Protein Information

Name cytochrome P450 (protein family or complex)
Synonyms cytochrome P450; cytochrome P 450; CYP450; CYP 450

Compound Information

Name ethoxyquin
CAS 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline

Reference List

PubMed Abstract RScore(About this table)
882982 Kahl R, Netter KJ: Ethoxyquin as an inducer and inhibitor of phenobarbital-type cytochrome P-450 in rat liver microsomes. Toxicol Appl Pharmacol. 1977 Jun;40(3):473-83.
81(1,1,1,1) Details
2730677 White IN, Legg RF, Manson MM, Wolf CR: Characteristics of rat hepatocytes sorted by fluorescence-activated flow cytometry. Biochem Pharmacol. 1989 May 15;38(10):1639-45.

In contrast, ethoxyquin caused enrichment of cytochrome P-450 in the hepatocytes in region 2.
8(0,0,1,3) Details
277136 Netter KJ, Kahl R, Elcombe CR: Significance of induction phenomena. Arch Toxicol Suppl. 1978;(1):85-99.

Recent studies with ethoxyquin (EQ) have shown that this antioxidant stimulates the formation of a form of cytochrome P 450 which resembles the phenobarbital-inducible type.
7(0,0,1,2) Details
7482539 Buetler TM, Gallagher EP, Wang C, Stahl DL, Hayes JD, Eaton DL: Induction of phase I and phase II drug-metabolizing enzyme mRNA, protein, and activity by BHA, ethoxyquin, and oltipraz. Toxicol Appl Pharmacol. 1995 Nov;135(1):45-57.

In this study, rats were treated with the monofunctional inducers tert-butylated hydroxyanisole, ethoxyquin, and oltipraz to study the inducibility of individual glutathione S-transferase isozymes, NADP (H):quinone oxidoreductase, gamma-glutamylcysteine synthetase, UDP-glucuronosyl transferase, and cytochrome P450 enzymes.
6(0,0,1,1) Details
6602752 Eisele TA, Sinnhuber RO, Nixon JE: Dietary antioxidant effects on the hepatic mixed-function oxidase system of rainbow trout (Salmo Gairdneri). Food Chem Toxicol. 1983 Jun;21(3):273-7.

Rainbow trout (Salmo gairdneri) were fed a control diet with or without an antioxidant--3,5-di-tert-butyl-4-hydroxytoluene (BHT), 2 (3)-tert-butyl-4-hydroxyanisole (BHA), mono-tert-butylhydroquinone (TBHQ) or ethoxyquin (EQ)--at a level of 5.56 mmol in 100 g oil/kg diet for 6 wk.
In comparison with trout fed control diet, microsomal protein content was lowered by 13% in TBQH-fed trout and elevated by 28% in EQ-fed trout, cytochrome P-450 content was 21% lower in BHA- and TBHQ-fed and 18% lower in EQ-fed trout and cytochrome b5 content was 46% lower in EQ-fed trout.
2(0,0,0,2) Details
12011477 Johnson DR, Klaassen CD: Regulation of rat multidrug resistance protein 2 by classes of prototypical microsomal enzyme inducers that activate distinct transcription pathways. Toxicol Sci. 2002 Jun;67(2):182-9.

Male Sprague-Dawley rats were treated with aryl hydrocarbon (Ah) receptor (AhR) ligands/cytochrome P450 (CYP) 1A inducers, constitutive androstane receptor (CAR) ligands/CYP2B inducers, pregnane-X receptor (PXR) ligands/CYP3A inducers, peroxisomal proliferator-activating receptor-alpha (PPARalpha) ligands/CYP4A inducers, antioxidant/electrophile response element (ARE/EpRE) ligands, CYP2E1 inducers, or control vehicle.
Mrp2 protein levels were significantly increased by all 3 PXR ligands/CYP3A inducers (pregnenolone-16alpha-carbonitrile [PCN], spironolactone [SP], and dexamethasone [DEX]) and by both ARE/EpRE ligands (ethoxyquin [EQ] and oltipraz [OPZ]).
1(0,0,0,1) Details
3969681 Rossing D, Kahl R, Hildebrandt AG: Effect of synthetic antioxidants on hydrogen peroxide formation, oxyferro cytochrome P-450 concentration and oxygen consumption in liver microsomes. Toxicology. 1985 Jan;34(1):67-77.

Butylated hydroxyanisole and ethoxyquin are more potent than propyl-, octyl-, and dodecyl gallate; butylated hydroxytoluene is only weakly active.
2(0,0,0,2) Details
2895690 Tsuda H, Moore MA, Asamoto M, Inoue T, Ito N, Satoh K, Ichihara A, Nakamura T, Amelizad Z, Oesch F: Effect of modifying agents on the phenotypic expression of cytochrome P-450, glutathione S-transferase molecular forms, microsomal epoxide hydrolase, glucose-6-phosphate dehydrogenase and gamma-glutamyltranspeptidase in rat liver preneoplastic lesions. Carcinogenesis. 1988 Apr;9(4):547-54.

2(0,0,0,2) Details
10746929 Bammler TK, Slone DH, Eaton DL: Effects of dietary oltipraz and ethoxyquin on aflatoxin B1 biotransformation in non-human primates. Toxicol Sci. 2000 Mar;54(1):30-41.

In addition, 10 microM oltipraz inhibited cytochrome P450-mediated activation of AFB to the ultimate carcinogenic metabolite, aflatoxin B1-8,9-epoxide, in vitro, up to 51%.
1(0,0,0,1) Details
6678746 Cha YN, Heine HS, Ansher S: Comparative effects of dietary administration of antioxidants and inducers on the activities of several hepatic enzymes in mice. Drug Nutr Interact. 1983;2(1):35-45.

Feeding mice with anticarcinogenic antioxidants, 2 (3)-tert-butyl-4-hydroxyanisole (BHA), ethoxyquin (EQ), disulfiram (DSF), and selenite (SE) resulted in selective changes in hepatic microsomal mixed function oxidases and in other enzymatic activities which were different from those obtained by feeding phenobarbital (PB), 3-methyl cholanthrene (MC), and Aroclor (ARO).
In addition, differential effects on cytochrome P-450, aminopyrine demethylase, and aniline hydroxylase were observed.
1(0,0,0,1) Details
494664 Wilson CG, Parke DV, Green J, Cawthorne MA: Inhibition of thiabendazole metabolism in the rat. Xenobiotica. 1979 Jun;9(6):343-51.


A single oral dose of ethoxyquin (200 mg/kg) to rats inhibited the hepatic microsomal hydroxylation of thiabendazole (65%), aniline (40%) and biphenyl (40%) in vitro at 1 h after dosage; inhibition was less at 5 h.
0(0,0,0,0) Details
2887284 Mandel HG, Manson MM, Judah DJ, Simpson JL, Green JA, Forrester LM, Wolf CR, Neal GE: Metabolic basis for the protective effect of the antioxidant ethoxyquin on aflatoxin B1 hepatocarcinogenesis in the rat. Cancer Res. 1987 Oct 1;47(19):5218-23.

0(0,0,0,0) Details