chrysoeriol and diosmetin

Topics: Animals; Calibration; Chromatography, High Pressure Liquid; Flavones; Flavonoids; Luteolin; Molecular Structure; Rats; Rats, Sprague-Dawley; Tandem Mass Spectrometry

Luteolin partially exerts its biologic effects via its metabolites catalyzed by UDP-glucuronosyltransferases (UGTs) and catechol-O-methyltransferases (COMTs). However, the interplay of UGTs and COMTs in mediating luteolin disposition has not been well clarified. In this study, we investigated the glucuronidation and methylation pathways of luteolin mediated by the interplay of UGTs and COMTs in vivo and in vitro. A total of nine luteolin metabolites was detected in rat plasma and bile by liquid chromatography-tandem mass spectrometry, namely, three glucuronides, two methylated metabolites, and four methylated glucuronides. Luteolin-3'-glucuronide (Lut-3'-G) exhibited the highest systemic exposure among these metabolites. Kinetics studies in rat liver S9 fractions suggested two pathways, as follows: 1) Luteolin was glucuronidated to luteolin-7-glucuronide, luteolin-4'-glucuronide, and Lut-3'-G by UGTs, and then Lut-7-G was methylated to chrysoeriol-7-glucuronide and diosmetin-7-glucuronide by COMTs. 2) Alternatively, luteolin was methylated to chrysoeriol and diosmetin by COMTs, and then chrysoeriol and diosmetin were glucuronidated by UGTs to their respective glucuronides. The methylation rate of luteolin was significantly increased by the absence of glucuronidation, whereas the glucuronidation rate was increased by the absence of methylation, but to a lesser extent. In conclusion, two pathways mediated by the interplay of UGTs and COMTs are probably involved in the metabolic disposition of luteolin. The glucuronidation and methylation of luteolin compensate for each other, although glucuronidation is the predominant pathway.

Topics: Animals; Bile; Catechol O-Methyltransferase; Chromatography, High Pressure Liquid; Flavones; Flavonoids; Glucuronides; Glucuronosyltransferase; Liver; Luteolin; Male; Metabolic Networks and Pathways; Methylation; Rats, Sprague-Dawley; Substrate Specificity; Tandem Mass Spectrometry; Tissue Distribution

This study aimed to determine the reaction kinetics of the regioselective glucuronidation of diosmetin and chrysoeriol, two important methylated metabolites of luteolin, by human liver microsomes (HLMs) and uridine-5'-diphosphate glucuronosyltransferase (UGTs) enzymes. This study also investigated the effects of breast cancer resistance protein (BCRP) on the efflux of diosmetin and chrysoeriol glucuronides in HeLa cells overexpressing UGT1A9 (HeLa-UGT1A9). After incubation with HLMs in the presence of UDP-glucuronic acid, diosmetin and chrysoeriol gained two glucuronides each, and the OH-in each B ring of diosmetin and chrysoeriol was the preferable site for glucuronidation. Screening assays with 12 human expressed UGT enzymes and chemical-inhibition assays demonstrated that glucuronide formation was almost exclusively catalyzed by UGT1A1, UGT1A6, and UGT1A9. Importantly, in HeLa-UGT1A9, Ko143 significantly inhibited the efflux of diosmetin and chrysoeriol glucuronides and increased their intracellular levels in a dose-dependent manner. This observation suggested that BCRP-mediated excretion was the predominant pathway for diosmetin and chrysoeriol disposition. In conclusion, UGT1A1, UGT1A6, and UGT1A9 were the chief contributors to the regioselective glucuronidation of diosmetin and chrysoeriol in the liver. Moreover, cellular glucuronidation was significantly altered by inhibiting BCRP, revealing a notable interplay between glucuronidation and efflux transport. Diosmetin and chrysoeriol possibly have different effects on anti-cancer due to the difference of UGT isoforms in different cancer cells.

Topics: Flavones; Flavonoids; Glucuronides; Glucuronosyltransferase; HeLa Cells; Humans; Luteolin; Microsomes, Liver; Stereoisomerism; UDP-Glucuronosyltransferase 1A9; Up-Regulation

We studied the effects of twelve 5,7-dihydroxyflavone analogs on adipogenesis in 3T3-L1 cells. Among the compounds, luteolin, diosmetin, and chrysoeriol partly inhibited adipogenesis by blocking the accumulation of triacylglycerol in the cells. Conversely, tricetin facilitated triacylglycerol accumulation in the cells. The induction of lipogenesis or lipolysis may depend on the number and bonding position of hydroxyl or methoxy groups on the B ring of 5,7-dihydroxyflavone. The mRNA expression levels of adipogenic and lipogenic genes were suppressed by luteolin treatment in the cells, while the mRNA levels of lipolytic genes were not affected. However, the expression levels of the adipogenic, lipogenic, and lipolytic genes, except for adipocyte protein 2 (aP2), were not affected by the addition of tricetin. Moreover, luteolin suppressed glucose transporter type 4 (GLUT4) gene and protein levels. These results indicate that luteolin decreased triacylglycerol levels in 3T3-L1 cells during adipogenesis through the suppression of adipogenic/lipogenic and GLUT4 genes and GLUT4 protein.

Topics: 3T3-L1 Cells; Adipocytes; Adipogenesis; Adipose Tissue; Animals; Chromones; Flavones; Flavonoids; Glucose Transporter Type 4; Lipid Metabolism; Luteolin; Mice; Plant Extracts; RNA, Messenger; Triglycerides

Flavonoids are widely occurring polyphenols that are found in plants. The aim of this study was to investigate the structure-activity relationships of 5,7-dihydroxyflavones, with a focus on the effect of B ring structure substitution on the antiproliferative effects of the compounds in human leukemia HL-60 cells. We prepared a series of 5,7-dihydroxyflavones and evaluated their ability to inhibit the proliferation of HL-60 cells by using the MTT assay. The apoptosis- and cell differentiation-inducing ability of the most potent flavones were investigated using staining and morphological analyses. This study explored the antileukemic and chemopreventive potency of 5,7-dihydroxyflavones, particularly diosmetin and chrysoeriol, which have both hydroxy and methoxy groups on the B ring.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Cell Differentiation; Cell Proliferation; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Flavones; Flavonoids; HL-60 Cells; Humans; Leukemia; Molecular Structure; Structure-Activity Relationship

To study on the chemical constituents of Lobelia chinensis.. The coloumn chromatographic techniques were applied to isolate constituents, and their structures were elucidated by means of spectral data analysis.. Sixteen compounds were isolated and identified as daucosterol (1), diosmetin (2), apigenin (3), chrysoeriol (4), loteolin (5), hesperidin (6), loteolin-7-O-beta-D-glucoside (7), apigenin-7-O-beta-D-glucoside (8), linarin (9), diosmin(10), 5,7-dimethoxy-8- hydroxycoumarin (11), palmitinic acid (12), lacceroic acid (13), stearic acid (14), beta-sitosterol (15), daucosterol (16).. All of these compouds were obtained from L. chinensis for the first time.

Topics: Apigenin; Cholestenones; Flavones; Flavonoids; Glycosides; Hesperidin; Lobelia; Plant Extracts; Sitosterols

A comprehensive profile of flavonoids in bergamot juice was obtained by a single DAD-ESI-LC-MS-MS course. Eight flavonoids were found for the first time, five of these are C-glucosides (lucenin-2, stellarin-2, isovitexin, scoparin, and orientin 4'-methyl ether), and three are O-glycosides (rhoifolin 4'-O-glucoside, chrysoeriol 7-O-neohesperidoside-4'-O-glucoside, and chrysoeriol 7-O-neohesperidoside). A method is proposed to differentiate chrysoeriol and diosmetin derivatives, which are often indistinguishable by LC-MS-MS. In-depth knowledge of the flavonoid content is the starting point for bergamot juice exploitation in food industry applications.

Topics: Citrus; Flavones; Flavonoids; Food Industry; Fruit; Glycosides; Models, Molecular