{"id":"d0657034-0e50-59dc-85de-81c21e33e7c3","stable_key":"35ec55a7-323c-5c28-979e-3bdafe9d5769:rat-p450-null","predicate":"no_detected_change_in_recorded_experiment","statement":"The tested NADPH-supported rat microsomal P450 system did not detect anthocyanin hydroxylation or demethylation.","claim_class":"observational","status":"source_derived_draft","evidence_grade":"ungraded","direction":"neutral","is_public":true,"mechanism_event_id":"76a7ca7c-d212-57ee-b0f1-154d969a3ac8","mechanism_event_label":"The tested NADPH-supported rat microsomal P450 system did not detect anthocyanin hydroxylation or demethylation.","subject":{"id":"d698d44e-2dc6-52b3-b23e-61437e2ed2f1","slug":"anthocyanins-fecal-incubation-mixture","display_name":"Anthocyanin preparations tested in human fecal incubations","entity_type_key":"chemical_species"},"object":{"id":"a24cb43c-4faa-5192-9cac-897351c48a84","slug":"rat-microsomal-anthocyanin-p450-metabolism","display_name":"Anthocyanin hydroxylation and demethylation in the tested rat microsomal P450 assay","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"76a7ca7c-d212-57ee-b0f1-154d969a3ac8","stable_key":"35ec55a7-323c-5c28-979e-3bdafe9d5769:rat-p450-null-event","event_type":"experimental_observation","label":"The tested NADPH-supported rat microsomal P450 system did not detect anthocyanin hydroxylation or demethylation.","description":"**Microbial cleavage and host conjugation are distinct steps.** Anaerobic human fecal incubations degraded glycosylated and acylated anthocyanins to B-ring-derived phenolic acids. Separate rat-liver microsome experiments produced glucuronides when supplied with activated glucuronic acid; the tested NADPH-supported P450 system did not hydroxylate or demethylate the pigments. These are model-specific positive and negative findings, not proof that all human metabolism is exclusively microbial or that every CYP interaction is absent. [Keppler and Humpf, 2005](https://pubmed.ncbi.nlm.nih.gov/15834757/).","status":"provisional","compartment":null,"participants":[{"entity":{"id":"d698d44e-2dc6-52b3-b23e-61437e2ed2f1","slug":"anthocyanins-fecal-incubation-mixture","display_name":"Anthocyanin preparations tested in human fecal incubations","entity_type_key":"chemical_species"},"role":"tested factor","stoichiometry":null,"state_label":"Anthocyanins with NADPH-supported microsomal oxidation system","sequence_order":0,"notes":""},{"entity":{"id":"a24cb43c-4faa-5192-9cac-897351c48a84","slug":"rat-microsomal-anthocyanin-p450-metabolism","display_name":"Anthocyanin hydroxylation and demethylation in the tested rat microsomal P450 assay","entity_type_key":"cellular_process"},"role":"measured outcome","stoichiometry":null,"state_label":"no_detected_change","sequence_order":1,"notes":""},{"entity":{"id":"4aba2a5e-8d06-5304-bb01-c0402b225a94","slug":"nadph","display_name":"NADPH","entity_type_key":"small_molecule"},"role":"provided reducing cofactor","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary indexed abstract reviewed; full methods, figures, exact doses or endpoint-specific species assignments may remain unextracted.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_contrast","value_text":"{\"intervention\": \"Anthocyanins with NADPH-supported microsomal oxidation system\", \"comparator\": \"Assay baseline parent/product profile\", \"endpoint\": \"The tested NADPH-supported rat microsomal P450 system did not detect anthocyanin hydroxylation or demethylation.\", \"effect_direction\": \"no_detected_change\", \"combination\": \"single\", \"conditions\": []}","comparator":null,"unit":null,"notes":"Explicit extracted experimental comparison; source-derived draft.","entity":null},{"dimension":"experimental_model","value_text":"Rat liver microsomes; NADPH-supported phase-I assay.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"interpretation_status","value_text":"Source-derived extraction of a fact-checked reference; access is explicit, not independent raw-data verification.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"No detected metabolism in this assay; not absence of every CYP-mediated reaction or drug interaction.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"The tested NADPH-supported rat microsomal P450 system did not detect anthocyanin hydroxylation or demethylation.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Stability and biotransformation of various dietary anthocyanins in vitro. | 2006 | DOI 10.1007/s00394-005-0557-8 | PMID 15834757 | https://pubmed.ncbi.nlm.nih.gov/15834757/ | https://doi.org/10.1007/s00394-005-0557-8","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"source_locator","value_text":"Reviewed reference lines 44-44; exact primary location described in quoted passage where extracted.","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"06e939af-876e-5a63-b0c2-321f64e7f66e","evidence_kind":"source_excerpt","locator":"Lines 44-44","start_line":44,"end_line":44,"excerpt":"**Microbial cleavage and host conjugation are distinct steps.** Anaerobic human fecal incubations degraded glycosylated and acylated anthocyanins to B-ring-derived phenolic acids. Separate rat-liver microsome experiments produced glucuronides when supplied with activated glucuronic acid; the tested NADPH-supported P450 system did not hydroxylate or demethylate the pigments. These are model-specific positive and negative findings, not proof that all human metabolism is exclusively microbial or that every CYP interaction is absent. [Keppler and Humpf, 2005](https://pubmed.ncbi.nlm.nih.gov/15834757/).","model_system":"Rat liver microsomes; NADPH-supported phase-I assay.","directness":"reported_statement","verification_status":"source_derived_draft","notes":"Exact excerpt of the retained AI-assisted reviewed reference; primary sources are cited in primary_references and access scope is retained. Not a verbatim quotation from a primary paper.","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"b08e7f7d-4d34-56d7-a185-2124f8d72b3c","stable_key":"import-35ec55a7-323c-5c28-979e-3bdafe9d5769","title":"Anthocyanins: detailed mechanisms of action (reviewed 4 October 2026)","document_type":"imported_text","citation_label":"Original AI-assisted review of primary studies and, where relevant, official regulatory records. Access level is retained per claim. Corrections, null results and unresolved questions remain explicit. Not publisher full text or independent replication.","file_path":"","sha256":"7cff1a47fbd9c625412b84162b1c823004b4162b7c009f9a11d5807fb8e04ef9","revision_id":"1bd4fa42-bfeb-5148-8250-fc363d8c1de0","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}