{"id":"85f6ffba-6880-578e-b960-f0a2e0ca9b79","stable_key":"548ab9d6-3a9b-5bed-879c-17d03813b636:b2-deficiency-methemoglobin","predicate":"marginal_deficiency_associated_with_more_methemoglobin","statement":"Methemoglobin was higher in erythrocytes from the marginally B2-deficient group; the other tested endpoints did not all differ from controls.","claim_class":"observational","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"9b47d866-40a3-57e1-9b60-2c6551574cbc","mechanism_event_label":"The study found a specific hemoglobin oxidation change, not failure of every antioxidant measure.","subject":{"id":"86eb1eee-a8d1-539c-8c17-0911f69b6f1b","slug":"riboflavin","display_name":"Riboflavin (vitamin B2)","entity_type_key":"small_molecule"},"object":{"id":"57bfadb3-ebb2-5856-a5a0-f5f6bd034598","slug":"erythrocyte-methemoglobin-concentration","display_name":"Erythrocyte methemoglobin concentration","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"9b47d866-40a3-57e1-9b60-2c6551574cbc","stable_key":"548ab9d6-3a9b-5bed-879c-17d03813b636:b2-deficiency-methemoglobin-event","event_type":"observed_intervention","label":"The study found a specific hemoglobin oxidation change, not failure of every antioxidant measure.","description":"Methemoglobin was higher in erythrocytes from the marginally B2-deficient group; the other tested endpoints did not all differ from controls.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"ae04c12f-c0ac-5c8d-9ee2-76e58156d105","slug":"gsr","display_name":"Glutathione reductase / GSR","entity_type_key":"protein"},"role":"associated_enzyme","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"86eb1eee-a8d1-539c-8c17-0911f69b6f1b","slug":"riboflavin","display_name":"Riboflavin (vitamin B2)","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"57bfadb3-ebb2-5856-a5a0-f5f6bd034598","slug":"erythrocyte-methemoglobin-concentration","display_name":"Erythrocyte methemoglobin concentration","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"availability_state","value_text":"nutrient_deficiency","comparator":null,"unit":null,"notes":"Imported condition classification; 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unverified.","entity":null}],"evidence":[{"id":"c3992b36-3e92-5af6-a219-b63b2a40f06b","evidence_kind":"source_excerpt","locator":"Lines 1705-1715","start_line":1705,"end_line":1715,"excerpt":"### b2-deficiency-methemoglobin\nMethemoglobin was higher in erythrocytes from the marginally B2-deficient group; the other tested endpoints did not all differ from controls.\nCondition category: nutrient_deficiency\nnutrient_topic: Riboflavin research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: The study found a specific hemoglobin oxidation change, not failure of every antioxidant measure.\norganism: Homo sapiens\ntissue_or_cell_type: Human clinical setting\nexperimental_model: Erythrocytes from marginally riboflavin-deficient people and controls separated into nine density fractions.\nlimitations: Does not identify a single responsible reductase or prove clinically significant anemia/hemolysis in each person.\nexposure: Red-cell age-fraction enzyme/cofactor assays, glutathione, hemoglobin species and peroxide susceptibility; observational comparison.\n[b2-powers1981] Riboflavin deficiency in man: effects on haemoglobin and reduced glutathione in erythrocytes of different ages (1981). https://pubmed.ncbi.nlm.nih.gov/7284295/ DOI: 10.1079/bjn19810031","model_system":"Erythrocytes from marginally riboflavin-deficient people and controls separated into nine density fractions.","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. 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