0000000000267568
AUTHOR
M.-h Siess
Effect of onion consumption by rats on hepatic drug-metabolizing enzymes
Fruits and vegetables or their natural constituents which increase detoxication enzymes and/or reduce activating enzymes are considered as good candidates to prevent chemically-induced carcinogenesis. In this study, rats were fed a diet supplemented with 20% onion powder for 9 days. Several cytochrome P450 (CYP)s enzymes (CYP 1A, 2B, 2E1, 3A), which are involved in carcinogen activation, were determined by measuring their enzyme activities using specific substrates. In addition, phase II enzymes activities such as UDP-glucuronosyltransferase (UGT) and glutathione S-transferase (GST), involved in detoxication of carcinogens, were measured. Protein levels of CYPs and GST A1/A2, A3/A5, Ml, M2 …
Induction of cytochrome P450 and/or detoxication enzymes by various extracts or rosemary: description of specific patterns
The ability of rosemary to modulate cytochrome P450 (CYP) and detoxication enzymes in rat liver was evaluated by comparing the effects of dried leaves and leaf extracts with different chemical compositions: essential oil (EO) containing monoterpenes, a dichloromethane extract (DCME) containing phenolic diterpenes and a water-soluble extract (WSE) containing phenolic compounds such as rosmarinic acid and flavonoids. Chemical analyses were done in order to characterize the composition of extracts. Male Wistar rats received the leaves or extracts of rosemary in their diet at 0.5% (w/w) for 2 weeks. The effects of such treatments were evaluated for CYP (1A, 2B, 2E1), glutathione S-transferase (…
Effects of a water-soluble extract of rosemary and its purified component rosmarinic acid on xenobiotic-metabolizing enzymes in rat liver
The effects of a water-soluble extract (WSE) of rosemary and its purified antioxidant rosmarinic acid (RA) on xenobiotic metabolizing enzymes (XME) were studied in rat liver after dietary administration. The modulation of phase I enzymes such as cytochrome P450 (CYP) 1A, 2B, 2E1, 3A, and phase II enzymes such as glutathione S-transferase (GST), quinone reductase (QR) and UDP-glucuronosyltransferase (UGT) was evaluated by measuring enzyme activities with specific substrates. Protein levels of CYPs and rGST A1/A2, A3/A5, M1, M2 and P1 were measured using antibodies in Western blots. Caffeic acid was also studied because it results from RA biotransformation in rat after oral administration. Ma…