Anthelmintic effect of 2H-chromen-2-one isolated from Gliricidia sepium against Cooperia punctata

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.

Anthelmintic evaluation of three ayurvedic formulations: a transmission electron microscopy study in Raillietina sp. (Cestoda)

Ayurveda is one of the ancient traditional medicine systems in India. However, several Ayurvedic medicines lack scientific evidence about their efficacy. This study reports the in vitro anthelmintic effects of three common Ayurvedic formulations, Krimimudgar Ras, Kriminol, and Birangasav on a poultry cestode Raillietina sp., using transmission electron microscopy (TEM). Adult cestodes were exposed to different concentrations of Ayurvedic formulations and the paralyzed parasites from the highest concentration (50 mg/mL) of Ayurvedic formulations, the reference anthelmintic praziquantel (PZQ) together with control were picked up and processed for TEM. The TEM studies of control cestode parasites revealed a normal arrangement of microthrix layer, basal lamina, longitudinal muscle layer, and a normal nucleus and mitochondria. Importantly, the cestodes that were exposed to 50 mg/mL concentration of Krimimudgar Ras revealed the most prominent ultrastructural alterations in the body of parasites in the form of a disrupted microthrix layer, basal lamina, muscle layer and mitochondria. The nucleus also appeared dense and irregular in shape with scattered chromatin and disrupted nuclear membrane. Kriminol-treated worms revealed considerably less damage, whereas Birangasav-treated worms revealed destructive effects in microthrix layer, nucleus and mitochondria. Through the findings of the present study, it can be concluded that of the three common Ayurvedic formulations studied, Krimimudgar Ras causes maximum degree of internal alterations in cestode parasites and thus may be considered as a good anthelmintic agent.

Anthelmintic-Like Activity and Ultrastructure Changes Produced by Two Polyphenolic Combinations against Cooperia punctata Adult Worms and Infective Larvae

Cooperia punctata is one of the most prevalent gastrointestinal nematodes affecting cattle under grazing conditions, and the increasing reports of anthelmintic resistance forces researchers to look for novel control measures. Previous reports have proposed the use of polyphenolic compound (PC) combinations (Coumarin:Quercetin (CuQ) and Caffeic-acid:Rutin (CaR)) against free-living stages (L₃) of C. punctata. The objective of this study was to assess the in vitro motility inhibition of C. punctata adult worms and infective larvae using the Larval Motility Inhibition Assay (LMIA) and Adult Motility Inhibition Assay (AMIA), and to assess the structural and ultrastructural changes induced by both treatments using Scanning and Transmission Electron Microscopy. For the LMIA, infective larvae were incubated for 3 h in 0.8 mg mL^-1 and 0.84 mg mL^-1 of CuQ and CaR, respectively. For AMIA, six concentrations and five incubation periods (2, 4, 6, 12 and 24 h) were assessed using each PC combination. Cooperia punctata motility was calculated as a percentage and corrected using control motility percentages. A multiple comparisons Brown-Forsythe and Welch ANOVA test was used to compare larval motility; and to fit the dose-response in AMIA, data were analyzed with a non-linear regression four-parameter logistic equation with a variable slope, using the computer program GraphPad Prism^® V.9.2.0. Although larval motility was barely affected by both treatments (p > 0.05), adult worm motility was inhibited 100% and 86.9% after 24 h incubation with CuQ and CaR, respectively (p < 0.05). The best fit EC₅₀ for adult worm motility inhibition were 0.073 ± 0.071 mg mL^-1 and 0.051 ± 0.164 mg mL^-1 for CuQ and CaR, respectively. Main structural and ultrastructural lesions observed in both biological stages were: (i) L₃ sheath-cuticle complex disruption, (ii) collagen fibers degradation; (iii) hypodermic detachment, (iv) seam cell apoptosis and (v) mitochondrial swelling. The alterations observed suggest that the PC combinations interfere with the anatomy and physiology of the locomotive apparatus of the nematodes.

Anthelmintic Agents from African Medicinal Plants: Review and Prospects

Soil-transmitted helminthiasis affects more than 1.5 billion people globally and largely remains a sanitary problem in Africa. These infections place a huge economic burden on poor countries and affect livestock production, causing substantial economic losses and poor animal health. The emergence of anthelmintic resistance, especially in livestock, and the potential for its widespread in humans create a need for the development of alternative therapies. Medicinal plants play a significant role in the management of parasitic diseases in humans and livestock, especially in Africa. This report reviews anthelmintic studies that have been conducted on medicinal plants growing in Africa and published within the past two decades. A search was made in various electronic databases, and only full articles in English were included in the review. Reports show that aqueous and hydroalcoholic extracts and polar fractions obtained from these crude extracts form the predominant (80%) form of the extracts studied. Medicinal plants, extracts, and compounds with different chemical groups have been studied for their anthelmintic potential. Polyphenols and terpenoids are the most reported groups. More than 64% of the studies employed in vitro assays against parasitic and nonparasitic nematode models. Egg hatch inhibition, larval migration inhibition, and paralysis are the common parameters assessed in vitro. About 72% of in vivo models involved small ruminants, 15% rodents, and 5% chicken. Egg and worm burden are the main factors assessed in vivo. There were no reports on interventions in humans cited within the period under consideration. Also, few reports have investigated the potential of combining plant extracts with common anthelmintic drugs. This review reveals the huge potential of African medicinal plants as sources of anthelmintic agents and the dire need for in-depth clinical studies of extracts, fractions, and compounds from African plants as anthelmintic agents in livestock, companion animals, and humans.

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.

In vitro ovicidal activity of Brongniartia montalvoana against small ruminant gastrointestinal nematodes

Several plants of the Fabaceae family have been assessed regarding their high nutritional value and anthelmintic properties. The ovicidal effect of the hydroalcoholic extract (Bm-HAE) and subfractions from the aerial parts of Brongniartia montalvoana (Fabaceae) against a mixed strain of gastrointestinal nematodes (GIN) (Haemonchus spp., Trichostrongylus spp. and Oesophagostomum spp.) resistant to albendazole sulfoxide, ivermectin and levamisole was evaluated by the egg hatch test (EHT). The Bm-HAE was subjected to liquid-liquid chemical separation with ethyl acetate giving two fractions, an aqueous (Bm-Aq) and an organic (Bm-EtOAct). The purification of the bioactive fraction (Bm-EtOAct) through chromatographic separation resulted in four bioactive subfractions (BmR6, BmR7, BmR8 and BmR10). The treatments were designed as follows: Bm-HAE at 800, 1,500, 3,000 and 6,000 μg/mL, and Bm-Aq, Bm-EtOAct and subfractions (BmR6, BmR7, BmR8 and BmR10) at 100, 200, 400 and 800 μg/mL. Two properly negative controls (distilled water and 2% methanol) and thiabendazole (100 μg/mL) as a positive control were used for each bioassay. The chemical identification of the extract, fractions and subfractions was performed through chromatographic processes like open column chromatography, thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC-PDA). Additionally, the GIN eggs exposed to the bioactive compounds were observed through confocal laser scanning microscopy (CLSM). The Bm-HAE showed 99.5% egg hatching inhibition (EHI) at 6,000 μg/mL with a lethal concentration (LC₅₀) of 1110 μg/mL. The Bm-EtOAc fraction displayed 99.1% EHI at 800 μg/mL with LC₅₀ = 180 μg/mL. The ovicidal activity of the four subfractions was similar at 800 μg/mL: BmR6 (92% EHI); BmR7 (100% EHI); BmR8 (97.8%); and BmR10 (99.1%). The HPLC-PDA analysis of the bioactive subfractions allowed identification of p-coumaric acid, ferulic acid and coumarin derivatives as major compounds. The CLSM analysis allowed observation of morphological alterations in unhatched larvae caused by bioactive compounds present in the Bm-EtOAc and BmR10. In addition, the flavonoids eriodyctiol, luteolin and cynaroside were described for the first time for B. montalvoana.

Analysis of Gliricidia sepium Leaves by MALDI Mass Spectrometry Imaging

When investigating the potential use of plants as a raw material for an all-natural cosmetic formulation, the main parameters are the chemical composition, antioxidant potential, antimicrobial action, and toxicity. Additionally, the production of natural cosmetics should also consider the availability of primary materials and the environmental and socioeconomic impact. Gliricidia sepium is a species that produces a large amount of plant material, being cultivated in the agroforestry system. However, studies of phytochemical composition and chemical spatial distribution are scarcely using the MALDI MS (matrix-assisted laser desorption ionization mass spectrometry) and MALDI MSI (mass spectrometry imaging) techniques. A methodology was developed to optimize ionization parameters and analysis conditions by evaluating the efficiency of three matrices: α-cyano-4-hydroxycinnamic acid, 2,5-dihydroxybenzoic acid (DHB), and 2-mercaptobenzothiazole in MALDI MS analysis. All results were compared to ESI MS (electrospray ionization mass spectrometry), and afterward, MALDI MSI analysis was performed on the leaf surface. This study showed through phytochemical analysis that G. sepium leaves are composed of polyphenols and tannins, concluding that the methanolic extract had a higher amount of flavonoid content. Four compounds were identified on the leaf surface, and their spatial distribution was analyzed by MALDI MS using DHB as a matrix. Kaempferol, isorhamnetin, and some fatty acids showed potential applicability for cosmetical use. All the extracts presented antioxidant activity or antimicrobial action and no cytotoxicity. Therefore, extracts of G. sepium could be used as raw materials in cosmetics.

The Possible Biotechnological Use of Edible Mushroom Bioproducts for Controlling Plant and Animal Parasitic Nematodes

The present paper reviewed publications on the nematocidal activity of edible mushrooms (EM) and their potential use as sustainable tools for the control of parasitic nematodes affecting agriculture and livestock industry. Nematodes are organisms living in the soil and animals' guts where they may live as parasites severely affecting economically important crops and farm animals, thus causing economic losses to worldwide agriculture. Traditionally, parasitic nematodes have been controlled using commercial pesticides and anthelmintic (AH) drugs. Over the years, nematodes developed resistance to the AH drugs, reducing the usefulness of many commercial drugs. Also, the use of pesticides/anthelmintic drugs to control nematodes can have important negative impacts on the environment. Different EM have been not only used as food but also studied as alternative methods for controlling several diseases including parasitic nematodes. The present paper reviewed publications from the last decades about the nematocidal activity of EM and assessed their potential use as sustainable tools for the control of nematodes affecting agriculture and livestock industry. A reduced number of reports on the effect of EM against nematodes were found, and an even smaller number of reports regarding the potential AH activity of chemical compounds isolated from EM products were found. However, those studies have produced promising results that certainly deserve further investigation. It is concluded that EM, their fractions and extracts, and some compounds contained in them may have biotechnological application for the control of animal and plant parasitic nematodes.

Plant-Based Natural Products for the Discovery and Development of Novel Anthelmintics against Nematodes

Intestinal parasitic nematodes infect approximately two billion people worldwide. In the absence of vaccines for human intestinal nematodes, control of infections currently relies mainly on chemotherapy, but resistance is an increasing problem. Thus, there is an urgent need for the discovery and development of new anthelmintic drugs, especially ones with novel mechanisms of action. Medicinal plants hold great promise as a source of effective treatments, including anthelmintic therapy. They have been used traditionally for centuries and are mostly safe (if not, their toxicity is well-known). However, in most medicinal plants the compounds active against nematodes have not been identified thus far. The free-living nematode C. elegans was demonstrated to be an excellent model system for the discovery of new anthelmintics and for characterizing their mechanism of action or resistance. The compounds discussed in this review are of botanical origin and were published since 2002. Most of them need further studies of their toxicity, mechanisms and structure-activity relationship to assess more fully their potential as drugs.

Abdel-Daim M, Mosqueda J, Igarashi I. Phytochemical Characterization and Chemotherapeutic Potential of Cinnamomum verum Extracts on the Multiplication of Protozoan Parasites In Vitro and In Vivo

Cinnamomum verum is a commonly used herbal plant that has several documented properties against various diseases. The existing study evaluated the inhibitory effect of acetonic extract of C. verum (AECV) and ethyl acetate extract of C. verum (EAECV) against piroplasm parasites in vitro and in vivo. The drug-exposure viability assay was tested on Madin-Darby bovine kidney (MDBK), mouse embryonic fibroblast (NIH/3T3) and human foreskin fibroblast (HFF) cells. Qualitative phytochemical estimation revealed that AECV and EAECV containing multiple bioactive constituents namely alkaloids, tannins, saponins, terpenoids and remarkable amounts of polyphenols and flavonoids. AECV and EAECV inhibited B. bovis, B. bigemina, B. divergens, B. caballi, and T. equi multiplication at half-maximal inhibitory concentrations (IC50) of 23.1 ± 1.4, 56.6 ± 9.1, 33.4 ± 2.1, 40.3 ± 7.5, 18.8 ± 1.6 µg/mL, and 40.1 ± 8.5, 55.6 ± 1.1, 45.7 ± 1.9, 50.2 ± 6.2, and 61.5 ± 5.2 µg/mL, respectively. In the cytotoxicity assay, AECV and EAECV affected the viability of MDBK, NIH/3T3 and HFF cells with half-maximum effective concentrations (EC50) of 440 ± 10.6, 816 ± 12.7 and 914 ± 12.2 µg/mL and 376 ± 11.2, 610 ± 7.7 and 790 ± 12.4 µg/mL, respectively. The in vivo experiment showed that AECV and EAECV were effective against B. microti in mice at 150 mg/kg. These results showed that C. verum extracts are potential antipiroplasm drugs after further studies in some clinical cases.

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.

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.

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.

Molecular marker sequences of cattle Cooperia species identify Cooperia spatulata as a morphotype of Cooperia punctata

The genus Cooperia includes important parasites of ruminants and currently contains 34 accepted species. However, even for those species infecting livestock, there is a considerable lack of molecular information and many species are only identifiable using subtle morphological traits. The present study aimed to provide molecular data to allow diagnosis of Cooperia species infecting cattle. Partial sequences of two mitochondrial (cytochrome oxidase 2, 12S rRNA gene) and two nuclear genes (isotype 1 β tubulin gene including two introns, internal transcribed spacers (ITS) were obtained from morphologically identified specimens of Cooperia pectinata, Cooperia punctata and Cooperia spatulata as well as from larvae of pure Cooperia oncophora and C. punctata laboratory isolates. Pairwise identity of ITS-2 sequences was very high and it was the only region able to identify a specimen as Cooperia sp. However, the ITS-2 was unreliable for diagnosis at the species level. All other marker sequences could not unequivocally be allocated to the genus Cooperia but allowed clear species identification with the exception of the pair C. punctata/C. spatulata for which no significant differences were found for any marker sequence. Maximum-likelihood phylogenetic analyses of individual genes as well as a multi-locus analysis covering all four sequences confirmed that specimen identified as C. spatulata were randomly distributed throughout the C. punctata cluster and formed no group of their own. In contrast, the other Cooperia species formed clearly separated and statistically supported clusters. These data indicate that C. spatulata is most likely only a morphotype of C. punctata and the name should be considered a synonym. Combinations of nuclear and mitochondrial markers should be used to identify morphotypes or cryptic species to benefit from excellent barcoding properties of the latter but allowing proper phylogenetic analyses and controlling for lineage sorting that might occur for mitochondrial genotypes within a species.