Metanil yellow: a bifunctional inducer of hepatic phase I and phase II xenobiotic-metabolizing enzymes

• Published in: Food and chemical toxicology Vol. 35; no. 8; pp. 835 - 838
• Main Authors: Das, M., Ramchandani, S., Upreti, R.K., Khanna, S.K.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.08.1997; New York, NY Elsevier Science
• Subjects: Administration, Oral; Animals; aryl hydrocarbon hydroxylase; Azo Compounds - toxicity; Biological and medical sciences; cytochrome P-450; Cytochrome P-450 Enzyme System - biosynthesis; Domestic and cosmetic products toxicology; enzyme activity; Enzyme Induction; ethoxyresorufin-o-deethylase; food coloring; Food Coloring Agents - toxicity; glutathione transferase; Glutathione Transferase - biosynthesis; Injections, Intraperitoneal; intraperitoneal injection; isozymes; liver; Liver - drug effects; Liver - enzymology; Male; Medical sciences; microsomes; Microsomes, Liver - drug effects; Microsomes, Liver - enzymology; NAD(P)H Dehydrogenase (Quinone) - biosynthesis; oral administration; oxidoreductases; oxygenases; quinone reductase; Rats; Rats, Wistar; stimulation; Toxicology; unspecific monooxygenase; Asia; India; AHH; BSA; QR; PB; SDS; APD; AH; 3-MC; GST; CDNB; LD 50; P-450; Enzyme inducer; Dyes; Rat; Enzyme; Toxicity; Cytochrome P450; Liver; Rodentia; Food additive; Microsome; Vertebrata; Mammalia; Animal; Domestic product; Drug-metabolizing enzyme
• ISSN: 0278-6915; 1873-6351
• DOI: 10.1016/S0278-6915(97)00047-1

Metanil yellow, a non-permitted food colour, has been found in various foodstuffs. The induction potential of metanil yellow on hepatic microsomal cytochrome P-450 ( P-450)-dependent mono-oxygenases and cytosolic detoxification enzymes, namely, glutathione S-transferase (GST) and quinone reductase (QR), was investigated. Oral administration of metanil yellow (430 mg/kg body weight) to four animals for seven days caused significant induction of hepatic P-450 (48%) and its dependent aryl hydrocarbon hydroxylase (100%) activity and cytosolic GST (136%) and QR (92%) activities. Parenteral administration of metanil yellow (80 mg/kg body weight) to another set of four animals for 3 days resulted in higher induction of ethoxyresorufin-O-deethylase (228%) as compared to other monooxygenases (64–92%), while GST and QR were also found to be induced (59–95%). Spectra of metanil yellow-induced microsomes showed an increase in P-450 with a shift of 2.2 nm in the soret region. The results suggest that metanil yellow acts as a bifunctional inducer of specific isozymes of P-450 and cytosolic enzymes and thus may involve the cytosolic aryl hydrocarbon (Ah) receptor for this type of induction.