Thiabendazole

Where it participates (unsigned role)

1. The relative potencies of the benzimidazole analogs in rat embryo micromass culture, nocodazole greater than mebendazole approximately equal to albendazole much greater than thiabendazole, mirrored their effectiveness in an assay for in vitro inhibition of mammalian tubulin polymerization, immunofluorescent staining with a monoclonal antibody to beta-tubulin revealed that these agents elicited mitotic arrest, and with the exception of thiabendazole these agents should be considered potential developmental toxicants since they inhibit cell growth and differentiation at nanomolar concentrations.

   Mebendazole → Differentiation of rat embryo midbrain and limb bud cells in micromass culture source_derived_draftungraded
   Experimental context and source evidence

   evidence_span

   {"source_cache": "artifacts/mebendazole-research/1553749.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "4c8ca680cbc4ebd8441d3d8c083a98587c81141280e9fa61388751264f1ea2ac", "start_char": 0, "end_char": 1384, "text_sha256": "4c8ca680cbc4ebd8441d3d8c083a98587c81141280e9fa61388751264f1ea2ac"}

   experimental_model

   Rat embryo midbrain and limb bud micromass cultures assessed for differentiation and cytotoxicity

   exposure

   Mebendazole, thiabendazole, nocodazole and colchicine, compared with albendazole

   limitations

   An in vitro developmental toxicity screen. It links the effect to the mammalian tubulin binding directly, by showing the potency order matches; it is not a pregnancy outcome.

   nutrient_topic

   Mebendazole research collection; topical membership is not evidence of a direct clinical effect, and mebendazole is recorded separately from albendazole, from the benzimidazole class and from its own crystal forms. · Mebendazole

   organism

   Rat

   plain_language

   The very property that makes it a cancer drug candidate is the property that makes it a suspected developmental toxin.

   primary_references

   [mbz-p1553749] Effects of benzimidazole analogs on cultures of differentiating rodent embryonic cells. (1992). https://pubmed.ncbi.nlm.nih.gov/1553749/ DOI: 10.1016/0041-008x(92)90019-o

   tissue_or_cell_type

   Embryonic midbrain and limb bud cells

   Mebendazole: the tubulin it binds, why that is selective, the crystal form that decides whether any of it works, and the off-target that became an oncology programme (2026-09-22) · lines 602–613

   AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Rat embryo midbrain and limb bud micromass cultures assessed for differentiation and cytotoxicity · source_derived_draft · unverified_draft

   ### mbz-developmental-toxicity-is-the-same-target The relative potencies of the benzimidazole analogs in rat embryo micromass culture, nocodazole greater than mebendazole approximately equal to albendazole much greater than thiabendazole, mirrored their effectiveness in an assay for in vitro inhibition of mammalian tubulin polymerization, immunofluorescent staining with a monoclonal antibody to beta-tubulin revealed that these agents elicited mitotic arrest, and with the exception of thiabendazole these agents should be considered potential developmental toxicants since they inhibit cell growth and differentiation at nanomolar concentrations. Condition category: normal nutrient_topic: Mebendazole research collection; topical membership is not evidence of a direct clinical effect, and mebendazole is recorded separately from albendazole, from the benzimidazole class and from its own crystal forms. plain_language: The very property that makes it a cancer drug candidate is the property that makes it a suspected developmental toxin. organism: Rat tissue_or_cell_type: Embryonic midbrain and limb bud cells experimental_model: Rat embryo midbrain and limb bud micromass cultures assessed for differentiation and cytotoxicity limitations: An in vitro developmental toxicity screen. It links the effect to the mammalian tubulin binding directly, by showing the potency order matches; it is not a pregnancy outcome. exposure: Mebendazole, thiabendazole, nocodazole and colchicine, compared with albendazole evidence_span: {"source_cache": "artifacts/mebendazole-research/1553749.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "4c8ca680cbc4ebd8441d3d8c083a98587c81141280e9fa61388751264f1ea2ac", "start_char": 0, "end_char": 1384, "text_sha256": "4c8ca680cbc4ebd8441d3d8c083a98587c81141280e9fa61388751264f1ea2ac"} [mbz-p1553749] Effects of benzimidazole analogs on cultures of differentiating rodent embryonic cells. (1992). https://pubmed.ncbi.nlm.nih.gov/1553749/ DOI: 10.1016/0041-008x(92)90019-o

   Complete structured claim and evidence

2. Colchicine and a range of anthelmintic benzimidazoles inhibited in vitro polymerisation of tubulin purified from Ascaridia galli more than that purified from mammalian tissue, with oxfendazole and thiabendazole having virtually no effect on mammalian tubulin assembly while both inhibited nematode tubulin, and electron microscopy revealed no morphological differences between microtubules polymerised with or without drug although their length and number were reduced.

   Mebendazole → Polymerisation of tubulin into microtubules source_derived_draftungraded
   Experimental context and source evidence

   evidence_span

   {"source_cache": "artifacts/mebendazole-research/6712717.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "dc6664076b62c0da221cce8e34690f297828b832da76857a2cc12cf9769fb282", "start_char": 0, "end_char": 949, "text_sha256": "dc6664076b62c0da221cce8e34690f297828b832da76857a2cc12cf9769fb282"}

   experimental_model

   In vitro polymerisation of tubulin purified from Ascaridia galli and from mammalian tissue, with electron microscopy

   exposure

   Colchicine and a range of anthelmintic benzimidazoles on both tubulins

   limitations

   Adds electron microscopy, which shows the drug reduces the number and length of microtubules without making abnormal ones. Purified protein rather than intact parasite.

   nutrient_topic

   Mebendazole research collection; topical membership is not evidence of a direct clinical effect, and mebendazole is recorded separately from albendazole, from the benzimidazole class and from its own crystal forms. · Mebendazole

   organism

   Nematode and mammal

   plain_language

   The microtubules that do form look normal; there are simply fewer and shorter ones.

   primary_references

   [mbz-p6712717] A comparison of the interaction of anthelmintic benzimidazoles with tubulin isolated from mammalian tissue and the parasitic nematode Ascaridia galli. (1984). https://pubmed.ncbi.nlm.nih.gov/6712717/ DOI: 10.1016/0006-2952(84)90515-x

   tissue_or_cell_type

   Purified tubulin

   Mebendazole: the tubulin it binds, why that is selective, the crystal form that decides whether any of it works, and the off-target that became an oncology programme (2026-09-22) · lines 173–184

   AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · In vitro polymerisation of tubulin purified from Ascaridia galli and from mammalian tissue, with electron microscopy · source_derived_draft · unverified_draft

   ### mbz-fewer-not-abnormal Colchicine and a range of anthelmintic benzimidazoles inhibited in vitro polymerisation of tubulin purified from Ascaridia galli more than that purified from mammalian tissue, with oxfendazole and thiabendazole having virtually no effect on mammalian tubulin assembly while both inhibited nematode tubulin, and electron microscopy revealed no morphological differences between microtubules polymerised with or without drug although their length and number were reduced. Condition category: normal nutrient_topic: Mebendazole research collection; topical membership is not evidence of a direct clinical effect, and mebendazole is recorded separately from albendazole, from the benzimidazole class and from its own crystal forms. plain_language: The microtubules that do form look normal; there are simply fewer and shorter ones. organism: Nematode and mammal tissue_or_cell_type: Purified tubulin experimental_model: In vitro polymerisation of tubulin purified from Ascaridia galli and from mammalian tissue, with electron microscopy limitations: Adds electron microscopy, which shows the drug reduces the number and length of microtubules without making abnormal ones. Purified protein rather than intact parasite. exposure: Colchicine and a range of anthelmintic benzimidazoles on both tubulins evidence_span: {"source_cache": "artifacts/mebendazole-research/6712717.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "dc6664076b62c0da221cce8e34690f297828b832da76857a2cc12cf9769fb282", "start_char": 0, "end_char": 949, "text_sha256": "dc6664076b62c0da221cce8e34690f297828b832da76857a2cc12cf9769fb282"} [mbz-p6712717] A comparison of the interaction of anthelmintic benzimidazoles with tubulin isolated from mammalian tissue and the parasitic nematode Ascaridia galli. (1984). https://pubmed.ncbi.nlm.nih.gov/6712717/ DOI: 10.1016/0006-2952(84)90515-x

   Complete structured claim and evidence

3. Fumarate reductase activity in a thiabendazole-resistant Haemonchus contortus strain was significantly lower than in a susceptible strain, but activity in a mebendazole-resistant strain did not differ from the susceptible strain even though it was cross-resistant to thiabendazole, and on reassessment two American strains resistant to thiabendazole and to cambendazole had activities indistinguishable from corresponding susceptible strains, so that benzimidazole resistance cannot be generally correlated with diminished fumarate reductase activity although it may be a contributory factor in the specific Australian thiabendazole-resistant strains.

   Fumarate reductase of Haemonchus contortus → Resistance to benzimidazole anthelmintics source_derived_draftungraded
   Experimental context and source evidence

   evidence_span

   {"source_cache": "artifacts/mebendazole-research/6877276.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "59837d0bc8f0d0c120dd9d647dcd86cd046545768ec6ab198e2262d381aafbf7", "start_char": 0, "end_char": 1052, "text_sha256": "59837d0bc8f0d0c120dd9d647dcd86cd046545768ec6ab198e2262d381aafbf7"}

   experimental_model

   Fumarate reductase activity compared across benzimidazole-susceptible and resistant Haemonchus contortus strains, with reassessment of published reports

   exposure

   Thiabendazole-resistant, mebendazole-resistant and susceptible strains

   limitations

   A proposed resistance mechanism tested across strains and largely rejected. The reassessment of other laboratories’ published values is the useful part.

   nutrient_topic

   Mebendazole research collection; topical membership is not evidence of a direct clinical effect, and mebendazole is recorded separately from albendazole, from the benzimidazole class and from its own crystal forms. · Mebendazole

   organism

   Nematode

   plain_language

   A once-popular explanation for resistance, checked across strains and found not to hold.

   primary_references

   [mbz-p6877276] Observations on the fumarate reductase system in Haemonchus contortus and their relevance to anthelmintic resistance and to strain variations of energy metabolism. (1983). https://pubmed.ncbi.nlm.nih.gov/6877276/ DOI: 10.1016/0166-6851(83)90011-7

   tissue_or_cell_type

   Mitochondrial electron transport

   Mebendazole: the tubulin it binds, why that is selective, the crystal form that decides whether any of it works, and the off-target that became an oncology programme (2026-09-22) · lines 329–340

   AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Fumarate reductase activity compared across benzimidazole-susceptible and resistant Haemonchus contortus strains, with reassessment of published reports · source_derived_draft · unverified_draft

   ### mbz-fumarate-reductase-retired Fumarate reductase activity in a thiabendazole-resistant Haemonchus contortus strain was significantly lower than in a susceptible strain, but activity in a mebendazole-resistant strain did not differ from the susceptible strain even though it was cross-resistant to thiabendazole, and on reassessment two American strains resistant to thiabendazole and to cambendazole had activities indistinguishable from corresponding susceptible strains, so that benzimidazole resistance cannot be generally correlated with diminished fumarate reductase activity although it may be a contributory factor in the specific Australian thiabendazole-resistant strains. Condition category: normal nutrient_topic: Mebendazole research collection; topical membership is not evidence of a direct clinical effect, and mebendazole is recorded separately from albendazole, from the benzimidazole class and from its own crystal forms. plain_language: A once-popular explanation for resistance, checked across strains and found not to hold. organism: Nematode tissue_or_cell_type: Mitochondrial electron transport experimental_model: Fumarate reductase activity compared across benzimidazole-susceptible and resistant Haemonchus contortus strains, with reassessment of published reports limitations: A proposed resistance mechanism tested across strains and largely rejected. The reassessment of other laboratories’ published values is the useful part. exposure: Thiabendazole-resistant, mebendazole-resistant and susceptible strains evidence_span: {"source_cache": "artifacts/mebendazole-research/6877276.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "59837d0bc8f0d0c120dd9d647dcd86cd046545768ec6ab198e2262d381aafbf7", "start_char": 0, "end_char": 1052, "text_sha256": "59837d0bc8f0d0c120dd9d647dcd86cd046545768ec6ab198e2262d381aafbf7"} [mbz-p6877276] Observations on the fumarate reductase system in Haemonchus contortus and their relevance to anthelmintic resistance and to strain variations of energy metabolism. (1983). https://pubmed.ncbi.nlm.nih.gov/6877276/ DOI: 10.1016/0166-6851(83)90011-7

   Complete structured claim and evidence

4. Of four benzimidazole anthelmintics tested on purified cytoplasmic and mitochondrial malate dehydrogenase from Ascaris suum, Fasciola hepatica and Moniezia expansa, mebendazole exhibited the highest percentage inhibitions, and the authors conclude that cytoplasmic and mitochondrial malate dehydrogenase regulating glycogen synthesis are the sites of mebendazole inhibitory activity while the sites for the other anthelmintics remain unclear.

   Mebendazole → Cytoplasmic and mitochondrial malate dehydrogenase of helminths source_derived_draftungraded
   Experimental context and source evidence

   evidence_span

   {"source_cache": "artifacts/mebendazole-research/3617430.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "addd86672cc2c829b72354c05387892908f94c49f81e1236e372432c68a622fe", "start_char": 0, "end_char": 589, "text_sha256": "addd86672cc2c829b72354c05387892908f94c49f81e1236e372432c68a622fe"}

   experimental_model

   Inhibition assays on purified cytoplasmic and mitochondrial malate dehydrogenase from three helminths

   exposure

   Albendazole, parbendazole, mebendazole and thiabendazole on purified enzyme extracts

   limitations

   A competing target claim. Enzyme inhibition percentages in purified extracts do not establish that this happens at therapeutic concentrations in a living parasite.

   nutrient_topic

   Mebendazole research collection; topical membership is not evidence of a direct clinical effect, and mebendazole is recorded separately from albendazole, from the benzimidazole class and from its own crystal forms. · Mebendazole

   organism

   Helminth

   plain_language

   A rival account: the drug jams an enzyme of the worm’s sugar metabolism, and mebendazole does it hardest.

   primary_references

   [mbz-p3617430] Inhibition of malate dehydrogenase enzymes by benzimidazole anthelmintics. (1987). https://pubmed.ncbi.nlm.nih.gov/3617430/ DOI: 10.1016/0304-4017(87)90048-3

   tissue_or_cell_type

   Ascaris suum, Fasciola hepatica and Moniezia expansa

   Mebendazole: the tubulin it binds, why that is selective, the crystal form that decides whether any of it works, and the off-target that became an oncology programme (2026-09-22) · lines 238–249

   AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Inhibition assays on purified cytoplasmic and mitochondrial malate dehydrogenase from three helminths · source_derived_draft · unverified_draft

   ### mbz-inhibits-malate-dehydrogenase Of four benzimidazole anthelmintics tested on purified cytoplasmic and mitochondrial malate dehydrogenase from Ascaris suum, Fasciola hepatica and Moniezia expansa, mebendazole exhibited the highest percentage inhibitions, and the authors conclude that cytoplasmic and mitochondrial malate dehydrogenase regulating glycogen synthesis are the sites of mebendazole inhibitory activity while the sites for the other anthelmintics remain unclear. Condition category: normal nutrient_topic: Mebendazole research collection; topical membership is not evidence of a direct clinical effect, and mebendazole is recorded separately from albendazole, from the benzimidazole class and from its own crystal forms. plain_language: A rival account: the drug jams an enzyme of the worm’s sugar metabolism, and mebendazole does it hardest. organism: Helminth tissue_or_cell_type: Ascaris suum, Fasciola hepatica and Moniezia expansa experimental_model: Inhibition assays on purified cytoplasmic and mitochondrial malate dehydrogenase from three helminths limitations: A competing target claim. Enzyme inhibition percentages in purified extracts do not establish that this happens at therapeutic concentrations in a living parasite. exposure: Albendazole, parbendazole, mebendazole and thiabendazole on purified enzyme extracts evidence_span: {"source_cache": "artifacts/mebendazole-research/3617430.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "addd86672cc2c829b72354c05387892908f94c49f81e1236e372432c68a622fe", "start_char": 0, "end_char": 589, "text_sha256": "addd86672cc2c829b72354c05387892908f94c49f81e1236e372432c68a622fe"} [mbz-p3617430] Inhibition of malate dehydrogenase enzymes by benzimidazole anthelmintics. (1987). https://pubmed.ncbi.nlm.nih.gov/3617430/ DOI: 10.1016/0304-4017(87)90048-3

   Complete structured claim and evidence

5. Median inhibitory concentrations for nocodazole, oxibendazole, parbendazole, mebendazole and fenbendazole against bovine brain tubulin polymerisation ranged from 1.97 x 10-6 to 6.32 x 10-6 molar, while benomyl, cambendazole and carbendazim had values from 5.83 x 10-5 to 9.01 x 10-5 molar and thiabendazole had a value of 5.49 x 10-4 molar.

   Mebendazole → Polymerisation of tubulin into microtubules source_derived_draftungraded
   Experimental context and source evidence

   evidence_span

   {"source_cache": "artifacts/mebendazole-research/728472.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "544c36409218c93ebff76d932a2bc6e14ccf7fd6e217d4614c4b561281c2555a", "start_char": 0, "end_char": 1025, "text_sha256": "544c36409218c93ebff76d932a2bc6e14ccf7fd6e217d4614c4b561281c2555a"}

   experimental_model

   Turbidimetric microtubule polymerisation assay and colchicine binding assay on purified bovine brain tubulin

   exposure

   Eleven benzimidazoles compared for inhibition of the initial rate of microtubule polymerisation

   limitations

   Purified mammalian tubulin, which is the off-target rather than the parasite target. It fixes where mebendazole sits in the class by potency.

   nutrient_topic

   Mebendazole research collection; topical membership is not evidence of a direct clinical effect, and mebendazole is recorded separately from albendazole, from the benzimidazole class and from its own crystal forms. · Mebendazole

   organism

   Cattle

   plain_language

   Mebendazole sits in the potent group; thiabendazole is about a hundred times weaker.

   primary_references

   [mbz-p728472] Interaction of anthelmintic benzimidazoles and benzimidazole derivatives with bovine brain tubulin. (1978). https://pubmed.ncbi.nlm.nih.gov/728472/ DOI: 10.1016/0304-4165(78)90334-3

   tissue_or_cell_type

   Brain tubulin

   Mebendazole: the tubulin it binds, why that is selective, the crystal form that decides whether any of it works, and the off-target that became an oncology programme (2026-09-22) · lines 82–93

   AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Turbidimetric microtubule polymerisation assay and colchicine binding assay on purified bovine brain tubulin · source_derived_draft · unverified_draft

   ### mbz-inhibits-polymerisation Median inhibitory concentrations for nocodazole, oxibendazole, parbendazole, mebendazole and fenbendazole against bovine brain tubulin polymerisation ranged from 1.97 x 10-6 to 6.32 x 10-6 molar, while benomyl, cambendazole and carbendazim had values from 5.83 x 10-5 to 9.01 x 10-5 molar and thiabendazole had a value of 5.49 x 10-4 molar. Condition category: normal nutrient_topic: Mebendazole research collection; topical membership is not evidence of a direct clinical effect, and mebendazole is recorded separately from albendazole, from the benzimidazole class and from its own crystal forms. plain_language: Mebendazole sits in the potent group; thiabendazole is about a hundred times weaker. organism: Cattle tissue_or_cell_type: Brain tubulin experimental_model: Turbidimetric microtubule polymerisation assay and colchicine binding assay on purified bovine brain tubulin limitations: Purified mammalian tubulin, which is the off-target rather than the parasite target. It fixes where mebendazole sits in the class by potency. exposure: Eleven benzimidazoles compared for inhibition of the initial rate of microtubule polymerisation evidence_span: {"source_cache": "artifacts/mebendazole-research/728472.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "544c36409218c93ebff76d932a2bc6e14ccf7fd6e217d4614c4b561281c2555a", "start_char": 0, "end_char": 1025, "text_sha256": "544c36409218c93ebff76d932a2bc6e14ccf7fd6e217d4614c4b561281c2555a"} [mbz-p728472] Interaction of anthelmintic benzimidazoles and benzimidazole derivatives with bovine brain tubulin. (1978). https://pubmed.ncbi.nlm.nih.gov/728472/ DOI: 10.1016/0304-4165(78)90334-3

   Complete structured claim and evidence

6. All Haemonchus contortus tub-1 constructs encoding phenylalanine at position 200 conferred susceptibility to thiabendazole in benzimidazole-resistant Caenorhabditis elegans ben-1 mutants, whereas constructs carrying tyrosine at position 200 did not alter the resistant phenotype, leading to the conclusion that the single phenylalanine to tyrosine mutation at position 200 in beta-tubulin isotype 1 is the cause of benzimidazole resistance in Haemonchus contortus.

   Beta-tubulin carrying tyrosine at position 200 → Resistance to benzimidazole anthelmintics source_derived_draftungraded
   Experimental context and source evidence

   availability_state

   machinery_impairment Imported condition classification; unverified.

   evidence_span

   {"source_cache": "artifacts/mebendazole-research/7877171.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "091ba3ac445b68112bac29dec56d0d1a48e0d258714ebdbe090b5e7728e6ceaa", "start_char": 0, "end_char": 1532, "text_sha256": "091ba3ac445b68112bac29dec56d0d1a48e0d258714ebdbe090b5e7728e6ceaa"}

   experimental_model

   Heterologous expression of Haemonchus contortus beta-tubulin alleles in Caenorhabditis elegans ben-1 mutants

   exposure

   Parasite benzimidazole-sensitive and resistant alleles and in vitro mutagenised constructs, assayed with benomyl and thiabendazole

   limitations

   A functional test rather than an association: the alleles were put into a resistant host and the phenotype followed the codon. The assay drugs were benomyl and thiabendazole rather than mebendazole.

   nutrient_topic

   Mebendazole research collection; topical membership is not evidence of a direct clinical effect, and mebendazole is recorded separately from albendazole, from the benzimidazole class and from its own crystal forms. · Mebendazole

   organism

   Nematode

   plain_language

   Swapping one amino acid back made resistant worms susceptible again, which makes it the cause and not a coincidence.

   primary_references

   [mbz-p7877171] Beta-tubulin genes from the parasitic nematode Haemonchus contortus modulate drug resistance in Caenorhabditis elegans. (1995). https://pubmed.ncbi.nlm.nih.gov/7877171/ DOI: 10.1006/jmbi.1994.0102

   tissue_or_cell_type

   Beta-tubulin isotype 1

   trigger_kind

   machinery_impairment Imported condition classification; unverified.

   Mebendazole: the tubulin it binds, why that is selective, the crystal form that decides whether any of it works, and the off-target that became an oncology programme (2026-09-22) · lines 264–275

   AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Heterologous expression of Haemonchus contortus beta-tubulin alleles in Caenorhabditis elegans ben-1 mutants · source_derived_draft · unverified_draft

   ### mbz-phe200-causes-resistance All Haemonchus contortus tub-1 constructs encoding phenylalanine at position 200 conferred susceptibility to thiabendazole in benzimidazole-resistant Caenorhabditis elegans ben-1 mutants, whereas constructs carrying tyrosine at position 200 did not alter the resistant phenotype, leading to the conclusion that the single phenylalanine to tyrosine mutation at position 200 in beta-tubulin isotype 1 is the cause of benzimidazole resistance in Haemonchus contortus. Condition category: machinery_impairment nutrient_topic: Mebendazole research collection; topical membership is not evidence of a direct clinical effect, and mebendazole is recorded separately from albendazole, from the benzimidazole class and from its own crystal forms. plain_language: Swapping one amino acid back made resistant worms susceptible again, which makes it the cause and not a coincidence. organism: Nematode tissue_or_cell_type: Beta-tubulin isotype 1 experimental_model: Heterologous expression of Haemonchus contortus beta-tubulin alleles in Caenorhabditis elegans ben-1 mutants limitations: A functional test rather than an association: the alleles were put into a resistant host and the phenotype followed the codon. The assay drugs were benomyl and thiabendazole rather than mebendazole. exposure: Parasite benzimidazole-sensitive and resistant alleles and in vitro mutagenised constructs, assayed with benomyl and thiabendazole evidence_span: {"source_cache": "artifacts/mebendazole-research/7877171.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "091ba3ac445b68112bac29dec56d0d1a48e0d258714ebdbe090b5e7728e6ceaa", "start_char": 0, "end_char": 1532, "text_sha256": "091ba3ac445b68112bac29dec56d0d1a48e0d258714ebdbe090b5e7728e6ceaa"} [mbz-p7877171] Beta-tubulin genes from the parasitic nematode Haemonchus contortus modulate drug resistance in Caenorhabditis elegans. (1995). https://pubmed.ncbi.nlm.nih.gov/7877171/ DOI: 10.1006/jmbi.1994.0102

   Complete structured claim and evidence