NISCAIR Online Periodicals Repository

NISCAIR ONLINE PERIODICALS REPOSITORY (NOPR)  >
NISCAIR PUBLICATIONS >
Research Journals >
Indian Journal of Biochemistry and Biophysics (IJBB) >
IJBB Vol.48 [2011] >
IJBB Vol.48(4) [August 2011] >


Title: Free radical reactions of a naturally occurring flavone baicalein and possible mechanisms towards its membrane protective properties
Authors: Adhikari, S
Tilak, Jai C
Devasagayam, T P A
Keywords: Baicalein
Rat liver mitochondria
Rat heart homogenate
Lipid peroxidation
Pulse radiolysis
Hydroxyl radical
Peroxyl radical
Peroxynitrite
Issue Date: Aug-2011
Publisher: NISCAIR-CSIR, India
Abstract: Baicalein (5, 6, 7-trihydroxy-2-phenyl-4H-1-benzopyran-4-one), a naturally occurring flavone present in some of the medicinal plants is known for its potential therapeutic effects, such as cardioprotective, anticancer and anti-inflammatory properties. However, detailed role and mechanisms behind its protective properties against different generators for oxidative stress have not been examined. In the present study, we investigated the possible protective ability of baicalein against the membrane damage caused by reactive oxygen species (ROS) and reactive nitrogen species (RNS) and the mechanisms involved using pulse radiolysis technique. Baicalein offered efficient protection even at a concentration of 10 M towards membrane damage caused by lipid peroxidation induced by the -radiation, peroxyl radicals, ascorbate-Fe2+ and peroxynitrite in rat liver mitochondria and heart homogenate. To elucidate its reaction mechanisms with biologically relevant radicals, transient absorption spectroscopy employing pulse radiolysis technique was used. Baicalein showed fairly high rate constants (3.7 × 109, 1.3 × 109 and 8.0 × 108 dm3 mol-1 s-1 for hydroxyl, azidyl and alkylchloroperoxyl radicals, respectively), suggesting that baicalein can act as an effective scavenger of these radicals. In each case, the phenoxyl radical of baicalein was generated. Thus, it was evident that the phenolic moiety of baicalein was responsible for the free radical scavenging process. Baicalein also reacts with linoleic acid peroxyl radical (LOO·), indicating its ability to act as a chain breaking antioxidant. Peroxynitrite-mediated radicals were shown to be reactive towards baicalein and the bimolecular rate constants were 2.5 × 107 and 3 × 108 dm3 mol-1 s-1 for ·NO2 and CO3·- radicals, respectively. In conclusion, our results revealed the potential of baicalein in protecting mitochondrial membrane against oxidative damage induced by the four different agents. We propose that the protective effect is mediated via scavenging of primary and secondary radicals generated during oxidative stress.
Page(s): 275-282
CC License:  CC Attribution-Noncommercial-No Derivative Works 2.5 India
ISSN: 0975-0959 (Online); 0301-1208 (Print)
Source:IJBB Vol.48(4) [August 2011]

Files in This Item:

File Description SizeFormat
IJBB 48(4) 275-282.pdf162.79 kBAdobe PDFView/Open
 Current Page Visits: 630 
Recommend this item

 

National Knowledge Resources Consortium |  NISCAIR Website |  Contact us |  Feedback

Disclaimer: NISCAIR assumes no responsibility for the statements and opinions advanced by contributors. The editorial staff in its work of examining papers received for publication is helped, in an honorary capacity, by many distinguished engineers and scientists.

CC License Except where otherwise noted, the Articles on this site are licensed under Creative Commons License: CC Attribution-Noncommercial-No Derivative Works 2.5 India

Copyright © 2012 The Council of Scientific and Industrial Research, New Delhi. All rights reserved.

Powered by DSpace Copyright © 2002-2007 MIT and Hewlett-Packard | Compliant to OAI-PMH V 2.0

Home Page Total Visits: 606186 since 06-Feb-2009  Last updated on 21-Oct-2014Webmaster: nopr@niscair.res.in