Nocodazole

Where it participates (unsigned role)

1. 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

2. Changing Saccharomyces cerevisiae beta-tubulin residue phenylalanine 167 to tyrosine produced at least 3 to 4 fold decreased sensitivity to carbendazim and nocodazole and the mutant was cold sensitive, implying a direct effect on benzimidazole binding rather than a nonspecific increase in microtubule stability, but surprisingly the mutant had 8 fold increased sensitivity to benomyl, which is structurally identical to carbendazim except at position 1, suggesting that residue 167 interacts with benzimidazoles in the vicinity of the 1 position.

   Beta-tubulin carrying tyrosine at position 167 → 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/8641470.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "35145959fc480be6039e088de374d7549dddc6f298511a41d2a760e7fdb8f455", "start_char": 0, "end_char": 917, "text_sha256": "35145959fc480be6039e088de374d7549dddc6f298511a41d2a760e7fdb8f455"}

   experimental_model

   Site-directed mutagenesis and gene replacement of Saccharomyces cerevisiae beta-tubulin residue 167

   exposure

   Phenylalanine 167 changed to tyrosine, then tested against carbendazim, nocodazole and benomyl

   limitations

   A clean genetic test in a tractable organism, and the cold sensitivity argues the effect is on binding rather than on general microtubule stability. Yeast beta-tubulin is not nematode beta-tubulin.

   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

   Yeast

   plain_language

   The same mutation that resists one compound makes the organism more vulnerable to its near twin.

   primary_references

   [mbz-p8641470] Site-directed mutagenesis of Saccharomyces cerevisiae beta-tubulin: interaction between residue 167 and benzimidazole compounds. (1996). https://pubmed.ncbi.nlm.nih.gov/8641470/ DOI: 10.1016/0014-5793(96)00334-1

   tissue_or_cell_type

   Beta-tubulin

   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 303–314

   AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Site-directed mutagenesis and gene replacement of Saccharomyces cerevisiae beta-tubulin residue 167 · source_derived_draft · unverified_draft

   ### mbz-tyr167-and-negative-effect Changing Saccharomyces cerevisiae beta-tubulin residue phenylalanine 167 to tyrosine produced at least 3 to 4 fold decreased sensitivity to carbendazim and nocodazole and the mutant was cold sensitive, implying a direct effect on benzimidazole binding rather than a nonspecific increase in microtubule stability, but surprisingly the mutant had 8 fold increased sensitivity to benomyl, which is structurally identical to carbendazim except at position 1, suggesting that residue 167 interacts with benzimidazoles in the vicinity of the 1 position. 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: The same mutation that resists one compound makes the organism more vulnerable to its near twin. organism: Yeast tissue_or_cell_type: Beta-tubulin experimental_model: Site-directed mutagenesis and gene replacement of Saccharomyces cerevisiae beta-tubulin residue 167 limitations: A clean genetic test in a tractable organism, and the cold sensitivity argues the effect is on binding rather than on general microtubule stability. Yeast beta-tubulin is not nematode beta-tubulin. exposure: Phenylalanine 167 changed to tyrosine, then tested against carbendazim, nocodazole and benomyl evidence_span: {"source_cache": "artifacts/mebendazole-research/8641470.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "35145959fc480be6039e088de374d7549dddc6f298511a41d2a760e7fdb8f455", "start_char": 0, "end_char": 917, "text_sha256": "35145959fc480be6039e088de374d7549dddc6f298511a41d2a760e7fdb8f455"} [mbz-p8641470] Site-directed mutagenesis of Saccharomyces cerevisiae beta-tubulin: interaction between residue 167 and benzimidazole compounds. (1996). https://pubmed.ncbi.nlm.nih.gov/8641470/ DOI: 10.1016/0014-5793(96)00334-1

   Complete structured claim and evidence