The cytochrome P-450-dependent aryl hydrocarbon hydroxylase (AHH) metabolizes a wide variety of endogenous and exogenous compounds to nontoxic metabolites and/or toxic products. We have utilized a series of 18 flavone modulators of AHH to distinguish and probe for different cytochrome P-450 isozymes in liver microsomes from control and 3-methylcholanthrene (MC)-injected rats. Some flavones (maackiain acetate, flavanone, mollisacacidin, embinin, sciadopitysin) activated, while most of the tested compounds inhibited the MC-induced type of AHH. Although all flavones either inhibited or had little effect on the constitutive AHH in microsomes from control rats, the degree of inhibition varied greatly: some flavones (chrysin, chrysoeriol, baicalein, maackiain acetate, isoliquiritigenin, sciadopitysin) inhibited over 75% of the AHH. The various flavones we screened may prove useful in defining the cytochrome P-450 content of tissues and for probing the active sites of individual isozymes. The modulatory effects of the naturally occurring flavones assume additional importance in that they may be factors in animal and human responsiveness to cytochrome P-450 substrates.

This content is only available via PDF.
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.