{"id":"0a7beb85-c088-5d57-a921-7aed64aa8e03","stable_key":"e0ea2d6a-7429-5e9f-b774-41e5e3288da3:e-sig-gamma-human-cox1","predicate":"inhibits","statement":"Gamma-tocopherol inhibited human recombinant COX-1 in a prostaglandin-product assay, with the tested non-alpha vitamin E forms showing IC50 values of 1–2.5 µM. 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Parent vitamin E forms did not significantly inhibit COX-2 in the same system.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"39f9446f-52a6-502d-b507-91137726f82c","slug":"arachidonic-acid","display_name":"AA","entity_type_key":"small_molecule"},"role":"substrate","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"2de3a4d0-56b1-57f9-9e9d-934ba52a1753","slug":"gamma-tocopherol","display_name":"Gamma-tocopherol","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"6284d26c-01e2-5e12-b192-ee391dd107e2","slug":"ptgs1","display_name":"Cyclooxygenase-1 (PTGS1)","entity_type_key":"protein"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"false","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Recombinant human COX enzyme assay; PGF2alpha readout after chemical reduction","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"10 min compound preincubation; arachidonic acid 5 µM for 2 min; stannous chloride converted PG intermediates to PGF2alpha for ELISA.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"This assay differs from older ovine COX-1/oxygen-electrode work; species and substrate differences preclude labeling every potency discrepancy as a contradiction.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Vitamin E research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"vitamin-e","display_name":"Vitamin E","entity_type_key":"chemical_species"}},{"dimension":"organism","value_text":"Homo sapiens","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Gamma-tocopherol reduced activity of purified human COX-1 under these assay conditions.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[park2022] Different forms of vitamin E and metabolite 13'-carboxychromanols inhibit cyclooxygenase-1 and its catalyzed thromboxane in platelets, and tocotrienols and 13'-carboxychromanols are competitive inhibitors of 5-lipoxygenase. (2022). https://pubmed.ncbi.nlm.nih.gov/34710615/ DOI: 10.1016/j.jnutbio.2021.108884","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Cell-free enzyme","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"157a0a8e-b3b4-5808-9b11-06ade80095f1","evidence_kind":"source_excerpt","locator":"Lines 1089-1100","start_line":1089,"end_line":1100,"excerpt":"### e-sig-gamma-human-cox1\nGamma-tocopherol inhibited human recombinant COX-1 in a prostaglandin-product assay, with the tested non-alpha vitamin E forms showing IC50 values of 1–2.5 µM. Parent vitamin E forms did not significantly inhibit COX-2 in the same system.\nCondition category: normal\nnutrient_topic: Vitamin E research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Gamma-tocopherol reduced activity of purified human COX-1 under these assay conditions.\norganism: Homo sapiens\ntissue_or_cell_type: Cell-free enzyme\nexperimental_model: Recombinant human COX enzyme assay; PGF2alpha readout after chemical reduction\nlimitations: This assay differs from older ovine COX-1/oxygen-electrode work; species and substrate differences preclude labeling every potency discrepancy as a contradiction.\nexposure: 10 min compound preincubation; arachidonic acid 5 µM for 2 min; stannous chloride converted PG intermediates to PGF2alpha for ELISA.\ncross_nutrient: false\n[park2022] Different forms of vitamin E and metabolite 13'-carboxychromanols inhibit cyclooxygenase-1 and its catalyzed thromboxane in platelets, and tocotrienols and 13'-carboxychromanols are competitive inhibitors of 5-lipoxygenase. 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