Bioorganic

Comparison of the Prevention of Aflatoxin B₁-Induced Genotoxicity by Quercetin and Quercetin Pentaacetate

Ekta Kohli^a, Hanumantharao G. Raj^a, Ranju Kumari^a, Vishwajit Rohil^a, Narendra K. Kaushik^b, Ashok K. Prasad^b and Virinder S. Parmar^,^,^b

^a Department of Biochemistry, V. P. Chest Institute, University of Delhi, Delhi-110 007, India
^b Bioorganic Laboratory, Department of Chemistry, University of Delhi, Delhi-110 007, India

Received 22 October 2001; accepted 20 June 2002. Available online 15 August 2002.

Abstract

Earlier work carried out in our laboratory highlighted the mode of action of acetoxy 4-methylcoumarins in preventing the genotoxicity of aflatoxin B₁ (AFB₁). We have in this report extended the observations to quercetin pentaacetate (QPA), which unlike quercetin (Q) has demonstrated time-dependent inhibition of liver microsome catalysed AFB₁ epoxidation as measured by AFB₁ binding to DNA. The action of QPA is similar to that of the acetoxy 4-methylcoumarins in that they are acted upon by microsomal transacetylase leading to modulation of catalytic activities of certain enzymes (such as P-450 enzymes, NADPH cytochrome C reductase and glutathione S-transferase) possibly by way of protein acetylation. In the present work, we have documented the transacetylase-mediated action of QPA in preventing genotoxicity due to AFB₁.

Graphical Abstract

Quercetin penta acetate (QPA) unlike quercetin demonstrated time-dependent inhibition of liver microsome-catalyzed AFB₁ epoxidation as measured by AFB₁ binding to DNA. In the present work, we have demonstrated the transacetylase-mediated action of QPA in the prevention of genotoxicity due to AFB₁.