scholarly journals In vitro comparative effect of extracts of the seeds of Embelia rowlandii (Myrsinaceae) on the eggs and L1 and L2 larval stages of the parasitic nematode Heligmosomoides bakeri (Nematoda; Heligmosomatidae)

2013 ◽  
Vol 12 (2) ◽  
pp. 205-211
Author(s):  
Payne ◽  
K V ◽  
Etung ◽  
N Kollins ◽  
Wabo ◽  
...  
Keyword(s):  
Parasitic Nematode ◽  
Comparative Effect ◽  
Larval Stages ◽  
Heligmosomoides Bakeri ◽  
L1 And L2

scholarly journals TheIn VitroEffects of Aqueous and Ethanolic Extracts of the Leaves ofAgeratum conyzoides(Asteraceae) on Three Life Cycle Stages of the Parasitic NematodeHeligmosomoides bakeri(Nematoda: Heligmosomatidae)

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
J. Wabo Poné ◽  
Olivia Fossi Tankoua ◽  
Jeannette Yondo ◽  
Marie Claire Komtangi ◽  
Mpoame Mbida ◽  
...  
Keyword(s):  
Ethanolic Extract ◽  
Larval Survival ◽  
Ageratum Conyzoides ◽  
Larval Stages ◽  
Life Cycle Stages ◽  
Ethanolic Extracts ◽  
Heligmosomoides Bakeri ◽  
Negative Controls ◽  
Dose Dependent

A comparativein vitrostudy was carried out to determine the ovicidal and larvicidal activity of aqueous and ethanolic extracts ofAgeratum conyzoides(Asteraceae) leaves on the eggs (unembryonated and embryonated), first and second larval stages ofHeligmosomoides bakeri. Four different concentrations (0.625, 1.25, 2.5, and 3.75 mg·mL−1) of both aqueous and ethanolic extracts were tested. Distilled water and 5% tween were used as negative controls in the bioassay. In fact, they did not affect development of eggs, hatching, and larval survival. The extract activities were dose dependent. The ethanolic extract was more potent against embryonation (39.6 ± 2.9%) than the aqueous extract (53.3 ± 10.9%) at the highest concentration (3.75 mg·ml−1). Both types of extracts killed larvae. Mebendazole proved more lethal (EC50of 0.745 and 0.323 mg·mL−1, resp., for L1and L2larvae). The aqueous extracts were the least lethal (EC50of 4.76 and 2.29 mg·mL−1, resp., for L1and L2larvae). The ethanolic extracts showed intermediate activity (EC50of 1.323 and 1.511 mg·mL−1, resp., for L1and L2larvae). It is concluded that the ovicidal and larvicidal properties of aqueous and ethanolic extracts ofAgeratum conyzoidesleaves are demonstrated in this work.

Efficacy of the cyclooctadepsipeptide PF1022A againstHeligmosomoides bakeri in vitroandin vivo

Parasitology ◽  
2011 ◽  
Vol 138 (9) ◽  
pp. 1193-1201 ◽  
Author(s):  
UZOMA NWOSU ◽  
MIREILLE VARGAS ◽  
ACHIM HARDER ◽  
JENNIFER KEISER
Keyword(s):  
Worm Burden ◽  
Anthelmintic Activity ◽  
Gastrointestinal Nematodes ◽  
Laboratory Model ◽  
Egg Hatch ◽  
Larval Stages ◽  
Nematocidal Activity ◽  
Heligmosomoides Bakeri

SUMMARYThe cyclooctadepsipeptide PF1022A derived from the fungus,Mycelia sterilia, is characterized by a broad spectrum of activity against different parasitic gastrointestinal nematodes of livestock. In the present work the anthelmintic activity of PF1022A againstHeligmosomoides bakeri, a widely used laboratory model was studied. Albendazole, ivermectin and levamisole served as reference.In vitro, PF1022A showed low activity on embryonation but significantly inhibited egg hatch (10 and 100μg/ml), whereas albendazole (10 and 100μg/ml) revealed statistically significant inhibitions of both embryonation and egg hatch. PF1022A (1–100μg/ml) completely inhibited larval movement at most examination points. Comparable significant anthelmintic activity on the larval stages ofH. bakeriwas observed with levamisole (48–100%), while slightly lower activities were observed with ivermectin (20–92%) and albendazole (0–87%) at 1–100μg/ml. PF1022A and levamisole significantly inhibited motility and egg release of adult worms, while albendazole and ivermectin failed to demonstrate activity. Significant worm burden reductions were achieved with PF1022A, levamisole and ivermectinin vivo. For example, at 0·125 mg/kg PF1022A a worm burden reduction of 91·8% was observed. The use of drug combinations did not further enhance thein vitroandin vivoactivity of PF1022A. In conclusion, further investigations are warranted with PF1022A, as the drug is characterized by significant larvicidal and nematocidal activityin vitroandin vivo.

The effect of catecholamines and catecholamine antagonists on the third larval moult of Dirofilaria immitis in vitro

1992 ◽  
Vol 66 (4) ◽  
pp. 273-278 ◽  
Author(s):  
E. V. Warbrick ◽  
S. A. Ward
Keyword(s):  
Dirofilaria Immitis ◽  
Parasitic Nematode ◽  
The Third ◽  
Adrenergic Antagonist ◽  
Third Stage ◽  
Larval Moult

ABSTRACTVarious catecholamines and catecholamine antagonists have been examined for their effects on the third larval moult of the parasitic nematode, Dirofilaria immitis, cultured in vitro. The non-selective α and β agonist, noradrenaline, and the β agonist, isoprenaline, had no effect on the timing of the third stage moult when used at a concentration of 10−5M. The α-adrenergic antagonist. phentolamine, resulted in worm mortality at 10−5M. At 10−7M, both phentolamine and the β-antagonist, propranolol caused a significant reduction in the numbers of larvae capable of completing the third stage moult. Idazoxan, an a2-antagonist, at 10−5M did not affect worm mortality but did completely prevent ecdysis. The potential of these compounds as possible filaricides is discussed.

Comparative Effect of the Calcium Antagonist Verapamil and the Synthetic Steroids Gestrinone and Danazol on Human Monocyte Phagocytosis in vitro

1997 ◽  
Vol 43 (1) ◽  
pp. 6-10 ◽  
Author(s):  
Barbara Magri ◽  
Paola Viganò ◽  
Gabriele Rossi ◽  
Edgardo Somigliana ◽  
Barbara Gaffuri ◽  
...  
Keyword(s):  
Calcium Antagonist ◽  
Human Monocyte ◽  
Comparative Effect ◽  
Synthetic Steroids

scholarly journals Synthesis , Spectroscopic and Antibacterial Studies of Zinc(II) Complexes Derived from Salicylaldehyde, Leucylalanine and Glycylglycine

2012 ◽  
Vol 9 (3) ◽  
pp. 532-540 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Schiff Base ◽  
Bacterial Species ◽  
Conductivity Measurement ◽  
Growth Inhibitor ◽  
Molar Conductance ◽  
Diffusion Method ◽  
Schiff Base Ligands ◽  
Elemental Analyses ◽  
L1 And L2

Two Schiff base ligands L1 and L2 have been obtained by condensation of salicylaldehyde respectively with leucylalanine and glycylglycine then their complexes with Zn(II)were prepared and characterized by elemental analyses , conductivity measurement , IR and UV-Vis .The molar conductance measurement indicated that the Zn(II) complexes are 1:1 non-electrolytes. The IR data demonstrated that the tetradentate binding of the ligands L1 and L2 . The in vitro biological screening effect of the investigated compounds have been tested against the bacterial species Staphlococcus aureus, Escherichia coil , Klebsiella pneumaniae, Proteus vulgaris and Pseudomonas aeruginosa by the disc diffusion method . A comparative study of inhibition values of the Schiff base ligands and their complexes indicated that the complexes exhibit higher antimicrobial activity than the free ligands . Zinc ions are proven to be essential for the growth-inhibitor effect. The extent of inhibition appeared to be strongly dependent on the initial cell density and on the growth medium .

scholarly journals Natural Compounds from the Marine Brown Alga Caulocystis cephalornithos with Potent In Vitro-Activity against the Parasitic Nematode Haemonchus contortus

Pathogens ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 550
Author(s):  
Aya C. Taki ◽  
Robert Brkljača ◽  
Tao Wang ◽  
Anson V. Koehler ◽  
Guangxu Ma ◽  
...  
Keyword(s):  
Haemonchus Contortus ◽  
Brown Alga ◽  
Parasitic Nematode ◽  
Anthelmintic Activity ◽  
Adult Males ◽  
Terrestrial Plants ◽  
Third Stage ◽  
Future Work ◽  
Marine Brown Alga

Eight secondary metabolites (1 to 8) were isolated from a marine sponge, a marine alga and three terrestrial plants collected in Australia and subsequently chemically characterised. Here, these natural product-derived compounds were screened for in vitro-anthelmintic activity against the larvae and adult stages of Haemonchus contortus (barber’s pole worm)—a highly pathogenic parasitic nematode of ruminants. Using an optimised, whole-organism screening system, compounds were tested on exsheathed third-stage larvae (xL3s) and fourth-stage larvae (L4s). Anthelmintic activity was initially evaluated on these stages based on the inhibition of motility, development and/or changes in morphology (phenotype). We identified two compounds, 6-undecylsalicylic acid (3) and 6-tridecylsalicylic acid (4) isolated from the marine brown alga, Caulocystis cephalornithos, with inhibitory effects on xL3 and L4 motility and larval development, and the induction of a “skinny-straight” phenotype. Subsequent testing showed that these two compounds had an acute nematocidal effect (within 1–12 h) on adult males and females of H. contortus. Ultrastructural analysis of adult worms treated with compound 4 revealed significant damage to subcuticular musculature and associated tissues and cellular organelles including mitochondria. In conclusion, the present study has discovered two algal compounds possessing acute anthelmintic effects and with potential for hit-to-lead progression. Future work should focus on undertaking a structure-activity relationship study and on elucidating the mode(s) of action of optimised compounds.

scholarly journals An integrative approach to the facile functional classification of dorsal root ganglion neuronal subclasses

2020 ◽  
Vol 117 (10) ◽  
pp. 5494-5501 ◽  
Author(s):  
Mario J. Giacobassi ◽  
Lee S. Leavitt ◽  
Shrinivasan Raghuraman ◽  
Rishi Alluri ◽  
Kevin Chase ◽  
...  
Keyword(s):  
Dorsal Root Ganglion ◽  
Single Cell ◽  
Genetic Markers ◽  
Dorsal Root ◽  
Large Diameter ◽  
Integrative Approach ◽  
K Channel ◽  
L1 And L2

Somatosensory neurons have historically been classified by a variety of approaches, including structural, anatomical, and genetic markers; electrophysiological properties; pharmacological sensitivities; and more recently, transcriptional profile differentiation. These methodologies, used separately, have yielded inconsistent classification schemes. Here, we describe phenotypic differences in response to pharmacological agents as measured by changes in cytosolic calcium concentration for the rapid classification of neurons in vitro; further analysis with genetic markers, whole-cell recordings, and single-cell transcriptomics validated these findings in a functional context. Using this general approach, which we refer to as tripartite constellation analysis (TCA), we focused on large-diameter dorsal-root ganglion (L-DRG) neurons with myelinated axons. Divergent responses to the K-channel antagonist, κM-conopeptide RIIIJ (RIIIJ), reliably identified six discrete functional cell classes. In two neuronal subclasses (L1 and L2), block with RIIIJ led to an increase in [Ca]i. Simultaneous electrophysiology and calcium imaging showed that the RIIIJ-elicited increase in [Ca]i corresponded to different patterns of action potentials (APs), a train of APs in L1 neurons, and sporadic firing in L2 neurons. Genetically labeled mice established that L1 neurons are proprioceptors. The single-cell transcriptomes of L1 and L2 neurons showed that L2 neurons are Aδ–low-threshold mechanoreceptors. RIIIJ effects were replicated by application of the Kv1.1 selective antagonist, Dendrotoxin-K, in several L-DRG subclasses (L1, L2, L3, and L5), suggesting the presence of functional Kv1.1/Kv1.2 heteromeric channels. Using this approach on other neuronal subclasses should ultimately accelerate the comprehensive classification and characterization of individual somatosensory neuronal subclasses within a mixed population.

scholarly journals Novel Production of Bovine Papillomavirus Pseudovirions in Tobacco Plants

Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 996
Author(s):  
Inge Pietersen ◽  
Albertha van Zyl ◽  
Edward Rybicki ◽  
Inga Hitzeroth
Keyword(s):  
Mammalian Cells ◽  
Bovine Papillomavirus ◽  
In Planta ◽  
Neutralising Antibodies ◽  
Native Virus ◽  
Cell Culture Systems ◽  
Virus Capsids ◽  
Plant Expression Systems ◽  
L1 And L2

Vaccine efficacy requires the production of neutralising antibodies which offer protection against the native virus. The current gold standard for determining the presence of neutralising antibodies is the pseudovirion-based neutralisation assay (PBNA). PBNAs utilise pseudovirions (PsVs), structures which mimic native virus capsids, but contain non-viral nucleic material. PsVs are currently produced in expensive cell culture systems, which limits their production, yet plant expression systems may offer cheaper, safer alternatives. Our aim was to determine whether plants could be used for the production of functional PsVs of bovine papillomavirus 1 (BPV1), an important causative agent of economically damaging bovine papillomas in cattle and equine sarcoids in horses and wild equids. BPV1 capsid proteins, L1 and L2, and a self-replicating reporter plasmid were transiently expressed in Nicotiana benthamiana to produce virus-like particles (VLPs) and PsVs. Strategies to enhance particle yields were investigated and optimised protocols were established. The PsVs’ ability to infect mammalian cells and express their encapsidated reporter genes in vitro was confirmed, and their functionality as reagents in PBNAs was demonstrated through their neutralisation by several different antibodies. This is the first report of BPV PsVs expressed in plants and demonstrates the potential for the development of therapeutic veterinary vaccines in planta.

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