A comparison of the individual and collective effects of four glucosinolate breakdown products from brussels sprouts on induction of detoxification enzymes.
Four glucosinolate derivatives were evaluated individually and as a mixture for their effects on hepatic P4501A (CYP1A), glutathione S-transferase (GST), quinone reductase (QR), glutathione reductase (G-Rd), and GSH levels. Doses of the derivatives were chosen to represent their relative abundance in Brussels sprouts. Adult male F344 rats received either corn oil (vehicle); one of the agents: indole-3-carbinol (I3C, 56 mg/kg), iberin (38 mg/kg), phenylethylisothiocyanate (PEITC, 0.1 mg/kg), or cyanohydroxybutene (crambene, 50 mg/kg); or all of the agents at the doses shown (as a mixture) given by gavage daily for 7 days. The mixture and I3C caused an 11- and 9.4-fold induction of CYP1A, respectively. Crambene and I3C each caused a 1.4-fold increase in GST, while the mixture caused a 2.5-fold increase. Crambene and I3C caused a 2.5- and 1.9-fold increase in QR, respectively. The mixture caused a 6.2-fold increase. Crambene, PEITC, and the mixture caused a 1.8-, 1.6-, and 2.0-fold increase in hepatic GSH levels, respectively. Crambene, I3C, iberin, and the mixture caused 1.3-, 1.4-, 1.2-, and 1.7-fold increases in G-Rd, respectively. In a second study the mixture was given at 60 and 20% of the original dose. CYP 1A, QR, G-Rd, and GST elevations were dose-dependent; GSH levels were not elevated. It is concluded that I3C and crambene are responsible for the majority of enzyme increases seen. A synergistic effect of I3C and crambene was evident on induction of GST and QR, but not on GSH, G-Rd, or P4501A.
Staack
R
R
Department of Veterinary Biosciences, University of Illinois, Urbana 61801, USA.
Kingston
S
S
Wallig
M A
MA
Jeffery
E H
EH
D000475:Alkenes / Q000494:pharmacology; D000818:Animals; D001937:Brassica; D019363:Cytochrome P-450 CYP1A1 / Q000096:biosynthesis; D004790:Enzyme Induction; D005961:Glucosinolates / Q000494:pharmacology*; D005980:Glutathione Reductase / Q000096:biosynthesis; D005982:Glutathione Transferase / Q000096:biosynthesis; D007211:Indoles / Q000494:pharmacology; D017879:Isothiocyanates / Q000494:pharmacology; D008099:Liver / Q000187:drug effects* / Q000201:enzymology; D008297:Male; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000096:biosynthesis; D009570:Nitriles / Q000494:pharmacology; D051381:Rats; D011916:Rats, Inbred F344
D000475:Alkenes; D005961:Glucosinolates; D007211:Indoles; D017879:Isothiocyanates; D009570:Nitriles; C055903:1-cyano-2-hydroxy-3-butene; C082585:iberin; C058305:phenethyl isothiocyanate; C016517:indole-3-carbinol; D019363:Cytochrome P-450 CYP1A1; D016660:NAD(P)H Dehydrogenase (Quinone); D005980:Glutathione Reductase; D005982:Glutathione Transferase