Activity of Xenobiotic-Metabolizing Enzymes in the Liver of Rats with Multi-Vitamin Deficiency

Abstract

The purpose of the study was to determine how multi-vitamin deficiency affects xenobiotic-metabolizing enzyme (XME) activities in the rat liver. Vitamin levels and XME activities were studied in the livers of male Wistar rats who were fed for 4 weeks with semi-synthetic diets containing either adequate (100 % of recommended vitamin intake) levels of vitamins (control), or decreased vitamin levels (50 % or 20 % of recommended vitamin intake). The study results have shown that moderate vitamin deficiency (50 %) leads to a decrease of vitamin A levels only, and to a slight increase, as compared with the control, in the following enzyme activities: methoxyresorufin O-dealkylase (MROD) activity of CYP1 A2 - by 34 % (p < 0.05), UDP-glucuronosyl transferase - by 26 % (p < 0.05), and quinone reductase - by 55 % (p < 0.05). Profound vitamin deficiency (20 %) led to a decrease of vitamins A, E, B1, B2, and C, and enzyme activities in the liver: MROD - to 78 % of the control level (p < 0.05), 4-nitrophenol hydroxylase - to 74 % (p < 0.05), heme oxygenase-1 - to 83 % (p < 0.05), and quinone reductase - to 60 % (p < 0.05). At the same time, the UDP-glucuronosyl transferase activity and ethoxyresorufin O-dealkylase activity of CYP1A1, pentoxyresorufin O-dealkylase activity of CYP2B1/2 and 6β-testosterone hydroxylase, as well as the total activity of glutathione transferase did not differ from the control levels. The study has demonstrated that profound multi-vitamin deficiency is associated with a decrease in the expression of CYP1A2 and CYP3A1 mRNAs to 62 % and 79 %, respectively. These data indicated that a short-term but profound multi-vitamin deficiency in rats leads to a decrease in the activities and expression of the some XME that play an important role in detoxification of xenobiotics and metabolism of drugs and antioxidant protection.

An assessment of molecular pathways of obesity susceptible to nutrient, toxicant and genetically induced epigenetic perturbation

“…Furthermore, nutrient availability can interfere with the levels of key enzymes required for toxicant metabolism. Such interactions influence metabolism required for toxicant inactivation and excretion [37–41] and metabolism required for toxicant activation, thus altering toxicity [42–44]. For example, Cytochrome p450 (Cyp450) enzymes have been shown to play critical roles in metabolizing POPs [35, 45].…”