New synthetic flavonoids as potent protectors against doxorubicin-induced cardiotoxicity

A series of 3,7-disubstituted-2(3',4'-dihydroxyphenyl) flavones has been st udied as potential cardioprotective agents in doxorubicin antitumor therapy . The influence of substituents on the 3 and 7 position of the flavone nucl eus on antioxidant activity cytotoxicity and cardioprotective properties wa s explored to improve the activity of our lead compound 7-monohydroxyethylr utoside. In the protection against Fe2+/vitamin C-induced microsomal lipid peroxidation (LPO assay), IC50 values ranged from 0.2 to 37 muM. In general , the 3-substituted flavones were the most potent compounds in this assay. The cytotoxicity of the new compounds was tested (up to 250 muM) in hepatoc ytes. LDH leakage ranged from 2.6-29.2%, whereas the GSH concentrations dec reased to 87.3-41.3%. Only four compounds out of this series protected the isolated mouse left atrium against doxorubicin-induced toxicity. Because of the positive inotropic effect of gd (N-(3-(3',4'-dihydroxyflavon-7-yl)oxyp ropyl)-N,N,N-trimethylammonium cloride) and 10e (3-hydroxyethoxy-7,3',4'-tr ihydroxyflavone) on the atrium, compounds 9i(3',4'-dihydroxy-3-glucosylflav one) and 10d (N-(3-(7,3',4'-trihydroxyflavon-3-yl)oxypropyl)-N,N,N-trimethy lammonium chloride) were selected to be evaluated as cardioprotective agent s in vivo. (C) 2001 Elsevier Science Inc.