Name: helminth drugs and how they work
Uploaded: 2026-03-12T13:35:47.000Z
Duration: 1 min 15 s
Channel: JoVE

Les agents anthelmintiques sont des médicaments qui éliminent les helminthes parasites, ciblant souvent les formes adultes, bien que certains affectent les stades larvaire ou œuf.Par exemple, les médicaments pyrazinoisoquinoline, tels que le praziquantel, ciblent les cellules tegumentales protectrices du parasite.Le Praziquantel pénètre dans ces cellules et déclenche un afflux rapide d’ions calcium via les canaux ioniques.L’entrée soudaine de calcium entraîne une contraction musculaire soutenue. Finalement, le parasite devient paralysé dans l’état contracté.Cette perturbation rend le tegument poreux, exposant les surfaces internes et les antigènes internes au système immunitaire de l’hôte.Ces changements morphologiques affaiblissent les défenses du parasite, le rendant plus vulnérable aux attaques immunitaires.En conséquence, des modulateurs immunitaires, tels que les anticorps, peuvent agir sur les antigènes parasites exposés, renforçant ainsi la reconnaissance immunitaire de l’hôte.Cette réponse immunitaire agit en synergie avec le praziquantel, accélérant l’élimination du parasite.

anthelminthic agents

Anthelminthic Agents

Les agents anthelminthiques diff&#xE8;rent consid&#xE9;rablement des traitements antiparasitaires ciblant les protozoaires, principalement en raison des diff&#xE9;rences de biologie parasitaire. Alors que la plupart des traitements antiprotozoaires agissent sur des cellules en prolif&#xE9;ration, les anthelminthiques ciblent g&#xE9;n&#xE9;ralement des helminthes matures et non prolif&#xE9;rants. L&#x27;approche th&#xE9;rapeutique repose sur la d&#xE9;pendance des helminthes &#xE0; la coordination neuromusculaire, au m&#xE9;tabolisme du glucose et &#xE0; l&#x27;int&#xE9;grit&#xE9; des microtubules pour leur survie, leur reproduction et leur localisation au sein de l&#x27;h&#xF4;te. La plupart des anthelminthiques exploitent ces vuln&#xE9;rabilit&#xE9;s.
Benzimidazoles&#xA0;: Perturbation de la fonction des microtubules
Les benzimidazoles, tels que l&#x27;albendazole, le m&#xE9;bendazole, le thiabendazole et le triclabendazole, sont des agents &#xE0; large spectre qui inhibent la polym&#xE9;risation de la tubuline. Cette inhibition compromet la motilit&#xE9;, le m&#xE9;tabolisme &#xE9;nerg&#xE9;tique et la reproduction des parasites. Leur efficacit&#xE9; s&#x27;&#xE9;tend aux n&#xE9;matodes intestinaux (par exemple, Ascaris, Trichuris), aux cestodes (par exemple, Taenia, Echinococcus) et &#xE0; certaines douves (par exemple, Fasciola). L&#x27;albendazole est &#xE9;galement actif contre Giardia et constitue un &#xE9;l&#xE9;ment cl&#xE9; des strat&#xE9;gies de traitement de masse de la filariose.
Bloqueurs neuromusculaires : T&#xE9;trahydropyrimidines et pip&#xE9;razinesLe pamoate de pyrantel, une t&#xE9;trahydropyrimidine, induit la d&#xE9;polarisation des cellules musculaires des n&#xE9;matodes en activant les r&#xE9;cepteurs cholinergiques, entra&#xEE;nant une paralysie et une expulsion. La di&#xE9;thylcarbamazine (DEC), un d&#xE9;riv&#xE9; de la pip&#xE9;razine, immobilise les microfilaires par des m&#xE9;canismes encore mal d&#xE9;finis, notamment une alt&#xE9;ration du m&#xE9;tabolisme de l&#x27;acide arachidonique et une &#xE9;limination immunitaire accrue par l&#x27;h&#xF4;te. La DEC est essentielle dans le traitement de la filariose et est de plus en plus utilis&#xE9;e en sch&#xE9;mas &#xE0; dose unique.
Modulateurs des canaux ioniques et agonistes du calcium
L&#x27;ivermectine, une avermectine, cible les canaux chlorure, provoquant une hyperpolarisation et une paralysie. Elle est efficace contre les n&#xE9;matodes et les filaires intestinaux, et r&#xE9;duit notamment la charge microfilarienne dans l&#x27;onchocercose. Le praziquantel, une pyrazinoisoquinol&#xE9;ine, agit comme un agoniste du calcium, augmentant la concentration intracellulaire de Ca2+ chez les tr&#xE9;matodes et les cestodes, ce qui entra&#xEE;ne une contraction musculaire et une rupture du t&#xE9;gument, exposant ainsi les antig&#xE8;nes aux r&#xE9;ponses immunitaires de l&#x27;h&#xF4;te.
Perturbateurs mitochondriaux et agents secondaires
La niclosamide, un compos&#xE9; ph&#xE9;nolique, d&#xE9;couple la phosphorylation oxydative chez les cestodes, &#xE9;puisant ainsi les r&#xE9;serves d&#x27;ATP et immobilisant le parasite. D&#x27;autres agents secondaires, tels que l&#x27;oxamniquine, le m&#xE9;trifonate et la suramine, sont utilis&#xE9;s de mani&#xE8;re s&#xE9;lective pour des infections sp&#xE9;cifiques &#xE0; tr&#xE9;matodes et &#xE0; filaires.
Cette diversit&#xE9; cibl&#xE9;e des m&#xE9;canismes d&#x27;action souligne la complexit&#xE9; de la biologie des helminthes et met en &#xE9;vidence la n&#xE9;cessit&#xE9; de strat&#xE9;gies anthelminthiques adapt&#xE9;es.

Anthelmintic drugs differ significantly from antiparasitic therapies targeting protozoa, primarily due to differences in parasite biology. Whereas most ...

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helminth drugs and how they work

Helminth drugs work by attacking the weak points of parasitic worms. These anthelmintic medicines are different from drugs used against protozoa, because they are usually aimed at mature helminths rather than fast-dividing cells. They target the worm’s movement, glucose use, and microtubule structure to stop survival, reproduction, and location inside the host.

Benzimidazoles are broad-spectrum anthelmintics that block tubulin polymerization, which means they interfere with microtubules, the cell structures that help maintain shape and movement. Drugs in this group include albendazole, mebendazole, thiabendazole, and triclabendazole. By disrupting microtubule function, they reduce motility, energy metabolism, and reproduction in intestinal nematodes such as Ascaris and Trichuris, in cestodes such as Taenia and Echinococcus, and in some flukes such as Fasciola.

Albendazole also has activity against Giardia and is used in mass drug administration programs for filariasis. Other anthelmintics act on the worm’s nervous system and muscles. Pyrantel pamoate, a tetrahydropyrimidine, activates cholinergic receptors in nematode muscle cells and causes depolarization, which leads to paralysis and expulsion.

Diethylcarbamazine, or DEC, is a piperazine derivative that immobilizes microfilariae, the early blood stages of filarial worms. Its exact action is not fully defined, but it may involve altered arachidonic acid metabolism and better clearance by the host immune system. DEC is important in filariasis treatment and is increasingly given in single-dose regimens.

Ivermectin and praziquantel work through different mechanisms. Ivermectin, an avermectin, acts on chloride channels and causes hyperpolarization and paralysis, especially in intestinal nematodes and filariae, and it helps lower microfilarial loads in onchocerciasis. Praziquantel, a pyrazinoisoquinoline, acts as a calcium agonist in trematodes and cestodes, causing muscle contraction and damage to the tegument, the worm’s outer covering, which exposes antigens to host immune responses.

Niclosamide works in another way by uncoupling oxidative phosphorylation in cestodes, which drains ATP and immobilizes the parasite. Other selective agents, including oxamniquine, metrifonate, and suramin, are used for specific trematode and filarial infections. Together, these drug classes show how different helminths require tailored treatment strategies based on their biology.

Helminth Drugs and How They Work

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Helminth drugs work by attacking the weak points of parasitic worms. These anthelmintic medicines are different from drugs used against protozoa, because they are usually aimed at mature helminths rather than fast-dividing cells. They target the worm’s movement, glucose use, and microtubule structure to stop survival, reproduction, and location inside the host. Benzimidazoles are broad-spectrum anthelmintics that block tubulin polymerization, which means they interfere with microtubules, the...

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key terms and concepts

Learn how anthelmintic drugs treat helminths by targeting microtubules, muscle control, ion channels, calcium signals, and parasite energy use.

Helminth Drugs and How They Work | JoVE K12

JoVE Core Microbiology provides an engaging introduction to the microbial world and its influence on health, industry, and the environment. This comprehensive collection covers key concepts such as microbial structure, metabolism, genetics, and ecology. It introduces essential laboratory techniques and microscopy methods through visually engaging animations. Corresponding scientist-in-action videos bridge classroom concepts with real-world research and applications.

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Helminth Drugs and How They Work

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