Phytother Res. 2002 Mar; 16 Suppl 1(): S63-7.

Influence of silymarin and its flavonolignans on doxorubicin-iron induced lipid peroxidation in rat heart microsomes and mitochondria in comparison with quercetin.

PsotovÃ¡ J, ChlopcÃkovÃ¡ S, Grambal F, SimÃ¡nek V, UlrichovÃ¡ J.

Institute of Medical Chemistry and Biochemistry, Faculty of Medicine, PalackÃ½ University, HnÄvotÃnskÃ¡ 3, 775 15 Olomouc, Czech Republic.

Silymarin, an extract of Silybum marianum seeds, and the constituent flavonolignans silybin, silydianin and silychristin, as well as the flavonol quercetin, protected rat heart microsomes and mitochondria against iron-dependent doxorubicin induced lipid peroxidation. Quercetin was found to be more potent than either silymarin or its three constituents, whose cytoprotectivity was comparable. The radical scavenging activity of the compounds was investigated using a DPPH colour reduction assay and cyclic voltametry to assess their antioxidant activities. In contrast to quercetin, silybin, silydianin and silychristin did not chelate iron in aqueous solution. The results suggest that silymarin may prevent doxorubicin-mediated damage to rat heart membrane primarily through a free radical scavenging mechanism.Copyright 2002 John Wiley & Sons, Ltd.