Egg Hatching Inhibition Research Articles

Harnessing the Phytochemistry Through Pesticidal Potential of Diverse Elsholtzia Species: A Path to Sustainable Agriculture.

This study investigates the phytochemical profiles and pesticidal activities of various Elsholtzia species, including E. ciliata, E. flava, E. fruticosa, and E. eriostachya, to discover their bioactive potential for sustainable pest management. Through comparative phytochemical analysis using GC-MS technique, key compounds in the essential oils were identified. The major components were thymoquinone (44.97%) in E. ciliata, shisofuran (28.66%) in E. flava, perillene (50.88%) in E. fruticosa, and pinocarvone (42.41%) in E. eriostachya. Despite variability in chemical composition, all species primarily contained oxygenated monoterpenes. The bioactivity of the oils was evaluated for their nematicidal and herbicidal bioassays. E. ciliata showed the highest egg hatching inhibition and juvenile mortality of M. incognita, while E. flava exhibited the lowest activity. For herbicidal activity, E. eriostachya achieved 96.70% seed germination inhibition, 100% root growth inhibition, and 95.56% shoot growth inhibition. E. flava showed the lowest inhibition in germination, root length, and shoot length at 66.70%, 81.56%, and 85.28%, respectively. The findings revealed significant variations in phytochemical composition and pesticidal efficacy, emphasizing the importance of species selection for pest management. This research highlights the bioactive potential of Elsholtzia species in sustainable pest management strategies.

In vitro anthelmintic activity of hydroethanolic extract of Artemisia herba aba and Juniperus phoenicea on abomasal Teladorsagia circumcincta of sheep.

The present study aimed to evaluate the in vitro anthelmintic activity of Juniperus phoenicea and Artemisia herba-alba against abomasal nematodes collected from naturally infected sheep. The anthelmintic activities of the extracts were assessed using egg hatch inhibition (EHIA) and adult motility assays (AMA) against Teladorsagia circumcincta. The parasites were stored in phosphate-buffered saline (PBS) until the in vitro assessment began. The leaf powders of J. phoenicea and A. herba-alba were extracted using the maceration procedure. Briefly, the leaf powders were mixed with a sufficient quantity of 99% ethanol and distilled water (80%/20%). The extracts were dissolved in a 3% dimethyl sulfoxide (DMSO) solution to improve water solubility. The hydroethanolic extracts were tested at concentrations of 1.562, 3.125, 6.25, 12.5, and 25 mg/ml. Adult motile worms were individually subjected to each treatment at laboratory temperature. The PBS and albendazole (25 mg/ml) were prepared and used as negative and positive controls, respectively. The test was repeated five times for each concentration. The results showed that both plant extracts exhibited anthelmintic effects. A. herba-alba extract at 25 mg/ml inhibited the motility of all T. circumcincta adult worms within 1 hour of administration, while J. phoenicea extract caused 100% mortality of adult worms after 4 hours at the same concentration. Neither of the extracts, at 1.562 mg/ml, had any inhibitory effect on motility. At 25 mg/ml, the A. herba-alba (98.67%) and J. phoenicea (96.24%) showed high activity with an inhibitory effect on hatchability compared to the other tested concentrations. The findings of the present study showed that hydroethanolic extracts of A. herba-alba and J. phoenicea leaves had in vitro anthelmintic activity on eggs and adult T. circumcincta of sheep.

In-vitro Study of Different Fungal Bio-agents against Root-knot Nematode, Meloidogyne incognita

To assess the antagonistic effect of fungal bio-control agents, such as Trichoderma harzianum, T. viride, Purpureocillium lilacinum, Metarhizium anisopliae, and Beauveria bassiana, on the hatching of egg masses of the root-knot nematode, Meloidogyne incognita, investigations were conducted in vitro. In comparison to the control, bio-control agents were tested at 106 and 107 dilutions on M. incognita egg hatching after 24, 48, 72, 96, and 120 hours of exposure. P. lilacinum 107 concentration and T. harzianum 106 concentration (83.90 % and 83.04 %) were found at par and significantly effective on egg hatching inhibition of M. incognita. Among different concentration, P. lilacinum at 106 concentration (85.46 %) gave maximum egg hatching inhibition followed by P. lilacinum at 107 concentration (83.90 %), T. harzianum at 106 concentration (83.04 %) and T. virideat 106 concentration (82.00 %) after 120 hrs. M. anisopliae at 107 concentration (69.46 %) was found least effective at different period of exposure. Further studies to be conducted in pot and field conditions to evaluate the efficacy of these bio-agents against root knot nematode, M. incognita.

In Vitro: Anthelmintic Activity of Aqueous Leaf Extract of Indigofera tintoria L Againts Haemonchus contortus

Gastrointestinal nematodes are one of the causes of reduced production efficiency in sheep and goats in Indonesia, especially the parasite abomasum Haemonchus contortus. This parasite causes the disease Haemonchosis which causes anemia and is fatal for productive sheep and goats. Economic losses caused by the morbidity and mortality of this parasite are quite high, so it can increase the cost of prevention and treatment of this disease. The aim of this study was to evaluate the inhibition of hatching eggs and mortality of adult H. contortus worms from Indigofera tintoria L leaf infusa on in vitro. Indigofera leaf infusa on was tested at five concentrations, namely 0% as negative control, 20%, 40%, 60% and 80%. Positive control used Albendazole with a concentration of 0,025 mg/ml. At the highest concentration of 80% indigofera leaf infusa on was able to inhibit egg hatching by 95,37% and had a mortality rate of 68,67% against adult H. contortus worms. The 80% concentration had the same effect when compared to the positive control using Albendazole. Phytochemical analysis of Indigofera tintoria L leaves containing condensed tannins.

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.

Design, Synthesis, Nematicidal Evaluation, and Molecular Docking Study of Pyrano[3,2-c]pyridones against Meloidogyne incognita.

Root-knot nematodes pose a serious threat to crops by affecting production and quality. Over a period of time, substantial work has been done toward the development of effective and environmentally benign nematicidal compounds. However, due to the inefficiencies of previously reported synthetics in achieving the target of safe, selective, and effective treatment, it is necessary to develop new efficacious and safer nematicidal agents considering human health and environment on top priority. This work aims to highlight the efficient and convenient l-proline catalyzed synthesis of pyrano[3,2-c]pyridone and their use as potential nematicidal agents. In vitro results of larval mortality and egg hatching inhibition revealed maximum nematicidal activity against Meloidogyne incognita from compounds 15b, 15m, and 15w with LC50 values of 28.8, 46.8, and 49.18 μg/mL at 48 h, respectively. Under similar conditions, pyrano[3,2-c]pyridones derivatives 15b (LC50 = 28.8 μg/mL) was found at par with LC50 (26.92 μg/mL) of commercial nematicide carbofuran. The in vitro results were further validated with in silico studies with the most active compound 15b nematicidal within the binding to the pocket of acetylcholine esterase (AChE). In docking, binding free energy values for compound 15b were found to be -6.90 kcal/mol. Results indicated that pyrano[3,2-c]pyridone derivatives have the potential to control M. incognita.

Volatile organic compounds released from entomopathogenic nematode-infected insect cadavers for the biocontrol of Meloidogyne incognita.

Root-knot nematodes (RKNs), Meloidogyne spp., are one of the most destructive polyphagous plant-parasitic nematodes. They pose a serious threat to global food security and are difficult to control. Entomopathogenic nematodes (EPNs) show promise in controlling RKNs. However, it remains unclear whether the volatile organic compounds (VOCs) emitted from EPN-infected cadavers can control RKNs. We investigated the fumigation activity of VOCs released from cadavers infected by five different species of EPNs on RKNs in Petri dishes, and found that VOCs released from Steinernema feltiae (SN strain) and S. carpocapsae (All strain) infected cadavers had a significant lethal effect on second-stage juveniles (J2s) of Meloidogyne incognita. The VOCs released from the cadavers infected with S. feltiae were analyzed using SPME-GC/MS. Dimethyl disulfide (DMDS), tetradecane, pentadecane, and butylated hydroxytoluene (BHT), were selected for a validation experiment with pure compounds. The DMDS compound had significant nematicidal activity and repelled J2s. DMDS also inhibited egg hatching and the invasion of tomato roots by J2s. In a pot experiment, the addition of S. feltiae-infected cadavers and cadavers wrapped with a 400-mesh nylon net also significantly reduced the population of RKNs in tomato roots after 7 days. The number of root knots and eggs was reduced by 58% and 74.34%, respectively, compared to the control. These results suggested that the VOCs emitted by the EPN-infected cadavers affected various developmental stages of M. incognita and thus have the potential to be used in controlling RKNs through multiple methods. © 2024 Society of Chemical Industry.

Synthesis of Nano Sulfur/Chitosan-Copper Complex and Its Nematicidal Effect against Meloidogyne incognita In Vitro and on Coffee Pots.

Sulfur is one of the inorganic elements used by plants to develop and produce phytoalexin to resist certain diseases. This study reported a method for preparing a material for plant disease resistance. Sulfur nanoparticles (SNPs) stabilized in the chitosan-Cu2+ (CS-Cu2+) complex were synthesized by hydrolysis of Na2S2O3 in an acidic medium. The obtained SNPs/CS-Cu2+ complex consisting of 0.32% S, 4% CS, and 0.7% Cu (w/v), contained SNPs with an average size of ~28 nm as measured by transmission electron microscopy images. The X-ray diffraction pattern of the SNPs/CSCu2+ complex showed that SNPs had orthorhombic crystal structures. Interaction between SNPs and the CS-Cu2+ complex was also investigated by ultraviolet-visible. Results in vitro nematicidal effect of materials against Meloidogyne incognita showed that SNPs/CS-Cu2+ complex was more effective in killing second-stage juveniles (J2) nematodes and inhibiting egg hatching than that of CS and CS-Cu2+ complex. The values of LC50 in killing J2 nematodes and EC50 in inhibiting egg hatching of SNPs/CS-Cu2+ complex were 75 and 51 mg/l, respectively. These values were lower than those of CS and the CS-Cu2+ complex. The test results on the nematicidal effect against M. incognita on coffee pots showed that the SNPs/CS-Cu2+ complex was 100% effective at a concentration of 150 mg/l. Therefore, the SNPs/CS-Cu2+ complex could be considered as a biochemical material with potential for agricultural applications to control root-knot nematodes.

In vitro ovicidal and larvicidal activity of a hydroalcoholic extract and its fractions from Cyrtocarpa procera fruits on Haemonchus contortus

This study describes the in vitro anthelmintic effect of a hydroalcoholic extract (HA-E) and its fractions from Cyrtocarpa procera fruits against Haemonchus contortus eggs and infective larvae. The HA-E was subjected to bipartition using ethyl acetate, which resulted in an aqueous fraction (Aq-F) and an organic fraction (EtOAc-F). The HA-E and both fractions were tested using the egg hatching inhibition assay (EHIA) and the larval mortality test (LMT). Fractionation of the EtOAc-F was achieved using different chromatographic processes, i.e., open glass column and HPLC analysis. Fractionation of the EtOAc-F gave 18 subfractions (C1R1-C1R18), and those that showed the highest yields (C1R15, C1R16, C1R17 and C1R18) were subjected to anthelmintic assays. The HA-E and the EtOAc-F displayed 100% egg hatching inhibition at 3 and 1 mg/mL, respectively, whereas Aq-F exhibited 92.57% EHI at 3 mg/mL. All subfractions tested showed ovicidal effect. Regarding the larval mortality test, HA-E and EtOAc-F exhibited a larvicidal effect higher than 50% at 50 and 30 mg/mL, respectively. The subfractions that showed the highest larval mortality against H. contortus were C1R15 and C1R17, with larval mortalities of 53.57% and 60.23% at 10 mg/mL, respectively. Chemical analysis of these bioactive subfractions (C1R15 and C1R17) revealed the presence of gallic acid, protocatechuic acid, and ellagic acid. This study shows evidence about the ovicidal and larvicidal properties of C. procera fruits that could make these plant products to be considered as a natural potential anthelmintic agents for controlling haemonchosis in goats and sheep.

A taste of a toxin paradise: Xenorhabdus and Photorhabdus bacterial secondary metabolites against Aedes aegypti larvae and eggs

Aedes-transmitted arboviral infections such as Dengue, Yellow Fever, Zika and Chikungunya are increasing public health problems. Xenorhabdus and Photorhabdus bacteria are promising sources of effective compounds with important biological activities. This study investigated the effects of cell-free supernatants of X. szentirmaii, X. cabanillasii and P. kayaii against Ae. aegypti eggs and larvae and identified the bioactive larvicidal compound in X. szentirmaii using The EasyPACId method. Among the three tested bacterial species, X. cabanillasii exhibited the highest (96%) egg hatching inhibition and larvicidal activity (100% mortality), whereas P. kayaii was the least effective species in our study. EasyPACId method revealed that bioactive larvicidal compound in the bacterial supernatant was fabclavine. Fabclavines obtained from promoter exchange mutants of different bacterial species such as X. cabanillasii, X. budapestensis, X. indica, X. szentirmaii, X. hominckii and X. stockiae were effective against mosquito larvae. Results show that these bacterial metabolites have potential to be used in integrated pest management (IPM) programmes of mosquitoes.

Evaluating anthelmintic activity through Caenorhabditis elegans egg hatching assay

The Caenorhabditis elegans egg hatching methodology is a valuable tool for assessing the anthelmintic activity of drugs and compounds and evaluating anthelmintic drug efficacy.Isolated eggs from gravid adults are exposed to different concentrations of selected drugs and the percentage of egg hatching is determined with respect to the control condition. The assay allows the construction of concentration-response curves and determination of EC50 or EC90 values for egg hatching inhibition. Also, it allows measurements of inhibition as a function of time of exposure.This approach addresses the urgent need for new anthelmintics, as resistance to current treatments poses a significant challenge in parasitic nematode infection. This resistance not only affects humans but also animals and plants, causing significant economic losses in livestock farming and agriculture.By using the free-living nematode C. elegans as a parasitic model organism, researchers can efficiently screen for potential treatments and assess drug combinations for synergistic effects. Importantly, this assay offers a cost-effective and accessible alternative to traditional methods, eliminating the need for specialized infrastructure, hosts, and trained animal maintenance personnel. Additionally, the methodology closely mimics natural conditions, providing insights into egg development and potential therapeutic targets.This method allows for evaluating the direct negative impact of drugs on egg hatching, which correlates with long-term anthelmintic effects, offering advantages in preventing or reducing the transmission and spread of worm infections by eggs.Overall, this approach represents a significant advancement for anthelmintic discovery, offering both practical applications and avenues for further scientific research.•The C. elegans egg hatching assay is a robust and effective method for assessing the anthelmintic potential of various drugs and compounds, allowing the generation of concentration-response curves.•By leveraging the free-living nematode C. elegans as a parasitic model organism, this method facilitates efficient screening of potential treatments and evaluation of drug combinations.•The method addresses the urgent need for new anthelmintics, offering a cost-effective and accessible alternative to traditional approaches.

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 300mg/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.

Sulfonamide modified chitosan oligosaccharide with high nematicidal activity against Meloidogyne incognita

Chitosan oligosaccharide (COS) modification is a feasible way to develop novel green nematicides. This study involved the synthesis of various COS sulfonamide derivatives via hydroxylated protection and deprotection, which were then characterized using NMR, FTIR, MS, elemental analysis, XRD, and TG/DTG. In vitro experiments found that COS-alkyl sulfonamide derivatives (S6 and S11–S13) exhibited high mortality (>98 % at 1 mg/mL) against Meloidogyne incognita second-instar larvaes (J2s) among the derivatives. S6 can cause vacuole-like structures in the middle and tail regions of the nematode body and effectively inhibit egg hatching. In vivo tests have found that S6 has well control effects and low plant toxicity. Additionally, the structure-activity studies revealed that S6 with a high degree of substitution, a low molecular weight, and a sulfonyl bond on the amino group of the COS backbone exhibited increased nematicidal activity. The sulfonamide group is a potential active group for developing COS-based nematicides.

Preliminary screening of plant essential oils from an oceanic climate zone (NW Spain) for the control of equine cyathostomins

Cyathostomins (Strongylida: Cyathostominae) are gastrointestinal nematodes (GIN) that affect equines in many parts of the world. Due to anthelmintic resistance (AR), it is necessary to search for control alternatives. The objective of the study was to carry out a screening of 26 essential oils (EOs) from plants to determine in vitro their action on cyathostomins. Essential oils were obtained by hydro-distillation from leaves, flowers, fruits, and seeds of the selected species and used against the eggs of cyathostomins by means of the tests of egg hatching and larval motility inhibition. For each EO, different concentrations were prepared (250, 125, 62.5, 31.3, 15.6, 7.8, 3.9, 2.0, 1.0, 0.5 and 0.24 mg/mL). Oxfendazole at 2.5% mixed with closantel 5% was used as positive control, and PBS served as negative control. Cyathostomin eggs were obtained from feces of infected horses and infective larvae were recovered after coproculture. The in vitro test was carried out 36 h after the challenge with the EOs. The highest production of EOs was obtained from leaves of bay, eucalyptus, mallow, and basil, as well as from seeds of black pepper, coriander, cinnamon, anise, and peel of orange and cloves, cumin, and Lawson’s cypress. The oils extracted from laurel leaves, ground cinnamon, anise, cumin, and coriander seeds had a very high effect on cyathostomins eggs up to concentrations lower than 3.9 mg/mL. Therefore, in addition to the uses against other pathogens such as fungi and bacteria, some EOs might attain great importance as an alternative control strategy in the control of nematode eggs.

Acaricidal Efficacy of Cassia sieberiana DC (Caesalpinaceae) Stem Bark Aqueous Extract on Hyalomma KOCH, 1844 (Acari: Ixodidae) Reproductive Stages

One of the most significant challenges facing tick control through chemical acaricides is resistance and environmental pollution, encouraging the need for natural plant products that are less toxic and environment friendly. This study was conducted to determine theacaricidal efficacy of Cassia sieberiana stem bark aqueous extract on Hyalomma species using immersion testing for egg-hatchinhibition and adult mortality. Both tests used ascending extract concentrations of 5%, 10%, 15% and 20%, at durations of 1, 2, 3, 4, 5, 6, 7 and 8 hours. Egg-hatch inhibition peaked at 5% concentration at 8hrs, 10% and 15% at 7 and 8hrs and 20% at 5, 6, 7 and 8hrs while adult mortality was highest at 20% concentration. There was a positive correlation between graded extract concentration, immersion period, egg-hatch inhibition and adult mortality. The LC50 values for adult mortality and egg-hatch inhibition were 13.1 mg/mL and 13.7 mg/mL and coefficient of determination were y = 3.7x +1.5 and y = 3.062 + 8.12 respectively. Both LC50 values were almost similar indicating a strong association between extract concentration and acaricidal activity in vitro.

Evaluation of bromocriptine and plumbagin against the monogenean Rhabdosynochus viridisi: Computational drug repositioning and in vitro approaches

Monogeneans are parasitic platyhelminths that can harm the health of farmed fish. Few treatments are available against monogeneans, and the incentive to develop new antiparasitic agents is similar or even lower than the incentive for neglected parasitic diseases in humans. Considering that searching for and developing new antimonogenean compounds may require enormous investments of time, money, and animal sacrifice, the use of a computer-guided drug repositioning approach is a reasonable alternative. Under this context, this study aimed to evaluate the effectiveness of plumbagin and bromocriptine against adults and eggs of the monogenean Rhabdosynochus viridisi (Diplectanidae). Plumbagin is a phytochemical compound that has recently emerged as a potent antimonogenean; however, further investigation is required to determine its effects on different monogenean species. Bromocriptine was selected through a computational approach that included molecular docking analyses of 77 receptors of monogeneans (putative drug targets) and 77 ligands (putative inhibitors). In vitro experiments showed that bromocriptine does not exhibit mortality at concentrations of 0.1, 1, and 10 mg/L whereas plumbagin at 2 and 10 mg/L caused 100% monogenean mortality after 3 h and 30 min, respectively. The most effective concentration of plumbagin (10 mg/L) did not completely inhibit egg hatching. These findings underscore plumbagin as a highly effective agent against adult monogeneans and highlight the need for research to evaluate its effect(s) on fish. Although computational drug repositioning is useful for selecting candidates for experimental testing, it does not guarantee success due to the complexity of biological interactions, as observed here with bromocriptine. Therefore, it is crucial to examine the various compounds proposed by this method.

Green synthesis and anthelmintic activity of silver nanoparticles using Morus Alba Fruit extract against different stages of equine strongyles.

The current study was designed to green synthesize silver nanoparticles (GRAgNPs) using Morus alba fruit extract and evaluate their nematicidal effects against strongyle nematodes compared to commercial silver nanoparticles (CAgNPs) in vitro. The nanoparticles were characterized by Ultraviolet-visual absorption spectrography, transmission electron microscopy, and X-ray diffraction. Next, uptake of AgNPs by the first stage larvae (L1), egg hatch inhibition (EHI) and the motility of infectious larvae (L3s), and the ultrastructural analysis of the eggs and worms were conducted. Moreover, some of oxidative/nitrosative stress indicators, including total antioxidant status content (TAC), protein carbonylation (PCO), lipid peroxidation (MDA), and DNA damage were assessed in the homogenized samples of strongyle L3s. We found that the GRAgNPs had spherical shape, 20-30nm in diameter with rough surface. Following incubation with GRAgNPs at concentrations of 43.40, 21.70 and 10.85 ppm and CAgNPs at concentrations of 43.40 and 21.70, EHI was more than 90%. In addition, concentrations of 43.40 and 21.70 ppm of GRAgNPs led to inhibition of larval motility by more than 90%. The LC50 at 24h of treatment for GRAgNPs and CAgNPs was determined to be 8.62 and 10.34 ppm, respectively. GRAgNPs and CAgNPs, in a concentration-dependent manner, resulted in the induction of oxidative/nitrosative stress evidenced by decreased TAC levels, and increased levels of MDA and PCO, together with increased DNA damage. The uptake of AgNPs by the L1 larvae revealed that FITC labeled GRAgNPs fluoresced with high intensity largely in the intestinal area. Scanning Electron Microscopy analysis of eggs and larvae revealed that GRAgNPs penetrated the cuticle of larvae, changed the tegmentum, and ultimately killed the worm. In conclusion, GRAgNPs had more robust anthelminthic effects than the standard antiparasitic and CAgNPs. They could be considered as a promising antiparasitic agent.

Synergistic Interaction Effect of Artemisia cina n-hexane Extract and Tagetes lucida Ethyl Acetate Extract on Haemonchus Contortus

PurposeWe analysed the possible synergistic activity among active extracts from Artemisia cina and Tagetes lucida combinations on Haemonchus contortus, a nematode parasitising sheep.MethodsThe work was carried out in vitro on eggs and infective larvae (L3) of H. contortus. The results were analysed with SAS 9.1, applying the ANOVA and Tukey test, and the lethal concentration (LC) values LC50 and LC90 were determined with regression analysis, employing Proc Probit of SAS 9.1. Additionally, the lethal concentration (LC) was calculated with LC50 and LC90 to determine the synergistic effect.ResultsThe results demonstrated a high efficacy of the two plants studied on both nematode eggs and L3 larvae as well as of their combinations. The highest egg hatching inhibition was obtained with a 50/50 combination, and the best larvae mortality was obtained with 25% A. cina and 75% T. lucida at 10 mg/mL. Additionally, this combination showed a synergistic effect.ConclusionThe two plant species studied here can be applied as natural anthelmintic alternatives due to their high bioactive effect and synergistic response.

Characterization and Effect of a Nematophagous Fungus Talaromyces cystophila sp. nov. for the Biological Control of Corn Cyst Nematode.

The dynamic of plant-parasitic nematode populations in soil is closely related to soil microorganisms. Fungi from Heterodera zeae cysts were isolated to explore the phenomenon of decline in the H. zeae population in the soil. Phylogenetic study of partial ITS, BenA, CaM, and RPB2 gene sequences, in addition to morphological investigations, was utilized to identify a nematode-destroyingfungus. The nematicidal activity of a novel strain GX1 against H. zeae was assessed in vitro and in the greenhouse. Our findings revealed that strain GX1 is a new species of Talaromyces, named Talaromyces cystophila. It has a strong parasitic and lethal effect on H. zeae cysts, with 91.11% parasitism on cysts at 3 days after treatment. The contents of second-stage juveniles (J2s) and eggs inside the cysts were degraded and formed dense vacuoles, and the damaged eggs could not hatch normally. The spore suspension exhibited high nematophagous activity against nematodes, and fermentation filtrate exhibited marked inhibition of egg hatching and nematicidal activities on J2s. The hatching inhibition rates of eggs exposed to 1 × 108 CFU/ml spore suspensions or 20% 1-week fermentation filtrate (1-WF) for 15 days were 98.56 and 100%, respectively. The mortality of J2s exposed to 1 × 108 CFU/ml spore suspension reached 100% at 24 h; exposure to 50% 2-WF was 98.65 and 100% at 24 and 48 h, respectively. Greenhouse experiments revealed that the spore suspension and fermentation broth considerably decreased H. zeae reproduction by 56.17 to 78.76%. T. cystophila is a potential biocontrol strain with nematophagous and nematicidal activity that deserves attention and application.

Evaluation of some bio pesticidal plants in the management of Meloidogyne incognita

Utilization of compounds in extracts derived from medicinal plants is in vogue now for managing Meloidogyne incognita on crops owing to the unpopular use of synthetic nematicides especially in Sub-Saharan Africa. In this study, extracts from Azadirachta indica A. Juss and Hyptis suaveolens obtained using hexane, chloroform, ethyl acetate and methanol were tested for their efficacy in inhibiting egg hatching and inducing larval mortality of Meloidogyne incognita obtained from tomato bioassay maintained in Screenhouse. The extracts obtained from each solvent were reconstituted using Tween80+Dimethylsulfoxide (DMSO) and evaluated on hatching inhibition and larval mortality of Meloidogyne incognita at concentrations of 0.5%, 1.0%, and 1.5%. Furadan served as standard checks while distilled water and Tween80+(DMSO) as controls. Two separate experiments were conducted with 39 treatments each arranged in a Completely Randomized Design (CRD) with four repetitions on the laboratory bench for the hatching inhibition and larval mortality. Ninety (90) µL of each extract was added to 10 µL suspension containing either 15 eggs or second-stage larvae of Meloidogyne incognita pipette into cavity glass blocks. Hatching inhibition and larval mortality readings were recorded at 6, 12, 24, and 36 hours. Results indicated that Neem and Hyptis mixture at all concentrations extracted using any of the solvents gave 100% egg hatching inhibition from the 6th to the 36th h after treatment application. Only Neem and Hyptis mixture at 0.5% extracted in chloroform gave 100% larval mortality at the 6th h till the 36th h among the lowest concentration of the mixtures of the plant extracts. Combined solvent extracts of the two plants showed the highest activity in both hatching inhibition and larval mortality but individual solvent extracts showed the highest activity only at the highest rates used. The acute toxicity test of the most effective solvent extract of Neem and Hyptis at 0.5% extracted in Chloroform did not cause any sign of toxicity or death in the test animals.