) at 3.12-25 mg/mL were analysed in the first selection phase. The purification of compounds through the chromatographic separation of the organic fraction resulted in nine less complex mixtures (C1F1, C1F2, C1F3, C1F4, C2F1, C2F2, C2F3, C2F4 and C2F5) that were assessed at 0.62-5 mg/mL concentrations. In addition, thiabendazole (0.6 mg/mL) and ivermectin (5 mg/mL) were used as positive controls. Likewise, distilled water and 4% methanol were used as negative controls. The bioactive compounds of EtOAc-F were obtained and characterised through chromatographic processes like open column chromatography, thin layer chromatography (TLC), high performance liquid chromatography (HPLC), ultra-performance liquid chromatography (UPLC) and gass chromatography-mass detection (GC-MS). Bioactive compounds were identified by spectroscopy (¹H and ¹³C NMR) and mass spectrometric analysis. Additionally, the H. contortus eggs and infective larvae exposed to the bioactive compounds were observed through environmental scanning electron microscopy (ESEM) and confocal laser scanning microscopy (CLSM). Data were analysed based on a completely randomised design using ANOVA through a general linear model.

RESULTS

The EtOAc-F fraction showed the highest ovicidal and larvicidal activities, at close to 100% at 3.12 and 6.25 mg/mL, respectively. The treatments C1F2, C1F3 and C2F3 displayed the main ovicidal activity (80-100%) at 2.5 mg/mL. The major compounds found in these sub-fractions were identified as galloyl derivatives and flavanones, including gallic acid (1), methyl gallate (2), ethyl gallate (3), naringin (4), naringenin 7-O-(4″, 6″-digalloylglucoside) (5), naringenin 7-O-(6″-galloylglucoside) (6) and naringenin (7). Likewise, the ESEM and CLSM images showed that the assessed compounds adhered to the eggshell and the external cuticle of the larvae.

CONCLUSION

These results indicate that A. farnesiana pods contain nematocidal compounds and might be promising natural anthelmintic agents against H. contortus. This leguminous plant could be used as a nutraceutical food source for the control of gastrointestinal nematodes in small ruminants.

Antibacterial and Hemolytic Activity of Crotalus Triseriatus and Crotalus Ravus Venom

Rattlesnakes have venoms with a complex toxin mixture comprised of polypeptides and proteins. Previous studies have shown that some of these polypeptides are of high value for the development of new medical treatments. The aim of the present study is to evaluate, in vitro, the antibacterial and hemolytic activity of Crotalus triseriatus and Crotalus ravus venoms. A direct field search was conducted to obtain Crotalus triseriatus and Crotalus ravus venom samples. These were evaluated to determine their antibacterial activity against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa through the techniques of Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC). Hemolytic activity was also determined. Antibacterial activity was determined for treatments (Crotalus triseriatus 2) CT2 and (Crotalus ravus 3) CR3, obtaining a Minimum Inhibitory Concentration of 50 µg/mL and a Minimum Bactericidal Concentration of 100 µg/mL against Pseudomonas aeruginosa. CT1 (Crotalus triseriatus 1), CT2, and CR3 presented hemolytic activity; on the other hand, Crotalus ravus 4 (CR4) did not show hemolytic activity. The results of the present study indicate for the first time that Crotalus triseriatus and Crotalus ravus venoms contain some bioactive compounds with bactericidal activity against Pseudomonas aeruginosa which could be used as alternative treatment in diseases caused by this pathogenic bacterium.

Antibacterial activity of compounds isolated from Caesalpinia coriaria (Jacq) Willd against important bacteria in public health

Antimicrobial resistance has been increasing in recent years and is most frequently found in pathogenic microorganisms resistant or multiresistant to drugs. The secondary metabolites of plants have been evaluated as alternatives for control and treatment of these microorganisms. The aim of this study was to isolate and identify the secondary metabolites with antibacterial activity from Caesalpinia coriaria (Jacq) Willd fruit. Hydroalcoholic extract (CCHA), was subjected to a bipartition with ethyl acetate giving two fractions an aqueous (Aq-F) and an organic (EtOAc-F). The isolation of bioactive fraction (EtOAc-F) allowed obtain two important compounds, methyl gallate (1) and gallic acid (2). These compounds were identified by high-performance liquid chromatography (HPLC) and nuclear magnetic resonance (NMR). The CCHA, both fractions and the isolated compounds were evaluated in vitro to determine their Minimal Inhibitory Concentration (MIC) and Minimal Bactericidal Concentration (MBC) against Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, Listeria monocytogenes and Staphylococcus aureus. Gallic acid (2) showed the lowest MIC on S. typhi, (0.156 mg/mL), L. monocytogenes and S. aureus (1.25 mg/mL), while methyl gallate (1) had the best inhibitory effect against E. coli and P. aeruginosa (1.25 mg/mL). On the other hand, methyl gallate (1) showed the best MBC on P. aeruginosa (2.50 mg/mL), and gallic acid (2) had the lowest MBC on P. aeruginosa and L. monocytogenes. In conclusion, methyl gallate (1) and gallic acid (2) are the compounds responsible for the antibacterial activity of Caesalpinia coriaria fruit.

In vitro predatory activity of nematophagous fungi isolated from water buffalo feces and from soil in the Mexican southeastern

Nematophagous fungi from the feces of water buffalo and soil from southeastern Mexico were isolated, and their in vitro predatory activity against Haemonchus contortus infective larvae (L3) (HcL3) was assessed. The fungi were isolated by sprinkling soil or feces on water agar plates. Six series of 10 Petri dishes containing a 7-day-old culture of each fungus and a series without fungi as the control were prepared. Five hundred HcL3 were added to each plate. The plates were incubated at room temperature. The average of recovered HcL3 was considered to estimate the larval reduction rate. Four nematophagous fungi isolates corresponding to Arthrobotrys oligospora, var microspora (strains 4-276, 269 and 50-80) and one identified as A. oligospora,var. oligospora (isolates 48-80) were obtained from water buffalo feces. From the soil, five isolates were isolated; three corresponded to A. musiformis (Bajío, Yumca and Macuspana isolates), and two isolates were identified as A. oligospora (Comalcalco and Jalapa de Méndez isolates). The predatory activity of isolates from water buffalo feces ranged between 85.9 and 100%. Meanwhile, the fungi from the soil ranged between 55.5 and 100% (p≤0.05). The nematophagous fungi obtained could have important implications in the control of parasites of importance in the livestock industry.

Galloyl derivatives from Caesalpinia coriaria exhibit in vitro ovicidal activity against cattle gastrointestinal parasitic nematodes

Gastrointestinal nematodes (GIN) are responsible for enormous economic losses worldwide. The use of anthelmintic drugs reduces the parasitic burden in ruminants. However, the excessive use of these drugs triggers anthelmintic resistance in these parasites, which leads to a worrisome inefficacy of most of the commercially available antiparasitic drugs. Caesalpinia coriaria is an arboreal legume possessing medical properties, although the antiparasitic potential of this plant against animal parasitic nematodes has not yet been studied. The aim of this study was to assess the in vitro ovicidal activity of a hydro-alcoholic extract (HA-E) from C. coriaria fruits against GIN and to identify the compounds responsible for this activity through an egg hatch inhibition (EHI) assay. GIN eggs obtained from cattle faeces were used in bio-guided assays. The HA-E was subjected to a liquid-liquid extraction using water and ethyl acetate to obtain two fractions, an organic fraction (EtOAc-F, 27% yield) and an aqueous (Aq-F, 73% yield) fraction. The chromatographic fractionation of the EtOAc-F (2 gr) was performed on a glass column packed with silica gel and eluted with dichloromethane/methanol with 10% ascending polarity. The bioactive compounds were analysed using high-performance liquid chromatography (HPLC) with UV detection, nuclear magnetic resonance (NMR) spectroscopy and mass spectroscopy (MS). The HA-E extract and the EtOAc-F showed ovicidal activity at a LC₅₀ of 0.92 and 0.16 mg/mL, respectively. A concentration-dependant effect was observed in both treatments. Chromatographic fractionation of the EtOAc-F, allowed for the isolation and characterisation of three important compounds: methyl gallate (1), gallic acid (2) and an unidentified compound (UC). The bioactive molecules (2 and UC) displayed an ovicidal activity close to 100% at 1 mg/mL concentration. The results of this work show that gallic acid (2) isolated from C. coriaria fruits is responsible for its ovicidal activity. The use of Caesalpinia coriaria could be explored in future studies as an environmentally-friendly alternative for the control of GIN in ruminants.

Caffeoyl and coumaroyl derivatives from Acacia cochliacantha exhibit ovicidal activity against Haemonchus contortus

ETHNOPHARMACOLOGY RELEVANCE

Acacia cochliacantha is a small tree whose foliage is traditionally used in Mexico for treatment of kidney pain, gastrointestinal illnesses and to kill intestinal parasites. In recent decades, the study of vegetal extracts has offered other possible alternatives for the control of Haemonchus contortus. Considering that this nematode affects dramatically the health and productivity of small ruminants, the aim of this study was to identify the anthelmintic compounds from A. cochliacantha hydro-alcoholic extract (HA-E) through an ovicidal test.

MATERIAL AND METHODS

In vitro egg hatch assay was conducted to determinate the anthelmintic effects of a HA-E (60g). Liquid-liquid ethyl acetate/water extraction gave two fractions (EtOAc-F, 1.92g; Aq-F; 58.1g). The less polar compounds from ethyl acetate fraction were extracted by addition of dichloromethane offering a precipitate phase (Mt-F, 1.25g) and a soluble mixture (DCMt-F 1.15g). All fractions were evaluated for ovicidal activity obtaining the egg hatching inhibition (EHI, 0.07-25mg/mL). Ivermectin (0.5mg/mL) was used as a reference drug (positive control), and distilled water, 2.5% DMSO and 2% methanol were used as negative controls. The isolated compounds from the most active fractions were subjected to spectroscopic (¹H NMR) Spectrometric (MS) and UV HPLC analysis in order to identify the bioactive compounds.

RESULTS

The less polar treatments (AcOEt-F, DCMt-F, DCMt-P) showed the highest ovicidal activities (98-100% EHI; at 0.62-1.56mg/mL) and the major compounds found in these fractions were identified as caffeoyl and coumaroyl derivatives, including caffeic acid (1), p-coumaric acid (2), ferulic acid (3), methyl caffeate (4), methyl-p-coumarate (5), methyl ferulate (6) and quercetin. In case of the less active fractions (Aq-F, Mt-F) were constituted principally by glycosylated flavonoids.

CONCLUSION

These results show that caffeoyl and coumaroyl derivatives from Acacia cochliacantha leaves had promising anthelmintic activity against Haemonchus contortus. This leguminous may offer an alternative source for the control of gastrointestinal nematodes of small ruminants.