Anthelmintic activity of acetone-water extracts against Haemonchus contortus eggs: interactions between tannins and other plant secondary compounds

Anthelmintic activity on Haemonchus contortus and toxicity of benzoyl-carvacrol: a study in vitro, in silico and in vivo

Carvacrol is isolated from essential oils and possesses activity against gastrointestinal nematodes of small ruminants. Benzoylation has been proposed to improve its pharmacological and pharmacokinetic properties. The objectives of this study were to evaluate the ovicidal activity of benzoyl-carvacrol (BC) against Haemonchus contortus, the in silico interaction of BC with the β-tubulin protein and the toxicity of this compound. Carvacrol was subjected to benzoylation and analyzed by gas chromatography coupled to mass spectrometry (GC/MS). The activity of BC and carvacrol was evaluated against H. contortus in the egg hatching test. The in silico study was based on molecular docking with the β-tubulin and thiabendazole used as control. The acute toxicity test was performed with BC and carvacrol by up-and-down procedure (limit test: 2,000 mg/kg) in Wistar rats. GC/MS confirmed the benzoylation. BC and carvacrol inhibited egg hatching by 99.70 and 98.89% at concentrations of 3.16 and 1 mg/mL, respectively, and interacted with β-tubulin. No mortality was caused by compounds, but rats treated with carvacrol demonstrated intoxication signs. These findings indicated that BC showed effect on H. contortus and can potentially interact with β-tubulin of nematodes in addition to presenting toxicological safety in laboratory animals.

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.

C, Marques MJ, Correia Ribeiro WL. Simarouba berteroana Krug & Urb. Extracts and Fractions Possess Anthelmintic Activity Against Eggs and Larvae of Multidrug-Resistant Haemonchus contortus

Gastrointestinal nematode infections significantly impact small ruminant production, causing substantial economic losses worldwide. The rising resistance to anthelmintics has led to the search for alternative treatments, including phytotherapeutic approaches. This study investigates the chemical composition and anthelmintic activity of crude extracts and fractions from Simarouba berteroana, an endemic plant from Hispaniola, against a multidrug-resistant isolate of Haemonchus contortus. Chemical analyses revealed high contents of phenolic compounds, tannins, and flavonoids and confirmed the presence of 22 quassinoids, 5 phytosterol lipids, 3 terpenoid quinones, 3 alkaloids, and 1 naphthoquinone. The hydroalcoholic and iso-butanol fractions showed the strongest egg hatching inhibition (IC50 = 0.93 and 1.21 mg/mL, respectively), while hexane fractions were less effective (p < 0.05). Fluorescence microscopy showed that the extracts and fractions adhered to eggshells, causing evisceration and cuticle detachment in hatched larvae. All extracts, except for hexane fractions, inhibited larval exsheathment at 0.3 mg/mL, with phenolic compounds being responsible for this effect. These results provide the first evidence of the ovicidal and larval exsheathment inhibition activities of S. berteroana extracts and fractions against H. contortus, highlighting their potential in managing gastrointestinal nematodes in small ruminants. Further in vivo studies are needed to confirm these findings.

Effect of green tea dust as a dietary additive and anthelminthic on performance, digestibility, and fecal egg counts in Priangan ewe lambs infected with Strongyles worms

Despite green tea dust (GTD) is a by-product of green tea fabrication, it has the potential as natural additive and anthelmintic in ruminant diets due to its high protein and bioactive contents. This study aimed to compare the effect of 3 different doses [0% (control), 0.75% (GTD-0.75), and 1.5% (GTD-1.5)] of GTD supplementation on dry matter intake (DMI, g/kg DM), average daily gain (ADG, g/kg DM), nutrient digestibility (%), and fecal egg counts (FEC, eggs/g feces) of local ewe lambs infected with Strongyles worms during 84 days feeding trial using a completely randomized design and six replicates (n = 6). The results showed that all lamb groups decreased body weight; however, GTD-1.5 supplemented lambs tended (P = 0.061) to have better ADG at the end of the trial compared to the other groups. In addition, GTD-1.5 supplemented lambs had lower (P < 0.05) FEC at day 42 and day 56 than those the control lambs. About 1.5% GTD supplementation in a diet has the potential as dietary additive and anthelmintic to maintain the productivity, health, and welfare in rearing lambs.

In vitro anthelmintic activity and colocalization analysis of hydroxycinnamic acids obtained from Chamaecrista nictitans against two Haemonchus contortus isolates

This study assessed the in vitro anthelmintic activity of ethyl acetate extract (Cn-EtOAc) and its bioactive fractions (CnR3 and CnR5) obtained from Chamaecrista nictitans aerial parts against two Haemonchus contortus (Hc) isolates, one resistant (strain HcIVM-R) and another susceptible (strain HcIVM-S) to ivermectin. Ferulic acid and p-coumaric acid were identified in the bioactive fractions; therefore, their commercial standards were also assessed. A colocalization analysis between the ferulic acid commercial standard and eggs of the HcIVM-R strain was performed using confocal laser scanning microscopy and the ImageJ program. The ovicidal effects of the Cn-EtOAc extract, bioactive fractions and commercial compounds were tested through the egg hatching inhibition (EHI) assay on H. contortus isolates HcIVM-R and HcIVM-S. The Cn-EtOAc caused 88 % and 92 % EHI at 5000 µg/mL on HcIVM-R and HcIVM-S, respectively. Fractions CnR3 and CnR5 displayed the highest ovicidal activity against HcIVM-S, with effective concentrations (EC90) of 2134 and 601 µg/mL, respectively. Meanwhile, the commercial standards ferulic acid and p-coumaric acid also resulted in higher effectiveness on the same strain, with EC90 of 57.5 and 51.1 µg/mL. A colocalization analysis of ferulic acid and eggs of HcIVM-R revealed that this compound is localized to the cuticle surface of the embryo inside the egg parasite. The results demonstrated that both ferulic and p-coumaric acids interrupt the egg-hatching processes of the two Hc isolates. Both phenolic acids isolated from C. nictitans and commercial standards exhibited the best anthelmintic effect on HcIVM-S. These findings indicate that the phenolic acids were less effective in egg hatch inhibiting on the HcIVM-R strain compared to the HcIVM-S strain.

Anthelmintic activity and chemical profile of native plant extracts from the Yucatan Peninsula against Toxocara canis

Toxocara canis can produce the "larva migrans" syndrome in humans, and in puppies, it can cause severe digestive disorders. The most used treatments are based on anthelmintics, although there are reports of anthelmintic (AH) resistance. The Yucatan Peninsula has a great variety of plant species whose AH properties are still unknown. The objective of this study was to evaluate the in vitro AH activity of ethanolic (EE), methanolic (ME) and aqueous (AE) extracts from the leaves of five native plant species of the Yucatan Peninsula on T. canis eggs of dogs from Merida, Yucatan. As part of a screening, the EE of the plants Alseis yucatanensis, Calea jamaicensis, Cameraria latifolia, Macrocepis diademata, and Parathesis cubana were evaluated at doses of 2400 and 3600 μg/ml. The EE and AE of A. yucatanensis and M. diademata presented high percentages (≥ 91.3%) of inhibition of the larval development of T. canis after six days of exposure. The lowest LC50 and LC99 was presented by the ME from A. yucatanensis (255.5 and 629.06 µg/ml, respectively) and the ME from M. diademata (222.4 and 636.5 µg/ml, respectively), and the AE from A. yucatanenesis (LC50 of 535.9 µg/ml). Chemical profiling of the most potent AH extract (Alseis yucatanensis) was carried out by LC-UV-HRMS. Data from the ME and AE from this plant indicated the presence of the known glucosylngoumiensine, kaempferol 3,7-diglucosyde, uvaol, linoleic acid and linolenic acid together with unknown alkaloids. The EE, ME and AE from leaves of M. diademata and A. yucatanensis could be developed as natural alternatives to control T. canis.

Phytochemicals, antioxidant ability and in vitro anthelmintic activity of crude extracts from Vitexnegundo leaves against Haemonchus contortus

The aim of this study was to evaluate the in vitro anthelmintic effect of crude aqueous, methanol, ethanol, hydro alcohol and acetone extracts of Vitex negundo leaves against Haemonchus contortus eggs and larvae. Phytochemical analysis to identify the number of compounds in extracts was done by chemical tests and gas chromatography coupled to a mass spectrophotometer detector (GC-MS). First off all the effectiveness of dried plant materials was evaluated on larval development by mixing powdered material (no nano particles) to faecal cultures from donor sheep. Adding powder to the faecal culture resulted into 100% inhibition in larval development at 200 and 300 mg/g of faeces. The anthelmintic activity was assessed using the egg hatch assay (EHA) and the larval mortality assay (LMA). Comparison of mean inhibition percentage of egg embryonation, mean inhibition percentage of egg hatching and mean percentage of larval mortality at different concentrations with control was performed by one-way ANOVA. The means were compared for statistical significance using DMRT at P < 0.05. For both the assays, 50% inhibitory concentration (IC50) and lethal concentration (LC50) were calculated by probit analysis. Chemical test revealed presence of high concentration of saponin and flavoinoids and moderate concentration of total phenols in leaves. The antioxidant activity (radical scavenging activity, RSA %) measured was 35.47%. On GC-MS, the methanolic leaves extract revealed 30 phyto-compounds. On EHA, there was marked effect on inhibition of egg hatching by aqueous, hydro alcohol and acetone extracts. On LMA all the five extracts showed excellent larvicidal activity. V. negundo leaves methanol extract mediated silver nanoparticles were found very effective at much lower concentrations as compared to crude methanol extract. The results indicated that the V. negundo leaves crude extracts possessed excellent in vitro ovicidal and larvicidal properties against H. contortus which needs more investigation, especially in vivo trials for the control of parasite.

Phytochemical analysis and anthelmintic activity of Combretum mucronatum leaf extract against infective larvae of soil-transmitted helminths including ruminant gastrointestinal nematodes

BACKGROUND

Soil-transmitted helminths (STH) infect more than a quarter of the world's human population. In the absence of vaccines for most animal and human gastrointestinal nematodes (GIN), treatment of infections primarily relies on anthelmintic drugs, while resistance is a growing threat. Therefore, there is a need to find alternatives to current anthelmintic drugs, especially those with novel modes of action. The present work aimed to study the composition and anthelmintic activity of Combretum mucronatum leaf extract (CMLE) by phytochemical analysis and larval migration inhibition assays, respectively.

METHODS

Combretum mucronatum leaves were defatted with petroleum ether and the residue was extracted by ethanol/water (1/1) followed by freeze-drying. The proanthocyanidins and flavonoids were characterized by thin layer chromatography (TLC) and ultra-high performance liquid chromatography (UPLC). To evaluate the inhibitory activity of this extract, larval migration assays with STH and GIN were performed. For this purpose, infective larvae of the helminths were, if necessary, exsheathed (Ancylostoma caninum, GIN) and incubated with different concentrations of CMLE.

RESULTS

CMLE was found to be rich in flavonoids and proanthocyanidins; catechin and epicatechin were therefore quantified for standardization of the extract. Data indicate that CMLE had a significant effect on larval migration. The effect was dose-dependent and higher concentrations (1000 µg/mL) exerted significantly higher larvicidal effect (P < 0.001) compared with the negative control (1% dimethyl sulfoxide, DMSO) and lower concentrations (≤ 100 µg/ml). Infective larvae of Ascaris suum [half-maximal inhibitory concentration (IC50) = 5.5 µg/mL], Trichuris suis (IC50 = 7.4 µg/mL), and A. caninum (IC50 = 18.9 µg/mL) were more sensitive to CMLE than that of Toxocara canis (IC50 = 310.0 µg/mL), while infective larvae of Toxocara cati were largely unaffected (IC50 > 1000 µg/mL). Likewise, CMLE was active against most infective larvae of soil-transmitted ruminant GIN, except for Cooperia punctata. Trichostrongylus colubriformis was most sensitive to CMLE (IC50 = 2.1 µg/mL) followed by Cooperia oncophora (IC50 = 27.6 µg/mL), Ostertagia ostertagi (IC50 = 48.5 µg/mL), Trichostrongylus axei (IC50 = 54.7 µg/mL), Haemonchus contortus (IC50 = 145.6 µg/mL), and Cooperia curticei (IC50 = 156.6 µg/mL).

CONCLUSIONS

These results indicate that CMLE exhibits promising anthelmintic properties against infective larvae of a large variety of soil-transmitted nematodes.

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.

Molecular interaction analysis of the lignans from Piper cubeba in complex with Haemonchus contortus phosphomethyltransferase

In vitro larvicidal assays carried out previously by our research group with cubebin, dihydrocubebin and hinokinin, lignans extracted from the fruits of Piper cubeba, against Haemonchus contortus larvae showed strong action larvicidal these compounds. Hinokinin was the most active (EC50 = 0.34 µg/mL) with strong action on the cuticle of the larvae as observed by scanning electron microscopy of the L3 stage. Therefore, to understand the mechanism of action of these compounds in silico studies were carried out using the enzyme phosphomethyltransferase of Haemonchus contortus that contain PMT-1 and PMT-2 di-domains responsible for phosphocholine synthesis, which is one of the main lipids in nematodes. This pathway is not found in mammals, so this enzyme is an important biological target for the development of new anthelmintics. Results of molecular docking, molecular dynamic and a density functional theory calculations studies with the three lignans show few interactions with PMT-1. However, hinokinin has important interactions with PMT-2, that can deactivate the enzyme and interrupt the phosphocholine synthesis, which is an essential compound for the development and maintenance of the nematode cuticle and its survive. Therefore, the previous results of the in vitro assay allied with in silico results, now realized; suggest that hinokinin may be a possible selective target for the development of new anthelmintics against Haemonchus contortus since the PMT-2 domain is present in this nematode.

Condensed tannins, novel compounds and sources of variation determine the antiparasitic activity of Nordic conifer bark against gastrointestinal nematodes

The antiparasitic potential of plants could offer a vital solution to alleviating the costs of gastrointestinal nematode (GIN) infections in ruminant production globally. Leveraging known bioactive molecules, however, is complex, where plant species, extraction processes and seasonality impact bioavailability and efficacy. This study assessed the impact of a comprehensive set of factors on the antiparasitic activity of Norwegian conifers to identify bark compounds specific against GIN. Antiparasitic activity was determined using in vitro assays targeting morphologically distinct life stages of ovine GIN: the egg hatch assay and larval motility assay. In depth characterisation of the chemical composition of the bark extracts was carried out using chromatographic separation, UV-absorbance, and molecular mass profiles to identify compounds implicated in the activity. Three key findings emerged: (1) the activity of bark extracts varied markedly from 0 to 100% antiparasitic efficacy, owing to tree species, extraction solvent and seasonality; (2) the GIN exhibited species-and stage-specific susceptibility to the bark extracts; (3) the presence of condensed tannins, amongst other compounds, was associated with anthelmintic activity. These findings add new insights into urgently needed alternative parasite control strategies in livestock.

Two in vitro anthelmintic assays of four Paraguayan medicinal plants for proof of concept of the role of polyphenols in their biological activities and LC-HRMS analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Gastrointestinal nematodes (GIN) control in small ruminants has relied on the systematic use of synthetic anthelmintics (AH), their effectiveness has been progressively decreasing due to the rise and diffusion of anthelmintic resistances. The most prevalent genera affecting small ruminants were Haemonchus spp., and Trichostrongylus spp. The investigation of new anthelmintics in plants is a highly studied option, especially when it is linked to ethnobotanical knowledge and phenolic compounds.

THE AIMS OF OUR STUDY

Four medicinal plants mentioned in traditional medicine were selected to evaluate their anthelmintic proprieties at different stages of the life cycle of GIN, namely: Kyllinga odorata Valh., Cassia occidentalis L., Artemisia absinthium L, and Verbena litoralis Kunth and to explore the role of polyphenols in the AH activity.

MATERIALS AND METHODS

To evaluate the anthelmintic activity in this study, two models of GIN species, namely Haemonchus contortus (Hc) and Trichostrongylus colubriformis (Tc) were selected and tested on two in vitro assays: 1) Larval Exsheathment Inhibition Assay (LEIA) and, 2) Egg Hatch Assay (EHA). To explore the role of tannins and polyphenols in AH activity by comparing the effects of LEIA and EHA with or without polyvinylpolypyrrolidone (PVPP) and to characterize the phytochemical composition of the most active plants using ultra-high performance liquid chromatography (UHPLC) coupled with high-resolution mass spectrometry (HRMS).

RESULTS

C. occidentalis exhibited the highest activity on LEIA (EC₅₀ = 250.42-41.80 μg/mL) and A. absinthium on egg hatching processes (EC₅₀ = 121.70-137.34 μg/mL) in both species of GIN. The inhibition in the development of eggs was from 67.70% to 96.36% on H. contortus, and from 78.87% to 99.65% on T. colubriformis. At the maximal dose, Additionally, it was observed that the AH on eggs varies according to the GIN species: on H. contortus the extracts tested blocked the formation of larvae Ovicidal Effect (% higher OE) and on T. colubriformis they blocked the appearance of L1 larvae, Larvae Failing Eclosion (% higher LFE). After PVPP, a reduction in AH activity on LEIA and EHA was noted, especially with C. occidentalis (87.20-67.00% of larvae exsheathment, (p < 0.05) and 40.51-24.96% of egg hatching, (p > 0.05) of both parasite species. Nine putative features were identified using HRMS and MS/MS after addition of PVPP.

CONCLUSIONS

The present study demonstrated that C. occidentalis, A. absinthium, and K. odorata, which parts have been traditionally used as medicinal plants are a valuable source of active compounds with anthelmintic activity. The medicinal use of these plants against GIN parasites was proven by in vitro analysis. Therefore exploration of the secondary metabolites of these plant extracts and testing of isolated fractions of active compounds under in vivo experiments are planned and represent a specific challenge for alternative drug research. Regarding the PVPP, in this study we hypotheses about the standard doses it was not able to completely absorb the polyphenols of extracts of K. odorata, C. occidentalis, and A. absinthium, which would lead to more studies to evaluate the role of this product in the absorption of phenolic compounds.

Anthelmintic Activity of Tanacetum vulgare L. (Leaf and Flower) Extracts against Trichostrongylidae Nematodes in Sheep In Vitro

Due to the high prevalence of gastrointestinal nematodes in sheep, the growing anthelmintic resistance, and the development of organic farming systems, sustainable alternatives are being sought. One such method is phytotherapy. This study aimed to evaluate the in vitro ovicidal and larvicidal activity of extracts of tansy (Tanacetum vulgare L.) growing in Latvia on gastrointestinal nematodes (Trichostrongylidae) in sheep. The leaves and flowers of the tansy were extracted separately in 70%, 50%, and 30% ethanol and acetone. Six concentrations were prepared from each extract 500 mg/mL, 200 mg/mL, 100 mg/mL, 50 mg/mL, 20 mg/mL, and 10 mg/mL. In vitro egg hatching test and micro-agar larval development test were performed. Extracts of tansy have strong larvicidal activity. The highest percentage of larvae inhibition for most of the extracts was 100%, but for egg inhibition, it was 95.8% for the 200 mg/mL concentration of 50% acetone and 93.3% for the 500 mg/mL concentration of 50% ethanol leaf extracts. All tansy extracts had ovicidal and larvicidal activity against Trichostrongylidae in sheep.

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.

An in vitro rumen incubation method to study exsheathment kinetics of Haemonchus contortus third-stage infective larvae

This study developed and evaluated an in vitro rumen incubation (IVRI) method to describe the exsheathment kinetics of Haemonchus contortus third-stage infective larvae (L₃) in ruminal liquor (RL). The specific objectives were (i) to standardize the IVRI method to facilitate the contact between L₃ and RL as well as the larval recovery, and (ii) to apply the IVRI method to describe the exsheathment kinetics of H. contortus and to select the best fitting nonlinear model. Incubation devices containing H. contortus larvae were incubated according to the IVRI technique in cattle RL or PBS. The incubation conditions included RL mixed with a nitrogen-rich media, maintained at 39 °C, with pH = 7.0, vented with CO₂ and manual agitation. The larvae were recovered after 0, 1, 3, 6, 9, 12, and 24 h. The exsheathed and ensheathed larvae were counted to estimate the exsheathment (%) in RL or PBS. Exsheathment in RL was analyzed with nonlinear regression models: Exponential, Gompertz, Logistic, Log-Logistic, and Weibull. The models' fit was compared to select the one that best described the exsheathment kinetics. The exsheathment in RL reached 6.52%, 20.65%, 58.22%, 69.24%, 73.08%, and 77.20% in 1, 3, 6, 9, 12, and 24 h, respectively. Although the Gompertz, Weibull, and Logistic models were adequate to describe the observed exsheathment, the Log-Logistic model had the best fit. The IVRI method using bovine RL represents a suitable tool for the study of the in vitro exsheathment kinetics of H. contortus L₃.

Bio-directed Chemical Study of Pleurotus ostreatus Spent Substrate and Its Nematicidal Activity

PURPOSE

In the present study, the nematicidal activity of the chemical fractionation of the spent substrate of the edible mushroom Pleurotus ostreatus against eggs and L3 larvae of Haemonchus contortus was evaluated.

METHODS

The hydroalcoholic extract of the spent substrate was subjected to a bipartition with ethyl acetate giving two fractions: one aqueous (F. Ac) and one organic (F. AcOET). Both fractions were evaluated against eggs and L3 larvae at different concentrations (5, 2.5, 1.25, 0.625 and 0.3125 mg/mL) and 2% methanol, PBS and thiabendazole (5 mg/mL) as controls. Chemical fractionation of F. AcOET was performed in open column chromatography where 76 fractions were obtained and when analyzed by thin layer chromatography (TLC) were grouped into 11 mixtures (R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11). These mixtures were evaluated at 10 mg/mL against eggs and L3 larvae. The data obtained were analyzed by ANOVA and a Tukey test in the SAS V9 program.

RESULTS

The results showed that, in the evaluation of F. AcOET and F. Ac, for the inhibition of egg hatching, the highest percentages were 78.80 and 76.89% at 5 mg/mL, respectively. As for the percentage of larval mortality, F. AcOET obtained 60.91 and F. Ac 29.77% at 5 mg/mL. The results of the evaluations of the mixtures showed that mixtures R4, R5 obtained 100 and 95.41% larval mortality and mixtures R6 and R7 presented 100% inhibitory activity of egg hatching, so these were analyzed by gas chromatography mass spectrometry finding compounds such as vanillin, β-sitosterol, ρ-methyl ρ-hydroxycinnamate and ρ-hydroxybenzaldehyde.

CONCLUSION

The results of the present study demonstrate that the spent substrate of P. ostreatus has potential anthelmintic activity against H. contortus. Moreover, by reusing and taking advantage of this substrate, its environmental pollution effects can be reduced.

Impact of Seasonal and Organ-Related Fluctuations on the Anthelmintic Properties and Chemical Profile of Cladium mariscus (L.) Pohl Extracts

The use of plants and their metabolites stands as a promising option to tackle parasitic infections by gastrointestinal nematodes (GIN) in integrated control strategies. Still, the influence of environmental and phenological factors, and their interactions, in the wild on the metabolomics and biological properties of target plant species, is often disregarded. In this work, we hypothesized that variations in the anthelmintic (AH) properties and chemical composition of extracts from the salt tolerant species Cladium mariscus L. Pohl (sawgrass) may be influenced by seasonal factors and organ-parts. To test this hypothesis, acetone/water extracts were prepared from dried biomass obtained from aerial organs collected from sawgrass in consecutive seasons and tested against Haemonchus contortus and Trichostrongylus colubriformis by the larval exsheathment inhibition assay (LEIA) and egg hatching inhibition assay (EHIA). To ascertain the role of plant organ, the activity of leaves and inflorescences extracts from summer samples was compared. The role of polyphenols in the anthelmintic activity depending on GINs and fluctuations across seasons and plant organs was assessed using polyvinylpolypyrrolidone (PVPP), coupled with an in-depth chemical profiling analysis using high-performance liquid chromatography completed with electrospray ionization mass spectrometric detection (HPLC-ESI-MSn). Main differences in anthelmintic activities were observed for summer and autumn samples, for both assays. Moreover, inflorescences' extracts were significantly more active than those from leaves against both parasite species on EHIA and against H. contortus on LEIA. Application of PVPP totally inhibit the AH effects based on EHIA and only partly for LEIA. Non-treated PVPP extracts were predominantly composed of flavan-3-ols, proanthocyanidins, luteolin and glycosylated flavonoids, while two flavonoid glycosides were quantified in all PVPP-treated samples. Thus, the activity of such compounds should be further explored, although some unknown metabolites remain to be identified. This study reinforces the hypothesis of the AH potential of sawgrass and of its polyphenolic metabolites uses as nutraceutical and/or phytotherapeutic drugs.

Use of agro-industrial by-products containing tannins for the integrated control of gastrointestinal nematodes in ruminants

Previous studies have illustrated that different bioactive legume fodders containing condensed tannins might represent one of the options for integrated sustainable control of gastrointestinal nematodes (GIN) in ruminants, which may help address the worldwide development of resistance to synthetic anthelmintics. More recently, impetus has been given to assess the potential antiparasitic activity of less conventional resources, represented by different agro-industrial by-products (AIBPs). This review presents in vitro and in vivo results obtained with a range of tannin-containing AIBPs of various geographical and botanical origins, namely AIBP of nuts, temperate and tropical barks, carob, coffee and cocoa. They tend to confirm the "proof of concept" for their antiparasitic effects and also for other aspects of ruminant production in an agro-ecological context. Socio-economic aspects of the exploitation of such non-conventional resources are also discussed as potential models of the circular economy, by using waste. The different modes of use of these resources are presented in this review, as well as strengths, weaknesses, opportunities, and threats (SWOT) analyses to illustrate the advantages and limitations of on-farm use.

Nematicidal activity of leaf extract of Moringa oleifera Lam. against Haemonchus contortus and Nacobbus aberrans

In the present study, the nematicidal activity of a Moringa oleifera ethyl acetate leaf extract against the eggs and larvae of Haemonchus contortus and Nacobbus aberrans, nematodes of agricultural importance, was evaluated. The experimental design for the evaluation of the effects against both nematodes consisted of eight treatments (n = 4). Distilled water, Tween (4%) and a commercial anthelmintic agent (ivermectin, 5 mg/mL) were used as controls, and for treatments 4-8, the concentrations of the extract were 20, 10, 5, 2.5 and 1.25 mg/mL, respectively. Readings were taken at 12 h and 24 h for N. aberrans and 48 h and 72 h for H. contortus post-treatment under an optical microscope (10× and 40×). The data obtained were analysed by analysis of variance through a completely randomized factorial design using the SAS V9 program. The results show that, for H. contortus egg hatching, 85.88% inhibition was obtained at a concentration of 20 mg/mL at 48 h, while for third-stage larva (L3) mortality, the highest percentage was 68.19% at 1.25 mg/mL at 72 h. In the case of N. aberrans, the greatest inhibition of egg hatching was 90.69% at 5 mg/mL at 12 h post-treatment, and for larval mortality, it was 100% at 10 mg/mL at 24 h post-treatment. The main major compounds identified by qualitative analysis and by gas chromatography coupled to mass spectrometry were 9,12,15-octadecatrienoic acid, (Z,Z,Z)-, n-hexadecanoic acid and 2,4-di-tert-butylphenol, and the minor compounds included phytol, γ-sitosterol and α-tocopheryl acetate. It was demonstrated that the ethyl acetate leaf extract of M. oleifera Lam. shows great potential for combating agricultural nematodes.

Disclosing the bioactive metabolites involved in the in vitro anthelmintic effects of salt-tolerant plants through a combined approach using PVPP and HPLC-ESI-MSn

Strategies to reduce dependence on synthetic drugs for the treatment of gastrointestinal nematodes (GIN) infections in ruminants include the search for novel anthelmintic scaffolds on plants, yet salt-tolerant plants remain overlooked. This study aims to evaluate the in vitro anthelmintic properties of selected salt-tolerant plants against GIN, and identify the potential bioactive secondary metabolites involved. For that purpose, 80% acetone/water extracts were prepared from dried biomass of aerial organs of nine salt-tolerant plant species and tested against Haemonchus contortus and Trichostrongylus colubriformis by the Larval Exsheathment Inhibition Assay (LEIA) and Egg Hatching Inhibition Assay (EHIA). Pistacia lentiscus, Limoniatrum monopetalum, Cladium mariscus and Helychrisum italicum picardi were the most active in both GIN and life stages. To investigate the role of polyphenols in the anthelmintic activity, four selected extracts were treated with polyvinylpolypyrrolidone (PVPP), and non-treated and treated samples were further characterized by high-performance liquid chromatography with electrospray ionization mass spectrometric detection (HPLC-ESI-MSⁿ). While polyphenols seem responsible for the EHIA properties, they are partially accountable to LEIA results. Several phenolics involved in the anthelmintic effects were identified and discussed. In sum, these species are rich sources of anthelmintic compounds and, therefore, are of major interest for nutraceutical and/or phytotherapeutic applications against GIN in ruminants.

In vitro Evaluation of the Nutraceutical Potential of Theobroma cacao pod Husk and Leaf Extracts for Small Ruminants

PURPOSE

Some agroindustrial by-products could be used as nutraceutical materials for small ruminants helping with their nutrition while controlling their gastrointestinal nematodes. This study evaluated the potential in vitro nutraceutical value of pod husks and leaves of three varieties of Theobroma cacao using two Haemonchus contortus isolates with different polyphenol susceptibility.

METHODS

Leaves and husks from three T. cacao varieties (AZT, CAL and CEY) were evaluated for their bromatological composition, in vitro dry matter digestibility and polyphenol content. Acetone:water extracts (70:30) of each plant variety were evaluated using the egg hatch and larval exsheathment inhibition tests, using two isolates (FESC and PARAISO) of H. contortus. Effective concentrations 50% (EC₅₀) were determined for both tests. The role of polyphenols was confirmed using polyvinylpolypyrrolidone. L₃ exposed to CAL leaf extract were submitted to transmission electron microscopy.

RESULTS

Both plant materials showed a good nutritional value to complement protein-rich diets for small ruminants. Extracts inhibited exsheathment of H. contortus L₃ more effectively than the egg hatching, and the leaf extracts were more active than husk extracts in the L₃ exsheathment inhibition. The FESC isolate was more sensitive to extracts. Polyphenols blocked exsheathment inhibition of leaf extracts. Structural damage was observed in the sheath and muscles of L₃ exposed to CAL leaf extracts.

CONCLUSION

The two T. cacao materials tested showed their potential to be used as ruminant feeds. Extracts affected H. contortus by blocking L₃ exsheathment, particularly with the leaf extracts. The in vivo nutraceutical value should be confirmed in small ruminants.

Nematocidal activity of hydroalcoholic extracts of spent substrate of Pleurotus djamor on L3 larvae of Haemonchus contortus

The objective of this study was to evaluate and compare the in vitro lethal effect of the hydroalcoholic extract of the spent substrate of Pleurotus djamor ECS-123, obtained at 15 days of colonization (SPS) and at the first (SPS1) and second (SPS2) harvests, against infective larvae L₃ of Haemonchus contortus. The in vitro lethal effect was evaluated by the L₃ larval mortality test (LM) using six concentrations: 1.25, 2.5, 5, 10, 20, and 40 mg/mL, with ivermectin and thiabendazole (5 mg/mL) as controls. The first harvest extract (SPS1) of strain ECS-123 was subjected to liquid-liquid bipartition, which resulted in two fractions: aqueous (PdAcO) and ethyl acetate (PdAct). The chemical fractionation of PdAct with the highest mortality rate (80.11 %) was carried out with open-column chromatography, giving a total of 13 fractions, which were analyzed by thin-layer chromatography (TLC) and grouped into 5 mixtures (R1;1-3, R2;4-7, R3;8-9, R4;10-11 and R5;12-13). Subsequently, the mixtures were evaluated against H. contortus L₃ larvae. Finally, the components of the mixtures with the highest nematocidal effects were evaluated by gas chromatography coupled to mass spectrometry (GC-MS). The data were analyzed with a completely randomized design through ANOVA using the generalized linear model (GLM) with the "R" program. The purification and characterization of R4 and R5 by GC-MS revealed the presence of the following compounds: veratryl alcohol, 4-hydroxy-3,5,5 trimethyl-4-[3-oxo-1-butenyl]-2- cyclohexen-1-one, caffeine and 5,6-dimethoxy-1(3 H) isobenzofuranone. This information allowed for the identification of nematocidal compounds in the degraded substrate of P. djamor, an activity that had not been reported previously.

Anthelmintic effect of four extracts obtained from Caesalpinia coriaria foliage against the eggs and larvae of Haemonchus contortus

To investigate the in vitro anthelmintic efficacy of dividivi (Caesalpinia coriaria), a traditional medicinal plant used in Central America and the northern part of South America, extracts from the foliage of this plant were subjected to the egg hatching test (EHT) and larval exsheathment inhibition test (LEIT), against Haemonchus contortus. Four different extracts were evaluated: acetone-water (AW), methanol-water (MW), acetone-water-dichloromethane (AWD) and methanol-water-dichloromethane (MWD). The concentrations used for the EHT and LEIT tests ranged from 500 to 4000 µg mL-1 and six repetitions per concentration. The effective concentrations (EC50) were calculated using Probit analysis. The EC50 for EHT were 2947.0, 3347.0, 3959.6 and 4538.7 µg mL-1 for MWD, MW, AW and AWD, respectively. The EC50 for LEIT were 2883.4, 5927.4, 9876.3 and 9955.4 µg mL-1 for AWD, AW, MWD and MW, respectively. The methanol extracts were the most effective in inhibiting the hatching of eggs, while the acetone extracts showed efficacy in inhibiting larval exsheathment. This study explains the importance that C. coriaria has as a medicinal plant in Central and South American countries.

Chemical characterisation and in vitro anthelmintic activity of phenolic-rich extracts from the leaves and branches of Maytenus ilicifolia, a native plant from South America

Free (epi) catechin, quercetin, (epi) gallocatechin, flavonol glycosides and condensed tannins were identified according to their molecular mass, characteristic product ions and retention times in extracts obtained from leaves and branches of Maytenus ilicifolia (Congorosa) by mass spectrometry. The in vitro anthelmintic activity against cattle gastrointestinal nematodes of Congorosa extract was determined using the Egg Hatch Inhibition Assay. Additionally, commercial quercetin, gallocatechin and epicatechin were evaluated. Although total phenolics, total tannins and condensed tannins contents were lower in branches extract than in leaves extract, the EC₅₀ were 0.065 mg/mL and 0.890 mg/mL for branches and leaves extract, respectively. Moreover, the use of polyvinylpyrrolidone as a blocking agent of tannins, did not change significantly the EC₅₀ for branches extract, but significantly changed for leaves extract. Quercetin and gallocatechin EC₅₀ values were in the range 0.03-0.05 mg/mL and epicatechin showed 100% inhibition of the egg hatching process at 0.004 mg/mL.

A Systematic Review on Comparative Analysis, Toxicology, and Pharmacology of Medicinal Plants Against Haemonchus contortus

Background:Haemonchus contortus is an important pathogenic nematode parasite and major economic constraint of small ruminants in tropics and subtropics regions. This review is an attempt to systematically address the; (a) efficacy of different plants against H. contortus by in vitro and in vivo proof; (b) toxicology, mechanism of action, and active phyto-compounds involve in anti-haemonchiasis activity; (c) and comparative analysis of plant species evaluated both in vitro and in vivo.

Methods: Online databases (Google Scholar, PubMed, Scopus, and ScienceDirect) were searched and published research articles (1980–2020) were gathered and reviewed.

Results: A total of 187 plant species were reported belonging to 59 families and 145 genera with Asteraceae and Fabaceae being frequently used. Out of the total plant species, 171 species were found to be evaluated in vitro and only 40 species in vivo. Twenty-four species were commonly evaluated for in vitro and in vivo anti-haemonchiasis activity. Among the reported assays, egg hatching test (EHT) and fecal egg count reduction (FECR) were the most widely used assays in vitro and in vivo, respectively. Moreover, sheep were the frequently used experimental model in vivo. After comparative analysis, Lachesiodendron viridiflorum, Corymbia citriodora, Calotropis procera, and Artemisia herba-alba were found highly effective both in vitro and in vivo. L. viridiflorum inhibited enzymatic activities and metabolic processes of the parasite and was found to be safe without toxic effects. C. citriodora was moderately toxic in vivo, however, the plant extract produced promising nematicidal effects by causing muscular disorganization and changes in the mitochondrial profile. Additionally, C. procera and A. herba-alba despite of their high anti-haemonchiasis activity were found to be highly toxic at the tested concentrations. C. procera caused perforation and tegumental disorganization along with adult worm paralysis. Nineteen compounds were reported, among which anethole and carvone completely inhibited egg hatching in vitro and significantly reduced fecal egg count, decreased male length, and reproductive capacity of female in vivo.

Conclusion: This review summarized different medicinal plants owing to nematicidal activities against H. contortus eggs, larvae, and adult worms. Plants like L. viridiflorum, C. citriodora, C. procera, and A. herba-alba, while compounds anethole and carvone having promising nematicidal activities and could be an alternative source for developing novel drugs after further investigation.

Laguncularia racemosa Phenolics Profiling by Three-Phase Solvent System Step-Gradient Using High-Performance Countercurrent Chromatography with Off-Line Electrospray Mass-Spectrometry Detection

The detailed metabolite profiling of Laguncularia racemosa was accomplished by high-performance countercurrent chromatography (HPCCC) using the three-phase system n-hexane–tert-butyl methyl ether–acetonitrile–water 2:3:3:2 (v/v/v/v) in step-gradient elution mode. The gradient elution was adjusted to the chemical complexity of the L. racemosa ethyl acetate partition and strongly improved the polarity range of chromatography. The three-phase solvent system was chosen for the gradient to avoid equilibrium problems when changing mobile phase compositions encountered between the gradient steps. The tentative recognition of metabolites including the identification of novel ones was possible due to the off-line injection of fractions to electrospray ionization mass spectrometry (ESI-MS/MS) in the sequence of recovery. The off-line hyphenation profiling experiment of HPCCC and ESI-MS projected the preparative elution by selected single ion traces in the negative ionization mode. Co-elution effects were monitored and MS/MS fragmentation data of more than 100 substances were used for structural characterization and identification. The metabolite profile in the L. racemosa extract comprised flavonoids, hydrolysable tannins, condensed tannins and low molecular weight polyphenols.

Anthelmintic Activity of Extracts and Active Compounds From Diospyros anisandra on Ancylostoma caninum, Haemonchus placei and Cyathostomins

The present study aimed to evaluate the anthelmintic activity of leaf and bark extracts of Diospyros anisandra collected during different seasons and their major constituents on eggs of Ancylostoma caninum, Haemonchus placei, and cyathostomins. Specifically, the eclosion inhibition of the methanolic extracts of the leaves and bark of D. anisandra collected during the dry and rainy seasons (600–37.5 μg/ml) were evaluated in addition to the fractions, sub-fractions (300–37.5 μg/ml) and active major constituents (150–2.3 μg/ml). The rainy season bark extract had the highest percentage of eclosion inhibition (PEI) against the evaluated nematodes (≥ 90% at 75 μg/ml) along with high ovicidal activity (90.0 to 93.4% at 75 μg/ml). The purification of the rainy season bark extract showed that its biological activity came from the non-polar n-hexane fraction (≥ 93% at 75 μg/ml). The bioguided fractionation pointed to sub-fraction 5 as having the highest anthelmintic activity against the three evaluated genera of nematodes (PEI ≥ 93% at 37.5 μg/ml). Gas chromatography and mass spectrometry revealed that the major constituent in sub-fraction 5 was plumbagin. Upon evaluation, plumbagin was confirmed to be responsible for the anthelmintic activity of D. anisandra, with a PEI ≥ 90% at 2.3 μg/ml on the three evaluated nematodes. Additionally, the compounds betulin and lupeol in the bark of D. anisandra were evaluated but presented low anthelmintic activity (PEI ≤ 5.3% at 2.3 μg/ml). In conclusion, the rainy season bark extract of D. anisandra exerts a high ovicidal activity against the eggs of the three studied nematodes. Plumbagin is the active compound responsible for this activity and represents a potential alternative for the control of different genera of gastrointestinal nematodes given the current scenario of anthelmintic resistance.

Assessment of in vitro anthelmintic activity and bio-guided chemical analysis of BRS Boyrá pineapple leaf extracts

Species of the Bromeliaceae are known for their pharmacological actions, including anthelmintic effects. The aim of this study was to investigate the in vitro anthelmintic activity of extracts and fractions of BRS Boyrá pineapple leaf against the eggs and infective larvae of gastrointestinal nematodes (Trichostrongylidae) of goats and to identify the compounds involved in this activity. Crude methanol, hexane, dichloromethane, ethyl acetate and residual hydromethanol extracts were investigated by quantitative analysis of phenolic and flavonoid contents, antioxidant activity, anthelmintic activity against gastrointestinal nematodes of goats. The extracts were submitted to chromatographic methods for substance isolation and spectrometric techniques to identify their structures. The anthelmintic activity was performed by in vitro assays with eggs and larvae of nematodes obtained from naturally infected donor goats. All extracts contained phenolic (2.22-14.12 g of gallic acid equivalent per 100 g of dry extract) and flavonoid compounds (0.13-1.45 g of quercetin equivalent per 100 g of dry extract). Bio-guided fractionation of the BRS Boyrá pineapple leaves showed high antioxidant activity (EC₅₀ for DPPH of 2.16-21.38 mg mL^-1 and inhibition of co-oxidation of β-carotene of 36.40-74.86%) and anthelmintic activity (15.69-100% inhibition of egg hatching). The ethyl acetate extract exhibited greatest activity in all assays. Through chromatographic column analysis it was possible to isolate three substances: β-sitosterol and stigmasterol mixture in dichloromethane and hexane extracts, identified by NMR and p-coumaric acid in the ethyl acetate extract, identified by HPLC-DAD. The isolated p-coumaric acid exhibited high ovicidal effect against goat gastrointestinal nematodes (IC₅₀: 0.12 mg mL^-1) and can be considered the active substance of the ethyl acetate extract. This study revealed for the first time that the pineapple BRS Boyrá possesses inhibitory activity against gastrointestinal nematodes (Haemonchus spp., Oesophagostomum spp. and Trichostrongylus spp.), and that p-coumaric acid is an important bioactive.

In Vitro Anthelmintic Evaluation of Gliricidia sepium, Leucaena leucocephala, and Pithecellobium dulce: Fingerprint Analysis of Extracts by UHPLC-Orbitrap Mass Spectrometry

In the present work, the anthelmintic activity (AA) of ethanolic extracts obtained from Gliricidia sepium, Leucaena leucocephala, and Pithecellobium dulce was evaluated using the third-stage-larval (L₃) exsheathment inhibition test (LEIT) and egg hatch test (EHT) on Haemonchus contortus. Extracts were tested at concentrations of 0.3, 0.6, 1.2, 2.5, 5.0, 10, 20, and 40 mg/mL. The larval exsheathment inhibition (LEI) results showed that G. sepium achieved the highest average inhibition of 91.2%, compared with 44.6% for P. dulce and 41.0% for L. leucocephala at a concentration of 40 mg/mL; the corresponding IC₅₀ values were 22.4, 41.7, and 43.3 mg/mL, respectively. The rates of egg hatching inhibition (EHI) at a concentration of 5 mg/mL were 99.5% for G. sepium, 64.2% for P. dulce, and 54% for L. leucocephala; the corresponding IC₅₀ values were 1.9 mg/mL for G. sepium, 3.9 mg/mL for P. dulce, and 4.3 mg/mL for L. leucocephala. The species extracts studied here were also analyzed by ultra-high performance liquid chromatography and Orbitrap high resolution mass spectrometry (UHPLC-Q/Orbitrap/MS/MS), resulting in the compounds' identification associated with AA. Glycosylated flavonoids and methoxyphenols were observed in all three species: fatty acids in G. sepium and P. dulce; phenylpropanoids, anthraquinone glycosides, amino acids and glycosylated phenolic acids in G. sepium; and flavonoids in L. leucocephala. Comparatively, G. sepium presented a greater diversity of compounds potentially active against the control of gastrointestinal nematodes, which was associated with the results obtained in the applied tests.

Isorhamnetin: A Nematocidal Flavonoid from Prosopis Laevigata Leaves Against Haemonchus Contortus Eggs and Larvae

Haemonchus contortus affect small ruminants all over the world. Anthelmintics cause resistance, contamination, and a risk of public health. Prosopis laevigata is a plant used as a home remedy against many diseases in Mexico. This study arose from a preliminary study where a P. laevigata hydroalcoholic extract (Pl-hae) showed anthelmintic activity (aa) against H. contortus. Searching for bioactive compounds (bac) with high aa, the Pl-hae was fractioned obtaining an aqueous (Aq-F) and an ethyl acetate fraction (EtAc-F), and a flavonoid with aa identified as isorhamnetin was obtained from EtAc-F. Both fractions were in vitro assessed by the egg hatch test (eht) and larval mortality (lm) assays. The bac obtained from EtAc-F were characterised by NMR analysis. The highest aa were recorded with EtAc-F, resulting in 100% eht and 80.45% lm at 0.75 and 30 mg/mL, respectively. Alterations in eggs and larvae attributed to isorhamnetin were recorded by environmental scanning electron microscopy, confocal laser scanning and by high-resolution digital-coupled camera. This flavonoid caused 100% eht at 0.07 mg/mL after 48 h and 100% lm at 7.5 mg/mL after 72 h exposure. Isorhamnetin has promising potential as an anthelmintic against sheep haemonchosis.

In Vitro Anthelmintic Activity of Saponins from Medicago spp. Against Sheep Gastrointestinal Nematodes

Gastrointestinal strongyle nematodes (GIS) are included among the most important parasites of small ruminants. The widespread drug resistance and drug residues in products of animal origin have increased the interest in the search for natural compounds with anthelmintic activity as a valid alternative to current synthetic drugs. The aim of the present investigation was to test the ‘in vitro’ anthelmintic activity of saponins and prosapogenins from different Medicago species, selected for their importance as a forage crop worldwide for animal feeding. From these plants, saponin mixtures were extracted, purified and used at scalar concentrations to evaluate their anthelmintic activities against sheep gastrointestinal strongyles (GISs), by the egg hatch test. Treated and untreated controls were used as the comparison. Data were statistically analyzed, and EC₅₀ and EC₉₀ were also calculated. All saponins and prosapogenins showed inhibiting effects on GIS eggs in a concentration-dependent manner. At higher concentrations, most of them showed an efficacy comparable to the reference drug (Thiabendazole 3 µg/mL) (P < 0.001). With 1.72 mg/mL EC₅₀ and 3.84 mg/mL EC₉₀, saponin from M. polymorpha cultivars Anglona was the most active. Obtained results encourage further studies aimed at evaluating the efficacy ‘in vivo’ of saponins which resulted as most effective ‘in vitro’ in this study.

Ultrastructural study of adult Haemonchus contortus exposed to polyphenol-rich materials under in vivo conditions in goats

This study assessed the ultrastructural changes caused in adult Haemonchus contortus obtained from goats fed fodder based on polyphenol-rich plants Lysiloma latisiliquum or Onobrychis viciifolia or from goats drenched with quebracho extract, Schinopsis spp. The H. contortus were obtained from artificially infected goats used as models to investigate the anthelmintic effect of feeding or drenching with the polyphenol-rich materials. Nematode populations were exposed to polyphenol-rich plant materials by feeding host goats for 8 consecutive days (D28 to D35 post-infection) with (a) L. latisiliquum fodder at 800 g fresh basis/day, (b) O. viciifolia fodder offered ad libitum, and (c) drenched with a solution containing quebracho extract (90 g/day). Meanwhile, control H. contortus were obtained from goats fed polyphenol-free diets. The H. contortus specimens were recovered from the goats on D36 post-infection, and transmission electron microscopy (TEM) was used to identify ultrastructural changes. In vivo exposure to different polyphenol-rich plant materials caused vacuolization of the nematodes’ intestinal, muscular and hypodermal cells. These alterations represent the first evidence of cell damage caused in H. contortus when hosts were fed or drenched with polyphenol-rich materials. Ultrastructural changes affecting several types of cells could explain modifications in worm motility and nutrition, eventually affecting H. contortus reproductive success. This study contributes to our understanding of the mechanisms of action of polyphenol-rich plants against H. contortus when given as nutraceuticals to goats.

Anthelmintic-like activity of polyphenolic compounds and their interactions against the cattle nematode Cooperia punctata

Polyphenolic compounds (PCs) have been proposed as one of the most bioactive group of secondary metabolites occurring in nature and have been associated to anthelmintic (AH)-like activity of plants against cattle nematodes. However, little is known regarding their synergetic / antagonistic interactions. This study assessed the in vitro AH-like activity of commercial PCs: quercetin, caffeic acid, rutin and coumarin, and their combinations against the egg hatching and larval exsheathment of Cooperia punctata; one of the most prevalent nematodes affecting grazing cattle in tropical regions. The molecules selected for the in vitro analysis were identified as bioactive phytochemicals of plants through bio-guided fractionation in previous studies. To estimate mean effective concentrations (EC₅₀) five increasing concentrations were used for both Egg hatching inhibition assay (EHIA) and larval exsheathment inhibition assay (LEIA) (0.6-9.8 mg mL^-1 and 0.15-2.4 mg mL^-1, respectively). From the four molecules, only rutin did not affect egg hatching; while quercetin, showed no bioactivity against eggs or larvae (P > 0.766 and P > 0.621, respectively). Best-fit EC₅₀ estimated through the EHIA was considered for PCs classification as bioactive (coumarin and caffeic acid) and non-bioactive (quercetin and rutin). Phytochemical interactions were subsequently assessed combining bioactive:non-bioactive PCs (8:2 ratio), and the nature of their interaction was classified using the fractional inhibitory concentration index (FIC_index). Combinations had a highly synergistic interaction against larval exsheathment (FIC_index < 0.5) except for coumarin:rutin against egg hatching (FIC_index> 0.5). Quercetin and rutin acted as PCs AH-like activity enhancers, reducing EC₅₀ of bioactive molecules in a range of 43%-64% and 68%-83% for EHIA and LEIA, respectively. A linear relationship between low molecular weight of molecules and ovicidal activity was observed; where, molecules with lower molecular weight displayed better-fit EC₅₀ for ovicidal activity. Furthermore, coumarin and caffeic acid bioactivity against free-living stages of C. punctata makes them suitable candidates as markers for anthelmintic-like activity in bioactive forages. Combinations used through this investigation showed a potent anthelmintic-like activity against free-living forms of C. punctata, representing a first step towards the identification of promising alternatives for nematode control.

Effects of different extracts of three Annona species on egg-hatching processes of Haemonchus contortus

This study assessed the in vitro anthelmintic (AH) activity of methanol and acetone:water leaf extracts from Annona squamosa, A. muricata and A. reticulata against Haemonchus contortus eggs. The egg hatch test was used to determine the effective concentrations required to inhibit 50% of eggs hatching (EC50). The role of polyphenols on AH activity was measured through bioassays with and without polyvinylpolypyrrolidone (PVPP). Methanolic extracts mainly caused the death of eggs at the morula stage (ovicidal activity). Meanwhile, acetone:water extracts caused egg-hatching failure of developed larvae (larvae failing eclosion (LFE) activity). The lowest EC50 values against H. contortus eggs were observed for the methanolic extracts from A. reticulata and A. muricata (274.2 and 382.9 µg/ml, respectively). From the six extracts evaluated, the methanolic extracts of A. muricata, A. reticulata and A. squamosa showed the highest ovicidal activity, resulting in 98.9%, 92.8% and 95.1% egg mortality, respectively. When the methanolic extract of A. squamosa was incubated with PVPP, its AH activity increased. Similarly, when acetone:water extracts of A. muriata and A. reticulata were incubated with PVPP, their LFE activity increased. Alkaloids were only evident in methanolic extracts, irrespective of PVPP incubation. The presence of acetogenins was not observed. In conclusion, methanolic extracts obtained from leaves of A. muricata, A. reticulata and A. squamosa showed ovicidal activity affecting the morula of H. contortus eggs, with minor LFE activity. Meanwhile, acetone:water extracts showed mostly LFE activity, with a lower proportion of ovicidal activity.

Evaluation of cinnamic acid and six analogues against eggs and larvae of Haemonchus contortus

This study evaluated the in vitro anthelmintic (AH) activity of cinnamic acid and six analogues against eggs and larvae of Haemonchus contortus. Stock solutions of each compound (trans-cinnamic acid, p-coumaric acid, caffeic acid, trans-ferulic acid, trans-sinapic acid, 3,4-dimethoxycinnamic acid, and chlorogenic acid) were prepared in PBS:Tween-20 (1%) for use in the egg hatch test (EHT) and larval exsheathment inhibition test (LEIT) at different concentrations (25-400 μg/mL). The respective effective concentration 50% (EC₅₀) values with 95% confidence intervals were estimated. Mixtures made of all cinnamic acid and its analogues as well as some selected individual compounds were also tested in the EHT. Only ferulic and chlorogenic acids showed AH activity in the EHT (EC₅₀: 245.2 μg/mL (1.26 mM) and 520.8 μg/mL (1.47 mM), respectively) (P < 0.05). A higher EC₅₀ (1628.10 μg/mL) of the mixture of cinnamic acid and its analogues was required to observe activity against eggs mostly blocking the larvae hatching. The analogues' mixtures tested were less active than ferulic or chlorogenic acid alone. The activity of ferulic and chlorogenic acids against eggs was associated with larvae failing to hatch, and the two compounds exhibited antagonistic effects when evaluated together. All standards had an EC₅₀ lower than 0.42 mM in the LEIT. Caffeic acid had the best activity in the LEIT (EC₅₀ 0.04 mM), followed by ferulic acid (EC₅₀ 0.11 mM) (P < 0.05). There was no clear, definitive structure-activity relationship for these non-flavonoid polyphenols against eggs or larvae of H. contortus in vitro. This study is the first to directly evaluate cinnamic acid and its derivatives as active compounds against eggs and larvae of H. contortus.

Bio-guided fractionation to identify Senegalia gaumeri leaf extract compounds with anthelmintic activity against Haemonchus contortus eggs and larvae

Small ruminants browsing in tropical forests readily consume the foliage of Senegalia gaumeri. A S. gaumeri methanol:water extract was recently shown to have ovicidal activity against Haemonchus contortus eggs in vitro. In the present study, the fraction of a S. gaumeri methanol:water extract with ovicidal activity against H. contortus eggs and the metabolites potentially involved in this activity were identified. Bio-guided fractionation of the S. gaumeri methanol:water extract identified high ovicidal activity (80.29%, EC₅₀ = 58.9 μg/mL) in the non-polar sub-fraction P1. Gas chromatography-mass spectrometry (GC-MS) identified several fatty acids: pentacosane (18.05%), heneicosane (18.05%), triacontane (30.94%), octacosane (18.05%), and hexanedioic acid bis-(2-ethylhexyl) ester (32.72%). Purification of the polar components of sub-fraction P1 led to the identification of p-coumaric acid as a major constituent. In egg hatch tests, 400 μg/mL p-coumaric acid resulted in an ovicidal effect of 8.7%, a larvae failing eclosion effect of 2.9%, and of the emerged larvae (88.4%), many were damaged. In conclusion, the low AH activity of p-coumaric acid against H. contortus eggs indicates that it is not solely responsible for the ovicidal activity of sub-fraction P1 but might act in synergy with other compounds in this fraction. However, p-coumaric acid showed potential anthelmintic effects against the larval stage of H. contortus.

In vitro anthelmintic activity and safety of different plant species against the ovine gastrointestinal nematode Teladorsagia circumcincta

The present study was conducted to evaluate the in vitro anthelmintic activity and safety of methanolic and aqueous extracts of 9 plants against the ovine GIN Teladorsagia circumcincta. Initially the ovicidal efficacy of all extracts was tested at 50 mg/ml and at 1%, this last concentration for the methanolic extract of Elettaria cardamomum, by the Egg Hatch Assay. In those extracts with efficacy higher than 95%, the effective concentration required to inhibit 50% of egg hatching (EC₅₀) and their cytotoxicity, as the lethal dose 50 (LC₅₀), was also measured. The aqueous extracts of Aesculus hippocastanum, Isatis tinctoria, Chelidonium majus, E. cardamomum and Sisymbrium irio, with EC₅₀ values ranging 1.30-2.88 mg/ml, and the aqueous extract of Jasminum polyanthum with a value of 6.41 mg/ml, showed the highest activities. The aqueous extract of J. polyanthum was the safest extract, followed by methanolic extract of E. cardamomum and aqueous extract of S. irio, all of them with a Selective Index higher than 1. According to our results, there is no correlation between the amount of total phenols or total tannins with the anthelmintic activity of the plants tested. Although results need to be interpreted with caution, as in vitro activity may not automatically translate into in vivo efficacy, those extracts with SI equal or higher than 1 and EC₅₀ equal or lower than 6 mg/ml, could be taken into account for being used subsequently as feed or food additives in infected sheep.

In vitro ovicidal effect of a Senecio brasiliensis extract and its fractions on Haemonchus contortus

BACKGROUND

Haemonchosis affects sheep husbandry and its treatment is often compromised due to the development of anthelminthic resistance. Plant-derived bioactive compounds have been studied as alternative to control Haemonchus contortus. The objective of this study was to evaluate the effect of Senecio brasiliensis extracts on H. contortus egg hatching and infective larvae migration.

RESULTS

The aqueous extract from dried and fresh plant and alkaloid-enriched fraction of the previously dried leaves of S. brasiliensis inhibited H. contortus egg hatching. The main plant compound in alkaloid fraction was integerrimine, a pyrrolizidine alkaloid (PA). However, the aqueous extract from dried plant displayed higher efficacy when compared to their alkaloid enriched or non-polar fractions, meaning that, although PAs contributed to the ovicidal effect, other compounds in the plant can also contribute to their effect. Furthermore, the aqueous extract from dried plant also had higher efficacy than aqueous extract from fresh plant in larvae migration inhibition. Finally, extract from dried plant presented low in vitro cytotoxic effect.

CONCLUSION

Taken together our results suggest a good anthelmintic effect of S. brasiliensis, especially when aqueous extract is prepared from dried plant. Further in vivo studies should be performed focused on forms of administration of this extract in rearing sheep.

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.

Insecticidal and Nematicidal Contributions of Mexican Flora in the Search for Safer Biopesticides

Plant metabolites have been used for many years to control pests in animals and to protect crops. Here, we reviewed the available literature, looking for the species of Mexican flora for which extracts and metabolites have shown activity against pest insects and parasitic nematodes of agricultural importance, as well as against nematodes that parasitize domestic cattle. From 1996 to 2018, the search for novel and eco-friendly biopesticides has resulted in the identification of 114 species belonging to 36 botanical families of Mexican plants with reported biological effects on 20 insect species and seven nematode species. Most plant species with detected pesticide properties belong to the families Asteraceae, Fabaceae, and Lamiaceae. Eighty-six metabolites have been identified as pesticidal active principles, and most have been terpenoids. Therefore, the continuation and intensification of this area of research is very important to contribute to the generation of new products that will provide alternatives to conventional pesticide agents. In addition, future studies will contribute to the recognition and dissemination of the importance of propagating plant species for their conservation and sustainable use.

An in vitro approach to evaluate the nutraceutical value of plant foliage against Haemonchus contortus

Nutraceutical plants provide nutrients for the animal as well as secondary compounds that can affect the biology and survival of gastrointestinal nematodes (GIN). Current screening of nutraceutical plants is based on in vitro evidence of anthelmintic (AH) activity against different life stages of GIN, but nutritional information is omitted or scarce. This study proposes an integral in vitro screening protocol to identify the nutraceutical value of the foliage from plant species consumed by small ruminants, using Haemonchus contortus as a biological model. The leaves from Acacia collinsii, A. pennatula, Bunchosia swartziana, Gymnopodium floribundum, Havardia albicans, Leucaena leucocephala, Lysiloma latisiliquum, Mimosa bahamensis, Piscidia piscipula, and Senegalia gaumeri were evaluated for their chemical composition and in vitro digestibility. Acetone:water extracts (70:30) from leaves of each plant were evaluated using the egg hatch assay and larval exsheathment inhibition assay. Respective effective concentrations 50% (EC₅₀) were determined for each assay. The ten plant species showed good nutritional value for ruminants, including crude protein (> 10%), metabolizable energy (> 2.9 MJ/kg DM), and varied CT content (from 1.0 to 37.6%). The best AH activity against H. contortus eggs (EC₅₀ = 401.8 μg/mL) and L₃ (EC₅₀ = 83.1 μg/mL) was observed for S. gaumeri extract. Although all the plant species showed in vitro nutraceutical potential, the leaves of S. gaumeri had the best values. The proposed in vitro protocol showed to be useful for the integral assessment of the nutraceutical potential of different plant species as it included the nutritional value and the AH activity against eggs and L₃ in the selected plant species.

Anthelmintic efficacy of Moringa oleifera seed methanolic extract against Fasciola hepatica

The current study was carried out to assess in vitro and in vivo effects of Moringa oleifera seed methanolic extract on Fasciola hepatica to develop an alternative source of treatment. The in vitro ovicidal effect of M. oleifera seed extract on immature F. hepatica eggs has provided evidence of inhibitory activity on the vitality and hatchability of F. hepatica eggs. This inhibitory activity was concentration-dependent and also correlated strongly with the exposure time. In the in vivo trial, the oral administration of F. hepatica experimentally infected rabbits with doses of 150 mg/kg BW prepared extract per day for 3 consecutive days on the 63rd day post infection confirmed potent fasciolicide activity of the extract. A gradual decrease in fecal egg count (FEC) was detected from the 1st day post treatment until reaching 100% FEC reduction by the 7th day post treatment. No flukes could be found at post mortem examinations. Significant increments of serum total protein, globulin, the activities of ALT and AST, total cholesterol, triglycerides and urea were recorded during the period of infection, which were improved by treatment. Remarkable histopathological alterations were observed in the infected liver and gallbladder tissues which decreased clearly in the treated rabbits. This study proposes that the used extract has promising and potent fasciolicide activity.

Anthelmintic efficacy of cranberry vine extracts on ovine Haemonchus contortus

The discovery that plant secondary compounds, including proanthocyanidins (PAC), suppress gastrointestinal nematode (GIN) infection has provided promise for alternative methods of GIN control in small ruminants. This investigation is the first to examine the anthelmintic potential of cranberry vine (CV) against the GIN Haemonchus contortus. The purpose of this study was to explore the anti-parasitic activity of CV in the form of a specific organic proanthocyanidin extract (CV-PAC) and an aqueous extract (CV-AqE) containing PAC and other compounds. In vitro egg hatching, first (L1) and third (L3) stage larval and adult worm motility and L3 exsheathment were evaluated after a 24-h incubation with CV products. In addition, CV treated worms were observed via scanning electron microscopy, and a preliminary investigation of the efficacy of CV powder against an experimental infection of H. contortus was conducted. The in vivo effect on an experimental infection was determined by administering 21.1 g CV powder to lambs (n = 9 per group) for three consecutive days, and collecting fecal egg count data for four weeks post-treatment. The effect of CV-PAC on egg hatching, L3 motility and exsheathment was limited. However, a substantial effect was observed on motility of post-hatch L1 (EC₅₀ 0.3 mg PAC/mL) and adults (EC₅₀ 0.2 mg PAC/mL). The CV-AqE showed more effect on egg hatching (EC₅₀ 5.3 mg/mL containing 0.6 mg PAC/mL) as well as impacting motility of L1 (EC₅₀ 1.5 mg/mL with 0.2 mg PAC/mL) and adults (EC₅₀ 3.4 mg/mL with 0.4 mg PAC/mL), but like CV-PAC, did not substantially effect L3 motility or exsheathment. Scanning electron microscopy revealed an accumulation of aggregate on the cuticle around the buccal area of adult worms incubated in CV-AqE and CV-PAC. In the preliminary in vivo study, there was a significant effect of treatment over time (p = .04), although differences in individual weeks were not significant. In summary, both extracts inhibited motility of L1 and adult worms. The higher efficacy of CV-AqE than CV-PAC at levels that contained the same concentrations of PAC tested alone, suggest that other secondary compounds in the CV-AqE contributed to the observed effects on the parasites. This first study of the in vitro and in vivo effects of CV suggest that this readily available plant product may have utility in integrated control of H. contortus and support the need for additional testing to provide further information.

Comparative ovicidal activity of Moringa oleifera leaf extracts on Fasciola gigantica eggs

BACKGROUND

Fasciolosis is an important zoonotic disease affecting the productive performance of farm animals in Egypt.

AIM

The aim of the present study was comparing the ovicidal effect of different extracts as an alcoholic (Methanolic and Ethanolic) and aqueous Moringa oleifera leaf extracts on Fasciola gigantica non-embryonated and developed eggs.

MATERIALS AND METHODS

Tested concentrations of extracts ranged from 12.5 to 800 mg/ml. Nitroxynil was used as reference drug with a dose of 100 mg/ml.

RESULTS

M. oleifera alcoholic and aqueous extracts showed a concentration-dependent ovicidal effect on F. gigantica non-embryonated and developed eggs. Based on LC50 values, water extract showed the highest ovicidal activity since it registered the lowest values of 2.6 mg/ml on non-embryonated eggs. Non-embryonated eggs were more susceptible to aqueous extract than developed eggs. On the other hand, the developed eggs were more susceptible to ethanolic extract than non-embryonated eggs even the lowest LC50 (12.38 mg/ml).

CONCLUSION

M. oleifera leaf extracts especially aqueous extract could be a promising step in the field of controlling fascioliasis. Further, in vivo studies are needed to enlighten the therapeutic potential of M. oleifera extracts in treating F. gigantica infection.

Supplementation with dry Mimosa caesalpiniifolia leaves can reduce the Haemonchus contortus worm burden of goats

Gastrointestinal nematodes (GINs) cause considerable economic losses in grazing goat herds. At present, GIN control cannot rely on conventional anthelmintic (AH) drugs because parasites have developed resistance against such drugs. Thus, alternative control methods are being sought to reduce the dependence on AH. Many tannin-rich plants exhibit AH activity and may be used as alternatives for GIN control. Mimosa caesalpiniifolia is a tannin-rich shrub consumed by small ruminants in Brazil. This study evaluated the in vivo AH effect of M. caesalpiniifolia leaf powder supplementation on GIN egg fecal excretion and worm burden in goats. Plant leaves were harvested, dried and ground to obtain a powder. Twenty-four castrated male goats, aged six to eight months, with a mean body weight of 15.0 ± 2.5 kg were used in the experiment. Animals were infected orally with 16,000 larvae comprising 50% Haemonchus spp., 41% Trichostrongylus spp. and 9% Oesophagostomum spp. Once the infection was patent, the goats were distributed into four groups of six animals. The control group received concentrate without condensed tannins (CTs) and did not receive any drench against GINs. The monepantel group received concentrate without CTs and were drenched once with monepantel. The other two groups received the M. caesalpiniifolia leaf powder in two periods of seven consecutive days (days 1-7 and 14-21), with one of the groups also receiving 10 g of polyethyleneglycol (PEG)/day. The animals were weighed weekly, and individual fecal eggs counts (FECs) were performed daily. After 28 days, the animals were humanly slaughtered, and the worm burden was estimated. Although live weight gain and FECs did not differ among the groups (P > 0.05), post-mortem worm counts showed a reduction in Haemonchus contortus adult worm burden (57.7%) in goats of the CT group compared to control goats (P < 0.05). The addition of PEG did not diminish AH activity in the CT + PEG group (66.9% reduction compared to the control). No AH effect against other GIN species was found. The result for the addition of PEG suggested that the observed AH activity was associated with plant secondary compounds, as opposed to CTs. As expected, no AH effect against Oesophagostomum columbianum was found for the monepantel group showed. Thus, feeding dry leaves of M. caesalpiniifolia represent a promising alternative for the control of GIN infections in goats.

Inhibitory Activities of Ethanolic Extracts of Two Macrofungi Against Eggs and Miracidia of Fasciola Spp

Fascioliasis is a disease of livestock which is now recognized as an emerging disease in humans. Cantharellus cibarius and Ganoderma applanatum are known for their medicinal properties. The use of ethanolic extracts of these macrofungi against the eggs and miracidia of Fasciola spp. is a promising method to break the parasite transmission cycle. The aim of the study is to evaluate the inhibitory effects of ethanolic extracts of the mushrooms on eggs and miracidia of Fasciola spp. Concentrated eggs and miracidia of Fasciola spp. were exposed to different concentrations (1-8 mg/ml) of extracts of Ganoderma applanatum (GEE) and Cantharellus cibarius (CEE) at different time intervals. GEE showed superior antiparasitic activities when compared to CEE at all concentrations tested. Significant positive correlations were observed between the concentration of GEE and mortality in miracidia (r=0.980, P <0.05) and CEE and mortality in miracidia (r= 0.968, P <0.05). The study showed that ethanolic extracts of G. applanatum and C. cibarius have ovicidal and miracicidal activities. While G. applanatum showed excellent activities, activities in C. cibarius were moderate. Therefore, these mushroom extracts can be regarded as promising sources of bioactive compounds that could be developed into ovicides and miracicides.

Do condensed tannins from Lysiloma latisiliquum have a role in its anthelmintic activity?

We would like to comment on a recent paper by Hernandez-Bolio et al. (2017, Nat. Prod. Res. DOI: 10.1080/14786419.2017.1317774) where an extract free of condensed tannin (CT) was evaluated and concluded that Lysiloma latisiliquum CT does not have a role in its anthelmintic (AH) activity. This letter discusses the AH potential of L. latisiliquum based on previously published evidence of a partial role of CT using different AH assays and Haemonchus contortus isolates. Because the experimental design employed in the above-mentioned paper did not allow a clear-cut conclusion regarding the role of CT, this suggests that a specific experiment must be designed to confirm or reject the involvement of CT fraction(s) on L. latisiliquum AH activity.

Comparison of the in vitro anthelmintic effects of Acacia nilotica and Acacia raddiana

Gastrointestinal nematodes are a major threat to small ruminant rearing in the Sahel area, where farmers traditionally use bioactive plants to control these worms, including Acacia nilotica and Acacia raddiana. The main aim of this study was to screen the potential anthelmintic properties of aqueous and acetone extracts of leaves of these two plants based on three in vitro assays: (1) the egg hatch inhibition assay (EHA); (2) the larvae exsheathment inhibition assay (LEIA) using Haemonchus contortus as a model; and (3) an adult mortality test (AMT) applied on Caenorhabditis elegans. For the EHA, only A. raddiana was effective with IC₅₀ = 1.58 mg/mL for aqueous extract, and IC₅₀ = 0.58 mg/mL for acetonic extract. For the LEIA, all extracts inhibited the exsheathment of larvae compared to the controls, and the aqueous extract of A. nilotica was more larvicidal with IC₅₀ = 0.195 mg/mL. In general, all responses to the substances were dose-dependent and were significantly different from the control group (p < 0.05). For the AMT, the extracts of the two Acacia species were effective but A. raddiana showed greater efficacy with 100% mortality at 2.5 mg/mL and LC₅₀ = 0.84 mg/mL (acetonic extract). The addition of polyvinyl polypyrrolidone (PVPP) to the extracts suggested that tannins were responsible for blocking egg eclosion and inducing adult mortality but were not responsible for exsheathment inhibition. These results suggest that the leaves of these Acacia species possess ovicidal and larvicidal activities in vitro against H. contortus, and adulticidal effects against C. elegans.