Azadirachta indica modulates carcinogen biotransformation and reduced glutathione at peri‐initiation phase of benzo(a)pyrene induced murine forestomach tumorigenesis
Authors:
- 27 August 2008
- journal article
- research article
- Published by Wiley in Phytotherapy Research
- Vol. 22 (9) , 1229-1238
Abstract
The present study evaluated the effects of aqueous Azadirachta indica leaf extract (AAILE) on the activities of certain phase I (cytochrome P450, cytochrome b5 and aryl hydrocarbon hydroxylase) as well as phase II (glutathione‐S‐transferase and UDP‐glucuronosyl transferase) biotransformation enzymes; and reduced glutathione (GSH) (in forestomach and hepatic tissues) during/after intra‐gastric instillations of B(a)P in murine forestomach tumorigenesis bioassay protocol. The activities of phase I biotransformation enzymes were found to increase, whereas a decrease in GSH content as well as glutathione‐S‐transferase was observed in mice receiving only B(a)P during as well as 2 weeks after B(a)P instillations. The activity of UDP‐glucuronosyltransferase decreased during B(a)P instillations, whereas after the latter, the activity increased when compared with the control mice. However, in mice that received AAILE along with B(a)P instillations, a decrease in phase I enzymes was accompanied by an increase in phase II enzymes as well as GSH contents. Only AAILE treatment reduced the activities of phase I biotransformation enzymes and enhanced the GSH contents as well as the activities of phase II enzymes. Observations of the present study seem to be quite significant and (when taken together with our earlier findings) provides evidence for A. indica mediated modulation of the peri‐initiation phase of the process of forestomach tumorigenesis. Copyright © 2008 John Wiley & Sons, Ltd.Keywords
Funding Information
- Council for Scientific and Industrial Research (CSIR), New Delhi, India
This publication has 40 references indexed in Scilit:
- Preventive effects of Azadirachta indica on benzo(a)pyrene‐DNA adduct formation in murine forestomach and hepatic tissuesPhytotherapy Research, 2006
- Chemomodulatory effects ofAzadirachta indica on the hepatic status of skin tumor bearing micePhytotherapy Research, 2006
- Metabolic activation of polycyclic aromatic hydrocarbons to carcinogens by cytochromes P450 1A1 and1B1Cancer Science, 2004
- The roles of cytochrome b5 in cytochrome P450 reactionsJournal of Biochemical and Molecular Toxicology, 2002
- Chemoprotection against cancer by Phase 2 enzyme inductionToxicology Letters, 1995
- Elevation of serum Phase II enzymes by anticarcinogenic enzyme inducers: markers for a chemoprotected state?Carcinogenesis, 1993
- The Role of Glutathione and Glutathione Transferases in Chemical CardnogenesiCritical Reviews in Biochemistry and Molecular Biology, 1990
- Conjugation of chemical carcinogens by primary cultures of human hepatocytesXenobiotica, 1990
- Polycyclic Aromatic Hydrocarbon Carcinogenesis1985
- Levels of glutathione, glutathione reductase and glutathione S-transferase activities in rat lung and liverBiochimica et Biophysica Acta (BBA) - General Subjects, 1979