Golden rain tree leaf extracts as potential inhibitor of lipid peroxidation and 4-nitroquinoline-1-oxide (4-NQO)- induced DNA damage

Abstract

This study was designed to evaluate the peroxyl radical scavenging capacity and deoxyribonucleic acid (DNA) protective effect of extract/fractions of Koelreuteria paniculata Laxm. (Golden rain tree) in lipid peroxidation assay and calf thymus DNA protection assay. The leaves of the plant were extracted with different solvents in the order of increasing polarity to obtain methanol extract (KME), chloroform fraction (KCF), ethyl acetate fraction (KEF), n-butanol fraction (KBF) and aqueous fraction (KAF). All the extract/fractions possessed the potential to inhibit lipid peroxidation and 4-nitroquinoline-1-oxide (4NQO)-induced genotoxicity. KEF showed the highest peroxyl radical scavenging activity (80.8 %) with IC₅₀ of 36.44 μg/ml while KAF showed the lowest activity (43.20 %). In DNA protection studies, all the extract/fractions showed potential to protect calf thymus DNA against 4-NQO induced DNA damage except KCF which showed slight protection at highest concentration tested (250 μg/ml).

Key words: Koelreuteria paniculata Laxm., lipid peroxidation, calf thymus DNA, 4-nitroquinoline-1-oxide