Hepatic drug-metabolising enzyme activity: molecular mechanisms & dependencies

How nutrients influence it

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Human evidence only

How nutrients reach it in more than one step

Chains of two or more recorded steps that end here, grouped by the nutrient they start from. Each step is a separate finding, so a chain is a route a mechanism could take, not proof that it does.

Tracing routes…

What it does

Every recorded relationship this component is part of, grouped by its role. Plain wording comes first; the technical statement follows.

Recorded relationships

What acts on it

Capsaicin interacted irreversibly with hepatic drug metabolizing enzymes, thereby inhibiting their activity as indicated by prolongation of pentobarbital sleeping time in rats, and such inhibition of drug metabolism was not observed with omega-hydroxycapsaicin; this arm of the study tested capsaicin rather than dihydrocapsaicin.
Capsaicin → Hepatic drug-metabolising enzyme activity source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/dihydrocapsaicin-research/8614248.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "7c4eee5bf34dac159665170e5eca63fcbf3a5146133b9d7dc0b6ec01bda4493a", "start_char": 0, "end_char": 1399, "text_sha256": "7c4eee5bf34dac159665170e5eca63fcbf3a5146133b9d7dc0b6ec01bda4493a"}
experimental_model
Incubation with phenobarbital-induced rat liver postmitochondrial supernatant, with rabbit urine confirmation and in vivo activity testing
exposure
Capsaicin, dihydrocapsaicin and nonivamide incubated with an NADPH-generating system, with pentobarbital sleeping time as a readout of enzyme inhibition
limitations
Identifies side-chain hydroxylation as a shared detoxification route and shows the products are inactive. The enzyme-inhibition arm tested capsaicin, not dihydrocapsaicin, which is recorded on that claim.
nutrient_topic
Dihydrocapsaicin research collection; topical membership is not evidence of a direct clinical effect, and dihydrocapsaicin is recorded separately from capsaicin. · Dihydrocapsaicin
organism
Rat
plain_language
The parent compound jams the liver’s drug-clearing machinery; its hydroxylated product does not.
primary_references
[dhc-p8614248] Metabolism of capsaicinoids: evidence for aliphatic hydroxylation and its pharmacological implications. (1995). https://pubmed.ncbi.nlm.nih.gov/8614248/ DOI: 10.1016/0024-3205(95)00091-7
tissue_or_cell_type
Liver
Dihydrocapsaicin: the second capsaicinoid, the hypothermia it is used to induce, what the gut and liver do to it, and what it does without TRPV1 (2026-09-21) · lines 543–554
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Incubation with phenobarbital-induced rat liver postmitochondrial supernatant, with rabbit urine confirmation and in vivo activity testing · source_derived_draft · unverified_draft
### dhc-capsaicin-inhibits-enzymes Capsaicin interacted irreversibly with hepatic drug metabolizing enzymes, thereby inhibiting their activity as indicated by prolongation of pentobarbital sleeping time in rats, and such inhibition of drug metabolism was not observed with omega-hydroxycapsaicin; this arm of the study tested capsaicin rather than dihydrocapsaicin. Condition category: normal nutrient_topic: Dihydrocapsaicin research collection; topical membership is not evidence of a direct clinical effect, and dihydrocapsaicin is recorded separately from capsaicin. plain_language: The parent compound jams the liver’s drug-clearing machinery; its hydroxylated product does not. organism: Rat tissue_or_cell_type: Liver experimental_model: Incubation with phenobarbital-induced rat liver postmitochondrial supernatant, with rabbit urine confirmation and in vivo activity testing limitations: Identifies side-chain hydroxylation as a shared detoxification route and shows the products are inactive. The enzyme-inhibition arm tested capsaicin, not dihydrocapsaicin, which is recorded on that claim. exposure: Capsaicin, dihydrocapsaicin and nonivamide incubated with an NADPH-generating system, with pentobarbital sleeping time as a readout of enzyme inhibition evidence_span: {"source_cache": "artifacts/dihydrocapsaicin-research/8614248.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "7c4eee5bf34dac159665170e5eca63fcbf3a5146133b9d7dc0b6ec01bda4493a", "start_char": 0, "end_char": 1399, "text_sha256": "7c4eee5bf34dac159665170e5eca63fcbf3a5146133b9d7dc0b6ec01bda4493a"} [dhc-p8614248] Metabolism of capsaicinoids: evidence for aliphatic hydroxylation and its pharmacological implications. (1995). https://pubmed.ncbi.nlm.nih.gov/8614248/ DOI: 10.1016/0024-3205(95)00091-7
Complete structured claim and evidence

Where it participates (unsigned role)

After two weeks of dihydrocapsaicin at 10 mg/kg/day the area under the plasma concentration-time curve for efavirenz increased from 8821 to 22347 micrograms per millilitre per hour, time to maximum plasma concentration increased from 2.50 to 3.50 hours and elimination half-life from 3.13 to 3.51 hours, while plasma clearance fell from 6.71 to 2.65 litres per hour per kilogram, and dihydrocapsaicin significantly inhibited the metabolism of efavirenz in rat liver microsomes; the authors conclude the dose should be monitored in patients on efavirenz maintenance therapy.
Dihydrocapsaicin → Plasma exposure to efavirenz measured as area under the curve source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/dihydrocapsaicin-research/41286578.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "9063b8f1265e2ca00078e7452f81fc480eea4995c88a595cfbd42d245e74f68e", "start_char": 0, "end_char": 1538, "text_sha256": "9063b8f1265e2ca00078e7452f81fc480eea4995c88a595cfbd42d245e74f68e"}
experimental_model
Twelve Sprague-Dawley rats pretreated for two weeks, with rat liver microsome experiments
exposure
Dihydrocapsaicin 10 mg/kg/day for two weeks before a single oral 56 mg/kg dose of efavirenz
limitations
A named drug interaction with both in vivo and in vitro arms. Twelve rats in two groups, and a rat liver microsome system rather than a human one.
nutrient_topic
Dihydrocapsaicin research collection; topical membership is not evidence of a direct clinical effect, and dihydrocapsaicin is recorded separately from capsaicin. · Dihydrocapsaicin
organism
Rat
plain_language
Two weeks of the compound left two and a half times as much of an HIV drug in the blood.
primary_references
[dhc-p41286578] Impact of Dihydrocapsaicin on the Metabolism of Efavirenz In Vitro and In Vivo. (2025). https://pubmed.ncbi.nlm.nih.gov/41286578/ DOI: 10.1002/prp2.70189
tissue_or_cell_type
Liver and plasma
Dihydrocapsaicin: the second capsaicinoid, the hypothermia it is used to induce, what the gut and liver do to it, and what it does without TRPV1 (2026-09-21) · lines 595–606
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Twelve Sprague-Dawley rats pretreated for two weeks, with rat liver microsome experiments · source_derived_draft · unverified_draft
### dhc-efavirenz-interaction After two weeks of dihydrocapsaicin at 10 mg/kg/day the area under the plasma concentration-time curve for efavirenz increased from 8821 to 22347 micrograms per millilitre per hour, time to maximum plasma concentration increased from 2.50 to 3.50 hours and elimination half-life from 3.13 to 3.51 hours, while plasma clearance fell from 6.71 to 2.65 litres per hour per kilogram, and dihydrocapsaicin significantly inhibited the metabolism of efavirenz in rat liver microsomes; the authors conclude the dose should be monitored in patients on efavirenz maintenance therapy. Condition category: normal nutrient_topic: Dihydrocapsaicin research collection; topical membership is not evidence of a direct clinical effect, and dihydrocapsaicin is recorded separately from capsaicin. plain_language: Two weeks of the compound left two and a half times as much of an HIV drug in the blood. organism: Rat tissue_or_cell_type: Liver and plasma experimental_model: Twelve Sprague-Dawley rats pretreated for two weeks, with rat liver microsome experiments limitations: A named drug interaction with both in vivo and in vitro arms. Twelve rats in two groups, and a rat liver microsome system rather than a human one. exposure: Dihydrocapsaicin 10 mg/kg/day for two weeks before a single oral 56 mg/kg dose of efavirenz evidence_span: {"source_cache": "artifacts/dihydrocapsaicin-research/41286578.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "9063b8f1265e2ca00078e7452f81fc480eea4995c88a595cfbd42d245e74f68e", "start_char": 0, "end_char": 1538, "text_sha256": "9063b8f1265e2ca00078e7452f81fc480eea4995c88a595cfbd42d245e74f68e"} [dhc-p41286578] Impact of Dihydrocapsaicin on the Metabolism of Efavirenz In Vitro and In Vivo. (2025). https://pubmed.ncbi.nlm.nih.gov/41286578/ DOI: 10.1002/prp2.70189
Complete structured claim and evidence

The events it takes part in

A mechanism often involves more than two components. These are the full events, with every participant and its role.

Situations it appears in

Low-supply and faulty-machinery situations recorded in the chapters where this component plays a part.

In the sources

Preserved passages that mention this component, quoted exactly. Open one to read it in context.

Open hypotheses

Proposed ideas that involve this component. They are labeled as hypotheses and do not change any recorded statement.

This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.

Hepatic drug-metabolising enzyme activity