The purpose of the study was to determine effects of rutin dietary administration on the activity of xenobiotic-metabolizing enzymes and antioxidant status. The study has been carried out on 3 groups of male Wistar rats (n = 8 in each), with initial body weight 100-120 g. Animals of the control group (1st group) received standard semi-synthetic diet, the experimental groups--the same diet with rutin in the amount of 40 mg/kg b.w. (2nd group) or 400 mg/kg b.w. (3rd group). The duration of the experiment was 2 weeks. In rat liver the activity of quinone reductase (QR), heme oxygenase-1 (HO-1), paraoxonase-1 (PON-1), glutathione-S-transferase (GST), ethoxyresorufin-O-dealkylase (EROD) activity of CYP1A1, methoxyresorufin-O-dealkylase (MROD) activity of CYP1A2, tes- tosterone 6β-hydroxylase (6β-TG) activity of CYP3A, total antioxidant activity (AOA) and malondialdehyde (MDA) content have been investigated. The expression of genes CYP1A1, CYP1A2 and CYP3A has been measured by reverse transcription-polymerase chain reaction (RT-PCR). The stability of lysosome membranes was estimated by the change of unsedimentable activity of lysosomal enzymes--arylsulfatase, β-galactosidase and β-glucuronidase. Rutin administration led to dose-dependent increase in the activity of antioxidant enzymes. In rats of the 3rd group received high-rutin diet the activity of QR, HO-1, PON-1 and GST increased by 68, 29, 17 and 22%, respectively, compared to the control (1st group); MDA level and AOA have not changed. Activity of EROD and MROD in liver microsomes of rats treated with rutin at a dose of 40 mg/kg b.w. (2nd group) increased by 33 and 58%, respectively, with a moderate increase in mRNA level of CYP1A1 and CYP1A2. Increasing the dose of rutin up to 400 mg/kg b.w. (3rd group) resulted in the decrease of the degree of EROD and MROD activation by 18 and 15%, respectively, compared to the 2nd group. Rutin had no significant effect on the activity of 6β-TG and on the expression of CYP3A1 gene. Rutin dietary administration led to dose-dependent reduction of the unsedimentable activity of lysosomal enzymes, indicating the strengthening of the stability of lysosomal membranes. Thus, the obtained results showed that in healthy, intact rats high doses of rutin in the diet moderately but statistically significantly activate enzyme systems responsible for the protective and adaptive capacity of the organism.