Search results for "FLAVONOIDS"
showing 10 items of 213 documents
Polyphenol intake and cardiovascular risk factors in a population with type 2 diabetes: The TOSCA.IT study
2017
Background: The role of polyphenol intake on cardiovascular risk factors is little explored, particularly in people with diabetes. Aim: To evaluate the association between the intake of total polyphenols and polyphenol classes with the major cardiovascular risk factors in a population with type 2 diabetes. Methods: Dietary habits were investigated in 2573 males and females participants of the TOSCA.IT study. The European Prospective Investigation on Cancer and Nutrition (EPIC) questionnaire was used to assess dietary habits. In all participants, among others, we assessed anthropometry, plasma lipids, blood pressure, C-reactive protein and HbA1c following a standard protocol. The USDA and Ph…
Direct and indirect measurements of enhanced phenolic bioavailability from litchi pericarp procyanidins by Lactobacillus casei-01
2017
Litchi pericarp procyanidins (LPP) are dietary supplements with high antioxidant activity, but poor oral bioavailability and efficacy. Lactobacillus casei (L. casei-01) can transform flavan-3-ols from litchi pericarp and increase their antioxidant ability; thus, L. casei-01 with LPP was administered to rats for four and eight weeks to study the effect of such a combination on metabolic parameters and on phase II metabolism and detoxification pathways in the liver as an indirect measure for phenolic bioavailability. Our data indicated that the T-AOC of the plasma, the liver GSH-Px and GSH-ST activity, and the expression of UGT and SULT isoforms in the liver of the rats were all enhanced afte…
Mechanisms involved in the chemoprevention of flavonoids
2001
Flavonoids, widespread in edible plants, have been studied extensively for their anticarcinogenic properties. However, only few studies have been done with these constituents being administered by the dietary route. In our research, the effects of feeding rats with flavone, flavanone, tangeretin, and quercetin were investigated on two steps of aflatoxin B1 (AFB1)-induced hepatocarcinogenesis (initiation and promotion). Nonpolar flavonoids such as flavone, flavanone and tangeretin administered through the initiation period, decreased the number of -gamma-glutamyl transpeptidase-preneoplastic foci. In the same conditions of administration, quercetin, a polyhydroxylated flavonoid, showed no pr…
Antioxidant Profile of Mono-and Dihydroxylated Flavone Derivatives in Free Radical Generating Systems
1995
Abstract A number of free radical generating systems were used to investigate the antioxidant properties and structure-activity relationships of a series of monohydroxylated and dihydroxylated flavones. Ortho-dihydroxylated flavones showed the highest inhibitory activity on en zymic and non-enzymic microsomal lipid peroxidation as well as on peroxyl radical scavenging. Most flavones were weak scavengers of hydroxyl radical, while ortho-dihydroxylated flavones interacted with superoxide anion generated by an enzymic system or by human neutrophils. This series of compounds did not exert cytotoxic effects on these cells. Scavenging of superoxide and peroxyl radicals may determ ine the anti…
Effects of a water-soluble extract of rosemary and its purified component rosmarinic acid on xenobiotic-metabolizing enzymes in rat liver
2001
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…
Hepatoprotective and anti-inflammatory effects of total flavonoids of Qu Zhi Ke (peel of Citrus changshan-huyou) on non-alcoholic fatty liver disease…
2019
Abstract Background Citrus flavonoids, consisting of naringin, narirutin, neohesperidine, etc., have therapeutic activities for the treatment of lipometabolic disorders. The peel of Citrus changshan-huyou (Qu Zhi Ke, QZK) is a new source of flavonoids, but attracted little attention so far. Hypothesis QZK should possess therapeutic effects against lipometabolic disorders due to the flavonoids it contains. Study design In this study, we extracted and purified the flavonoids of QZK (TFCH) and established an obesity-induced non-alcoholic fatty liver disease (NAFLD) model of rats. TFCH was given orally for 8 weeks, and its anti-NAFLD effects and potential mechanism were evaluated. Methods The f…
The inhibition by flavonoids of 2-amino-3-methylimidazo[4,5-f]quinoline metabolic activation to a mutagen: a structure-activity relationship study.
1997
The mutagenicity of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) in Salmonella typhimurium TA98 is inhibited by flavonoids with distinct structure-antimutagenicity relationships (Edenharder, R., I. von Petersdorff I. and R. Rauscher (1993). Antimutagenic effects of flavonoids, chalcones and structurally related compounds on the activity of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) and other heterocyclic amine mutagens from cooked food, Mutation Res., 287, 261-274). With respect to the mechanism(s) of antimutagenicity, the following results were obtained here. (1) 7-Methoxy- and 7-ethoxyresorufin-O-dealkylase activities in rat liver microsomes, linked to cytochrome P-450-dependent 1A1 and…
Differential Effects of Nonhydroxylated Flavonoids as Inducers of Cytochrome P450 1A and 2B Isozymes in Rat Liver
1996
Flavanone, flavone, and tangeretin differentially affected the activities of cytochrome P540 1A and 2B isozymes in rat liver. Flavone and, to a lesser extent, tangeretin, increased activities of ethoxyresorufin O-deethylase, methoxyresorufin O-demethylase, and pentoxyresorufin O-dealkylase (PROD), whereas flavanone mainly enhanced PROD activity. Immunoblot analysis indicated that flavone and tangeretin increased cytochrome P450 1A1, 1A2, and 2B1,2 forms, whereas flavanone only enhanced the cytochrome P450 2B isozymes. Northern blot study showed that flavone and tangeretin increased the level of the cytochrome P450 1A2 mRNAs. The concentration of the other mRNAs were slightly or not affected…
Metabolism of apigenin by rat liver phase I and phase II enzymes and by isolated perfused rat liver
2004
The metabolism of apigenin, a low estrogenic flavonoid phytochemical, was investigated in rat using liver models both in vitro (subcellular fractions) and ex vivo (isolated perfused liver). In vitro, phase I metabolism led to the formation of three monohydroxylated derivatives: luteolin which was the major metabolite (K(m) = 22.5 +/- 1.5 microM; V(max) = 5.605 +/- 0.090 nmol/min/mg protein, means +/- S.E.M.), scutellarein, and iso-scutellarein. These oxidative pathways were mediated by cytochrome P450 monooxygenases (P450s). The use of P450 inhibitors and inducers showed that CYP1A1, CYP2B, and CYP2E1 are involved. In vitro studies of phase II metabolism indicated that apigenin underwent co…
Enzymic control of irreversible binding of metabolically activated benzo(a)pyrene in perfused rat liver by monooxygenase activity.
1977
Addition of [3H]-benzo(a)pyrene to the perfusion medium of isolated rat livers results in irreversible binding of radioactivity to DNA, RNA and protein. Binding to DNA accounted for about 0.1% of the total radioactivity which was bound in livers from animals treated with oil or saline and was increased by a factor of 3–5 after pretreatment of the animals with β-naphthoflavone or with phenobarbital. When the inhibitiors of monooygenase activity, α-naphthoflavone or metyrapone, were present in the perfusion medium, irreversible binding was reduced in livers from both β-naphthoflavone- and phenobarbital-pretreated animals, irrespective of the inhibitor used.